For women undergoing implant-based breast reconstruction after a mastectomy, use of shorter radiotherapy (RT) courses (hypofractionation) is as effective as conventionally fractionated (CF) RT, according to a study presented at the annual meeting of the American Society for Radiation Oncology, held from Oct. 1 to 4 in San Diego.
Julia S. Wong, M.D., from the Dana-Farber Brigham Cancer Center in Boston, and colleagues conducted a randomized trial of fractionation after breast reconstruction to compare quality of life and clinical outcomes of HF (16 fractions; 42.56 Gy total) versus CF (25 fractions; 50 Gy total) postmastectomy RT to the chest wall (CW) in the setting of immediate prosthetic reconstruction. A total of 385 patients with stage 0 to III breast cancer were analyzed for a median of 31.8 months.
The researchers found that in each arm, there were eight distant and one local-regional recurrences. In 35 patients, CW toxicity occurred (19 with HF and 16 with CF), at a median of 3.4 and 4.8 months after RT initiation, respectively. In a multivariate analysis, postoperative infection before RT, irradiation of tissue explant versus implant, preoperative endocrine therapy, and number of lymph nodes removed were significant for developing CW toxicity (hazard ratios, 3.31, 7.74, 3.45, and 1.06/node, respectively), but fractionation was not.
