BRACHYTHERAPY, DEVICES AND METHODS OF USING THEM

摘要

Brachytherapy devices are provided for delivering a substantially uniform dose rate of radiation to a treatment area at a predetermined treatment depth. The devices include a holder defining a cavity, and a radioactive material located within the cavity. The holder comprises radiation-shielding material therein. The holder and the radioactive material are positioned to cooperatively provide a substantially uniform dose rate of radiation to a treatment area at a predetermined treatment depth. Also disclosed are methods for treating macular degeneration or ocular melanoma. The methods involve positioning a brachytherapy device in contact with or in close proximity to tissue located in a treatment area and exposing the tissue located in the treatment area to a therapeutic dose of radiation, which is delivered at a substantially uniform dose rate over the treatment area at a predetermined treatment depth. The devices and methods of the invention also ensure that the radiation delivered outside the treatment area is substantially reduced relative to the radiation delivered within the treatment area to minimize exposure of healthy tissue to radiation. The provision of a substantially uniform dose rate in the treatment area prevents substantial over- and under- exposure to radiation of different portions of the tissue in the treatment area.