Geometric Calibration of Cone-beam CT System for Image Guided Proton Therapy / 의학물리
Korean Journal of Medical Physics
; : 209-218, 2008.
Article
em Ko
| WPRIM
| ID: wpr-93139
Biblioteca responsável:
WPRO
ABSTRACT
According to improved radiation therapy technology such as IMRT and proton therapy, the accuracy of patient alignment system is more emphasized and IGRT is dominated research field in radiation oncology. We proposed to study the feasibility of cone-beam CT system using simple x-ray imaging systems for image guided proton therapy at National Cancer Center. 180 projection views (2,304x3,200, 14 bit with 127 micrometer pixel pitch) for the geometrical calibration phantom and humanoid phantoms (skull, abdomen) were acquired with 2degrees step angle using x-ray imaging system of proton therapy gantry room (360degrees for 1 rotation). The geometrical calibration was performed for misalignments between the x-ray source and the flat-panel detector, such as distances and slanted angle using available algorithm. With the geometrically calibrated projection view, Feldkamp cone-beam algorithm using Ram-Lak filter was implemented for CBCT reconstruction images for skull and abdomen phantom. The distance from x-ray source to the gantry isocenter, the distance from the flat panel to the isocenter were calculated as 1,517.5 mm, 591.12 mm and the rotated angle of flat panel detector around x-ray beam axis was considered as 0.25degrees. It was observed that the blurring artifacts, originated from the rotation of the detector, in the reconstructed toomographs were significantly reduced after the geometrical calibration. The demonstrated CBCT images for the skull and abdomen phantoms are very promising. We performed the geometrical calibration of the large gantry rotation system with simple x-ray imaging devices for CBCT reconstruction. The CBCT system for proton therapy will be used as a main patient alignment system for image guided proton therapy.
Palavras-chave
Texto completo:
1
Índice:
WPRIM
Assunto principal:
Prótons
/
Crânio
/
Vértebra Cervical Áxis
/
Calibragem
/
Artefatos
/
Isotiocianatos
/
Radioterapia (Especialidade)
/
Abdome
/
Tomografia Computadorizada de Feixe Cônico
/
Terapia com Prótons
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
Ko
Revista:
Korean Journal of Medical Physics
Ano de publicação:
2008
Tipo de documento:
Article