Shared Decision-Making for Determining Treatment Strategies in Low-Risk Thyroid Cancer: Protocol of a Multicenter Cluster-Randomized Trial (MAeSTro-SDM).

Active surveillance (AS) is recommended for low-risk papillary thyroid microcarcinoma (PTMC) in many guidelines. However, while its clinical application requires incorporation of patient values, implementing shared decision-making (SDM) in practice remains challenging. To generate reliable evidence, facilitate the integration of SDM into routine PTMC managements and improve patient satisfaction, this study developed a PTMC-specific SDM model (SM group) and aims to evaluate whether it improves patient-reported outcomes (PROs) compared to usual care (UC group) in patients with low-risk PTMC. This multicenter, parallel-group, cluster-randomized controlled trial will enroll 310 patients with low-risk PTMC across seven academic hospitals in Korea. Participants will be assigned to either the SM group (model) or the UC group (control) through cluster randomization of 26 clinicians, stratified by specialty and AS experience. The SM group will receive structured counseling using a newly developed PTMC-specific SDM model, supported by decision aids such as educational videos, web-based card news, and illustrated leaflets regarding disease-information and patients' values. The UC group will receive standard counseling. The primary outcome is the Decisional Conflict Scale score. Secondary outcomes include satisfaction with decision-making process, decision regret, anxiety, and thyroid-specific quality of life. Data will be collected via the iCReaT v2.0 electronic Case Report Form, supplemented by electronic and paper-based PRO surveys. Assessments will be conducted at baseline, 1-4 weeks, and 6 months after the treatment decision. ClinicalTrials.gov Identifier: NCT06730893.