According to research presented at the recent 58th Annual Meeting of the American Society for Radiation Oncology (ASTRO), high dose stereotactic body radiotherapy (SBRT) for men newly-diagnosed with low- or intermediate-risk prostate cancer results in shorter treatment times, low severe toxicity, and excellent cancer control rates.
Although prostate tumors generally respond well to radiation therapy (RT), the possibility of radiation exposure to healthy tissue in the genitourinary (GU) and gastrointestinal (GI) systems can be of concern. SBRT is an advanced technique that precisely targets high doses of RT to the tumor in a small number fractions, simultaneously avoiding surrounding tissue and reducing toxicity to non-cancerous cells. The technique has become the standard of care for many non-surgical lung cancer patients, as it limits exposure to the heart and surrounding lungs. When treating tumors in the prostate, SBRT avoids the adjacent bladder, sex organs and rectum.
For the study, which was the first large multi-institutional study of SBRT in prostate cancer with long-term follow-up, a total of 309 men with newly diagnosed prostate cancer were enrolled in the trial at 21 community, regional, and academic hospitals across the U.S. Eligible patients had either low-risk disease or intermediate-risk disease and all of the men received SBRT. At five years following SBRT, 97 percent of patients were free from prostate cancer progression and fewer than two percent of all patients experienced serious side effects.
“Our results illustrate how advanced technology has radically improved our ability to target cancer,” said Robert Meier, M.D., lead author of the study and a radiation oncologist at Swedish Medical Center in Seattle. “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.”
At San Francisco CyberKnife, men diagnosed with prostate cancer are treated with SBRT with the CyberKnife® Robotic Radiosurgery System. CyberKnife is a painless, nonsurgical prostate cancer treatment technology in which high-dose radiation is delivered to the tumor from a linear accelerator mounted on a highly maneuverable robotic arm. Hundreds of different angles enable the radiation to be contoured to the shape of the prostate, resulting in treatment aimed directly to the prostate gland, avoiding nearby critical anatomy. This precision reduces treatment time to just five outpatient visits, compared to the average 40 – 45 visits conventional radiation therapy requires.
To learn more about how San Francisco CyberKnife treats prostate cancer, please click here.