Radiotherapy of choroidal melanoma with iodine 125.

Although specific data on patients will be useful only after a 5- to 10-year follow up, radiotherapy of choroidal malignant melanoma with 125iodine has several advantages over the other radioactive sources that are presently being used. The low gamma energy of 125iodine allows for construction of metal eye plaques that can attenuate the radiation preferentially so that the tumor is treated while the rest of the eye receives minimal irradiation. This ability to direct the radiation is not possible with high energy sources such as 60cobalt. The ability to control the dose rate as well as the total dose is yet another advantage. Exact positioning of the 125iodine seeds in a plaque allows for an even distribution of the radiation throughout the tumor. Six patients have been treated. We are enthusiastic, but consider this an experimental procedure until our follow-up is complete.