Protons offer promise for reirradiation


For those with cancer who have already an initial course of radiation therapy, a recurrence of their disease can be an understandable cause for concern.

With conventional (X-ray) based radiation, we generally can only safely give one round of treatment to the primary site of disease. But with proton therapy, because of its ability to zero in on the cancer and spare healthy surrounding tissue, a second course of treatment could offer hope to patients with recurrent tumors.

In a recent presentation at the 2017 Multidisciplinary Thoracic Cancers Symposium, a group of researchers revealed intensity modulation proton therapy showed promise for recurring lung cancer. In most cases, neither surgery nor chemotherapy are viable options for treatment, and conventional radiation would be too toxic for patients.

“In lung cancer, tumors are close to the esophagus, aorta and spinal cord, and all of these critical structures are vital for the body to function,” said lead author Jennifer Ho, as quoted in “The proton beam—and pencil beam in particular—provides much more conformal radiation, which means higher doses to tumors and lower dosages to critical structures nearby.”

The study retrospectively looked at results of treatment for 27 patients who underwent proton therapy treatment for lung cancer recurrence. In an average follow-up time of 11.2 months (25.9 months for those still alive) the median overall survival was 18 months, with more than 54 patients surviving at least one year. At the one-year market 61 percent of patients were free of cancer in the chest and lungs and 51 percent had no progression of their cancer.

In another recent article, researchers studied the reirradiation of esophageal cancer to determine the impact on radiation-related complications as a result of the therapy. Researchers determined that reirradiation is feasible using protons with patients responding well to the treatment, both in terms of their cancer and related side effects.

Proton therapy can also be used to successfully treat patients with other types of recurrent cancer including brain tumors, head and neck cancers, breast cancer, gynecologic cancer as well as prostate cancer that has been treated either with conventional radiation therapy or brachytherapy.

“The precision of proton therapy offers options for treating cancer that we simply did not have before,” says Dr. Ben Wilkinson, Medical Director for Provision Proton Therapy Center. “It’s wonderful to be able to give more options to patients seeking both longer life and better quality of life as they deal with their disease.”