Comparison of modulated electron radiotherapy to conventional electron boost irradiation and volumetric modulated photon arc therapy for treatment of tumour bed boost in breast cancer

MERT plans were a considerable improvement in dosimetry over DE boost plans. There was a dosimetric advantage in using MERT over VMAT for increased DEV conformity and low-dose sparing of healthy tissue including the integral dose; however, the cost is often an increase in the ipsilateral lung high-dose volume.