An analysis of applicator volume elimination methods and its influence on DVH analysis of HDR Prostate brachytherapy implants.

Abstract

In CT anatomy based inverse treatment planning of interstitial High Dose Rate Brachytherapy planning, the PTV delineated by the radiation oncologist includes the applicator volume. The applicator volume can be eliminated with the help of two methods based on Boolean operations and erasing option of the application software. Both the methods are compared and the results are discussed. The elimination of applicator volume results in proper estimation of PTV volume and exclusion of the clinically insignificant hot volume from PTV in the dose volume histogram analysis. Five Prostate cancers are considered for analysis. The PTV volume, Applicator Volume, Maximum, Mean, Modal and Minimum dose and the percentage volume of PTV structure receiving the percent dose for both the cases i.e., with and without applicator volume are tabulated and analyzed. It can be concluded that elimination of applicator volume results in proper volume estimation of PTV structure and leads to better dose volume histogram analysis of interstitial HDR Brachytherapy implants.