Brachytherapy is a form of radiation treatment in which radioactive materials are placed directly into a cancer-affected organ with the intent of destroying the malignancy. When treating prostate cancer, approximately 80 to 120 radioactive "seeds" are implanted directly into the prostate gland. The seeds are approximately the size of a grain of rice and are directed into the prostate using transrectal ultrasound imaging (TRUS), an ultrasound wand inserted into the rectum for precise radiation distribution. The transrectal ultrasound allows the oncologist to plan and customize the seed implant based on the patient's prostate size and shape by providing a 3-dimensional, exact proportioned, computer generated image of the prostate gland.

Two types of radioactive seeds are used in brachytherapy, Iodine and Palladium. Although the seeds remain permanently implanted in the prostate, the Iodine seed delivers 90% of its radiation dosage in roughly six months and takes approximately one year to lose its energy. The Palladium seed delivers 90% of its radiation dosage in approximately two months and loses its energy in roughly six months. Both types emit low energy radiation.

This sophisticated technique of prostate radiation therapy allows a high concentration of radiation where it is needed most, the prostate, while reducing the radiation exposure to surrounding healthy tissues. Brachytherapy is performed on an outpatient basis in a same-day procedure, completed in approximately one hour under a spinal or general anesthesia. Hospital time is minimal, patients are able to leave the hospital within a few hours after the procedure and in most cases resume their normal activities within a few days. In fact, many patients return to work the next day.