BACKGROUND AND PURPOSE: The retrospective planning study for intensity-modulated radiotherapy (IMRT) of prostate cancer evaluated whether proximal rectum and supra-anal rectum/anal canal should be delineated as separated organs-at-risk (OARs) to achieve optimal dose distributions to the anorectal region. PATIENTS AND METHODS: For 10 patients with localized prostate cancer IMRT plans were generated with the rectum and anal canal as separated OARs (Rec-sep) and as one single OAR (Rec-tot). Two different treatment planning systems (TPS) were utilized. Influence on dose distributions to target and OARs was analyzed. RESULTS: Results from both TPS showed significantly increased doses to the distal rectum/anal canal for plans Rec-tot compared with Rec-sep in case of a distended rectum in the planning CT study: doses were increased by up to mean 31% (P = 0.02) and 18% (P = 0.03), respectively, in both TPS. For the patient with the largest rectum, the maximum dose increase was 61%. No significant differences in doses to target, bladder, femoral head and proximal rectum were seen. CONCLUSIONS: For patients with a distended rectum in the planning CT, delineation of separated OARs for proximal rectum and distal rectum/anal canal resulted in superior dose distributions to the anorectal region and therefore, we recommend this as standard procedure for IMRT planning of prostate cancer.
BACKGROUND AND PURPOSE: The retrospective planning study for intensity-modulated radiotherapy (IMRT) of prostate cancer evaluated whether proximal rectum and supra-anal rectum/anal canal should be delineated as separated organs-at-risk (OARs) to achieve optimal dose distributions to the anorectal region. PATIENTS AND METHODS: For 10 patients with localized prostate cancer IMRT plans were generated with the rectum and anal canal as separated OARs (Rec-sep) and as one single OAR (Rec-tot). Two different treatment planning systems (TPS) were utilized. Influence on dose distributions to target and OARs was analyzed. RESULTS: Results from both TPS showed significantly increased doses to the distal rectum/anal canal for plans Rec-tot compared with Rec-sep in case of a distended rectum in the planning CT study: doses were increased by up to mean 31% (P = 0.02) and 18% (P = 0.03), respectively, in both TPS. For the patient with the largest rectum, the maximum dose increase was 61%. No significant differences in doses to target, bladder, femoral head and proximal rectum were seen. CONCLUSIONS: For patients with a distended rectum in the planning CT, delineation of separated OARs for proximal rectum and distal rectum/anal canal resulted in superior dose distributions to the anorectal region and therefore, we recommend this as standard procedure for IMRT planning of prostate cancer.
Authors: M D Falco; M D'Andrea; D Fedele; R Barbarino; M Benassi; E Giudice; E Hamoud; G Ingrosso; P Ladogana; F Santarelli; G Tortorelli; R Santoni Journal: Br J Radiol Date: 2011-09 Impact factor: 3.039
Authors: Nicholas G Zaorsky; Timothy N Showalter; Gary A Ezzell; Paul L Nguyen; Dean G Assimos; Anthony V D'Amico; Alexander R Gottschalk; Gary S Gustafson; Sameer R Keole; Stanley L Liauw; Shane Lloyd; Patrick W McLaughlin; Benjamin Movsas; Bradley R Prestidge; Al V Taira; Neha Vapiwala; Brian J Davis Journal: Adv Radiat Oncol Date: 2016-10-20
Authors: Ingrid White; Dualta McQuaid; Helen McNair; Alex Dunlop; Steven Court; Naomi Hopkins; Karen Thomas; David Dearnaley; Shree Bhide; Susan Lalondrelle Journal: Phys Imaging Radiat Oncol Date: 2019-04-05
Authors: Nicholas G Zaorsky; Timothy N Showalter; Gary A Ezzell; Paul L Nguyen; Dean G Assimos; Anthony V D'Amico; Alexander R Gottschalk; Gary S Gustafson; Sameer R Keole; Stanley L Liauw; Shane Lloyd; Patrick W McLaughlin; Benjamin Movsas; Bradley R Prestidge; Al V Taira; Neha Vapiwala; Brian J Davis Journal: Adv Radiat Oncol Date: 2017-03-20