Timing of Radiotherapy in Uveal Melanoma: A SEER-Based Comparison of Preoperative, Postoperative, and Intraoperative Approaches

Purpose: To analyze the effect of radiotherapy timing relative to surgery on patients' survival and mortality rates in uveal melanoma (UM). Design: Retrospective cohort study using registry data from the Surveillance, Epidemiology, and End Results (SEER) database. Subjects: A total of 1,198 patients with UM were extracted from the SEER database and divided into three groups: preoperative radiotherapy, intraoperative radiotherapy (IORT), and postoperative radiotherapy. Methods: UM cases were extracted from the SEER database. Survival curves were generated based on the Kaplan-Meier method. An extended Cox regression was used to estimate the cancer-specific and all-cause mortality. Main Outcome Measures: Overall survival (including median survival) and hazard reductions for cancer-specific and all-cause mortality. Results: Preoperative radiotherapy revealed the highest median survival (4.93 years), followed by postoperative radiotherapy (4.76 years), and IORT (4.02 years). The preoperative strategy reduced the hazard of all-cause mortality by 42%, 50%, and 60% at 5-, 7-, and 10-year follow-up, respectively, compared with IORT. Findings were consistent in the cancer-specific sensitivity analysis (45%, 53%, and 62% reductions at the same time points). However, postoperative radiotherapy did not significantly reduce the cancer-specific mortality in comparison to IORT. Conclusions: Preoperative radiotherapy was associated with higher median overall survival and lower all-cause and cancer-specific mortality than IORT over 10 years of follow-up. Postoperative radiotherapy showed intermediate outcomes that did not differ significantly from IORT. Prospective studies with more detailed data on the temporal relation of radiotherapy timing and surgery are needed to confirm these findings.