Effect of bra use during radiation therapy for large-breasted women: Acute toxicity and treated heart and lung volumes.

Abstract

Large breast size presents special problems during radiation simulation, planning, and patient treatment, including increased skin toxicity, in women undergoing breast-conserving surgery and radiation therapy (BCT). We report our experience using a bra during radiation in large-breasted women and its effect on acute toxicity and heart and lung dosimetry. From 2001 to 2006, 246 consecutive large-breasted women (bra size ≥38 or ≥D cup) were treated with BCT using either 3-dimensional conformal radiation therapy (3DCRT) or intensity modulated radiation therapy (IMRT). In 58 cases, at the physicians' discretion, a custom-fit bra was used during simulation and treatment. Endpoints were acute radiation dermatitis and dosimetric comparison of heart and lung volumes in a subgroup of 12 left-sided breast cancer patients planned with and without a bra. The majority of acute skin toxicities were grade 2 and were experienced by 90% of patients in a bra compared with 70% of patients not in a bra (P = .003). On multivariate analysis significant predictors of grade 2 or 3 skin toxicity included the use of 3DCRT instead of IMRT (odds ratio, 3.9; 95% confidence interval, 1.8-8.5) and the use of a bra (odds ratio, 5.5; 95% confidence interval, 1.6-18.8). For left-sided patients, the use of a bra was associated with a volume of heart in the treatment fields decreased by 63.4% (P = .002), a volume of left lung decreased by 18.5% (P = .25), and chest wall separation decreased by a mean of 1 cm (P = .03). The use of a bra to augment breast shape and position in large-breasted women is an alternative to prone positioning and associated with reduced chest wall separation and reduced heart volume within the treatment field.