Toward an accurate real-time simulation of internal organ motions during free breathing from skin motion tracking and an a priori knowledge of the diaphragm motion.

Date publication

juin 2007

Auteurs

Membres identifiés du Cancéropôle Est :
Pr SOLER Luc

Tous les auteurs :
Hostettler A, Nicolau SA, Soler L, Remond Y

Résumé

Prediction of internal organ motions is very important for radiotherapy since it allows to reduce the healthy tissue irradiation. In this paper, we present a new method to predict in real time the internal organ motions of a patient induced by free breathing, from a complete preoperative CT image acquired in inspired position and a second one in expired position, which range is limited to the diaphragm. This method needs a segmentation of viscera and skin in the complete CT acquisition, of the diaphragm in both preoperative images, and a structured light system that track the skin motion. In a first part, we analyze physically the breathing motion and show that it is possible to predict organ motions from the skin position. Then, we propose an original method to compute, from the skin position and an a priori knowledge of the diaphragm motion, a deformation field to the internal organ that takes breathing into account. Finally, our predictive simulation, evaluated on human data, reach a prediction of the liver position with an accuracy within 4 mm at 30 Hz.

Référence

Int J Comput Assist Radiol Surg. 2007 Jun;2 1:S100-2.