Proton Therapy Shown to Increase Survival and Reduce Side Effects

Proton Therapy showed increased survival and a low incidence of severe side effects when used to treat patients with Stage III non-small cell lung cancer, according to a recent study published in the Medical Journal Thoracic Cancer.1 The study looked at patients treated between 2007 and 2018 at the University of Tsukuba Hospital in Japan.

Proton therapy has been used to treat lung cancer, including non-small cell lung cancer, for a number of years. It is often delivered in conjunction with chemotherapy. Proton therapy can reduce the radiation exposure to healthy tissue and critical organs such as the heart versus other forms of radiation treatment using x-rays or photons. This is important because the amount of radiation to the heart has been shown to impact side effects and overall survival after treatment.

Side effects from lung cancer treatment can include pneumonitis and esophagitis. The severity of these side effects is graded on a scale from 1 to 5, with 5 being the most severe. For patients in this study, there were no incidences of Grade 4 or 5 pneumonitis or esophagitis, and less than 10% of patients incurred Grade 3 side effects.

Historically, stage III lung cancer has proven difficult to treat with 3-year survival rates ranging from 23.8% to 38% across multiple studies1 2. Patients on this proton study had a 3-year survival rate of 63.7%, which represents a significant improvement over survival rates historically seen using traditional x-ray or photon based treatment methods.

Additionally, the median survival rate for patients treated with proton therapy in this study was 49.1 months. This compares favorably to a recent multi-institutional study conducted in the United States which found a median survival of just 28.7 months for patients treated using X-Rays or photons.

Doses to the heart and healthy lung tissue have been shown to be associated with overall survival rates with increased exposure resulting in reduced survival rates. Thus, the ability to reduce radiation dose to the heart and healthy lung with proton therapy is likely one factor that led to the increased survival rates.

“Our goal when treating lung cancer is always to deliver more radiation to the tumor and less radiation to healthy tissue,” said Dr. John Chang, Medical Director of Oklahoma Proton Center. “Proton Therapy is simply the best way to accomplish this. It should be considered standard of care for many stage III lung cancer patients, and this study validates that.”

Patients interested in learning more about proton therapy for lung cancer can contact Oklahoma Proton Center at (405) 773-6700 or visit their website at

1 Ohnishi K, Ishikawa H, et al. Long-term outcomes of high dose proton therapy with concurrent chemotherapy for stage III nonsmall-cell lung cancer. Thorac Cancer. 2021 Mar 6. Doi: 10.111/1759-7714.13896.

2 Aupérin A, Le Péchoux C, Rolland E, Curran WJ, Furuse K, Fournel P, et al. Meta‐analysis of concurrent versus sequential radiochemotherapy in locally advanced non-small-cell lung cancer. J Clin Oncol. 2010;28:2181–90.

3 Machtay M, Paulus BS, Moughan J, Komaki R, Bradley J, Choy H, et al. Defining local‐regional control and its importance in locally advanced non-small-cell lung carcinoma: an RTOG analysis. J Thorac Oncol. 2012;7:716–22.

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