Radiotherapy of malignant melanoma of the choroid.

: Twenty-two patients with choroidal melanomas were treated conservatively using radioactive radon rings with a mean follow-up of 43 months. In 14 patients there was successful tumor regression. Eight eyes were enucleated because of inadequate tumor response. Of the patients whose tumors were apparently destroyed, two have subsequently died of metastases and one eye was enucleated due to scleral rupture. Of the eight cases unsuccessfully treated, one has subsequently died of metastases. Radiation therapy is likely to be effective in patients with tumors 7 mm in diameter and 2 mm in elevation or less. Tumors larger than 12 mm in diameter and 3 mm in elevation do not respond adequately to irradiation. Relatively large doses of radiation (at least 8,000 rads to the tumor apex) must be used if the tumor is to be effectively obliterated. We believe that radiation effectively can destroy small choroidal melanomas.