IMRT cuts GI side effects from prostate cancer in half vs. 3D-CRT

Intensity modulated radiation therapy, a newer, more precise form of radiation therapy, causes fewer gastrointestinal side effects when combined with hormone therapy than using three-dimensional radiation therapy, according to a study published in the June issue of the International Journal of Radiation Oncology·Biology·Physics, the official scientific journal of the American Society for Radiation Oncology (ASTRO).

Three-dimensional radiation therapy (3D-CRT) combined with hormone therapy has been proven very effective at treating men with intermediate to high-risk prostate cancer. However, these treatments can cause very uncomfortable gastrointestinal side effects due to exposure of the rectum to radiation during treatment.

Researchers at Fox Chase Cancer Center in Philadelphia conducted a study to see if IMRT, which allows doctors to better concentrate radiation in the prostate and limit rectal exposure, reduces the side effects while continuing to deliver the necessary radiation to successfully treat the cancer.

Two hundred ninety-three men were studied – 170 received 3D-CRT and 123 received IMRT. With a mean follow-up of 86 months, a multivariate analysis shows that patients treated with 3D-CRT were more than twice as likely to develop gastrointestinal toxicity compared to patients treated with IMRT.

"The use of IMRT significantly reduces the risk of late GI toxicity in men undergoing concurrent radiation therapy and hormone therapy for prostate cancer," Mark Buyyounounski, MD, MS, a radiation oncologist at Fox Chase Cancer Center, said. "I encourage men with prostate cancer receiving hormone therapy and radiation therapy to talk their doctors about whether IMRT has advantages over other types of radiation therapy."

For more information on radiation therapy for prostate cancer, visit www.rtanswers.org/treatmentinformation/cancertypes/prostate. For more information on ASTRO’s official scientific journal, visit www.redjournal.org.