This treatment option employs high-energy x-rays to destroy cancer cells. Such high-energy x-rays are delivered by the following methods:
External Beam Radiation Therapy
Directs high-energy x-rays from a machine outside the body onto the area affected by the cancer. Usually this involves a base-line evaluation to be followed by approximately six weeks of treatment. Treatments are given Monday through Friday and last a few minutes for each session. Since the x-ray beams have to travel through the skin onto the prostate (see figure), because of male anatomy, the x-ray beam very often has to travel through the bladder and the rectum. Side-effects include: radiation cystitis (inflammation of the bladder) and radiation proctitis (inflammation of the rectum). Most patients get relief from this within a few weeks after the radiation is completed.
Sometimes the radiation oncologist will suspend radiation if the side effects are significant and will resume it once these symptoms have subsided.
Brachytherapy
Also known as internal radiation therapy, this procedure involves small radioactive seeds placed directly into the prostate. Brachytherapy is performed under anesthesia and is a team effort between the urologist, the radiation oncologist, and the radiation physicist so as to provide safe application of this treatment. This procedure also involves mapping and evaluating the prostate in order to estimate the number of radioactive seeds needed for a given brachytherapy procedure.
Advantages of brachytherapy include fewer complications from treating adjacent organs, such as the bladder and the rectum. Long-term studies are pending to see the overall effectiveness of brachytherapy. However, short-term data is promising.
Your radiation oncologist can answer further questions on radiation therapy, including brachytherapy.
Radioactive iodine and palladium are used to deliver the energy into the prostate.
3-D Conformal Radiation Therapy
This is a newer type of radiation therapy which focuses high-energy x-ray beams very precisely, with less effect on normal surrounding organs.