Iyas Hamdan1,2, Julien Bert1,2, Catherine Cheze Le Rest1,3, Jean Pierre Tasu4, Nicolas Boussion1,5, Antoine Valeri6, Guillaume Dardenne1,2, Dimitris Visvikis1,2. 1. LaTIM, INSERM, UMR 1101, CHRU Morvan, Brest, France. 2. Institut de Recherche Technologique b<>com, Cesson-Sévigné, France. 3. Department of Nuclear Medicine, CHU Milétrie, Poitiers, France. 4. Department of Radiology, CHU Milétrie, Poitiers, France. 5. Department of Radiotherapy, CHRU Morvan, Brest, France. 6. Department of Urology, CHRU Morvan, Brest, France.
Abstract
PURPOSE: In prostate radiotherapy, dose distribution may be calculated on CT images, while the MRI can be used to enhance soft tissue visualization. Therefore, a registration between MR and CT images could improve the overall treatment planning process, by improving visualization with a demonstrated interobserver delineation variability when segmenting the prostate, which in turn can lead to a more precise planning. This registration must compensate for prostate deformations caused by changes in size and form between the acquisitions of both modalities. METHODS: We present a fully automatic MRI/CT nonrigid registration method for prostate radiotherapy treatment planning. The proposed registration methodology is a two-step registration process involving both a rigid and a nonrigid registration step. The registration is constrained to volumes of interest in order to improve robustness and computational efficiency. The method is based on the maximization of the mutual information in combination with a deformation field parameterized by cubic B-Splines. RESULTS: The proposed method was validated on eight clinical patient datasets. Quantitative evaluation, using Hausdorff distance between prostate volumes in both images, indicated that the overall registration errors is 1.6 ± 0.2 mm, with a maximum error of less than 2.3 mm, for all patient datasets considered in this study. CONCLUSIONS: The proposed approach provides a promising solution for an effective and accurate prostate radiotherapy treatment planning since it satisfies the desired clinical accuracy.
PURPOSE: In prostate radiotherapy, dose distribution may be calculated on CT images, while the MRI can be used to enhance soft tissue visualization. Therefore, a registration between MR and CT images could improve the overall treatment planning process, by improving visualization with a demonstrated interobserver delineation variability when segmenting the prostate, which in turn can lead to a more precise planning. This registration must compensate for prostate deformations caused by changes in size and form between the acquisitions of both modalities. METHODS: We present a fully automatic MRI/CT nonrigid registration method for prostate radiotherapy treatment planning. The proposed registration methodology is a two-step registration process involving both a rigid and a nonrigid registration step. The registration is constrained to volumes of interest in order to improve robustness and computational efficiency. The method is based on the maximization of the mutual information in combination with a deformation field parameterized by cubic B-Splines. RESULTS: The proposed method was validated on eight clinical patient datasets. Quantitative evaluation, using Hausdorff distance between prostate volumes in both images, indicated that the overall registration errors is 1.6 ± 0.2 mm, with a maximum error of less than 2.3 mm, for all patient datasets considered in this study. CONCLUSIONS: The proposed approach provides a promising solution for an effective and accurate prostate radiotherapy treatment planning since it satisfies the desired clinical accuracy.
Authors: Allison Payne; Robb Merrill; Emilee Minalga; J Rock Hadley; Henrik Odeen; Lorne W Hofstetter; Sara Johnson; Christine Tunon de Lara; Sophie Auriol; Stephanie Recco; Erik Dumont; Dennis L Parker; Jean Palussiere Journal: IEEE Trans Biomed Eng Date: 2021-02-19 Impact factor: 4.538