Clinical Evaluation of Soft Tissue Organ Boundary Visualization on Cone-Beam Computed Tomographic Imaging

Journal Article · Mon Nov 01 00:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.02.007· OSTI ID:21438026

Weiss, Elisabeth ^[1]; Jian, Wu; Sleeman, William; Bryant, Joshua; Mitra, Priya; Myers, Michael; Ivanova, Tatjana ^[1]; Mukhopadhyay, Nitai; Ramakrishnan, Viswanathan ^[2]; Murphy, Martin; Williamson, Jeffrey ^[1]

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1. Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States)
2. Department of Biostatistics, Virginia Commonwealth University, Richmond, VA (United States)

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.

• OSTI ID: 21438026
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2010.02.007; PII: S0360-3016(10)00235-X; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLADDER
COMPUTERIZED TOMOGRAPHY
IMAGES
NEOPLASMS
PROSTATE
RADIOTHERAPY
RECTUM
VARIATIONS
BODY
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
DISEASES
GASTROINTESTINAL TRACT
GLANDS
INTESTINES
LARGE INTESTINE
MALE GENITALS
MEDICINE
NUCLEAR MEDICINE
ORGANS
RADIOLOGY
THERAPY
TOMOGRAPHY
URINARY TRACT