Numerical phantom generation to evaluate non-rigid CT/CBCT registration algorithms for prostate cancer radiotherapy.
Résumé
In Image-Guided Radiation Therapy of prostate cancer, the CBCT scan acquired at each treatment fraction could be used to estimate a cumulative dose distribution thanks to non-rigid registration. However, this cumulative dose estimation is highly sensitive to non-rigid registration errors. For this reason, validation of the registration algorithm with organ overlap measures or visual assessment is not sufficient. In this paper, we describe the construction of a numerical phantom based on a finite element model of the prostate and the neighbor organs which can be used to assess the non-rigid registration accuracy. Preliminary results show the potential of this phantom to better characterize registration algorithms than traditional Dice score.