Intensity modulated radiotherapy and volumetric modulated arc therapy technique and comparison prostate, stomach and rectum cancer treatment plans comparing mapcheck2 and portal dosimetry methods

Intensity Modulated Radiotherapy and Volumetric Modulated Arc Therapy Technique and Comparison Prostate, Stomach and Rectum Cancer Treatment Plans Comparing MapCheck2 and Portal Dosimetry Methods. The aim of this study is to verify the planned dose distribution for three different cancer groups which are treated by IMRT and VMAT and compare in terms of practicality The target volume and risked organs are determined by using computed tomography (CT) images transferred to 40 prostate, 40 stomach and 40 rectum cancer patients contouring computer in Ankara Numune Eğitim ve Araştırma Hospital Radiation Oncology Clinic. For every group of cancer, IMRT and VMAT plans are prepared in accordance to clinic protocols by transferring the images to TPS (Treatment Planning System). to verify the dosimetric accuracy of the plans, verification plans of IMRT and VMAT plans are generated. Verification plans are irradiated in varian trilogy device by using EPID and MapCheck2 which are dosimetric verification systems. Dosimetric verification process is done by using Gamma Analysis method in accordance to Dose Difference (DD) %3 and Distance To Agrement (DTA) 3mm criteria. The results after the measurement are like this. For 120 IMRT plans, avarage pass rate ıs found as 98.45±1.12 for TPS-MapCheck2 comparison and 96.36±2,99 for TPS-EPID comparison. For 120 VMAT plans, avarage pass rate is found as 99.32±1.01 for TPS-MapCheck2 comparison and 97.21±2,92 for TPS-EPID comparison. Treatment groups and treatment methods are compared either. In conclusion, it is determined that both devices give acceptable and consıstent results to TPS altough MapCheck2 device provide more successful values and lower deviation than EPID device.