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Theses

Recalage d'images 3D : positionnement non-invasif pour la radiothérapie intracrânienne

Abstract : This work presents a patient positioning method allowing the radiologists to combine conformaI radiotherapy and dose fractioning. This method, developed for the treatment of intracranial lesions, is non invasif and does not need stereotactic frames. Data related to the patient's head (cloud of points spread out over the cutaneous surface of the head) and to the lesion (3D position and shape) are obtained via a CT-scan which is usually performed before a treatment. A surfacing sensor, fixed in the treatment room, delivers points distributed over the surface of the patient's face. These data represent the information replacing the stereotactic frame. The lesion can be precisely positioned onto the treatment machine isocenter thanks to two geometric transformations. The first transformation, computed during a calibration step, gives the position of 3D-sensor in the coordinate system of the treatment machine. The second transformation (geometric reltltionship between the coordinate systems of the CT -scanner and of the 3D- sensor) is obtained by registering the data of the two modalities (CT -scan data and visible light data of the 3D-structured light sensor). The global transformation is used to estimate the lesion position in the treatment room by applying sequentially the two transformations at the tumour position given in the CT coordinate system. The patient can then be displaced to bring the les ion onto the isocenter. Tests with a phantom (plaster head) including halls simulating intracraniallesions have shown that tumours can be positioned with a mean euor smaller than 2 mm. This accuracy is better than the one of the best known non invasif method.
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Theses
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http://docnum.univ-lorraine.fr/prive/INPL_T_2004_POSADA_GOMEZ_R.pdf
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https://hal.univ-lorraine.fr/tel-01750056
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Submitted on : Thursday, March 29, 2018 - 12:36:49 PM
Last modification on : Wednesday, August 19, 2020 - 11:12:42 AM

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  • HAL Id : tel-01750056, version 1

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Rubén Posada Gomez. Recalage d'images 3D : positionnement non-invasif pour la radiothérapie intracrânienne. Autre. Institut National Polytechnique de Lorraine, 2004. Français. ⟨NNT : 2004INPL056N⟩. ⟨tel-01750056⟩

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