Usefulness of a thermoplastic breast bra for breast cancer radiotherapy : A prospective analysis

Despite modern techniques, in some patients receiving whole breast radiotherapy (WBI) parts of the heart and the lung might receive doses which are nowadays considered relevant for the development of late morbidity. Our aim was to analyze the usefulness of a thermoplastic breast brassiere to reduce lung and heart doses.

A total of 29 patients with left-sided and 16 patients with right-sided breast cancer treated with breast conserving surgery and WBI between 2012 and 2013 were included in a prospective study analyzing the effectiveness of a thermoplastic breast bra. WBI was performed using 3D tangential fields up to 50.4 Gy. Treatment planning was performed with and without bra. Several dosimetrical parameters were analyzed comparatively focusing on the heart and ipsilateral lung. For heart dose comparisons, subvolumes like the left anterior descending artery (LAD) and a defined apical region, so-called "apical myocardial territory" (AMT), were defined.

By using the bra, the mean lung dose was reduced by 30.6 % (left-sided cancer) and 29.5 % (right-sided; p < 0.001). The V20Gy for the left lung was reduced by 39.5 % (4.9 vs. 8.1 % of volume; p < 0.001). The mean and maximum heart doses were significantly lower (1.6 vs. 2.1 Gy and 30.7 vs. 39.3 Gy; p = 0.01 and p < 0.001), which also applies to the mean and maximum dose for the AMT (2.5 vs. 4.4 Gy and 31.0 vs. 47.2 Gy; p < 0.01 and p < 0.001). The mean and maximum dose for LAD was lower without reaching significance. No acute skin toxicities > grade 2 were observed.

By using a thermoplastic breast bra, radiation doses to the heart and especially parts of the heart apex and ipsilateral lung can be significantly lowered without additional skin toxicity.