Prostate Cancer Volumetric Arc Therapy (VMAT) Analysis

Abstract

Aim: The purpose of this study was to derive radiobiological parameters from the dose volume histogram of patients that undergone prostate cancer radiotherapy via the VMAT technique. Material and Methods: A total of twenty-two cases of prostate cancer of 70.2 and 81 Gy were selected for this study. Radiobiological parameters were evaluated by the Poisson equation for the tumor and LKB model for organs at risk. Results: For prostate tumor, the average TCP was 96.28, 86.45, 68.57 for α/β of 1.2, 3.0, and 10, respectively. The average EUD was 37.98 Gy, 59.23 Gy, 21.19 Gy, 20.65 Gy, 16.32 Gy, and 21.87 Gy for bladder, rectum, right femoral head, left femoral head, small bowel, and large bowel respectively. The average NTCP was 7.6 % for the rectum and negligible for other organs at risk. Conclusion: NTCP for critical organs and TCP for prostate cancer can be determined via dose volume histogram.