A comparison of dosimetric parameters between tomotherapy and three-dimensional conformal radiotherapy in rectal cancer

摘要

Purpose Tomotherapy for intensity-modulated radiation has been demonstrated to reduce unnecessary irradiations to adjacent organs at risk (OARs). The purpose of this study was to compare the dosimetric parameters between Tomotherapy and three-dimensional conformal radiotherapy (3D-CRT) in rectal cancer patients. Materials and methods We redesigned three-dimensional conformal plans for 20 rectal cancer patients who had received short-course preoperative radiotherapy with Tomotherapy. The target coverage for 3D-CRT and Tomotherapy was evaluated with the following including the mean dose, VnGy, Dmin, Dmax, radiation conformality index (RCI), and radical dose homogeneity index (rDHI). Results The mean PTV dose for Tomotherapy is significantly higher than that observed for the 3D-CRT (p?=?0.043). However, there is no significant difference in the V23.25Gy, V26.25Gy, V27.5Gy, and RCI values between Tomotherapy and 3D-CRT. However, the average rDHI (p?