Proton Therapy for Lung Cancer may Help Decrease Heart Disease Risk

Treating lung cancer patients with proton therapy may help decrease the risk of radiation-induced heart diseases, according to a new study.

Proton therapy may help reduce the risk of radiation-induced heart diseases for lung cancer patients, finds a new study. The findings of the study are presented at the American Society for Radiation Oncology (ASTRO) 62nd Annual Meeting.//

In a retrospective trial of more than 200 patients, mini-strokes were significantly less common among patients who underwent proton therapy versus conventional photon-based radiation therapy. Proton therapy patients also experienced fewer heart attacks.

Proton Beam Therapy for Cancer Treatment
Proton therapy is a form of radiotherapy for cancer treatment which uses a proton beam that is targeted precisely on the tumor cells, destroying them with minimal damage to surrounding healthy tissue. Proton therapy can treat various types of cancer.

‘Proton therapy has a potential cardiac benefit for lung cancer patients.’

"This shows us another potential benefit of proton therapy for lung cancer patients," Kegelman said. "We know proton has the ability to minimize radiation doses to surrounding organs like the heart. And these latest findings suggest that sparing correlates with fewer cardiac problems compared to conventional therapy."

Abigail T. Berman, MD, MSCE, as an assistant professor of Radiation Oncology at Penn, serves as senior author on the study.

Cardiac toxicity from radiation therapy remains a significant concern for lung cancer patients. One strategy to minimize dose is the use of proton therapy, which has the ability to more precisely target tumors and spare adjacent vital organs and healthy tissue.

Proton Therapy Curbs Side Effects More Than Photons
In largest study of its kind, Penn researchers compare overall adverse events of proton and photon therapies and found that proton therapy reduces side effects more.

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 a median follow up of 29 months compared to 8.2 percent of patients treated with photon radiation therapy. Myocardial infarctions were also less common in the proton therapy group compared to the photon group, though 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 by looking more closely at the severity of the cardiac events and radiation dose to specific parts of the heart. The analysis will help radiation oncologists have a better understanding of how to minimize these risks further with newer technologies.

NCI in Haryana Will Soon Offer Proton Therapy for Cancer
National Cancer Institute (NCI) in Haryana to be the first government hospital to provide Proton Therapy for cancer.

A large prospective, international phase III clinical trial investigating the difference between proton therapy and photon therapy in lung cancer patients, which includes patients treated in Penn's Roberts Proton Therapy Center, has also been underway since 2014. The expectation is that protons will reduce cardiac-related morbidity and mortality, which will translate into a higher cure rate, the authors said. The trial is expected to complete patient accrual in 2022.

This study is the first experience suggesting a benefit of proton therapy over intensity-modulated radiotherapy, or IMRT, in reducing cardiac dose effects.

Proton Therapy Shown to be Less Costly Than Alternative Techniques
Patients with early stage breast cancer may benefit from accelerated partial breast irradiation (APBI) with proton therapy versus whole breast irradiation (WBI) in terms of duration of treatment and cost.

"While these findings are promising and add to growing evidence, more research and the results of the randomized trial will help us better determine and understand how treating with protons may reduce cardiac event risk," Kegelman said.

Source-Eurekalert