DocumentCode :
471368
Title :
MRI alone simulation for conformal radiation therapy of prostate cancer: technical aspects
Author :
Pasquier, D. ; Betrouni, N. ; Vermandel, M. ; Lacornerie, T. ; Lartigau, E. ; Rousseau, J.
Author_Institution :
Dept. Univ. de Radiotherapie, Lille II Univ.
fYear :
2006
fDate :
Aug. 30 2006-Sept. 3 2006
Firstpage :
160
Lastpage :
163
Abstract :
The value of MRI in defining target volumes and organs at risk is established. Numerous difficulties appear to stand in the way of using MRI alone in dose planning, with the result that this imaging modality is used in most cases in conjunction with computerized X-ray tomography (CT). The aim of this paper is to appreciate these difficulties: geometrical distortion, chemical shifts, dosimetric accuracy. Geometrical distortion measurements were carried out on two 1.5 T MR scanners and the effect of chemical shift and magnetic susceptibility were evaluated in volunteers. The effect on dosimetric calculations of uncertainty in determining electron densities was evaluated too. Geometrical distortion remained at small values: less than 2 mm and 3 mm for field of view of 20 cm and 45 cm. The chemical shift and magnetic susceptibility values obtained, ranging from 0.3 to 3 mm, were well below the theoretical values. The assignment of relative electron densities to only two structures in MR images seems to permit dose planning that is identical with that obtained with CT. None of the technical obstacles mentioned represents a stumbling block. The access to MRI facility could represent a persisting problem
Keywords :
biological organs; biomedical MRI; cancer; chemical shift; dosimetry; electron density; magnetic susceptibility; radiation therapy; tumours; 1.5 T; MRI; chemical shift; computerized X-ray tomography; conformal radiation therapy; dose planning; dosimetric accuracy; electron density; geometrical distortion; magnetic susceptibility; organs at risk; prostate cancer; target volume; Biomedical applications of radiation; Chemicals; Computed tomography; Distortion measurement; Electrons; Magnetic resonance imaging; Magnetic susceptibility; Optical imaging; Prostate cancer; X-ray tomography; Conformal radiotherapy; MRI;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE
Conference_Location :
New York, NY
ISSN :
1557-170X
Print_ISBN :
1-4244-0032-5
Electronic_ISBN :
1557-170X
Type :
conf
DOI :
10.1109/IEMBS.2006.260341
Filename :
4461709
Link To Document :
بازگشت