Is irradiation a justifiable treatment of choroidal melanoma? Analysis of published results.

Abstract

Analysis of the literature shows that dissemination of choroidal melanomas generally occurs after the 7 mm diameter stage, that doubling times of uveal melanomas vary from 30 to 365 days, and that death from metastases occurs 30-40 doubling times after dissemination. Tumour related death within three years after therapy is caused by pre-existing metastases. Survival rates for less than four years after therapy are therefore irrelevant in evaluating the efficacy of therapeutic regimens. Considerably higher postirradiation than postenucleation death rates after a mean 10-year follow-up period have been reported, and this difference can be explained by a reported mean clinical tumour regression rate of 31% two years after irradiation and histopathological studies which revealed that 42 out of 43 irradiated melanomas contained viable tumour, while only 50% showed necrosis. The doubtful value of preserving vision does not justify the high risk of avoidable death from metastases in irradiated patients.