Long-term outcomes after enucleation or plaque brachytherapy of choroidal melanomas touching the optic disc

To investigate local and systemic outcomes after enucleation, brachytherapy with ruthenium-106, iodine-125, notched and non-notched plaques and transpupillary thermotherapy (TTT) of choroidal melanomas touching the optic disc.

All patients treated for choroidal melanoma touching the optic disc at St. Erik Eye Hospital, Stockholm, Sweden between 1984 and 2015 (n = 165) were included. Retrospective clinicopathological data was collected and 3D dosimetry performed.

Ninety-five patients (58 %) had been treated with ruthenium-106 brachytherapy, 21 (13 %) with iodine-125 brachytherapy and 49 (30 %) with enucleation. Median follow-up was 12.3 years. In simulations, some tumor areas were underdosed with non-notched plaques. Fifty of 116 patients (43 %) underwent a secondary brachytherapy (n = 5), enucleation (n = 29) or TTT (n = 16). In multivariate Cox Regressions, there were no significant differences in the risk for tumor progression or lack of regression between radioisotopes and notched and non-notched plaques. Adding TTT did not reduce the risk for a second treatment. The number of clock hours of circumpapillary tumor growth did not correlate to the risk for treatment failure or mortality. There were no significant differences in melanoma-related mortality for any treatment including enucleation. Kaplan-Meier disease-specific survival was 77 % at 5 years, 72 % at 10 years and 67 % at 20 years.

Plaque brachytherapy of choroidal melanomas touching the optic disc entails a two to threefold increased risk for treatment failure. This risk is similar between radioisotopes, notched and non-notched plaque designs and if TTT is used or not. The high rate of treatment failure does not lead to increased mortality.