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Titolo:
Patient position verification using CT images
Autore:
Kress, J; Minhara, S; Endo, M; Debus, J; Kanai, T;
Indirizzi:
Deutschanyebsforschungszentrum, Dept Radiat Oncol, D-69120 Heidelberg, Germ Deutsch Krebsforschungszentrum Heidelberg Germany D-69120 idelberg, Germ Natl Inst Radiol Sci, Div Accelerator Phys & Engn, Inage Ku, Chiba 2638555, Natl Inst Radiol Sci Chiba Japan 2638555 Engn, Inage Ku, Chiba 2638555, Natl Inst Radiol Sci, Med Phys & Engn Off, Inage Ku, Chiba 2638555, Japan Natl Inst Radiol Sci Chiba Japan 2638555 Inage Ku, Chiba 2638555, Japan
Titolo Testata:
MEDICAL PHYSICS
fascicolo: 6, volume: 26, anno: 1999,
pagine: 941 - 948
SICI:
0094-2405(199906)26:6<941:PPVUCI>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
DIGITALLY RECONSTRUCTED RADIOGRAPHS; PORTAL IMAGES; PROTON-BEAM; RADIOTHERAPY; THERAPY; SYSTEM;
Keywords:
position verification; image registration; image interpolation; minimization algorithms; patient repositioning;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
18
Recensione:
Indirizzi per estratti:
Indirizzo: Kress, J Deutsch69120sforschungszentrum, Dept Radiat Oncol, Neuenheimer Feld 280, D- Deutsch Krebsforschungszentrum Neuenheimer Feld 280 Heidelberg Germany D-69120
Citazione:
J. Kress et al., "Patient position verification using CT images", MED PHYS, 26(6), 1999, pp. 941-948

Abstract

The use of ions in the radiotherapy of cancer patients requires am accurate patient positioning in order to exploit its potential benefits. Using CT images as the basis for the setup verification offers the advantage of a high in-plane resolution in combination with a geometrically accurate, volumetric information. Before each fraction a single CT slice is acquired at theisocenter level after the positioning procedure. This single slice is registered to the planning CT cube using automated image registration algorithms. Thus any erreonous translation or rotation can be detected and quantified. The registration process involves the interpolation of the volumetric data, the calculation of an energy function, and the minimization of this energy function. Several data interpolation functions as well as minimization algorithms were compared. CT studies with a head phantom were performed in which defined translations and rotations were simulated by moving a motor-driven treatment chair. Different slice thicknesses and anatomical sites were studied to investigate their potential influence on the registration accuracy. The accuracy of the registration was found to be a fraction of a voxel size for suitable combinations of algorithms (typically better than 0.16 mm/deg). A significant dependancy of the registration accuracy on the CT slice thickness and the anatomical site was found (the accuracy ranges from 0.05 mm/deg to 0.16 mm/deg depending on the site). The calculation time is dependant on the used algorithms and the magnitude of the setup error. For the standard combination of algorithms as proposed by the authors (Downhill Simplex minimization with Trilinear interpolation) the typical calculation time is about 20 s for a Sun UltraSPARC processor. Taking into account the mechanical accuracy of the setup device (motor-driven chair) the registration of CT images is thus a useful tool for detecting and quantifying any significant error in the patient position. (C) 1999 American Association of Physicists in Medicine.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/07/20 alle ore 08:46:07