Proton Therapy for Breast Cancer: A Consensus Statement From the Particle Therapy Cooperative Group Breast Cancer Subcommittee.

Robert W Mutter
J Isabelle Choi
Rachel B Jimenez
Youlia M Kirova
Marcio Fagundes
Bruce G Haffty
Richard A Amos
Julie A Bradley
Peter Y. Chen, Beaumont Health
Xuanfeng Ding, Beaumont Health
Antoinette M. Carr, Beaumont Health
Leslie M Taylor, Beaumont Health
Mark Pankuch
Raymond B Mailhot Vega
Alice Y Ho
Petra Witt Nyström
Lisa A McGee
James J Urbanic
Oren Cahlon
John H Maduro
Shannon M MacDonald


Radiation therapy plays an important role in the multidisciplinary management of breast cancer. Recent years have seen improvements in breast cancer survival and a greater appreciation of potential long-term morbidity associated with the dose and volume of irradiated organs. Proton therapy reduces the dose to nontarget structures while optimizing target coverage. However, there remain additional financial costs associated with proton therapy, despite reductions over time, and studies have yet to demonstrate that protons improve upon the treatment outcomes achieved with photon radiation therapy. There remains considerable heterogeneity in proton patient selection and techniques, and the rapid technological advances in the field have the potential to affect evidence evaluation, given the long latency period for breast cancer radiation therapy recurrence and late effects. In this consensus statement, we assess the data available to the radiation oncology community of proton therapy for breast cancer, provide expert consensus recommendations on indications and technique, and highlight ongoing trials' cost-effectiveness analyses and key areas for future research.