Immediate breast reconstruction with anatomical implants following mastectomy: The radiation perspective

Immediate implant-based breast reconstruction followed by postmastectomy radiation therapy (PMRT) is controversial because of the risk of compromised treatment plans and concerns regarding cosmetic outcomes. We evaluated the effects of immediate direct-to-implant breast reconstruction with anatomical implants on the quality of PMRT delivered by 3-dimensional conformal radiotherapy (3D-CRT). In this retrospective, single-institution study, patients who had undergone reconstruction with direct anatomic implant, performed by a single surgeon, received 3D-CRT between 2008 and 2013. For each patient, 2 plans (including or excluding internal mammary nodes [IMN]) were created and calculated. The primary end point was the dose distribution among reconstructed breasts, heart, lungs, and IMNs, and between right and left breasts. Of 29 consecutive patients, 11 received right-sided and 18 received left-sided PMRT to a total dose of 50 Gy. For plans excluding IMN coverage, mean D_mean for right and left reconstructed breasts was 49.09 Gy (98.2% of the prescribed dose) and 48.51 Gy (97.0%), respectively. For plans including IMNs, mean D_mean was 49.15 Gy (98.3%) for right and 48.46 Gy (96.9%) for left reconstructed breasts; the mean IMN D_mean was 47.27 Gy (right) and 47.89 Gy (left). Heart D_mean was below 1.56 Gy for all plans. Mean total lung volume receiving a dose of ≥ 20 Gy was 13.80% to 19.47%. PMRT can be delivered effectively and safely by 3D-CRT after direct-to-implant breast reconstruction with anatomical implants, even if patients require IMN treatment.