Utilization of Different Registration Methods in Evaluation of Series Dose Variation for Cone Beam Computed Tomography Verification in Prostate Cancer Radiotherapy

Abstract

Synopsis:This study aims to investigate the dosimetric accuracy and performance stability of different registration methods for CBCT-guided prostate radiotherapy. The planning CT (pCT) was deformably registered to CBCT to construct a deformed pCT (dpCT). Image registrations were conducted between pCT and dpCT, by using automatic whole image, automatic PTV-based and manual registration. Dose distribution in each registered dpCT datasets and dose accumulation for each patient were calculated. Statistically significant difference was observed in bladder dose. However, there was no significant differences in target and rectal doses. Additionally, increasing target hotspots over time was observed in all techniques. Synopsis: This study aims to investigate the dosimetric accuracy and performance stability of different registration methods for CBCT-guided prostate radiotherapy. The planning CT (pCT) was deformably registered to CBCT to construct a deformed pCT (dpCT). Image registrations were conducted between pCT and dpCT, by using automatic whole image, automatic PTV-based and manual registration. Dose distribution in each registered dpCT datasets and dose accumulation for each patient were calculated. Statistically significant difference was observed in bladder dose. However, there was no significant differences in target and rectal doses. Additionally, increasing target hotspots over time was observed in all techniques.