Planning comparison of imrt versus vmat techniques for boost treatments during breast cancer radiotherapy

Abstract

In this study, the IMRT and VMAT boost plans for 10 left-sided breast cancer patients were analysed using DVH parameters and treatment delivery parameters. Before treatments, IMRT and VMAT plans were made for every patient and they were evaluated qualitatively by noting the dose distributions slice-by-slice and then quantitatively by analysing various DVH parameters. The results were noted and statistically analysed for the significant differences in the mean values.It was noted that the VMAT plans resulted in significantly higher mean doses as well as higher near-maximum doses. The doses to the Heart, contralateral breast, contralateral lung, were found to be statistically similar in both techniques. However, the mean doses to the ipsilateral lung were significantly lesser in IMRT techniques. Similarly, the IMRT technique gave lesser low dose volume V5%(%) than that of VMAT. In contrast, VMAT plans required significantly less MUs per fraction as compared to IMRT plansIt is concluded that both IMRT and VMAT plans resulted in good conformation of dose with homogenous dose distribution, depending on dose-volume tolerance of the ipsilateral lung being exceeded or not, and on compliance issues of the patient during treatment, the final decision of choosing the technique is to be made.