Clinical evaluation of soft tissue organ boundary visualization on cone-beam computed tomographic imaging.
Int J Radiat Oncol Biol Phys
; 78(3): 929-36, 2010 Nov 01.
Article
en En
| MEDLINE
| ID: mdl-20542644
ABSTRACT
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Próstata
/
Neoplasias de la Próstata
/
Recto
/
Vejiga Urinaria
/
Tomografía Computarizada de Haz Cónico
Tipo de estudio:
Prognostic_studies
Límite:
Humans
/
Male
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos