PHILADELPHIA (April 9, 2021)—Researchers from Fox Chase Cancer Center recently published new data showing that moderately hypofractionated photon and proton therapies are both safe for patients with low- or intermediate-risk prostate cancer.
The researchers found that rates of toxicity in the bladder and rectum, the two organs most at risk of side effects from radiation treatment due to their proximity to the prostate, were very low. In fact, the vast majority of patients had no late toxicity at all.
According to study author Jessica Karen Wong, MD, MEng, assistant professor in the Department of Radiation Oncology and assistant director of the Radiation Oncology Residency and Fellowship Training Program at Fox Chase, the finding is significant for treatment centers.
Elizabeth Handorf, PhD, associate professor in the Cancer Prevention and Control program, and Eric M. Horwitz, MD, FABS, FASTRO, chair of the Department of Radiation Oncology at Fox Chase, were co-authors on the study. This collaboration, which includes researchers from several centers, was initiated by first author Neha Vapiwala, MD, FACR, a professor of Radiation Oncology in the Perelman School of Medicine at the University of Pennsylvania.
The findings demonstrate that moderate hypofractionation is safe when used to treat patients with low- or intermediate-risk prostate cancer, whether they use photon or proton modalities. Patients “cannot make a wrong decision—both forms of treatment are safe and effective,” Wong said.
The study, which included nearly 2,000 patients from Fox Chase and six other national referral centers across the United States, compared the two approaches to radiation treatment. Radiation can be delivered via two competing modalities: intensity-modulated radiotherapy (IMRT), which uses photons such as X-rays, or proton beam therapy (PBT).
All patients in the study were treated with moderate hypofractionation—a shorter, more concentrated regimen in which patients complete their full course of radiation in about five weeks as opposed to the standard eight weeks—and with either IMRT or PBT. Follow-up was conducted about four to six years after treatment, at which point the researchers looked at rates of toxicity specifically in the bladder and rectum.
Wong is optimistic about extending the research to look at long-term cure and control rates. “In forming this consortium, we can combine the power of each of our individual institutional experiences into one big cohort to study important clinical questions over a long period of follow up,” she said.
“By collaborating with radiation oncologists across the county, we can work together to get better outcomes faster for our patients,” Wong added.
The study, “A Pooled Toxicity Analysis of Moderately Hypofractionated Proton Beam Therapy and Intensity Modulated Radiation Therapy in Early-Stage Prostate Cancer Patients,” was published in the International Journal of Radiation Oncology*Biology*Physics.