The outlook for men diagnosed with low- or intermediate-risk prostate cancer has gotten a little sunnier. Research presented at the 58th Annual Meeting of the American Society for Radiation Oncology details how high dose stereotactic body radiotherapy (SBRT) results in shorter treatment times, low severe toxicity and excellent cancer control rates for this group of cancer patients.
Prostate cancer tumors respond well to radiation therapy in most circumstances already, but complications cloud the procedure. Healthy tissue in the gastrointestinal and and genitourinary tracts can be compromised by exposure to the radiation.
But with SBRT, doctors can precisely beam in high doses of radiation directly to the tumor. This both avoids the surrounding tissue and reduces toxicity to cells free of cancer. It's an alternative to intensity-modulated radiation therapy (IMRT), which uses advanced technology to manipulate photon and proton beams of radiation to conform to the shape of a tumor.
"Single-institution studies on the use of SBRT as the primary treatment for prostate cancer have illuminated the treatment as a cost-effective and faster alternative to IMRT," said Robert Meier, MD, lead author of the study and a radiation oncologist at Swedish Medical Center in Seattle. "Our study is the first to contribute multi-center data that support the use of SBRT as front-line therapy for men with prostate cancer."
The trial involved 309 men who had been newly diagnosed with prostate cancer, and classified as either low-risk or intermediate-risk. The men were being cared for in 21 hospitals across the U.S.
Five years following SBRT, the prostate cancer progression in 97 percent of the patients had ceased. Impressively, fewer than two percent of all patients experienced serious side effects in the five years following the therapy.
"Our results illustrate how advanced technology has radically improved our ability to target cancer," said Dr. Meier. "After following patients for more than five years, we found that serious side effects from a brief course of SBRT were uncommon and that cancer control rates were very favorable compared to historical data. Our trial confirms that SBRT may be preferable to other treatment approaches for newly-diagnosed cases of prostate cancer, including more aggressive disease."