The high mobility of the bladder and the rectum causes uncertainty in radiation doses prescribed to patients with prostate cancer who undergo radiotherapy (RT) multifraction treatments.
The purpose of this study was to estimate the dose received by the bladder, rectum, and prostate from multifraction treatments using daily cone-beam computed tomography (CBCT). Overall, 28 patients with prostate cancer who planned to receive radiation treatments were enrolled in the study. The acquired CBCT before the treatment delivery was registered with the planning CT to map the dose distribution used in the treatment plan for estimating the received dose during clinical treatment. For all 28 patients with 112 data sets, the mean percentage differences (± standard deviation) in the volume and radiation dose were 44% (± 41) and 18% (± 17) for the bladder, 20% (± 21) and 2% (± 2) for the prostate, and 36% (± 29) and 22% (± 15) for the rectum, respectively. Substantial differences between the volumes and radiation dose and those specified in treatment plans were observed. Besides the use of image-guided RT to improve patient setup accuracy, further consideration of large changes in bladder and rectum volumes is strongly suggested when using external beam radiation for prostate cancer.
Huang TC, Chou KT, Yang SN, Chang CK, Liang JA, Zhang G. Are you the author?
Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan; Department of Biomedical Informatics, Asia University, Taichung City, Taiwan; Department of Radiation Oncology, China Medical University Hospital, Taichung City, Taiwan; Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL.
Reference: Med Dosim. 2015 Feb 12. pii: S0958-3947(14)00133-2.