Episcleral iridium-192 wire therapy for choroidal melanomas

To evaluate the effectivity of high-dose episcleral iridium-192 wires in the treatment of choroidal melanoma.

In 1983, the Departments of Radiation Oncology and Ophthalmology at the Clínica Puerta de Hierro, Madrid, Spain, initiated a clinical study using removable episcleral iridium-192 wires in the treatment of choroidal melanoma. Sixty-six evaluable patients were treated from January 1983 through July 1992. Two patients had a small sized tumor (3%), 28 had a medium sized tumor (42%), and 36 patients had a large tumor (54%). The mean follow-up was 40 months (6-118 months). The dose to the apex of the tumor ranged from 66 to 97 Gy (mean 76.6 Gy), and the doses at 2 mm depth ranged from 77 to 433 Gy (mean 200 Gy).

Tumor regression or stabilization was observed in 53 of the 66 patients (90%). Visual acuity improved following treatment in 5 out of 54 patients (9%), remaining unchanged in 30 out of 54 (56%), and decreased in 19 out of 54 (35%) patients. The remaining seven patients had undergone enucleation. Late complications have been documented in 20 out of 66 patients (30%), including 6 patients in whom enucleation was required because of radiation-related complications. The probability of survival and survival free of local progression was 93% at 5 years and 79% at 10 years. The probability of retaining the treated eye is 82% after the fifth year posttreatment.

Treatment of choroidal melanomas with episcleral iridium-192 wires is as effective as treatment with other radioactive applications. We feel that our results using iridium-192 wires are comparable to the other methods. However, we think that our technique is simple to implement, relatively inexpensive, and well tolerated.