Free breathing VMAT versus deep inspiration breath-hold 3D conformal radiation therapy for early stage left-sided breast cancer

The purpose of the in silico study was to compare free breathing volumetric modu-lated arc therapy (VMAT) to standard deep inspiration breathhold (DIBH) threedi-mensional conformal radiotherapy (3DCRT) and determine whether the former is aviable option for elderly patients with leftsided early stage breast cancer. Data from22 patients with earlystage left breast carcinoma requiring breastonly radiationtherapy were used for this planning study. The robustness of VMAT plans whenusing the free breathing method was compared to that of standard 3DCRT plansusing the DIBH method. The endpoints for evaluation were the target dose cover-age as well as doses to the organsatrisk. The free breathing VMAT plans produceda signicantly higher mean dose to the heart and right breast than the DIBH3DCRTplans. Free breathing VMAT plans resulted in signicantly better target coveragethan did 3DCRT using DIBH. The external volume that received more than 40 Gywas signicantly smaller in the VMAT plans. Free breathing VMAT is a viable alter-native to DIBH 3DCRT in elderly patients with a limited life expectancy and in sub-jects who are unable to perform DIBH. The choice of treatment should beindividualized, and all relevant risks ought to be considered.