St. Anthony’s Cancer Care Center

Radiation Therapy

Radiation therapy is often used to treat prostate cancer. During radiation therapy, you either receive the radiation via a machine (external-beam radiation), or through a radioactive seed placed directly in the tumor.

The Cancer Care Center at St. Anthony’s is equipped with state-of-the-art linear accelerators, used to deliver radiation therapy. The new technology is able to aim the radiation directly at the tumor, sparing the rest of your body the radiation exposure.

Because radiation affects your entire body, there are often unpleasant side effects, though these are minimized through the use of targeted radiation. Your health care team is here to help you manage pain and other side effects to make you as comfortable as possible.

Intensity-Modulated Radiation Therapy (IMRT)

The goal of radiation therapy is to deliver high-powered radiation beams to the tumor, in order to destroy it. IMRT is a form of external beam radiation, meaning that a machine outside your body aims radiation at the tumor. Advances in technology allow doctors to sculpt the radiation beam so it matches your tumor as closely as possible. Because it targets just your tumor, surrounding nerves and tissues are spared, and doctors can safely use a higher dosage.

This precise sculpting requires careful planning. You will undergo a series of magnetic resonance imaging (MRI) scans, which allow your health care team to map out exactly where the tumor is located and what is precise shape is. Then your radiation oncologist can sculpt the beam to match your tumor. Even during the IMRT treatment, the radiation beam is changing hundreds of times in order to target only the tumor.

Usually, you receive radiation therapy in cycles. You may have a session every day for a few weeks, then you have a break for your body to recover, then you return for another treatment.

Trilogy System to Treat Prostate Cancer

The Trilogy™ Stereotactic Image-Guided Radiotherapy (IGRT) System is the most advanced form of external-beam radiation therapy. The Trilogy system is able to deliver higher doses of radiation to a smaller area of your body over a shorter period of time.


Brachytherapy is an internal radiation treatment. Unlike IMRT, which is delivered from outside your body, during brachytherapy, radioactive material is placed inside your body near the tumor. Radiation oncologists and surgeons place radiation “seeds” directly into the prostate gland, fighting the cancer from the inside. This also leads to fewer side effects, since only the cancer is targeted.