Worldwide research on 3D printing for cancer: a dual-method analysis of bibliometrics and stratified focused thematic.

Background
Three-dimensional (3D) printing, also known as additive manufacturing, is an advanced technology that creates objects by sequentially depositing material layer by layer[1]. Unlike traditional subtractive manufacturing methods, 3D printing precisely controls material deposition using digital models, enabling the production of complex and customized structures with enhanced accuracy[2]. Among the various branches of 3D printing, 3D bioprinting represents a significant advancement in biomedical applications. It involves the precise, layer-by-layer deposition of living cells, biomaterials, and growth factors to fabricate biologically functional, tissue-like constructs. With over 30 years of development, 3D printing has become widely adopted in the medical field, particularly for creating surgical guides, prosthetics, and applications in tissue engineering[3].
In recent years, the use of 3D printing in treating malignant tumors has expanded significantly. It has significantly improved the planning and execution of tumor resection surgeries[4]. By transforming CT or MRI scan data into 3D printing models, surgeons can better assess a tumor’s size, location, and relationship to surrounding tissues. This improved visualization enhances surgical precision, shortens operation time, and reduces the risk of potential complications, particularly in complex cases or procedures involving delicate structures. Similarly, 3D printing guides and templates serve as essential tools for precise tumor excision[5,6]. The use of biocompatible materials to create patient-specific 3D printing tumor models enables the replication of an individual’s tumor characteristics, supporting clinical practice, medical education[7,8], drug delivery[9,10], and personalized treatment strategies[11]. These models simulate tumor growth and treatment response, offering valuable insights for optimizing therapeutic approaches. In cases where tumors cause bone defects, 3D printing provides innovative solutions for bone reconstruction[12]. Customized 3D printing bone implants can be tailored to match a patient’s unique anatomy, enhancing post-resection functionality. These implants can be integrated with drugs or metal nanoparticles to simultaneously target and eliminate tumor cells[13,14]. Furthermore, 3D printing plays a crucial role in radiation therapy by enabling the creation of custom immobilization devices, including patient-specific templates and bolus materials. These tailored solutions enhance the precise positioning of radiation sources, ensuring optimal dose delivery to the tumor while minimizing exposure to surrounding healthy tissues[15,16].
The application of 3D printing in oncology – which integrates surgical planning, materials engineering, radiotherapy, pharmacology, and computational design – is an inherently multidisciplinary, rapidly evolving field, characterized by diverse translational trajectories. This complexity poses significant challenges for conventional methodologies. While traditional meta-analyses, AI-based trend analyses, or expert-derived insights from conferences can provide valuable information on specific clinical interventions or recent advances, they often fall short in capturing the broader structural, interdisciplinary, and temporal dynamics of the vast research domain. Scientometric analysis, by contrast, offers a macro-level, data-driven framework that enables the systematic identification of influential contributors, international collaborations, institutional networks, and thematic clusters[17,18]. It is uniquely equipped to trace research evolution in complex and multidisciplinary fields such as 3D printing in oncology, due to its ability to map co-occurrence patterns and uncover the intellectual structure of the domain[19]. Unlike traditional review methods, scientometric approaches offer a comprehensive overview of temporal and geographical trends, thematic developments, and translational pathways. This panoramic perspective enables the identification of key research hotspots and emerging frontiers, providing critical insights for researchers, clinicians, and policymakers working to keep pace with this rapidly advancing field.
The major gaps in the current body of research on 3D printing in oncology are the absence of a comprehensive and structured evaluation of the global research architecture, geographical disparities, emerging hotspots, and the extent of interdisciplinary integration. In particular, no prior study has systematically characterized how various cancer types are represented across clinical applications, technical methodologies, and translational pathways within this field. To bridge these gaps and enhance clinical relevance, this review introduces a stratified and focused thematic analysis based on cancer type. By segmenting the scientometric data accordingly, this approach enables the identification of tumor-specific research priorities, levels of translational maturity, and critical unmet needs, insights that are often beyond the reach of conventional meta-analyses or AI-driven trend assessments. Accordingly, this study offers methodological innovation by integrating a comprehensive scientometric framework with cancer-type-specific thematic stratification.
HIGHLIGHTS
3D printing in oncology is a complex, multidisciplinary, and rapidly evolving field. By applying scientometric methods combined with cancer-type-specific thematic analysis, we provide researchers, clinicians, and policymakers with a structured overview of the global research landscape, translational progress, and interdisciplinary integration – insights that traditional reviews cannot fully capture.

Thematic stratification by tumor type reveals major differences in research focus and clinical translation, with bone cancer centers on reconstruction and tissue regeneration, breast cancer emphasizes radiotherapy bolus customization with partial clinical translation, lung cancer focuses on surgical planning, and cervical cancer prioritizes individualized brachytherapy.

Key research hotspots include preoperative planning (to enhance surgical precision and patient comprehension), malignant bone tumors (focusing on reconstruction and tissue regeneration), tumor radiotherapy (aimed at dose optimization and healthy tissue preservation), in vitro tumor modeling (to accurately replicate tumor microenvironments), and therapeutic 3D bioprinting (e.g., for photothermal therapy, immunotherapy, and radiotherapy). Identifying these trends reveals areas of high clinical relevance and translational momentum, helping prioritize future research directions and resource allocation.

Emerging frontiers such as AI-assisted modeling (to reduce manual workload and improve anatomical precision), 3D printing in rare pediatric tumors (addressing anatomically complex surgical challenges with high accuracy), and nanorobotic platforms (improving tumor targeting while minimizing collateral damage), highlight promising future directions for personalized cancer care.

This study exclusively addresses malignant tumors, deliberately excluding benign tumors due to their distinct therapeutic approaches and prognostic implications. To the best of our knowledge, no previous scientometric study has specifically investigated the role of 3D printing in cancer treatment. This work is the first to apply scientometric methods to map the current landscape, key research areas, and emerging directions of 3D printing in cancer treatment, with an emphasis on stratification by tumor type, offering critical insights and addressing an evident gap in the literature. This work has been reported in line with the TITAN criteria[20], with the corresponding checklist provided in Supplementary Digital Content 1 (available at: http://links.lww.com/JS9/E985).

Materials and methods

Data sources and search strategy
The Web of Science Core Collection (WOSCC) is a widely recognized academic database, offering comprehensive coverage of scholarly journals across various disciplines. Compared to other databases like PubMed and Scopus, WOSCC provides the most extensive dataset for scientometric analysis, making it a preferred resource for evaluating research trends and impact[21]. Accordingly, the WOSCC was selected as the target database, covering the period from 1 January 2000 to 31 December 2024. The detailed search strategy is provided in Supplementary Digital Content Table S1 (available at: http://links.lww.com/JS9/E986).

Literature selection and data collection
Two independent reviewers screened the literature based on titles and abstracts, selecting only articles and reviews. To ensure relevance, publications such as meeting abstracts, editorials, letters, book chapters, and withdrawn studies were excluded. Benign tumors and other unrelated literature were also excluded. Any disagreements during the screening process were resolved through discussions with a third reviewer. The final set of selected references was exported as a plain text file in the “full records and cited references” format. This manuscript follows the bibliometric analysis guidelines proposed by Naveen Donthu[22], with the corresponding checklist provided in Supplementary Digital Content 3 (available at: http://links.lww.com/JS9/E987).

Bibliometric software tools
The bibliometric analysis in this study was conducted using the Bibliometrix R package (version 4.4.2)[23], VOSviewer (version 1.6.20)[24], and CiteSpace (version 6.3.R1)[25]. The Bibliometrix package was employed to generate the country collaboration map and the three-field plot, providing a quantitative overview of the research domain.
VOSviewer (version 1.6.20) was utilized to perform co-occurrence analyses of countries, authors, institutions, and keywords. The time-overlap function was employed to illustrate keyword trends over time. In the co-occurrence network map (e.g., Figs. 1-3), nodes represent individual countries, authors, institutions, or keywords, with node size corresponding to their frequency of occurrence; larger nodes indicate higher frequency. Nodes of the same color belong to the same cluster, and the proximity between nodes reflects their degree of correlation. In the time-overlap visualization, node colors indicate the average active years of the entities, with darker shades (e.g., deep blue) representing earlier occurrences and lighter shades (e.g., pale yellow) denoting more recent activity.

CiteSpace (version 6.3.R1), a citation analysis and visualization tool, was used to detect significant citation bursts in keywords and references over time. This analysis facilitated the identification of academic trends and emerging research hotspots.

Stratified and focused thematic analysis
To enhance the clinical relevance and interpretability of the scientometric findings, a stratified and focused thematic analysis was conducted by cancer type. Based on the scientometric results, relevant clinical studies and technological prototypes were reviewed to further clarify how 3D printing is applied across different tumor types.

Results

Annual publication output analysis
In total, 3122 articles were retrieved from the Web of Science Core Collection (WOSCC) database, spanning the period from 1 January 2000 to 31 December 2024. After applying inclusion criteria limited to “articles” and “reviews,” 2943 publications were selected. Further refinement to include only English-language publications reduced the count to 2923. Following a thorough screening of titles and abstracts to eliminate irrelevant studies, a final total of 2312 articles were included. The detailed selection process is presented in Supplementary Digital Content Table S1 (available at: http://links.lww.com/JS9/E986).
The first article on the application of 3D printing in malignant tumors was published in 2006, marking an 18-year research span. The highest annual publication count was recorded in 2024, with 392 articles. Figure 4 presents the annual publication trends. Between 2006 and 2014, research activity remained limited, with only 38 articles published (1.64%). However, from 2015 to 2019, the number of publications increased significantly, reaching 561 articles (24.26%). A substantial surge occurred between 2020 and 2024, with 1713 articles published (74.09%), reflecting the growing interest and advancements in this area.

Country publication output and collaboration analysis
A total of 82 countries have contributed to research in this field. Table 1 presents the top 10 countries by publication volume. China ranks first with 779 publications, representing 33.69% of the total output. This prominent position likely reflects a combination of robust national policies supporting advanced manufacturing and biomedical innovation, significant research investment, accelerated clinical integration within leading medical institutions, and a large patient population driving the demand for novel healthcare technologies. The United States follows with 559 publications (24.18%). Other key contributors include South Korea, Germany, the United Kingdom, and Italy, each exceeding 100 publications.

Regarding international collaboration, the United States exhibited the strongest collaboration network, with a total link strength of 331. The United States’ extensive international collaboration likely stems from its significant investment in research and development, the presence of globally recognized academic and clinical institutions, and a highly internationalized research ecosystem that fosters global partnerships and multi-center studies. This is followed by China (186), the United Kingdom (168), and Germany (117). Figure 5 visualizes the collaboration patterns among countries. Supplementary Digital Content Table S2 (available at: http://links.lww.com/JS9/E986) details the most frequent collaborations among the top 10 countries, with the most prominent collaborations observed between China and the United States (n = 68), followed by collaborations between the United States and Canada (n = 24), the United States and the United Kingdom (n = 24), the United States and Iran (n = 19), and the United States and Germany (n = 17). Among the top 10 collaborations, all international partnerships, except for one between Germany and the United Kingdom, involved either China or the United States. This highlights the central roles of China and the United States as global research hubs, likely driven by their expansive research communities, substantial funding resources, and well-developed international collaboration networks.

Supplementary Digital Content Figure S1 (available at: http://links.lww.com/JS9/E986) presents the country time-overlay visualization, where color intensity represents the average publication year for each country in this field. The analysis indicates that the United States, Japan, and Ireland were among the earliest contributors, while Iran and India have emerged as active participants in recent years.

Institutional output and collaboration analysis
A total of 2740 institutions have contributed to publications in this field. Among them, 2091 institutions (76.31%) published only one article, while 386 institutions (14.09%) produced between two and four publications. Moreover, 180 institutions (6.57%) published five to nine articles, and 83 institutions (3.03%) published more than ten. Figure 1 illustrates the collaboration network among these institutions, while Table 2 highlights the top 10 institutions by publication volume. Sichuan University ranked first with 75 publications, followed by Shanghai Jiao Tong University with 68 publications and the Chinese Academy of Sciences with 59 publications. Of the top 10 institutions by publication volume, seven were based in China.

Shanghai Jiao Tong University demonstrated the strongest collaboration link strength (n = 150), followed by the Chinese Academy of Sciences (n = 125) and Harvard Medical School (n = 73). Supplementary Digital Content Figure S2 (available at: http://links.lww.com/JS9/E986) presents the institutional time-overlay visualization, indicating that early contributors included the University of Connecticut, the University of California San Diego, Tsinghua University, Brigham and Women’s Hospital, the University of Florida, and the University of Sydney. More recent contributors to the field include Islamic Azad University, Fudan University, the University of Illinois, Queen’s University Belfast, University College London, and Peking University Third Hospital.

Journal output and impact analysis
The retrieved publications were distributed across 672 journals. Among these, 347 journals (51.63%) published only a single article, while 211 journals (31.40%) published between two and four articles. Further, 65 journals (9.67%) published five to ten articles, and 49 journals (7.29%) published more than ten.
Table 3 presents the top 10 journals by publication volume and the most co-cited journals. Frontiers in Oncology ranked first with 49 publications, followed by Scientific Reports with 43. The top 10 journals accounted for 343 articles. These journals were published by institutions from the United States (3), Switzerland (3), England (2), Germany (1), and Singapore (1). The average impact factor (IF) of these journals was 5.43, with eight classified in Journal Citation Reports Quartile 1 (JCR Q1).

The co-citation analysis identified 29 journals with over 500 total citations, including nine that exceeded 1000 citations. The five most frequently cited journals were Biomaterials with 3354 citations, Scientific Reports with 1660 citations, Acta Biomaterialia with 1635 citations, Biofabrication with 1540 citations, and Advanced Materials with 1388 citations, with Biomaterials leading by a substantial margin. Among the top 10 most co-cited journals, five were published in the United States, four in England, and one in the Netherlands. These journals had an average impact factor (IF) of 8.85, and all were classified within Journal Citation Reports Quartile 1 (JCR Q1).

Author impact and co-occurrence analysis
Altogether, 13 066 authors have contributed to research in this field. Of these, 11 067 (87.70%) participated in a single study, while 1829 authors authored 2 to 4 publications. A total of 143 researchers published 5 to 10 articles, and 27 authors contributed more than 10 publications. Table 4 presents the top 10 authors based on publication count and citation frequency. Tu Chongqi had the highest number of publications (39), whereas Wu Chengtie received the most citations (2299).

Figure 2 depicts the collaborative network among 107 authors with at least five publications. Eleven distinct collaboration groups were identified, with the top 10 authors forming four clusters, seven of whom belonged to the same cluster. Supplementary Digital Content Figure S3 (available at: http://links.lww.com/JS9/E986) provides a time-overlay visualization of author contributions. Wu Chengtie and Tan Zhikai’s teams were among the earliest contributors to this research area, while Li Zhuangzhuang and Gong Taojun are actively leading recent advancements in the field.

Hotspot analysis

Keyword occurrence and co-occurrence analysis
In all, 5318 keywords were identified in the retrieved publications. Table 5 presents the top 20 keywords associated with the application of 3D printing in malignant tumors. The most frequently occurring keyword was “3D printing” (n = 636), followed by “tissue engineering” (n = 76). Among the top 20 keywords, two specific types of malignant tumors were mentioned: breast cancer (n = 62) and osteosarcoma (n = 40).

The co-occurrence analysis identified 99 keywords that appeared at least 10 times, which were categorized into six distinct clusters, as shown in Figure 3. Cluster 1 (red, 22 items) focuses on the application of 3D printing in radiation therapy, with key terms such as “brachytherapy” (n = 65), radiation therapy, and dosimetry, primarily applied in breast cancer, prostate cancer, head and neck cancer, and cervical cancer. Cluster 2 (green, 21 items) relates to the use of 3D printing in tumor drug screening and biomaterial fabrication, including keywords like tissue engineering, microfluidics, drug screening, tumor microenvironment, and organ-on-a-chip, which are primarily used for tumor model construction. Cluster 3 (blue, 21 items) is associated with the application of 3D printing in tumor surgical planning, incorporating terms such as augmented reality, surgery, simulation, surgical planning, preoperative planning, and rapid prototyping. Cluster 4 (yellow, 19 items) focuses on using 3D printing for reconstructing bone defects caused by bone tumors, with key terms including reconstruction, prosthesis, mandibular reconstruction, computer-aided design, bone defect, cranioplasty, and bone tumor. Cluster 5 (purple, 16 items) covers the application of 3D printing in cancer therapy, including photothermal therapy, immunotherapy, regenerative medicine, drug delivery, bone regeneration, and angiogenesis, particularly in osteosarcoma and glioblastoma treatment. Figure 3 provides a comprehensive visualization of these keyword clusters and their interconnections, illustrating the diverse applications of 3D printing in oncology research.
Supplementary Digital Content Figure S4 (available at: http://links.lww.com/JS9/E986) illustrates the time-overlay visualization of the keyword network. Early research in this field primarily centered on rapid prototyping, surgical simulation, and neurosurgery. In recent years, the focus has shifted toward emerging topics such as bone tissue engineering, virtual surgical planning, interstitial brachytherapy, and bioink.
Figure 6 presents the relationships and distribution patterns among the top 10 countries, institutions, and research themes in the field of 3D printing for malignant tumors. While most institutions and countries have contributed to these key areas, significant differences exist. Sichuan University demonstrated a stronger emphasis on “reconstruction,” “resection,” and “scaffolds,” whereas Harvard University focused primarily on surgery-related research. The Chinese Academy of Sciences and Shanghai Jiao Tong University were more engaged in studies involving “nanoparticles.” At the national level, China and the United States made substantial contributions across all major research topics. However, Iran exhibited a particular focus on “in-vitro” studies, while Italy contributed less to research on “scaffolds,” Canada placed less emphasis on “resection,” and Spain showed limited engagement in “fabrication.”

Keyword burst analysis
Figure 7 highlights the top 25 keywords with the strongest citation bursts. Among them, surgical simulation exhibited the longest burst period, spanning from 2015 to 2020, indicating sustained research interest. The earliest burst keywords were cancer (2013–2015) and surgery (2015–2017). More recent burst keywords include limb salvage (2021–2024), mechanisms (2022–2024), behavior (2022–2024), endoprosthetic reconstruction (2022–2024), and resistance (2022–2024). These emerging terms suggest evolving research priorities and potential future directions in the field.

Tumor type keyword statistics
Based on keyword frequency, Supplementary Digital Content Table S3 (available at: http://links.lww.com/JS9/E986) summarizes the most common tumor types associated with the application of 3D printing in malignant tumors. Tumor types with fewer than 10 occurrences, such as nasopharyngeal carcinoma and thyroid cancer, were grouped under “Other.” The five most frequently mentioned tumor types, bone cancer, breast cancer, osteosarcoma, lung cancer, and cervical cancer, highlight key areas of research where 3D printing is extensively applied.

Co-citation analysis and co-citation burst analysis
Co-cited references are studies frequently cited together within the 2312 publications analyzed in this research. Table 6 presents the top 10 most co-cited references, comprising four review articles and six original research articles. The review articles primarily discuss the applications of 3D printing in medical settings, while the original research articles focus on tumor epidemiology, the use of 3D printing in tumor surgeries, and the development of tumor cell models. The most frequently cited reference, 3D Bioprinting of Tissues and Organs by Murphy SV et al, received 117 citations.

Co-citation burst analysis identifies references that have received a surge in citations over a specific period, highlighting their impact within the field. Figure 8 presents the top 25 references with the strongest citation bursts, comprising 18 original research articles and 7 review articles, each with a minimum burst duration of 2 years. The reference with the highest burst intensity is Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries by Sung H et al (Strength = 16.33). This is followed by 3D Bioprinting of Tissues and Organs by Murphy SV et al (Strength = 16.29), which also exhibited the longest burst duration. Another reference with a prolonged burst period is Physical Models of Renal Malignancies Using Standard Cross-sectional Imaging and 3-Dimensional Printers: A Pilot Study by Silberstein JL et al (Strength = 11.05).

From 2022 to 2024, four references have exhibited sustained citation bursts, indicating their significant impact on the field. The reference with the highest burst intensity (7.52) is 3D Bioprinting for Reconstituting the Cancer Microenvironment by Datta P et al. Another important reference is 3D-Printed Modular Hemipelvic Endoprosthetic Reconstruction Following Periacetabular Tumor Resection: Early Results of 80 Consecutive Cases by Ji T et al. These highly co-cited references highlight key research directions in the application of 3D printing for malignant tumors.

Discussion
This study utilizes scientometric analysis to assess the current state, key research areas, and emerging trends in the application of 3D printing for malignant tumors. The first publication in this field appeared in 2006[26], authored by Weinand C et al from Harvard University, who successfully engineered bone tissue in vitro using collagen I hydrogel, mesenchymal stem cells (MSCs), and three-dimensionally printed porous beta-TCP scaffolds. The publication trend can be categorized into two distinct phases: a slow-growth phase (2006–2016), characterized by fewer than 100 publications per year, and a rapid-growth phase (2017–2024), during which the annual output surged from 100 to 392 articles. This sharp increase suggests that research in this domain will continue to expand in the coming years. The accelerated growth is likely driven by advancements in interdisciplinary fields such as medicine and engineering, alongside progress in translational medicine[27]. Furthermore, the growing emphasis on personalized medicine[28,29] has significantly contributed to the rising interest in this field. As more countries and institutions recognize the potential of 3D printing in cancer treatment, research activity has intensified, leading to a substantial increase in publications and greater visibility of this emerging area.

International collaboration and institutional contributions
Table 1 highlights China’s leading contribution to publications in this field, as well as its significant role in international collaboration. China is the only developing country among the top 10 contributing nations in terms of both publication volume and citation count; the remaining countries are all classified as developed economies. Research output in this area is predominantly driven by European and North American institutions, reflecting the substantial financial and technological resources available in these regions to support scientific advancements.
Furthermore, seven of the top 10 contributing institutions allowed by documents and citations are based in China, reinforcing its leading position in publication output. This reflects China’s substantial investment in the field, highlighting it as a key research priority. Regarding international collaboration, the United States exhibits the highest collaboration strength (n = 331), followed by China and the United Kingdom. While China leads in total publications, its level of international cooperation remains relatively limited. In resource-constrained settings, fostering global collaborations can enhance research impact and efficiency by optimizing available resources[30]. The current level of international collaboration in this field is moderate. However, fostering stronger global partnerships has the potential to drive significant advancements and contributions in the future[31].

Author contributions and collaboration analysis
Among the top 10 authors ranked by publication count and citations, Tu Chongqi has the highest number of publications. Cluster analysis reveals that seven of these authors are affiliated with Sichuan University, while the remaining three are associated with Peking University Third Hospital, forming a distinct cluster. The author’s co-occurrence network (Fig. 2) demonstrates strong intra-group collaboration within each cluster but limited interaction between different teams. Strengthening cross-team collaboration is crucial for future advancements. By integrating diverse research perspectives, methodologies, and resources, as well as expanding the diversity of the author pool, the field can foster more innovative and comprehensive research outcomes.

The potential geographical differences among institutions in different countries
To investigate potential geographic disparities in research focus, we selected the top two institutions by publication volume from each of the five leading countries (China, the United States, South Korea, Germany, and the United Kingdom), yielding a total of ten institutions for comparative analysis. This approach revealed distinct geographic trends in both research priorities and translational emphasis (Table 7). Chinese institutions, in particular Sichuan University and Shanghai Jiao Tong University, lead in publication output and concentrate on technologically advanced scaffold design, surgical navigation, and biomimetic tissue reconstruction. Sichuan University, in particular, has demonstrated significant progress in clinical translation; for instance, its development of a 3D-printed bolus for postmastectomy radiotherapy has been validated through patient follow-up and dosimetric assessments, showing enhanced skin dose conformity with minimal associated toxicity[32,33]. Similarly, customized hemipelvic prostheses incorporating negative Poisson’s ratio structures have been clinically validated, demonstrating improved functional outcomes in patients with pelvic sarcoma[34–36]. Shanghai Jiao Tong University developed image-guided implant navigation systems for pelvic tumor resection with pilot clinical validation[5,37–39]. The institution is advancing organoid models aimed at precision drug screening[40,41].

Leading U.S. institutions such as Harvard University and the Mayo Clinic primarily concentrate on preclinical innovation. Their research efforts include the development of platforms such as paper-based tumor models[42–44], microfluidic/lab-on-chip systems for cancer drug screening[44–46], and bioengineered scaffolds[47,48]. Despite these technological advancements, clinical translation remains limited. This disparity is largely due to the rigorous regulatory requirements imposed by the FDA, which necessitate extensive validation for patient-specific devices. Other obstacles include challenges in workflow standardization and the lack of established reimbursement mechanisms for novel 3D printing technologies, all of which contribute to a slower pace of clinical adoption despite significant progress in research and development.
Korean institutions such as Seoul National University and the University of Ulsan have placed a stronger emphasis on clinical feasibility. Seoul National University conducted a prospective trial utilizing personalized 3D transparent kidney models, which significantly reduced operative time in robotic partial nephrectomy, demonstrating clinical efficacy in the management of complex renal tumors[49,50]. Ulsan’s work includes the development of 3D-printed anatomical models for cervical[51] and thyroid cancer[52,53], as well as surgical guides for precise breast tumor localization and enhanced surgical accuracy[54–61].
European institutions exhibit a comparable emphasis on clinical integration. Heidelberg University and the German Cancer Research Center (DKFZ) focus primarily on head and neck oncology, developing personalized radiotherapy instruments that have been validated in patient cohorts[62–65]. UCL and King’s College London in the UK focus on the use of 3D-printed models for surgical planning, simulation, and patient education within the field of urology.[66–68]. This comparatively higher rate of clinical adoption is likely supported by more flexible regulatory frameworks, robust cross-institutional collaborations, and well-established translational infrastructures within European healthcare systems.
These findings reveal a geographic divergence in research priorities and translational trajectories. East Asian countries, particularly China and South Korea, exhibit a balanced approach that integrates both technological development and clinical validation. However, Western countries, especially the United States, lead in preclinical technological innovation but face significant barriers to clinical translation, largely due to stringent regulatory requirements, economic constraints, and institutional complexities. European nations occupy an intermediate position, with a growing emphasis on clinical studies supported by more flexible regulatory frameworks and established infrastructures for translational research. These patterns underscore the importance of interpreting bibliometric “hotspots” not only as indicators of research intensity but also in the context of regional publication norms and the practical implementation of innovations in clinical settings.

Journal impact factor and JCR ranking analysis
Impact factor[69] and Journal Citation Reports (JCR) ranking[70] serve as key metrics for evaluating journal influence. Among the top 10 journals by publication volume, the average impact factor is 5.43, with 80% classified within the JCR Q1 category. The top 10 most-cited journals have a higher average impact factor of 8.85, with all ranked in JCR Q1. These findings highlight the strong academic quality and significant impact of research in this field.
The high publication volume in top-tier journals underscores the prominence of high-impact platforms in disseminating research within this field. This reflects the rigorous and cutting-edge nature of the studies being conducted. The increased average impact factor and Q1 ranking of the most-cited journals indicate that foundational literature in this domain originates from leading academic sources. This not only sets a high standard for research but also ensures that peer citations are primarily drawn from authoritative works, fostering continuous advancements in the field. Moreover, these trends highlight the field’s strong presence in the global academic landscape, attracting extensive attention and participation from researchers worldwide.

Discussion for hotspots and future research trends
This study aims to explore the scientific hotspots and future research trends in the application of 3D printing in malignant tumors. To achieve this, multiple analytical approaches are integrated, including co-cited reference analysis, highlighted co-cited references, keyword clustering analysis, and keyword burst analysis. Through the synthesis of these methodologies, a comprehensive overview of the current research landscape is provided, emerging themes are identified, and valuable insights into future directions in this rapidly evolving field are offered.

Enhancing preoperative planning and patient education in tumor surgery through 3D printing
In the field of preoperative planning and patient education for tumors, the application of 3D printing technology has significantly enhanced surgical precision and patient comprehension. Research has demonstrated that personalized 3D printing models, generated from CT or MRI data, are extensively utilized in the planning of complex tumor surgeries, including lung cancer resection[71], malignant kidney tumor resection[72], living donor liver transplantation[73], and laparoscopic partial nephrectomy[74]. These models enable surgeons to visualize anatomical structures more clearly, refine surgical strategies, and make well-informed decisions before surgery, thus reducing intraoperative complications[75]. Further, by providing patients with a tangible representation of their condition and surgical plan, 3D printing models improve patient understanding, enhance confidence in treatment, and contribute to more effective preoperative informed consent and higher overall patient satisfaction[76]. Some studies have also employed patient-specific 3D printing models made from silicone or biomaterials for preoperative rehearsals, emphasizing their practical value in surgical planning and training[77]. For example, 3D printing models generated from MRI data have been instrumental in planning complex renal cancer surgeries, particularly in assessing surgical access routes and defining resection margins. The integration of these models has resulted in modifications to 30–50% of surgical plans and has significantly enhanced surgeons’ confidence in their chosen strategies[78]. Currently, 3D printing technology has not only introduced advanced visualization tools for tumor surgeries but has also enhanced preoperative planning, patient education, and postoperative recovery strategies. Its significant potential for future clinical applications continues to expand[79].

3D printing in the treatment of bone malignant tumors
3D printing technology has shown considerable promise in the treatment of bone tumors and post-surgical functional reconstruction, providing innovative solutions for personalized therapy and tissue regeneration. In particular, 3D printing bioceramic scaffolds have been widely utilized in bone tissue regeneration and tumor treatment. Their hierarchical structure enhances mechanical strength, optimizes degradation rates, and improves biocompatibility, making them highly effective in clinical applications[80]. For instance, a 3D printing nanostructured bioceramic scaffold inspired by mussel adhesion has been designed to facilitate bone regeneration while simultaneously leveraging photothermal effects to eradicate residual tumor cells. This dual-function approach integrates bone repair with targeted tumor treatment, enhancing therapeutic efficacy[81]. Moreover, a composite scaffold incorporating graphene oxide and β-tricalcium phosphate has been developed to integrate photothermal therapy with bone regeneration capabilities. Under near-infrared laser irradiation, this scaffold effectively eradicates osteosarcoma cells while simultaneously supporting bone tissue regeneration, offering a promising strategy for post-surgical bone tumor reconstruction[82].
Furthermore, 3D printing technology enables the customization of implants for bone tumor resections, offering tailored solutions for various anatomical sites. For instance, in cases of sacral bone removal, personalized implants provide robust mechanical support while facilitating bone regeneration[83]. In hip acetabulum tumors, 3D printing modular hemipelvic prostheses have demonstrated exceptional stability and functional recovery in clinical applications[84]. Similarly, for spinal tumors, patient-specific 3D printing vertebrae have been successfully utilized in cervical spine reconstruction for individuals with Ewing’s sarcoma, effectively restoring spinal stability and optimizing biomechanical performance[85]. In cranial tumor cases, 3D printing polymethyl methacrylate (PMMA) molds have been introduced as alternatives to traditional autologous bone grafts for skull reconstruction. Studies conducted in Canada[86] and India[87] indicate that these PMMA-based 3D printing molds not only offer a cost-effective solution but also deliver favorable aesthetic outcomes.
Despite the ongoing challenges of functional reconstruction following musculoskeletal tumor surgery, the integration of 3D printing technology has facilitated the use of standardized functional assessment systems, allowing for comparative evaluations of different reconstruction methods. This has contributed to the refinement of post-surgical rehabilitation strategies, ultimately enhancing patient quality of life[88]. To elucidate the characteristics of various materials used in bone reconstruction, the following section presents an overview of commonly employed biomaterials in bone tumor reconstruction, highlighting their respective advantages and limitations. Among these, titanium alloy (Ti6Al4V) remains the most widely utilized due to its superior mechanical strength, corrosion resistance, and favorable osteoconductive properties[89]. However, the inherent stiffness of titanium alloy can result in stress shielding, potentially impairing long-term bone remodeling. Similarly, its non-biodegradable nature requires permanent implantation, which may not be appropriate for all patient populations. Polyetheretherketone (PEEK) presents a modulus of elasticity more closely aligned with that of cortical bone and exhibits favorable radiolucency, improving the quality of postoperative imaging and assessment[13,90]. However, PEEK’s biological inertness limits its ability to integrate with surrounding bone tissue, often necessitating surface modification techniques to improve osseointegration. Hydroxyapatite (HA), a bioactive ceramic with inherent osteoconductive properties, offers excellent biological affinity and is commonly employed as a coating material or integrated into porous scaffolds to promote bone regeneration[91]. Its fragility, however, restricts its use in load-bearing reconstructions. β-tricalcium phosphate (β-TCP) and composite materials offer faster degradation and remodeling but may compromise mechanical integrity in large or complex defects[92]. Emerging polymer-ceramic hybrids and bioresorbable metals (e.g., magnesium alloys)[93] aim to balance structural support with gradual resorption, but clinical data remain limited.
This comparison highlights the inherent difficulty in identifying a single biomaterial that simultaneously satisfies mechanical strength, biological compatibility, and clinical applicability. Current research predominantly centers on biomechanical performance and early-stage osseointegration, often lacking robust validation through long-term clinical outcomes. To advance evidence-based material selection in bone tumor reconstruction, future studies should prioritize comparative in vivo investigations that assess host tissue responses, complication profiles, and functional recovery across different materials, tailored to specific defect types and anatomical locations.

Application of 3D printing in tumor radiotherapy
3D printing technology has transformed tumor radiotherapy by facilitating the development of patient-specific treatment plans tailored to individual anatomical structures. This advancement includes the fabrication of personalized anatomical models, radiation-enhancing devices, and implantable structures, all of which enhance the precision of radiotherapy, optimize dose distribution, and minimize radiation exposure to adjacent healthy tissues[94,95]. 3D printing has proven highly advantageous in the treatment of various tumor types. For instance, in gynecological malignancies[96], skin cancer[97], and head and neck cancers[98], the use of customized 3D printing adapters has enabled precise targeting, leading to enhanced treatment efficacy and improved clinical outcomes[99]. In prostate cancer treatment, 3D printing has been utilized to develop drug-loaded implants for brachytherapy, enabling controlled local drug release alongside radiation therapy. This approach enhances therapeutic efficacy while minimizing systemic side effects[100]. Moreover, in the treatment of superficial tumors, 3D printing technology enables the precise replication of a patient’s external contours, facilitating the fabrication of customized tissue compensation membranes. These personalized membranes optimize radiation dose distribution at the skin surface, enhancing therapeutic efficacy[101,102]. 3D printing has also shown evident potential in the implantation of radioactive seeds. 3D printing has demonstrated significant potential in the precise implantation of radioactive seeds. Customized three-dimensional printed templates have been successfully utilized for the targeted implantation of 125I seeds in prostate cancer[103], lung cancer[104], colorectal cancer[105], and gynecological malignancies[106], enhancing both treatment accuracy and therapeutic outcomes. These templates also contribute to preoperative planning, real-time dose optimization, and postoperative monitoring. Furthermore, 3D printing technology enables the conversion of medical imaging data, such as DICOM formats, into tangible anatomical models, providing valuable support for tumor localization and aiding in clinical decision-making[107].
It is essential to acknowledge that various 3D printing technologies possess distinct advantages and constraints in terms of material compatibility, printing resolution, fabrication complexity, and clinical applicability within the context of radiotherapy. The following section provides an overview of several widely utilized techniques, namely Fused Deposition Modeling (FDM), Stereolithography (SLA), Selective Laser Sintering (SLS), and silicone molding, highlighting their respective characteristics and relevance to radiotherapeutic applications.
FDM remains the most widely utilized technique, primarily due to its ease of access and compatibility with affordable materials such as Polylactic Acid (PLA)[108] and Thermoplastic Polyurethane (TPU)[109]. However, the relatively low resolution and anisotropic mechanical properties of FDM may limit the precision of radiation bolus fabrication, particularly in anatomically complex regions. SLA printing provides higher resolution and superior surface finish, essential for producing conformal skin-contact devices such as facial boluses and surface applicators. SLA resins frequently exhibit limited biocompatibility, and their inherent brittleness restricts their structural flexibility[110]. SLS enables high-resolution, support-free printing of mechanically robust materials such as nylon, offering clear advantages in durability and anatomical fidelity[111]. However, its high operational costs, powder handling complexities, and extensive post-processing requirements hinder widespread clinical scalability. Although not a true 3D printing technique, silicone molding remains preferred in certain contexts due to its superior biocompatibility and patient comfort[112]. Its reliance on manual labor and mold fabrication limits its capacity for rapid customization. These differences illustrate a fundamental trade-off in 3D printing–assisted radiotherapy: improving anatomical accuracy often involves greater complexity and higher costs. While the dosimetric feasibility of these techniques has been established, there is a significant lack of comparative clinical data on outcomes such as patient comfort, reproducibility, and treatment accuracy. Therefore, future research should focus on direct clinical comparisons and cost-effectiveness evaluations to guide evidence-based integration of these technologies into routine radiotherapy practice.

3D printing for construction of in vitro tumor cell models
Compared to conventional 2D cell culture methods, 3D bioprinting technology provides distinct advantages by accurately replicating the three-dimensional architecture of cellular growth using scaffold-based or scaffold-free techniques[113]. This enables the development of tumor models with functional characteristics that closely mimic the intricate microenvironment of tumor tissues. These advanced models offer reliable in vitro platforms for investigating tumor progression, facilitating drug screening, and advancing personalized treatment strategies[3,114]. For example, 3D printing cervical cancer models demonstrate improved biological characteristics compared to traditional 2D cell cultures, including enhanced tumor cell proliferation, upregulated expression of matrix metalloproteinases, and increased resistance to chemotherapy. These attributes increase their clinical relevance, providing a more accurate representation of tumor behavior in vivo[115]. Similarly, 3D printing has been effectively utilized to develop pancreatic cancer[116] and glioblastoma models[117], which closely mimic the native tumor microenvironment. Despite these promising advances, significant limitations persist. Many existing 3D bioprinted tumor models continue to face challenges in accurately replicating the physiological complexity of human tumors, particularly regarding vascularization, immune system components, and stromal interactions[118]. The mechanical properties and degradation rates of bioinks can vary substantially, affecting cellular behavior and model stability[119]. Moreover, the limited resolution and reproducibility of current bioprinting technologies can constrain the accurate reproduction of microarchitectural features essential to tumor biology. Integration with microfluidic systems, such as liver cancer drug screening platforms utilizing anti-CD147 monoclonal antibodies[120], represents a promising advancement. However, these platforms remain labor-intensive, costly, and lack standardization, limiting their readiness for clinical translation[121]. To improve the fidelity and applicability of bioprinted tumor models, future research should prioritize the development of advanced bioink formulations, improvements in spatial resolution, and the incorporation of diverse cellular components, including immune and stromal cells. Thorough validation against in vivo models will be critical to ensure their clinical relevance and potential utility in precision oncology[122,123].

Expanded applications of 3D bioprinting technology in cancer therapies
3D bioprinting technology has greatly expanded the landscape of cancer treatment, particularly in immunotherapy, photothermal therapy, and personalized medicine. In immunotherapy, it has shown significant potential, especially in the development of scaffold-based vaccines. Porous 3D printing scaffolds can replicate the structural and functional characteristics of lymphoid organs, facilitating immune cell recruitment and enhancing both humoral and cellular immune responses. When combined with immune checkpoint inhibitors, these scaffolds effectively inhibit tumor growth and reduce the risk of metastasis[124]. Similarly, 3D printing dendritic cell (DC) vaccines have demonstrated a significant improvement in dendritic cell survival and lymph node migration, leading to a more robust anti-tumor immune response. In mouse models of breast cancer, this approach has effectively suppressed tumor recurrence and significantly improved survival rates[125].
3D printing-based photothermal therapy has shown significant potential in treating not only bone tumors[126] but also breast cancer[127] and malignant colorectal cancer[128]. In these malignancies, 3D bioprinting scaffolds contribute to both tissue regeneration and tumor suppression. Moreover, the advancement of integrated tissue-organ printing systems has further refined personalized treatment in precision oncology. By generating tumor-associated tissues with vascularization and structural integrity tailored to individual patient characteristics, these systems present promising solutions for post-surgical tissue reconstruction and repair[129].
Furthermore, 3D bioprinting allows for the precise design and fabrication of personalized radiation therapy molds, enabling more accurate dose modulation and improved treatment precision tailored to each patient’s needs[130]. This technology has also paved the way for personalized drug delivery in cancer treatment. For instance, a 3D printing polyurethane scaffold loaded with 5-FU has demonstrated sustained drug release in esophageal cancer therapy, improving treatment efficacy while minimizing the risk of stent restenosis[131]. Furthermore, 3D printing enables the fabrication of personalized oral drug formulations pre-loaded with anti-cancer agents, ensuring precise dosing and optimized therapeutic efficacy[132]. 3D bioprinting addresses the limitations of traditional two-dimensional imaging by generating patient-specific models from medical imaging data, providing a more intuitive and accurate approach to precision medicine[133]. These advancements highlight the immense potential of 3D bioprinting in cancer therapy, paving the way for the evolution of personalized treatment strategies and offering innovative tools for the future of precision oncology.

Current clinical translation and challenges of hot topics
To further investigate the connection between research hotspots and clinical translation, we analyzed highly cited references, focusing on clinical studies and meta-analyses relevant to these key themes. This approach seeks to evaluate the current impact and ongoing challenges of applying 3D printing technologies in clinical oncology.

Preoperative planning and patient education
Among the key hotspots identified in Figure 3, “preoperative planning” and “patient education” have emerged as major thematic clusters. While bibliometric analysis reflects strong academic interest, it is equally important to evaluate how these areas impact clinical outcomes. A review of highly cited references and major clinical studies, including randomized trials, prospective cohorts, and feasibility studies in urologic, hepatobiliary, and colorectal surgery, has highlighted several clinical advantages of 3D printing. These include improved spatial understanding of complex anatomy and surgical planning[76,134,135], improved preoperative decision-making and surgical efficiency[78,136,137], better patient education and informed consent[68,138,139], and more effective training for surgical skills and resident education[77,140,141]. 3D printing has enabled the development of personalized simulation models tailored for robot-assisted surgery, improving procedural planning and surgical precision[142,143].
The clinical benefits of 3D printing in these areas are increasingly acknowledged; however, most studies concentrate on surrogate measures such as complication rates, patient understanding, and operative metrics, rather than on long-term outcomes like reoperation rates or survival. Further, there is a scarcity of economic analyses assessing the cost-effectiveness of producing and implementing 3D models in clinical settings[134,143]. To date, no comprehensive meta-analyses have synthesized these advantages across various surgical specialties, highlighting a significant gap between technological progress and thorough evidence-based validation.

Bone tumor
Among the co-occurrence clusters identified in Figure 3, “bone tumor reconstruction” is recognized as a high-frequency term. To further connect bibliometric findings with clinical relevance, highly cited clinical studies and systematic reviews on this topic were reviewed. Current evidence highlights several key advantages and clinical potential of 3D printing in bone tumor reconstruction. One major benefit is the precise customization of patient-specific prostheses and bone reconstruction. This is achieved through individualized modeling and implant fabrication based on CT or MRI data. Such customization ensures improved anatomical fit and stability, which can help prevent postoperative loosening and reduce the need for revision surgeries[144–146]; 3D printing improves preoperative planning and surgical visualization. The models provide clear spatial representations of tumors and critical structures, aiding surgeons in determining resection margins and prosthesis design while minimizing intraoperative errors[135]. Improved surgical efficiency and functional recovery have also been reported. Studies indicate reduced intraoperative blood loss, shorter operative times, higher postoperative MSTS scores, and satisfactory functional outcomes for patients receiving 3D printing implants[147–149]; High feasibility has been demonstrated for reconstruction in complex anatomical regions (e.g., pelvis, sacrum), where standard prostheses are often unsuitable. This approach offers both structural support and preservation of joint function[83]. Excellent biomechanical performance and effective complication control have been demonstrated through finite element analysis and clinical follow-up. These findings indicate favorable load transfer, structural stability, and low complication rates in pelvic and spinal reconstructions[144,150]. New options for limb-salvage and long-segment reconstructions have been provided, with 3D-printed titanium or PEEK prostheses demonstrating promising outcomes in structural repair and long-term weight-bearing. These prostheses offer viable solutions for young or high-demand patients[151].
Despite these promising outcomes, quantifying survival benefits remains challenging due to confounding factors such as tumor biology and adjuvant treatments. Economic evaluations are also limited; most studies provide qualitative assessments, such as improved implant fit and reduced revision surgeries, but lack comprehensive cost-effectiveness analyses. One biomechanical study[144] supports the structural integrity of printed sacral constructs, suggesting the potential for reducing long-term complications and associated costs. However, the absence of formal health economic assessments restricts definitive conclusions about cost efficiency.

Radiotherapy
While strong academic interest and rapid technological advances are highlighted by bibliometric data, these trends must be contextualized within the broader framework of clinical evidence. To further connect the bibliometric findings with clinical research, highly cited references for systematic reviews and clinical trials on the application of 3D printing in radiotherapy were screened. Current clinical studies predominantly focus on improving the precision of individualized treatment[152–154], optimizing target dose coverage and sparing organs at risk[63,155,156], improving patient comfort and compliance[96,157,158], and streamlining treatment workflows for greater efficiency and consistency[156,159], and advancing safety and clinical standardization[160,161]. However, the majority of existing studies are limited in scale, with few assessing long-term survival outcomes or performing formal cost-effectiveness analyses. Although some reviews, such as Tino et al
[162], acknowledge that 3D printing phantoms may reduce costs through lower material and fabrication expenses, comprehensive health economic evaluations have yet to be conducted. Current systematic reviews[96,162] do not analyze survival outcomes or cost-effectiveness, reflecting a broader deficiency in clinical trials reporting for these endpoints These reviews highlight the pressing need for large-scale, multicenter clinical trials to substantiate the translational benefits of 3D printing technologies. A systematic review of the advantages and limitations of 3D printing in surgery[163] also identified increased costs as a significant obstacle to routine clinical adoption, highlighting the critical role of comprehensive cost analyses in advancing clinical integration.

Cancer therapies
Although 3D bioprinting has shown significant advancements in preclinical cancer models, its clinical translation remains at an early and evolving stage. In the field of drug delivery, various studies have introduced novel 3D-printed implants designed for sustained local administration of chemotherapeutic agents. For instance, a 3D-printed polyurethane stent loaded with 5-FU demonstrated extended drug release and showed potential therapeutic benefits in esophageal cancer models[131]. Similarly, 3D-printed drug-loaded prosthetic implants have been developed to prevent local recurrence of breast cancer following breast-conserving surgery, demonstrating favorable antitumor efficacy in preclinical animal models[164]. However, despite these advancements, the majority of systems remain at the preclinical stage. Key challenges, including long-term biosafety, regulatory approval, personalized anatomical fitting, and seamless integration into surgical workflows, must be addressed to enable broader clinical adoption.
Photodynamic therapy (PDT) supported by 3D printing technologies has begun progressing toward clinical application. A low-cost, mobile fluorescence-guided PDT system was clinically evaluated in India for early-stage oral cancer, achieving a complete response rate exceeding 70% and demonstrating both safety and feasibility in resource-constrained settings[165]. Moreover, anatomically accurate 3D printed pleural cavity models are now being used to improve light dosimetry in PDT for malignant pleural mesothelioma, thus improving treatment planning and delivery[166]. However, the wider clinical application of photodynamic therapy (PDT) continues to be hindered by technical challenges, including shallow light penetration, reliance on sufficient tissue oxygenation, and inconsistencies in photosensitizer pharmacokinetics.
Future investigations should prioritize multicenter, prospective clinical trials that systematically compare outcomes between interventions with and without the use of 3D printing across diverse tumor types and surgical procedures. These studies should employ standardized endpoints, including functional recovery, surgical margin status, local disease control, overall survival, patient-reported outcomes, and cost-effectiveness metrics. Aligning technological innovation with clinically meaningful outcomes and rigorous economic evaluation will be essential to address current translational gaps. Such evidence will be critical to support the broader clinical integration of 3D bioprinting in oncologic care. As bioprinting technologies and regulatory pathways continue to advance, the incorporation of bioprinted systems into precision oncology is poised to transition from experimental application to clinical practice.

Comparison of FDA/EMA-approved and experimental 3D printing approaches in oncology
As summarized in Table 8, a few 3D-printed medical devices have received regulatory approval from agencies such as the Food and Drug Administration (FDA) and European Medicines Agency (EMA), particularly in the fields of radiation therapy and orthopedics. Particular examples include the Adaptiiv 3D Bolus Software and Kallisio Stentra™ oral stent for radiation therapy, as well as the DB-CSD implant for orthopedic reconstruction. These devices have been clinically adopted for applications such as structural reconstruction, personalized treatment planning, and improved precision in radiation dose delivery. Regulatory approval has been granted based on evidence of biocompatibility, safety, manufacturing reproducibility, and adherence to established criteria for clinical efficacy within their intended use.

Currently, 3D printing has already been applied in clinical studies involving radiotherapy bolus fabrication[96,158,167–169], post-tumor bone reconstruction[34,170], preoperative planning and surgical navigation[33,68,171,172], applications that align closely with those approved by the FDA and EMA. By contrast, most innovative 3D printing approaches in oncology remain at the experimental or proof-of-concept stage, with limited progression toward clinical translation. As summarized in Table 8, these include the development of 3D printing based drug delivery systems[173–175], functional materials for photothermal therapy[176–178], tumor-on-a-chip organoid models for drug screening[179–181], and nanorobotics for targeted delivery[182], and algorithm validation[183–185]. These approaches are primarily assessed through in vitro experiments or preclinical animal studies, emphasizing mechanistic innovation and therapeutic potential rather than immediate clinical application. While they demonstrate the transformative promise of 3D printing for personalized medicine, significant challenges, including scalable manufacturing, regulatory compliance, biocompatibility, and long-term safety, remain unresolved. The contrast between approved and experimental applications underscores a critical translational gap: FDA and EMA-approved 3D printing technologies have predominantly been integrated into clinical practice in supportive or ancillary roles, whereas most experimental efforts focus on novel therapeutic paradigms and advanced drug delivery systems that have yet to undergo the rigorous evaluation necessary for clinical adoption.
Moving forward, bridging the gap between experimental innovation and clinical application will necessitate multidisciplinary collaboration. Future research efforts should extend beyond technological development to emphasize standardized validation protocols, regulatory compliance, and rigorous evidence-based clinical evaluation. Such a comprehensive approach is essential to ensure the safe and effective translation of experimental 3D-printed modalities into routine oncological practice.

Analysis of keyword frequency and cancer type research trends
An analysis of keyword frequency identified bone cancer, breast cancer, osteosarcoma, lung cancer, and cervical cancer as the top five cancer types studied in relation to 3D printing applications. Bone cancer and osteosarcoma, previously discussed as key research hotspots, have received significant attention. The following introduces the application of 3D printing in breast cancer, lung cancer, and cervical cancer.

Breast cancer
The integration of 3D printing technology into breast cancer research and clinical management has driven significant advancements across multiple domains. Current research primarily concentrates on five key areas: tumor microenvironment modeling, surgical planning, radiotherapy bolus customization, imaging phantoms, and emerging applications in drug delivery as well as photothermal and photodynamic therapies. The fabrication of biological scaffolds and tumor organoid models via 3D printing has been extensively employed to investigate breast cancer cell behavior, microenvironmental interactions, and mechanisms of drug resistance in both in vitro and in vivo settings[179,180,186–190]. Most of these advances remain at the laboratory or animal experiment stage since the challenge of fully replicating in vivo tumor heterogeneity and achieving scaffold standardization has limited their direct clinical application. Secondly, case studies and feasibility studies have demonstrated the utility of patient-specific 3D-printed breast tumor models and resection guides, supporting improved precision in breast-conserving surgery[33,55,61,171,191,192]. However, large-scale randomized controlled trials remain lacking, and anatomical discrepancies between printed models and actual intraoperative findings continue to pose technical challenges. Thirdly, among all applications, the clinical translation of 3D-printed patient-specific bolus for breast cancer radiotherapy is the most advanced. Multiple centers have implemented individualized bolus for postmastectomy radiotherapy, achieving improved skin dose distribution and enhanced patient comfort[167,193]. The effectiveness and safety of these boluses have been validated through dosimetric analyses and corroborated by clinical follow-up data[33,194]. However, challenges remain in cost-effectiveness, workflow standardization, and the availability of long-term outcome data. Furthermore, 3D-printed phantoms for multimodal imaging have been instrumental in validating and calibrating medical imaging systems; however, their clinical impact remains indirect and is currently limited to imaging research and training[195–197]. Finally, 3D printing is being investigated in conjunction with advanced therapies, including drug delivery systems and photothermal/photodynamic treatments[176,177,198–200]. These approaches, although demonstrating promise in vitro and animal models, have yet to surmount challenges related to biocompatibility, delivery efficiency, and faithful replication of the human tumor microenvironment. In summary, 3D printing holds transformative potential across multiple aspects of breast cancer care, spanning from preclinical research to patient-specific clinical applications. The progression from laboratory innovation to broad clinical implementation is hindered by a paucity of large-scale clinical evidence, issues with reproducibility and standardization, and technical constraints in accurately modeling complex tumor biology. Future efforts should emphasize multicenter clinical trials, the establishment of regulatory standards, and interdisciplinary collaboration to expedite clinical translation and optimize patient outcomes.

Lung cancer
3D printing is being increasingly integrated into the management of lung cancer, with current research concentrated in five key domains: surgical planning and simulation, imaging and radiotherapy phantom development, in vitro tumor modeling, emerging therapeutic strategies, and applications in molecular diagnostic. In clinical settings, patient-specific 3D-printed lung and tumor models generated from medical imaging data have enhanced preoperative planning, improved anatomical understanding, and facilitated surgical simulation and training.[71,201–203]. These models support the execution of complex surgical procedures and have been reported to improve anatomical comprehension and, in some cases, reduce operative time. Broader clinical adoption is constrained by factors such as high production costs, complex manufacturing workflows, and the absence of large-scale randomized clinical trials. In parallel, 3D-printed phantoms have been effectively utilized for imaging calibration, radiotherapy quality assurance, and algorithm validation by accurately replicating lung tissue characteristics and tumor heterogeneity, therefore advancing both laboratory research and software development[183–185]. While these applications hold significant technical value, they remain largely preclinical and have yet to exert a direct impact on patient care. In vitro, 3D bioprinted lung cancer models and drug screening platforms offer enhanced replication of the tumor microenvironment compared to conventional 2D cultures, improving the relevance of drug sensitivity testing and supporting translational cancer research[181,204,205]. However, several challenges, such as achieving physiological relevance, ensuring reproducibility, and enabling scalable production, must be overcome before these technologies can be translated into clinical practice. Emerging applications, including patient-specific devices for photodynamic therapy and nanorobotic platforms for targeted radiotherapy, underscore the innovative potential of 3D printing in oncology. These approaches remain in the experimental stage, with clinical pathways and regulatory frameworks yet to be established[182,206]. The application of 3D-printed systems in molecular diagnostics and risk stratification remains at the proof-of-concept stage, with limited validation in clinical settings[207,208]. Thus, 3D printing has significantly enriched the landscape of lung cancer management, particularly in areas such as preoperative planning, surgical training, and translational research. Despite these advances, several critical challenges persist, including the lack of large-scale clinical validation, the need for standardized manufacturing workflows, high production costs, and limitations in accurately replicating human tumor biology. Overcoming these barriers will be essential to transitioning 3D printing from an adjunctive innovation to an integrated and standardized element of personalized lung cancer care.

Cervical cancer
3D printing technology has shown substantial promise in cervical cancer, mostly in individualized brachytherapy applicators such as multichannel cylinders and personalized templates[96,168,209–211]. These customized devices offer improved dose conformity, better anatomical fit in complex cases, and the potential to reduce radiation exposure to surrounding healthy tissues. Although several clinical centers have reported successful implementation and encouraging preliminary outcomes, broader adoption remains constrained by the absence of large-scale randomized controlled trials, lack of standardized fabrication protocols, and the need for streamlined clinical workflows. In addition to radiotherapy, 3D-printed anatomical models are increasingly being employed for surgical simulation and patient education, supporting more accurate preoperative planning and facilitating shared decision-making[212,213]. Although these applications enhance both physician workflow and patient experience, widespread adoption is hindered by challenges such as high production costs and limited model accuracy. In the preclinical setting, 3D bioprinted cervical cancer models provide more physiologically relevant platforms for drug screening and mechanistic studies compared to traditional approaches but require further improvement in their reproducibility, scalability, and clinical applicability before clinical translation[214,215]. Overall, while 3D printing is driving meaningful advances in individualized cervical cancer care, broader clinical adoption will require continued efforts to standardize clinical workflows, reduce production costs, and generate robust, high-quality evidence through well-designed clinical studies.
To facilitate targeted use of this bibliometric analysis by researchers focusing on specific cancer types, supplementary overviews have been provided in Supplementary Digital Content Tables S4–8 (available at: http://links.lww.com/JS9/E988). In these appendices, the principal research directions, significant advancements, clinical trial progress, translational status, and key limitations for the sixth to tenth most-studied cancers, namely, liver cancer, prostate cancer, head and neck cancer, colorectal cancer, and glioblastoma, are summarized. Researchers with interests in these cancer types or related areas are encouraged to consult the corresponding references to identify potential collaborators within their field.

Emerging research trends in 3D printing for cancer treatment
A detailed analysis of emerging burst keywords and recent citations highlights several potential future research hotspots, including limb-salvage surgery and prosthetic reconstruction, the use of 3D bioprinting to develop tumor microenvironment (TME) models for investigating anti-tumor mechanisms, and the application of 3D printing in overcoming cancer drug resistance.
One study explored the use of 3D printing modular hemipelvic prostheses for patients undergoing tumor resection around the acetabulum. With a median follow-up of 32.5 months, 73.8% of patients showed no evidence of disease, achieving a favorable Musculoskeletal Tumor Society (MSTS) score of 83.9%, while the complication rate remained low at 20%[84]. Another study utilized 3D printing to design personalized pelvic prostheses for 28 patients with pelvic tumors. Following pelvic osteotomy, the prosthesis-bone interface displayed excellent integration, leading to significant functional recovery in the early postoperative period[216]. This technology has also been employed in upper limb bone tumor resections, ensuring precise matching of prosthesis-bone joint surfaces. After a follow-up period of 49.36 months, no cases of metastasis, recurrence, infection, dislocation, or implant loosening were reported[217]. In recent years, 3D printing prosthetics have been increasingly utilized in the treatment of various bone tumors[218–220]. Their widespread application in limb-salvage procedures and prosthetic reconstruction following bone tumor resections is expected to become a key focus of future research.
A recent study on 3D bioprinting for tumor microenvironment reconstruction demonstrated several key advantages, including precise spatial control over matrix properties and the integration of perfusable vascular networks, enabling a more accurate replication of the in vivo tumor microenvironment. 3D bioprinting also facilitates the high-throughput fabrication of cancer models[114]. Significant advancements have been made in developing 3D printing tumor microenvironments for various cancers, including intrahepatic cholangiocarcinoma[221], glioblastoma[222], and ovarian cancer[223]. Recent studies have reported increased drug resistance in 3D printing tumor cell models used for drug treatment[117,224,225]. 3D bioprinting in vitro tumor models have emerged as valuable tools for investigating drug resistance in cancer treatment, as they closely mimic the tumor microenvironment. Their biomimetic architecture offers a more physiologically relevant platform for anti-cancer drug screening and gaining deeper insights into drug resistance mechanisms[226,227]. While 3D bioprinting of tumor microenvironment (TME) models represents a rapidly advancing research frontier, several critical limitations must be acknowledged. Reproducing the full physiological complexity of the native TME remains a formidable challenge, given its intricate and dynamic interplay among heterogeneous cell populations, extracellular matrix components, and spatially and temporally regulated signaling gradients. Current bioprinting platforms are often limited by suboptimal resolution, restricted bioink compatibility, and challenges in sustaining cell viability and function over prolonged culture durations. Further, the absence of standardized evaluation criteria and persistent issues with reproducibility pose significant barriers to clinical translation. Therefore, although 3D bioprinted TME models offer substantial potential for drug screening and personalized oncology, their application in clinical settings remains in the experimental stage and will require continued technological and biological optimization. The integration of 3D-printed scaffolds with advanced materials, such as those used in photothermal and magnetic hyperthermia therapies, shows promise in overcoming drug resistance and suppressing metastasis in difficult-to-treat cancers like osteosarcoma, offering new therapeutic avenues[228]. Future research is expected to further investigate the role of 3D printing in overcoming cancer drug resistance and expanding its applications in developing innovative therapeutic strategies.
Beyond the dominant themes of prosthesis innovation and radiotherapy enhancement, our review of institutional data reveals three nuanced yet potentially transformative subfields that remain underrepresented but could significantly shape future oncologic care.

AI-assisted automated modeling for precision oncology
While most current 3D-printed solutions rely on manual segmentation and model construction, some institutions in China, the UK, and the US have started integrating artificial intelligence (AI) and deep learning into the 3D modeling workflow. AI-driven approaches enable faster, more consistent, and anatomically accurate reconstructions from medical imaging, improving the development of personalized surgical guides and tumor models. Early reports suggest that AI-assisted modeling can significantly reduce manual workload, limit inter-operator variability, and accommodate complex anatomies, especially in pelvic, liver, breast, and head and neck cancers[229–233].
However, despite these technical advancements, clinical translation of AI-assisted modeling remains limited by the absence of standardized protocols, insufficient validation across diverse patient populations, and unclear regulatory frameworks for AI-integrated medical devices. Furthermore, concerns about the interpretability of AI “black box” algorithms and their implications for clinical responsibility persist. To enable widespread adoption, large-scale, multicenter studies with transparent evaluation criteria are essential.

3D printing in pediatric and rare tumors
Although most high-impact studies have centered on common adult cancers, several research groups have investigated the application of 3D printing in pediatric and rare oncologic conditions, such as neuroblastoma[234], Wilms tumor[235], or retroperitoneal sarcomas[236]. These cases often involve complex anatomical and surgical challenges that can greatly benefit from patient-specific modeling[237,238].
Despite encouraging results, the existing evidence remains limited and fragmented, frequently consisting of single-center case reports or technical descriptions. Barriers to broader implementation include limited funding, low case volumes, and ethical constraints. Moreover, the clinical value of these technologies must be carefully weighed against their cost and operational complexity, particularly in resource-constrained settings. To advance the field, coordinated registries and collaborative research networks are essential for generating robust, generalizable data on the utility of 3D printing in pediatric oncology.

Nanorobotic platforms for precision radiotherapy
Emerging research in nanorobotics is paving the way for a new era in precision radiotherapy. Unlike conventional methods that fixedly deliver radiation, nanorobotic systems are designed to actively navigate the TME, guided by external cues such as magnetic fields or ultrasound. These systems can be programmed to deliver radiation-sensitizing agents or therapeutic payloads with sub-millimeter precision, improving tumor targeting while minimizing damage to surrounding healthy tissues. Early animal studies suggest that nanorobotic-assisted radiotherapy improves local tumor control and enables real-time, adaptive treatment modulation in response to the tumor’s evolving characteristics[182,239,240].
However, the translation of nanorobotic systems into clinical practice remains constrained by challenges related to biocompatibility, safety, large-scale manufacturing, and regulatory approval. Further preclinical studies and early-phase clinical trials are essential to establish their safety, efficacy, and feasibility for broader clinical adoption.
In summary, emerging trends such as AI-assisted modeling, applications in pediatric and rare tumors, and high-fidelity simulation represent promising frontiers in the evolution of 3D printing in oncology. To prevent the recurrence of cycles marked by initial technical enthusiasm followed by limited clinical impact, future research must emphasize rigorous validation, methodological transparency, and demonstrable real-world benefit. The active engagement of funding agencies, regulatory authorities, and interdisciplinary consortia will be essential to support the maturation, clinical translation, and equitable integration of these innovations into standard oncologic care.

Comparative analysis of 3D printing applications in cancer, cardiovascular, and orthopedic medicine
A comparison of 3D printing applications in oncology with those in other medical fields, such as cardiovascular disease and orthopedics, offers valuable insight into the distinct challenges and opportunities within cancer research. In cardiovascular medicine, 3D printing has seen widespread application in the fabrication of personalized implants and prosthetics, particularly in heart valve replacements and vascular grafts[241,242]. These uses capitalize on the technology’s ability to accurately reproduce intricate anatomical geometries, a capability that holds significant promise in oncology as well, particularly for the creation of patient-specific tumor models and customized surgical guides[78,243]. Although oncology shares advances with other fields in biocompatible materials and personalized therapies, it faces distinct challenges, such as the complexity of tumor microenvironments and the rapid genetic heterogeneity of cancers, which necessitate more advanced and precise bioprinting strategies[244].
In orthopedics, 3D printing has been used to produce customized implants and prostheses for bone reconstruction, including applications specific for bone tumor repair[245,246]. The focus, in orthopedic applications, is largely on optimizing the mechanical properties of materials to meet the load-bearing demands of bone. In the context of bone tumor reconstruction, however, materials must simultaneously provide structural integrity and biological compatibility to facilitate tissue regeneration. This dual requirement adds complexity to the use of 3D printing in oncology, as it necessitates both advanced material engineering and the ability to replicate the tumor’s biological microenvironment with high fidelity[247,248]. Therefore, while there are significant parallels between these fields, oncology presents distinct challenges that necessitate continuous technological advancement to enable effective clinical translation.

Limitations of the study
This review has several limitations. First, it relies solely on the Web of Science Core Collection (WoSCC), which primarily indexes English-language journals. As a result, clinical studies published in non-English or regional journals, particularly those from developing countries, may be underrepresented. This linguistic and geographic bias could shift the focus toward high-output regions rather than truly impactful clinical advancements. To address this, future scientometric analyses should incorporate multilingual databases and stratify findings by study type to more accurately distinguish between early-stage research and clinically implemented technologies. Second, data processing and visualization rely on software tools, which, while essential for analyzing large datasets, may introduce minor discrepancies due to unrecognized data. Third, citation and co-citation burst analyses are subject to inherent delays, thus implying that some recently published high-quality studies may not have been fully accounted for. Fourth, it is important to recognize that the selection of keywords in bibliometric analyses can significantly impact the results. In this study, we employed specific keywords related to 3D printing in oncology; however, variations in terminology across the literature may have resulted in the omission of relevant studies. Fifth, the exclusion of patents, industry white papers, and regulatory documents may bias the identification of emerging trends and future directions, as many technological innovations initially appear in industrial or translational settings rather than peer-reviewed publications. Sixth, bibliometric indicators are inherently subject to biases such as citation lag, where recently published but impactful studies have yet to accumulate citations, and self-citation practices that can artificially elevate an author’s or institution’s perceived influence. To address these limitations, future research should consider integrating data from multilingual databases (e.g., Scopus, CNKI), patent repositories (e.g., Google Patents, WIPO), and industry reports. Moreover, employing normalized citation metrics (e.g., field-weighted citation impact) and excluding self-citations could improve the accuracy of influence assessments. Seventh, a significant limitation of this study is its broad scope. While this enables a comprehensive overview, it may reduce the granularity required to thoroughly explore specific subfields. Therefore, future bibliometric studies focusing on individual cancer types or targeted applications are mandatory. However, this analysis effectively identifies major research hotspots and emerging trends within this expansive domain. Continuous updates and future research are necessary to track these evolving trends. Despite these limitations, this study provides valuable insights into the current landscape, key research areas, and future directions of 3D printing applications in cancer treatment.

Conclusion
This study analyzes the applications of 3D printing in cancer research from 2000 to 2024, highlighting key trends and emerging areas such as preoperative planning, bone malignancy treatment, radiation therapy, tumor model construction, and strategies for overcoming drug resistance. Several potentially transformative subfields were identified, including the intersection of 3D printing with artificial intelligence, frontier applications involving nanorobotics, and the use of 3D printing in rare pediatric tumors. The incorporation of a cancer-type-specific stratified and focused thematic analysis enhances the clinical relevance of the findings by revealing tumor-specific research priorities, varying levels of translational advancement, and distinct challenges associated with cancers such as bone, breast, lung, and cervical cancer. Supplementary summaries of other tumor types provide a valuable resource for researchers seeking targeted insights and potential avenues for collaboration. While 3D printing holds substantial promise for advancing personalized cancer therapy, several challenges persist. These include difficulties in replicating physiologically relevant tumor microenvironments, limitations in material compatibility and printing resolution, and the ongoing gap between laboratory findings and clinical translation, particularly in addressing cancer drug resistance. 3D printing remains a transformative technology, underscoring the need for continued innovation and rigorous clinical validation to fully realize its potential in oncologic applications. These findings offer valuable insights to inform future research, supporting the development of more precise and innovative applications of 3D printing in cancer therapy.

Supplementary Material