A review by Hug EB on PT for breast cancer. The author stated that in a small but significant percentage of patients requiring adjuvant radiotherapy for left-sided breast cancer, photon-based RT can lead to cardiac complications during long-term follow-up. Dosimetric comparison has identified advantages of proton therapy in accomplishing sparing of the heart with increasing target complexity while permitting uncompromised target coverage of the chest wall ± breast plus draining lymphatics.

Early clinical data indicate good clinical tolerance to proton therapy without unexpected complications. Several clinical trials are presently ongoing to prospectively confirm a clinical benefit and to identify the subgroup of patients benefitting most from proton therapy for breast cancer.