Brachytherapy of choroidal melanomas

In the management of patients with primary malignant melanoma of the uvea, treatment techniques have included not only enucleation but also photocoagulation, cryotherapy, photoradiation, a limited resection, as well as circumstances indicating exenteration of the orbit. Surgical management has been the primary treatment program for over 100 years. In a compilation of nine reported series consisting of 2,024 enucleations, the five- and ten-year survivals following surgery were 63% and 43%, respectively. The 25-year survival has been reported to be 40%. In 1974 at Wills Eye Hospital and Hahnemann University, the cobalt-60 plaques technique was introduced. During the following years, other radioactive isotopes were introduced including iridium-192, iodine-125, ruthenium-106/rhodium-106 and more recently palladium-103. At the present time, iodine-125 is the most widely used radionuclide. Until now, 302 patients treated with plaque brachytherapy showed an actuarial survival of 77% and 67.8% at five and eight years, respectively. There was no significant survival difference when compared with a similar group of patients undergoing enucleation. Other retrospective studies show similar excellent results. In spite of these convincing results, the decision making process in management melanoma remains unsettled primarily due to the absence of prospective randomized trials. Because of this, the Collaborative Ocular Melanoma Study was initiated. From the standpoint of toxicity, the data are available on ocular radiation toxicity. In an analysis of 77 patients from the Wills Eye Hospital with pretreatment visual acuities of 20/25 or better, it was noted that 90% of patients who had received less than 500 Gy to the fovea retained visual acuity of 20/200 or better while only 52% of patients receiving more than 5,000 Gy to the fovea had vision of 20/200 or better. A serious late effect of radioactivity plaque treatment is scleral necrosis which may require repair or enucleation even in the absence of tumor progression. Enucleation may be necessary in approximately 10% of patients. We conclude that malignant melanoma of the uvea can be safely treated with radioactive plaques.