C. Drogula

Effect of reduction mammoplasty on acute radiation side effects and use of lumpectomy cavity boosts

PURPOSE Reduction mammoplasty (RM) during breast-conserving surgery is popular among women with large-volume breasts because it reduces redundant breast folds and may decrease skin-related morbidity from radiation therapy. However, RM may obscure the lumpectomy cavity (LC) and pose challenges to administering an LC boost, potentially affecting local control. We investigated the impact of RM on acute side effects and use of LC boosts. METHODS AND MATERIALS The records of 645 consecutive women treated with whole-breast irradiation at an urban university and 2 community practices between January 2012 and December 2014 were reviewed on an institutional review board-approved study. The primary endpoint was grade ≥3 radiation dermatitis; the secondary endpoint was use of LC boost. Student 2-sample t tests, Pearson χ2 tests, Fisher exact tests, and univariate and multivariable logistic regression analyses were performed. RESULTS Forty-three (7%) RMs were performed in 650 treated breasts. No significant differences in grade 3 toxicities were identified among RM and non-RM patients. LC boost was delivered to 474 breasts. Fewer (16/43) RM patients received LC boosts compared with non-RM patients (458/607), P = .0001. RM patients were more likely to have neoadjuvant chemotherapy, stage III or multifocal disease, higher body mass index, larger planning treatment volumes, and conventional fractionation (P < .05). CONCLUSIONS RM was associated with decreased use of LC boost without significant differences in acute toxicities. Further investigation to delineate LCs in patients undergoing RM or identify alternative strategies for delivering LC dose is needed.

What is the impact of reduction mammoplasty for women undergoing breast-conserving surgery for breast cancer?

49 Background: Reduction mammoplasty (RM) at time of breast conserving surgery (BCS) is an increasingly popular procedure that reduces redundant breast folds and skin toxicity from whole breast irradiation (WBI). However, the tissue manipulation may obscure the lumpectomy cavity (LC) and hinder the ability to deliver a radiation boost to the LC, potentially impacting local control. We studied the impact of RM on acute radiation side effects and the use of LC boost. METHODS From Jan 2012 to Dec 2014, 652 consecutive women with DCIS or Stage I-III invasive cancer were treated with curative intent BCS and WBI at an urban university and 2 community practices. We reviewed the charts on an IRB-approved study with the primary endpoint of ≥ grade 3 radiation dermatitis scored via the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Secondary endpoint was the use of LC boost. Tested variables included age, race, body mass index, menopausal status, multi-focal disease, stage, tumor grade, receptor status, chemotherapy administered, specimen volume, 3D or intensity modulated radiation, fractionation, nodal irradiation, and planning treatment volume (PTV). Students t-tests and Pearsons chi-square tests were utilized. RESULTS Forty-three (7%) of 652 patients underwent RM. Larger volumes of tissue were removed from the RM patients (median 366.5 g v 35.3 g, P= 0.0001). No grade 4 toxicities and few (2-3%) grade 3 toxicities were seen, P= 1.00. Narcotic use was similar (4-5%), P= 0.70. A LC boost was used in 476 (73%) patients; RM significantly decreased the use of a boost [16/43 (37%) v 460/609 (76%)], P= 0.0001. RM patients were more likely to have neoadjuvant chemotherapy, stage III or multi-focal disease, higher BMI, nodal irradiation, and conventional fractionation (P< 0.05). Subgroup analysis of the patients with available PTVs (67%) revealed similar volumes (P= 0.16). CONCLUSIONS RM was associated with a decrease in the use of LC boost without significant differences in acute toxicities; however, the result is not surprising given that PTVs were similar. Further investigation is needed to better delineate LCs in patients undergoing RM to increase the use of LC boosts.