Is the dose distribution distorted in IMRT and RapidArc treatment when patient plans are swapped across beam-matched machines?

Is the dose distribution distorted in IMRT and RapidArc treatment when patient plans are swapped across beam-matched machines? J Appl Clin Med Phys. 2016;17(5):6104 Authors: Chockkalingam K, Radha CA, Subramani V, Subramani V, Gunasekaran MK Abstract The purpose of this study is to evaluate the degree of dose distribution distortion in advanced treatments like IMRT and RapidArc when patient plans are swapped across dosimetrically equivalent so-called "beam-matched" machines. For this purpose the entire work is divided into two stages. At forefront stage all basic beam properties of 6 MV X-rays like PDD, profiles, output factors, TPR20/10 and MLC transmission of two beam-matched machines - Varian Clinac iX and Varian 600 C/D Unique - are compared and evaluated for differences. At second stage 40 IMRT and RapidArc patient plans from the pool of head and neck (H&N) and pelvis sites are selected for the study. The plans are swapped across the machines for dose recalculation and the DVHs of target and critical organs are evaluated for dose differences. Following this, the accuracy of the beam-matching at the TPS level for treatments like IMRT and RapidArc are compared. On PDD, profile (central 80%) and output factor comparison between the two machines, a maxi-mum percentage disagreement value of -2.39%, -2.0% and -2.78%, respectively, has been observed. The maximum dose difference observed at volumes in IMRT and RapidArc treatment...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research