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

Abstract

The purpose of the in silico study was to compare free breathing volumetric modulated arc therapy (VMAT) to standard deep inspiration breath-hold (DIBH) three-dimensional conformal radiotherapy (3DCRT) and determine whether the former is a viable option for elderly patients with left-sided early stage breast cancer. Data from 22 patients with early-stage left breast carcinoma requiring breast-only radiation therapy were used for this planning study. The robustness of VMAT plans when using the free breathing method was compared to that of standard 3DCRT plans using the DIBH method. The endpoints for evaluation were the target dose coverage as well as doses to the organs-at-risk. The free breathing VMAT plans produced a significantly higher mean dose to the heart and right breast than the DIBH-3DCRT plans. Free breathing VMAT plans resulted in significantly better target coverage than did 3DCRT using DIBH. The external volume that received more than 40 Gy was significantly smaller in the VMAT plans. Free breathing VMAT is a viable alternative to DIBH 3DCRT in elderly patients with a limited life expectancy and in subjects who are unable to perform DIBH. The choice of treatment should be individualized, and all relevant risks ought to be considered.