PURPOSE: Cone-beam computed tomographic images (CBCTs) are increasingly used for setup correction, soft tissue targeting, and image-guided adaptive radiotherapy. However, CBCT image quality is limited by low contrast and imaging artifacts. This analysis investigates the detectability of soft tissue boundaries in CBCT by performing a multiple-observer segmentation study. METHODS AND MATERIALS: In four prostate cancer patients prostate, bladder and rectum were repeatedly delineated by five observers on CBCTs and fan-beam CTs (FBCTs). A volumetric analysis of contouring variations was performed by calculating coefficients of variation (COV: standard deviation/average volume). The topographical distribution of contouring variations was analyzed using an average surface mesh-based method. RESULTS: Observer- and patient-averaged COVs for FBCT/CBCT were 0.09/0.19 for prostate, 0.05/0.08 for bladder, and 0.09/0.08 for rectum. Contouring variations on FBCT were significantly smaller than on CBCT for prostate (p < 0.03) and bladder (p < 0.04), but not for rectum (p < 0.37; intermodality differences). Intraobserver variations from repeated contouring of the same image set were not significant for either FBCT or CBCT (p < 0.05). Average standard deviations of individual observers' contour differences from average surface meshes on FBCT vs. CBCT were 1.5 vs. 2.1 mm for prostate, 0.7 vs. 1.4 mm for bladder, and 1.3 vs. 1.5 mm for rectum. The topographical distribution of contouring variations was similar for FBCT and CBCT. CONCLUSION: Contouring variations were larger on CBCT than FBCT, except for rectum. Given the well-documented uncertainty in soft tissue contouring in the pelvis, improvement of CBCT image quality and establishment of well-defined soft tissue identification rules are desirable for image-guided radiotherapy.
PURPOSE: Cone-beam computed tomographic images (CBCTs) are increasingly used for setup correction, soft tissue targeting, and image-guided adaptive radiotherapy. However, CBCT image quality is limited by low contrast and imaging artifacts. This analysis investigates the detectability of soft tissue boundaries in CBCT by performing a multiple-observer segmentation study. METHODS AND MATERIALS: In four prostate cancerpatients prostate, bladder and rectum were repeatedly delineated by five observers on CBCTs and fan-beam CTs (FBCTs). A volumetric analysis of contouring variations was performed by calculating coefficients of variation (COV: standard deviation/average volume). The topographical distribution of contouring variations was analyzed using an average surface mesh-based method. RESULTS: Observer- and patient-averaged COVs for FBCT/CBCT were 0.09/0.19 for prostate, 0.05/0.08 for bladder, and 0.09/0.08 for rectum. Contouring variations on FBCT were significantly smaller than on CBCT for prostate (p < 0.03) and bladder (p < 0.04), but not for rectum (p < 0.37; intermodality differences). Intraobserver variations from repeated contouring of the same image set were not significant for either FBCT or CBCT (p < 0.05). Average standard deviations of individual observers' contour differences from average surface meshes on FBCT vs. CBCT were 1.5 vs. 2.1 mm for prostate, 0.7 vs. 1.4 mm for bladder, and 1.3 vs. 1.5 mm for rectum. The topographical distribution of contouring variations was similar for FBCT and CBCT. CONCLUSION: Contouring variations were larger on CBCT than FBCT, except for rectum. Given the well-documented uncertainty in soft tissue contouring in the pelvis, improvement of CBCT image quality and establishment of well-defined soft tissue identification rules are desirable for image-guided radiotherapy.
Authors: Monique H P Smitsmans; Josien de Bois; Jan-Jakob Sonke; Anja Betgen; Lambert J Zijp; David A Jaffray; Joos V Lebesque; Marcel van Herk Journal: Int J Radiat Oncol Biol Phys Date: 2005-11-15 Impact factor: 7.038
Authors: Song Gao; Lifei Zhang; He Wang; Renaud de Crevoisier; Deborah D Kuban; Radhe Mohan; Lei Dong Journal: Med Phys Date: 2006-09 Impact factor: 4.071
Authors: Dominique P Huyskens; Philippe Maingon; Luc Vanuytsel; Vincent Remouchamps; Tom Roques; Bernard Dubray; Benjamin Haas; Patrik Kunz; Thomas Coradi; René Bühlman; Robin Reddick; Ann Van Esch; Emile Salamon Journal: Radiother Oncol Date: 2008-09-21 Impact factor: 6.280
Authors: C Rasch; P Remeijer; P C Koper; G J Meijer; J C Stroom; M van Herk; J V Lebesque Journal: Int J Radiat Oncol Biol Phys Date: 1999-11-01 Impact factor: 7.038
Authors: Douglas J Moseley; Elizabeth A White; Kirsty L Wiltshire; Tara Rosewall; Michael B Sharpe; Jeffrey H Siewerdsen; Jean-Pierre Bissonnette; Mary Gospodarowicz; Padraig Warde; Charles N Catton; David A Jaffray Journal: Int J Radiat Oncol Biol Phys Date: 2007-03-01 Impact factor: 7.038
Authors: Daniel Létourneau; Alvaro A Martinez; David Lockman; Di Yan; Carlos Vargas; Giovanni Ivaldi; John Wong Journal: Int J Radiat Oncol Biol Phys Date: 2005-07-15 Impact factor: 7.038
Authors: Kirsten E I Deurloo; Roel J H M Steenbakkers; Lambert J Zijp; Josien A de Bois; Peter J C M Nowak; Coen R N Rasch; Marcel van Herk Journal: Int J Radiat Oncol Biol Phys Date: 2005-01-01 Impact factor: 7.038
Authors: George X Ding; Dennis M Duggan; Charles W Coffey; Matthew Deeley; Dennis E Hallahan; Anthony Cmelak; Arnold Malcolm Journal: Radiother Oncol Date: 2007-08-20 Impact factor: 6.280
Authors: Yanfeng Li; Xiaoqian Guo; Xiaoxue Sun; Ning Wang; Min Xie; Jianqiang Zhang; Yuan Lv; Weili Han; Min Hu; Hongchen Liu Journal: Int J Clin Exp Med Date: 2015-09-15
Authors: Salim Balik; Elisabeth Weiss; Nuzhat Jan; Nicholas Roman; William C Sleeman; Mirek Fatyga; Gary E Christensen; Cheng Zhang; Martin J Murphy; Jun Lu; Paul Keall; Jeffrey F Williamson; Geoffrey D Hugo Journal: Int J Radiat Oncol Biol Phys Date: 2013-02-22 Impact factor: 7.038
Authors: John Rodgers; Rosie Hales; Lee Whiteside; Jacqui Parker; Louise McHugh; Anthea Cree; Marcel van Herk; Ananya Choudhury; Peter Hoskin; Alan McWilliam; Cynthia L Eccles Journal: Br J Radiol Date: 2020-06-16 Impact factor: 3.039