[Retrospective Evaluation of the Clinical Value of Interim PET-CT in Hodgkin Lymphoma Treated with ABVD (2017-2023)].

[UNLABELLED] Hodgkin's Lymphoma (HL) is a highly curable hematologic malignancy. Interim PET-CT plays a critical role in monitoring early treatment response and guiding therapeutic decisions. The Deauville Score (DS) is the standard qualitative tool for interpreting PET-CT, while semi-quantitative parameters such as Delta SUV (DSUV) and Tumor Liver ratio (TLr) may offer additional prognostic value.

[AIM] To evaluate the clinical value of interim PET-CT in assessing treatment response in patients with HL treated with the ABVD regimen, and to compare the predictive performance of qualitative and semi-quantitative assessment methods.

[METHODS] A retrospective cohort study was conducted including 28 patients with histologically confirmed HL treated with ABVD at the Hospital de Clínicas "Dr. Manuel Quintela" and imaged at CUDIM between 2017 and 2023. PET-CT scans were analyzed at three time points: baseline, interim (after 2 cycles), and end-of-treatment. The Deauville Score was used to categorize interim PET-CT results (scores 1-3 as negative; 4-5 as positive). DSUV and TLr were also calculated to assess their prognostic value.

[RESULTS] Interim PET-CT using DS showed a strong negative predictive value (NPV) of 95%. DSUV demonstrated 100% sensitivity but lower specificity (64%) compared to DS. TLr achieved higher specificity (96%) than both DS and DSUV. Hematologic analysis showed increased red blood cell parameters and decreased white cell counts after 2 cycles, consistent with treatment-related effects. Concordance between DS and DSUV was moderate (Cohen's Kappa = 0.462).

[CONCLUSIONS] The Deauville Score remains a robust primary tool for evaluating early treatment response in HL. Semi-quantitative parameters such as DSUV and TLr may provide complementary prognostic information. Further studies with larger cohorts are needed to validate their role in clinical decision-making.