Long-Term Local Control and Mortality After Transpupillary Thermotherapy of Small Uveal Melanomas

Transpupillary thermotherapy (TTT) is used for selected small choroidal melanocytic tumours, either as primary treatment or as an adjunct to plaque brachytherapy. We compared long-term local recurrence and mortality outcomes after primary TTT alone, plaque brachytherapy combined with TTT (brachy+TTT), and plaque brachytherapy alone (brachy alone).

This retrospective cohort study included 850 patients with choroidal melanocytic tumours treated with eye-preserving modalities at St. Erik Eye Hospital, Stockholm, Sweden, 2008-2020. Primary treatment was TTT alone (n = 48), brachy+TTT (n = 105), or brachy alone (n = 697). Outcomes included local recurrence, local recurrence with extraocular extension (EXE), and mortality.

At 15 years, Kaplan-Meier local recurrence-free survival was 8% after TTT alone, 34% after brachy+TTT, and 86% after brachy alone (log-rank test for trend, p < 0.001). Disease-specific survival at 15 years was 46%, 85%, and 90%, respectively (p = 0.03). In multivariable Fine-Gray regression adjusting for American Joint Committee on Cancer stage, TTT alone was associated with a higher subdistribution hazard of local recurrence (sHR, 6.7; p < 0.001) and melanoma-related death (sHR, 3.9; p < 0.001). Among patients treated for local recurrence, subsequent recurrences occurred more frequently after TTT than after treatments involving brachytherapy. The risk of EXE increased with the number of TTT sessions.

In this single-centre retrospective cohort, TTT was associated with higher rates of local recurrence and melanoma-related mortality compared with plaque brachytherapy. Future studies should assess whether similar results are observed in external long-term cohorts; such findings would inform whether the role of TTT in the management of choroidal melanocytic tumours warrants reconsideration.