BY JULIA EVANGELOU STRAIT

The current age of cancer care employs surgery, chemotherapy and radiation, in combination or alone, to eradicate tumors and offer the potential for remission. But the side effects of some of these therapies can introduce new complications requiring additional treatment. Oncologists and their patients work in tandem to fight the disease in ways that preserve life and protect health with as little risk as possible.

To that end, a research team from Washington University School of Medicine in St. Louis and the Perelman School of Medicine at University of Pennsylvania designed a study to compare the side effects of proton therapy with traditional X-ray radiation therapy. Brian Baumann, MD, the study’s senior author, a Washington University radiation oncologist and an adjunct assistant professor of radiation oncology at Penn, sums up the team’s findings this way: “Proton therapy was associated with a substantial reduction in the rates of severe acute side effects—those that cause unplanned hospitalizations or trips to the emergency room—compared with conventional photon, or X-ray, radiation for patients treated with concurrent radiation and chemotherapy.” And even with reduced side effects, proton therapy resulted in cure rates similar to those of X-ray radiation therapy. Baumann treats patients at the Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine.

Proton therapy uses relatively heavy, positively charged particles that hit their target and stop. X-ray radiation therapy uses beams of photons. These rays are made of much smaller particles that have almost no mass, which allows them to travel all the way through the body, passing through healthy tissue on the way out. Both types of treatment are approved by the Food and Drug Administration for cancer care.

The study included almost 1,500 patients who received combined chemotherapy and radiation therapy for lung, brain, head and neck, gastrointestinal and gynecologic cancers that had not yet spread to other parts of the body. This type of combined treatment regimen often cures nonmetastatic cancer. But it also can cause severe side effects—such as difficulty swallowing, nausea and diarrhea—that reduce quality of life and sometimes results in hospitalization.

Baumann notes that patients in the proton group had fewer side effects despite the fact that they were older—with an average age of 66—than patients in the X-ray radiation therapy group—with an average age of 61. This age difference is due to a quirk of insurance. Medicare, with its minimum enrollment age of 65, covers proton therapy. But since proton therapy is more expensive to administer than X-ray radiation therapy, many private insurers don’t cover it. Baumann says he and his colleagues did not compare the costs of the two different therapies and their associated adverse events, but they plan to in future studies.

He also notes: “The opportunity to reduce the risk of severe side effects for patients and thereby improve their quality of life is very exciting to me. While there have been other studies suggesting that proton therapy may have fewer side effects, we were somewhat surprised by the large magnitude of the benefit.”

PROTON THERAPY INVOLVES IRRADIATING CANCER CELLS BY CONCENTRATING A PROTON BEAM ON THE HEART OF THE TUMOR, WHILE PRESERVING THE SURROUNDING HEALTHY TISSUE.
Image courtesy of Science Photo Library / Amelie-Benoist / BSIP

Originally published by Washington University School of Medicine at medicine.wustl.edu/news