New Study Shows Could Lead to More Effective Prostate Cancer Treatment

Prostate bed displaced during Intensity Modulated Radiation Therapy

(RxWiki News) For many prostate cancer patients, treatment includes prostate removal followed by rounds of radiation therapy. New advances in radiotherapy may help improve the recovery process for prostate cancer patients.

A recent study involving Intensity Modulated Radiation Therapy (IMRT) on men following prostatectomy (prostate gland removal) found inaccuracies in set up which could reduce the therapy's effectiveness. IMRT is a very accurate form of radiotherapy that conforms closely to the tumor and reduces unnecessary radiation to surrounding healthy tissue.

"Ask your physician what type of radiotherapy or chemotherapy is right for you."

The results of the study concluded that in about 10 to 20 percent of the sessions, 5mm of the prostate bed fell outside of IMRT margins. The prostate bed is located just below the bladder in the body. The prostate gland is located there and when it is removed due to prostate cancer, the prostate bed is exposed.

This is the first test to really look at the location and motion of the prostate bed while undergoing IMRT.

The study localized the prostate bed of 20 patients who underwent over 600 IMRT treatments. The Calypso 4D Localization System was used to determine the prostate bed location at the beginning of each session and tracking the movement of the prostate bed throughout the IMRT process.

The reason for this movement could be due to the bladder and bowels filling up but more importantly by inaccuracies with the set up of IMRT. In about 25% of all sessions, the prostate bed was offset by 1mm in either direction because the IMRT was not set up properly.

Since the IMRT treatment is so specific, any offsetting of the prostate bed could lead to improper treatment for the day, possibly reducing the effectiveness of IMRT as well as potentially reducing the chance for controlling the tumor.

For Tracy Klayton, M.D., a senior radiation oncology resident at Fox Chase Cancer Center, this study could lead to more efficient IMRT treatments. According to. Dr. Klayton, if the prostate bed is not localized properly, part of the prostate bed would not receive treatment and could cause unneeded radiation to surrounding areas such as the bladder.

Using the Calypso system or similar imaging technology, physicians may be able to reduce inaccuracies and reduce harmful radiation to the healthy area surrounding the prostate. Future research could calculate margins of treatment for IMRT to make it more effective by evaluating a large group of patients over the course of many years.

The study was presented at the 53rd Annual Meeting of the American Association for Radiation Oncology.

Research is considered preliminary until published in a peer-reviewed journal.  

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Review Date: 
October 8, 2011