Plaque radiotherapy for juxtapapillary choroidal melanoma: tumor control in 650 consecutive cases

To evaluate treatment of juxtapapillary choroidal melanoma with plaque radiotherapy and to investigate the role of supplemental transpupillary thermotherapy (TTT).

Retrospective, comparative case series.

We included 650 consecutive eyes with juxtapapillary choroidal melanoma within 1 mm of the optic disc.

Eyes with juxtapapillary choroidal melanoma receiving plaque radiotherapy over a 31-year period from October 1974 to November 2005 were included in the study. The TTT and no TTT groups were analyzed separately and compared.

Local tumor control, metastasis, and tumor-related mortality.

The median basal tumor diameter was 10 mm (range, 1.5-21) and median thickness was 3.5 mm (range, 0.5-14.8). In 481 eyes (74%), the tumor was directly adjacent to the optic disc and in 169 eyes (26%) the posterior tumor margin was between 0.1 and 1.0 mm from the optic disc. The circumpapillary extent of the tumor was <4 clock-hours in 321 eyes (50%), 4-8 clock-hours in 250 eyes (38%), and >8 clock-hours in 79 eyes (12%). Plaque radiotherapy using iodine-125 in 616 eyes (95%), cobalt-60 in 19 eyes (3%), iridium-192 in 12 eyes (2%), and ruthenium-106 in 3 eyes (<1%) delivered a median radiation dose of 8000 cGy (range, 3600-15 500) to the tumor apex and adjunctive TTT was used in 307 eyes (56%). Kaplan-Meier estimates for tumor recurrence, metastasis, and death were 14%, 11%, and 4% at 5 years and 21%, 24%, and 9% at 10 years, respectively. Eyes treated with additional TTT showed slight (statistically nonsignificant) reduction in recurrence and metastasis. Using multivariable analysis, factors predictive of tumor recurrence included foveolar tumor requiring TTT (hazard ratio, 5.07; P<0.001) and greater tumor thickness (hazard ratio, 1.29 per mm increase; P<0.001). Factors predictive of metastasis included greater tumor base (hazard ratio, 1.21 per mm increase; P<0.001) and increasing intraocular pressure (hazard ratio, 1.11 per mmHg increase; P = 0.020).

Plaque radiotherapy for juxtapapillary melanoma provides local tumor control in approximately 80% of eyes at 10 years. In subjects who received TTT, there was slight but nonsignificant improved local tumor control and lower metastatic rate.