Late Toxicity And Cosmesis In Women Receiving Hypofractionated Radiotherapy After Breast-Conserving Therapy And Oncoplastic Reconstruction

Hypofractionated (HF) radiotherapy (RT) is now recommended for the majority of women undergoing breast conserving surgery (BCS). Oncoplastic reconstruction (OR) combines BCS with plastic surgery techniques to allow for oncologic resection while preserving cosmesis. Cosmesis and toxicity for OR with conventionally fractionated (CF) RT is well established. While HFRT is now standard of care, there are limited data reporting cosmesis for women undergoing HFRT after OR. Given OR is a cosmetic procedure, this study aimed to demonstrate acceptable late toxicity and post-treatment cosmesis with HFRT after BCS and OP. Women with > 3 months of follow-up after treatment with BCS, OR and HFRT between 2010 and 2018 were identified. Surgery was performed either as a single or staged procedure with immediate or delayed reconstruction. All women received 42.56 Gy to the whole breast using field-in-field technique. A lumpectomy cavity boost was performed at the discretion of the treating physician. Demographic, disease and treatment characteristics, and toxicity outcomes were recorded. For a subset of patients, pre and post-operative photos were maintained. Cosmesis at the time of most recent follow-up was independently rated by two plastic surgeons and two radiation oncologists (excellent, good, fair, poor). Chi-squared, Mann-Whitney U, and logistic regression were used to assess association between patient/treatment related factors and toxicity. 38 women were identified with a median follow-up of 12 months from completion of HFRT. Median age was 61.5 (61% white, 30% black, and 9% mixed /other). 55% underwent a single procedure with immediate reconstruction. 61% had local tissue rearrangement alone, 20% had mastopexy and reduction, and 24% had flap rearrangement. 16% of women received a lumpectomy cavity boost. Due to inability to accurately delineate the post-surgical tumor bed, the lumpectomy cavity was only contoured in 66% of women. Surgical toxicities were reported in 12% women prior to HFRT. Late cosmesis related toxicities were found in 52% women (table 1) of which the majority (58%) were skin toxicity (all RTOG grade 1). There was no significant association between age, race, BMI, comorbidities, receptor status, chemotherapy status, HFRT treatment position, boost, V105, or max point dose and late cosmesis. Of the cohort with longitudinal photos, cosmesis was rated as excellent in 42%, good in 46%, and fair in 12%. There were no locoregional failures. OR with HFRT has good toxicity profiles and favorable physician rated cosmetic outcomes. It offers an acceptable alternative to CFRT. Further investigation of patient reported cosmesis and prospective evaluation of OR and HFRT is warranted.Abstract 2113; Table 1Late Toxicityn (%)Pain3 (7)Edema4 (12)Fibrosis2 (5)Dimpling0 (0)Nipple retraction2 (5)Volume loss1 (2)Skin changes11 (29) Open table in a new tab