ESTRO 2021 Abstract Book

S927

ESTRO 2021

Results Both 3DCRT and Tomotherapy plans achieved excellent target coverage. Tomotherapy plans were able to deliver more conformal and homogenous plans compared to 3DCRT. With respect to normal tissue sparing, 3DCRT plans could achieve much lower mean heart ipsilateral and opposite lung doses as opposed to Tomotherapy where the OAR exposure was almost three times higher. Of note was the ipsilateral and Non PTV ipsilateral whole breast exposure which was found to be significantly lower with Tomotherapy. Figure 1: Comparison of two APBI plans - Tomotherapy[Right] and 3DCRT [Left].