[Computerized tomography for dosimetry purposes: technical factors in helical acquisition. Importance and limits of this technique in target-volume delineation and dose calculation].
The computerized tomography (CT) used for target volumes contouring is an essential step of the radiotherapy process. The CT technical factors must be adapted to explored organs and anatomic regions: data acquisition parameters and reconstruction algorithm, digestive or intravenous contrast. The choice of these parameters and its consequences for contouring are discussed. Respiratory motion must be considered for some organs. Helical CT allow a data acquisition during one apnoea. Knowledge of these technical factors is essential for good contouring and for the future use of multiple row detectors. Precise exams protocols depending on lesions, on treatment methods and patients are demanded. Close cooperation between radiation oncologists, physicists and radiologists is not only a wish but becomes a necessity.
Ceugnart
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Département d'imagerie médicale, centre de lutte contre le cancer Oscar-Lambret, 3, rue Fréderic-Combemale, 59020 Lille, France. L-ceugnart@o-lambret.fr
Taïeb
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S
D016477:Artifacts; D003287:Contrast Media; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D009038:Motion; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D011187:Posture; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D012119:Respiration; D014057:Tomography, X-Ray Computed
D003287:Contrast Media