Postmastectomy radiation therapy using VMAT technique for breast cancer patients with expander reconstruction.

Postmastectomy radiotherapy (PMRT) following immediate breast reconstruction is increasingly adopted in the management of breast cancer patients. We retrospectively evaluate the complication rates of PMRT using VMAT technique to immediate tissue expander-based reconstructions and the possible impact of tissue expander volume on radiotherapy planning. We reviewed the data of patients who underwent immediate expander breast reconstruction and received PMRT with VMAT (50 Gy in 25 fractions) on the reconstructed breast and axillary levels III-IV. Neoadjuvant or adjuvant systemic therapy was administered in most of the patients. Autologous fat grafting was routinely performed at the time of second-stage reconstruction. Between 2015 and 2017, PMRT was delivered to 46 consecutive patients (median age 50 years) with expander reconstruction. Median follow-up was 27 months (range 10-41). Two patients (4.3%) had a reconstruction failure, as expander rupture and infection, following the first- and the second-stage reconstruction, respectively. In most cases expanders were completely inflated before PMRT (65.2%). Median expander volume before PMRT was 425 cm