IMRT ( intensity modulated radiation therapy) or IGRT (image guided radiation therapy)

Patients with more aggressive or advanced stages of cancer have a higher than ideal risk of cancer outside the prostate. This is an area beyond the surgeon’s reach. External beam radiation delivered from a high-energy X-ray machine called a linear accelerator can help treat just outside the prostate, where the prostate cancer cells may reside. Using the latest computer technology, the prostate can be precisely targeted within the body, and radiation can be safely delivered.

Intensity modulated radiation therapy (or IMRT) is an advanced system for the delivery of external radiation. This technique allows for maximum radiation to be delivered to the prostate and the surrounding areas at risk for harboring cancer cells, while minimizing radiation to the normal areas, such as the bladder and rectum. Image guided radiation therapy (or IGRT) uses IMRT techniques, but matches these techniques with extremely accurate near real-time tumor localization or imaging.

Prior to beginning this treatment, our patients undergo a CT scan of the pelvis in the Radiation Oncology department. This scan is used to create a customized plan, tailored to fit each patient’s anatomy precisely. The IGRT-based IMRT is typically given for only a few minutes a day, five days a week. When combined with a seed implant, this part of the treatment is approximately five weeks long. If given alone, without a seed implant, the treatment is typically for eight or nine weeks.

The IGRT precision localization capabilities of our machines can be realized in one of three ways. Many of our centers use BAT ® ultrasound technology [See photo right] as part of your daily IMRT treatment. The BAT® (B-mode Acquisition and Targeting) localizer integrates ultrasound imaging with sophisticated robotic computer technology. Before each daily IMRT treatment, the B.A.T. ® acquires an image of the prostate and surrounding anatomy using an ultrasound probe placed on the skin surface. This is a painless non-invasive procedure which takes only a few minutes prior to each treatment. The goal is to detect any slight change in position of the prostate gland that may result from movement or variations in filling of the bladder or rectum. An alternative way to localize the prostate daily is via the use of gold marker seeds placed within the prostate gland prior to treatment. These are called fiducial markers, and are visualized via x-rays on the actual treatment table just prior to turning the real beam on. Finally, some machines have the capability to obtain a quick CT scan of the prostate with you in the treatment position each day.

Using this information from either the BAT system, the fiducial marker system, or the CT scan, the computer adjusts the radiation beam accordingly in order to precisely target the IMRT to your prostate. By performing these IGRT techniques, we can further maximize the radiation does to the prostate and minimize the dose to the surrounding normal organs.

The radiation treatment is completely painless and non-invasive. During treatment, the most commonly reported side effects are slight fatigue and having to go to the bathroom more frequently. You should NOT develop any nausea, abdominal pain or loss of hair on your head. You will NOT lose your ability to control your bowels or bladder. You will be able to continue working full-time and should enjoy all of your regular activities