Patient positioning error measurement based on dynamic template matching techniques.

The decrease of accuracy in patients' repeated positioning in radiotherapy due to body's transformation is considered and a positioning error measurement method using dynamic template matching technique is brought forward in this paper. This method is an improvement of the matching method to correct positioning error based on the CT digitally reconstructed radiograph(DRR), which uses the video reconstructed 3D surface model that can reflect the body's transformation as the matching template instead of DRR. This method can not only improve the positioning accuracy but also eliminate the adverse influence brought by body's transformation.

Effect of CT Image-Based Voxel Size On Monte Carlo Dose Calculation.

Currently, the conventional empirical or semi-empirical dose calculation algorithms for radiation treatment planning system have been selected as dose engines. The accuracy of these dose calculation algorithms is limited. The main problem is that they fail to adequately consider the lateral transport of radiation or loss of electronic equilibrium near interface between two heterogeneous mediums.

Repeated positioning in accurate radiotherapy based on virtual net technique and contrary reconstruction scheme.

This paper presents a new repeated positioning system for external radiotherapy. A new scheme is proposed to rebuild patient's body surface 3-D image based on simple stereo vision model and virtual net technique, which improves the reconstruction precision of the template. For the calculation of the positioning error, the contrary reconstruction scheme is adopted and the positioning speed is greatly improved.