Intra-operative radiation therapy (IORT) is the use of radiation therapy in the operating room during a surgical procedure. IORT allows for delivery of high radiation doses to a tumor while sparing skin and nearby normal tissues. During the surgical procedure, after removal of the tumor, the surgeon shows the radiation oncologist the areas of the tumor bed at risk for residual microscopic disease. The sensitive normal tissues are moved out of the radiation field, and then the radiation oncologist directs a single high dose of radiation to this high risk area. At UCSF, we have two types of machine for delivery of IORT. One is called Mobetron; we have a Mobetron located in the operating room at the Parnassus campus, and another located at Mission Bay. These are used for tumors such as sarcomas, neuroblastoma, recurrent pelvic malignancies, and recurrent head and neck cancer. Our other type of IORT machine is called IntraBeam, and it is located in the operating room at the Mount Zion campus. Our IntraBeam is used to treat breast cancer at the time of lumpectomy.
IORT may be used alone, but is frequently complemented by additional external beam radiation therapy after a patient has healed from surgery.