Dosimetric comparison of stereotactic body radiotherapy treatment plans in localized prostate cancer

Objective: The aim of this study was to compare the dose distributions of Volumetric Modulated Arc Therapy (VMAT) and Streotactic Body Radiotherapy (SBRT) treatment plans using Flattening Filter (FF) and Flattening Filter Free (FFF) beams for radiotherapy treatment in clinically localized prostate cancer patients. Methods: Seventeen moderate and high risk patients with localized prostate cancer were included in the study. For each patient, 2 full arc FFF and FF VMAT plans with a single isosentrite and SBRT plans with FFF beams were prepared. The plans prepared for each patient were planned to have a total target dose of 33.5 Gy in 5 fractions at a fraction dose of 6.7 Gy at 6 MV energy. For all plans, cumulative dose volume histograms (DVHs) were generated for target volumes and organs at risk (OAR). The values obtained for each plan were compared. At the end of the study it was compared dosimetrically with treatment plan prepared by FF rays with VMAT and SBRT treatment plan prepared using FF rays. The maximum, minimum and mean dose values of PTV, CI, HI, and the doses corresponding to different volumes of critical organs were compared and reported. It has been shown that VMAT-FF and CK-FFF plans are suitable as SBRT technique for dosimetric distribution in the treatment of localized prostate cancer patients from the data obtained and similar studies in the literatüre.