Proton therapy leaves patients cancer-free, with fewer side effects

Researchers from the MD Anderson Cancer Center found that 93% of head and neck cancer patients treated with multi-field optimization intensity modulated proton therapy (MFO-IMPT) were cancer-free 28 months after treatment. Side effects typical of standard radiation also were reduced in some cases.

“Though early, this study provides the first evidence that proton therapy for head and neck cancers, which are becoming increasingly common, is safe and effective,” said Steven J. Frank, M.D., medical director of the Proton Therapy Center.

Published in the International Journal of Radiation, Oncology, Biology, Physics, the first of its kind study supports ongoing research by MD Anderson’s Proton Therapy Center regarding the benefits of proton therapy and, most recently, MFO-IMPT, which is best used to deliver a precise dose of protons to the most complicated tumors — ones that largely reside embedded in the nooks and crannies of the head and neck or at the base of the skull.

MFO-IMPT has the ability to spare surrounding healthy tissue from damage and help preserve quality of life measures such as neurocognitive function, vision, the ability to swallow, hearing, taste and speech. The current standard of treatment delivery for head and neck cancers, intensity modulated radiation therapy (IMRT), destroys both cancerous and healthy cells, impairing some of these functions.

“As incidence of HPV-related head and neck cancers rise, it’s important to have treatment options that minimize long-term side effects,” said Frank, associate professor in Radiation Oncology. “These patients typically are younger — many are raising families — and we want them to have 30-40 years to look forward to as cancer survivors. The quality of those years is crucial.”

The prospective study followed 15 head and neck cancer patients: 10 squamous cell carcinoma (SCC) and five adenoid cystic carcinoma (ACC) cases treated with MFO-IMPT. Five of the SCC patients underwent induction chemotherapy before receiving proton therapy. All five ACC patients received chemotherapy concurrent with MFO-IMPT. At 28 months, all 10 SCC patients and four of the ACC patients remained cancer-free. The results also showed a reduction in side effects:

All patients completed treatment without any breaks, chemotherapy dose reductions or hospitalizations.

None of the patients who underwent MFO-IMPT with concurrent chemotherapy experienced nausea or vomiting.

Also, none of the patients experienced severe dermatitis (inflammation of the skin).

According to Frank, also the study’s lead author, ongoing research will determine if MFO-IMPT is able to reduce toxicity and improve survival.

MD Anderson treated its first MFO-IMPT patient in 2010. Approximately 300 patients, many with complex head and neck cancers, have been treated with this form of proton therapy at the Proton Therapy Center since then.

Other MD Anderson researchers contributing to this study were James D. Cox, M.D., Michael Gillin, Ph.D., Radhe Mohan, Ph.D., Adam S. Garden, M.D., David I. Rosenthal, M.D., G. Brandon Gunn, M.D., Randal S. Weber, M.D., Merrill S. Kies, M.D., Jan S. Lewin, Ph.D., Mark F. Munsell, M.S., Matthew B. Palmer, B.S., Narayan Sahoo, Ph.D., Xiaodong Zhang, Ph.D., Wei Liu, Ph.D., and X. Ronald Zhu, Ph.D.