研究実績の概要 |
Currently, we do not have any approaches to estimate the displacements of applicator, source, tumor, and organs at risk (OAR), and to monitor in-vivo dose distributions in real time for intracavitary brachytherapy. This is a crucial problem from the quality assurance point of view in the brachytherapy. Our purpose is to develop a dynamic adaptive brachytherapy system for real-time visualization of in-vivo locations of an applicator, 192Ir source, tumor, OAR, and dose distributions for intracavitary brachytherapy using a pixel-based portable radiation camera. We developed an approach to correct the source dwelling positions and times based on those determined on treatment plans. Furthermore, we investigated whether in-room computed tomography (CT)-based adaptive treatment planning (ATP) is robust against interfractional location variations, namely, interfractional organ motions and/or applicator displacements, in 3D intracavitary brachytherapy (ICBT) for uterine cervical cancer. The results of this study suggest that the interfractional location variations give smaller impacts on the planning evaluation indices in 3D ATP than in 2D ATP. Therefore, the 3D plans with ATP are expected to be robust against interfractional location variations in each treatment fraction.
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