Radiation complications and tumor control after plaque radiotherapy of choroidal melanoma with macular involvement.

PURPOSE

To determine the outcome of plaque radiotherapy in the treatment of macular choroidal melanoma and to identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis.

METHODS

Chart analysis of 630 consecutive patients (630 eyes) with macular choroidal melanoma managed by plaque radiotherapy between July 1976 and June 1992.

RESULTS

The median largest basal tumor diameter was 10 mm, and the median tumor thickness was 4 mm. By means of Kaplan-Meier estimates, visually significant maculopathy developed at 5 years in 40% of the patients, cataract in 32%, papillopathy in 13%, and tumor recurrence in 9%. Vision decrease by 3 or more Snellen lines was found in 40% of the patients at 5 years. Sixty-nine eyes (11%) were enucleated because of radiation complications and recurrence. Twelve percent of the patients developed metastasis by 5 years and 22% by 10 years. Results of multivariate Cox proportional hazards analyses showed that the significant predictors for tumor recurrence were a distance of tumor margin from the optic disk of less than 2 mm (P = .003) and retinal invasion (P = .009). The significant variables that were predictive of metastasis included tumor thickness greater than 4 mm (P = .02) and largest basal tumor diameter greater than 10 mm (P = .03).

CONCLUSIONS

Plaque radiotherapy offers a 91% 5-year local tumor control rate for macular choroidal melanoma. Despite good local tumor control, the risk for metastasis is 12% at 5 years and 22% at 10 years. In 11% of the patients, enucleation eventually became necessary because of radiation complications and tumor recurrence.