Treating lung cancer patients with proton therapy may help reduce the risk of radiation-induced heart disease, suggests a new study from Penn Medicine. In a retrospective study of more than 200 patients, mini-strokes were significantly less common among patients undergoing proton therapy compared to conventional photon-based radiation therapy. Proton therapy patients also had fewer heart attacks.
Timothy Kegelman, MD, Ph.D., chief resident of the Radiation Oncology department of the University of Pennsylvania’s Perelman School of Medicine, will present the results on Sunday, October 25, at the American Society for Radiation Oncology Virtual Annual Meeting (Summary # 1046).
“This shows us another potential benefit of proton therapy for lung cancer patients,” said Kegelman. “We know that the proton has the ability to minimize radiation doses to neighboring organs, such as the heart. And these latest findings suggest that saving correlates with fewer heart problems compared to conventional therapy.”
Abigail T. Berman, MD, MSCE, as assistant professor of Radiation Oncology at Penn, serves as the study’s senior author.
Cardiac toxicity from radiation therapy remains a significant concern for patients with lung cancer. One strategy to minimize the dose is the use of proton therapy, which has the ability to target tumors more accurately and save adjacent vital organs and healthy tissue.
The study found that 1.1 percent of patients with locally advanced non-small cell lung cancer treated with proton therapy experienced post-treatment mini-strokes, also known as transient ischemic attacks, after an average 29-month follow-up compared with 8.2 percent of patients treated with photon radiation. Myocardial infarctions were also less common in the proton therapy group compared to the photon group, although the difference was not statistically significant: 2.3 percent versus nine percent.
There was no difference in the number of cases of atrial fibrillation, coronary artery disease, heart failure or stroke. The researchers continue to compare the two approaches, taking a closer look at the severity of cardiac events and the radiation dose to specific parts of the heart. The analysis will help radiation oncologists better understand how to minimize these risks even more with newer technologies.
A large prospective international phase III clinical trial that investigates the difference between proton therapy and photon therapy in patients with lung cancer – which includes patients treated at Penn’s Protons Roberts Therapy Center – has also been underway since 2014 The protons are expected to reduce related morbidity and mortality, which will translate into a higher cure rate, the authors said. The study is expected to complete the accumulation of patients in 2022.
This study is the first experiment suggesting a benefit of proton therapy over intensity-modulated radiation therapy, or IMRT, in reducing the effects of the cardiac dose.
“While these findings are promising and add increasing evidence, more research and the results of the randomized trial will help us determine and better understand how proton treatment can reduce the risk of cardiac events,” said Kegelman.
Proton therapy reduces the risk of side effects in cancer compared to traditional radiation
Kegelman will present the results as an oral summary at 1 pm EST at the virtual conference.
Provided by the Perelman School of Medicine at the University of Pennsylvania
Quote: Proton therapy for lung cancer can help reduce the risk of heart disease (2020, October 24), obtained on October 24, 2020 at https://medicalxpress.com/news/2020-10-proton- therapy-lung-cancer-heart.html
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