Guided radiation therapy for prostate cancer prevents damage to surrounding organs

October 28, 2007

Oregon Health & Science University Cancer Institute researchers have found that highly targeted radiation therapy for prostate cancer can ensure that the majority of persons with this tumor will not have any long-term rectal damage.

A group of 231 study participants received a combination of intensity-modulated radiation and seed marker-based image-guided radiation therapies (IM-IGRT) for prostate cancer then were tracked for 1.4 years. Nearly 98 percent of these participants had no rectal damage, according to Todd Scarbrough, M.D., principal investigator, associate professor, radiation medicine, OHSU School of Medicine; and an OHSU Cancer Institute member. This combination allows for millimeter targeting accuracy of the tumor.

“If these outcomes hold over time and the results can be reproduced by others, then this combination of radiation therapies for prostate cancer will yield some of the lowest toxicity rates of any definitive treatments for prostate cancer. This would be the treatment for prostate cancer. A patient could cruise through treatment with no side effects,” explained Scarbrough who also serves as director of the MIMA Cancer Center, Melbourne, Fla.

A poster of this study will be presented Monday, Oct. 28, at the 2007 annual American Society of Therapeutic Radiology and Oncology (ASTRO) meeting in Los Angeles.

Scarbrough explained that the one of the main considerations of radiation oncologists treating prostate cancer is to reduce rectal damage. Previously, 10 percent to 50 percent of men treated for prostate cancer had some level of rectal pain or complaints after radiation.

The image-guided radiation method used placed tiny gold pellets in the subject’s prostate prior to treatment and then imaged these markers immediately prior to treatment. Placing of the markers is fast and relatively painless. The heightened accuracy allows for a more precise radiation dose and a more targeted area for treatment of the tumor.

In this study the researchers also found that of the potent men completing sexual satisfaction questionnaires post-treatment, 72 percent reported they had maintained sexual activity. The average age for the study participants was 74. Also, the combination radiation therapy caused no long-term urinary side effects.

Source: Oregon Health & Science University