Brachytherapy is a radiation therapy modality that allows the escalation of radiation dose while sparing normal tissues. Increased radiation dose has been shown in many situations to provide improved results by improving local tumor control. Brachytherapy involves the placement of radioactive sources ("seeds" or wires) either in tumors (interstitial implants) or near tumors (intracavitary therapy and mold therapy). The radiation is emitted outward, unlike external beam radiotherapy, where radiation must transverse normal tissue in order to reach the tumor. The word "brachytherapy" means "short therapy", appropriately implying that the radiation is limited to short distances. This results in decreased toxicity and/or allows the escalation of radiation dose. Brachytherapy can be used intraoperatively in situations where surgery is not possible or not optimal or in situations where prior dose-limiting external radiotherapy has already been given. Combined approaches of surgery and brachytherapy can often improve the results of surgery alone in a variety of malignancies.
At Columbia University Medical Center, brachytherapy has successfully been used to treat a variety of tumors, including tumors of the cervix, esophagus, biliary tract, pancreas, head and neck, soft tissue sarcomas, and prostate cancer. Efforts are currently under way to optimize the use of brachytherapy by altering dose rate and fractionation. High dose rate, low dose rate, and pulsed dose rate techniques are being explored. Novel approaches combining chemotherapy with external beam radiotherapy and brachytherapy may improve the results in treatment of a variety of tumors.