CHICAGO—Hypofractionated radiation treatment—an approach in which higher doses of radiation are delivered in fewer treatments compared with conventional radiation therapy—may improve outcomes in high-risk prostate cancer patients, a study found.
“The study not only shows that hypofractionated radiation improves the control of prostate cancer, but it also cuts the number of treatment visits in half for patients,” said lead researcher Giorgio Arcangeli, MD, a radiation oncologist at the Regina Elena National Cancer Institute in Rome.
“This is an important benefit for these high-risk patients, who are typically an older, less mobile population. It’s also especially helpful for those living at long distance from radiation treatment centers.”
At the American Society of Radiation Oncology’s annual meeting here, he presented the findings of a study of 168 men with high-risk prostate cancer. All patients received a nine-month course of androgen deprivation therapy. Researchers randomized subjects to receive either hypofractionated radiation (85 patients) or conventional 3D conformal radiotherapy (83 patients).
Hypofractionated radiation therapy consisted of only 20 sessions of radiation (five days a week for four weeks) instead of the usual 40 to 45 sessions (five days a week for eight to nine weeks). The two treatment arms were similar with respect to age, T-stage, and pretreatment PSA level.
The patients treated with hypofractionated radiation were significantly more likely than those undergoing standard radiation therapy to be free from biochemical failure three years following treatment (87% vs. 79%).
No patient died, and the three-year rates of freedom from distant metastases were 88% with hypofractionated radiation treatment compared with 82% for the standard radiation group. The two groups had similar rates of genitourinary (GU) and gastrointestinal (GI) adverse effects.
In a separate study presented at this meeting, researchers at the University of Miami and Fox Chase Cancer Center found similar results in a trial involving 303 men with intermediate- and high-risk prostate cancer. In this study, all patients were randomized to receive 26 daily sessions of hypofractioned intensity-modulated radiotherapy or 38 daily sessions of standard IMRT. High-risk men also received treatment to the pelvic lymph nodes.
In addition to radiation treatment, 34 of the 200 intermediate-risk patients received short-term hormone therapy for a median of four months, while 102 of 103 high-risk patients in the hypofractionated group received long-term hormone therapy for 25 months.
At a median of 39 months after treatment, the investigators observed no significant difference in biochemical failure between hypofractionated and standard radiation groups (14% and 19%, respectively) or in GU and GI adverse effects.
“The study shows that hypofractionated radiation could potentially be used in place of standard radiation therapy for intermediate- and high-risk prostate cancer patients, but the results are still preliminary,” said lead investigator Alan Pollack, MD, Professor of Radiology and Chairman of the Department of Radiation Oncology.
“We are excited about this research because the shorter course of treatment is more convenient, would reduce health care costs and appears just as effective.”