Published in the Red Journal, the study by University of Maryland examined the acute skin toxicity in the form of radiation dermatitis (RD) or skin hyperpigmentation (SH) after proton or photon radiotherapy. The highest recorded grades of acute RD and SH were analyzed in 86 patients undergoing adjuvant radiation therapy to the breast with or without regional lymph nodes after lumpectomy (breast-conserving surgery) or mastectomy with either proton pencil-beam scanning (n = 39) or photon (n = 47).

This study reported that the highest reported grade of RD was significantly higher in women undergoing proton radiation compared with photon radiation. Grade ≥2 RD was present in 69.2% versus 29.8% of patients receiving proton and photon therapy (P = .002). Rates of grade 3 RD were 5.1% versus 4.3% for proton versus photon radiation (P = .848). Overall, there were no significant differences in rates of SH between modalities. There were no grade 4 to 5 toxicities in either cohort.