@article {Poulin2017b, title = {Validation of MRI to TRUS registration for HDR prostate brachytherapy}, journal = {Brachytherapy}, volume = {17}, number = {2}, year = {2018}, month = {2018/04}, pages = {283-290}, abstract = {

Purpose: The objective of this study was to develop and
validate an open-source module for MRI to transrectal ultrasound (TRUS)
registration to support tumor-targeted prostate brachytherapy.

Methods and Materials: In this study, fifteen patients with prostate
cancer lesions visible on multiparametric MRI were selected for the
validation. T2-weighted images with 1 mm isotropic voxel size and
diffusion weighted images were acquired on a 1.5T Siemens. Three
dimensional (3D) TRUS images with 0.5 mm slice thickness were acquired.
The investigated registration module was incorporated in the open-source
3D Slicer platform and can compute rigid and deformable transformations.
An extension of 3D Slicer, SlicerRT, allows import and export to DICOM-RT
formats. For validation, similarity indices, prostate volumes and
centroid positions were determined in addition to registration errors for
common 3D points identified by an experienced radiation oncologist.

Results: The average time to compute the registration was 35{\textpm}3 seconds.
For the deformable and rigid registration respectively, Dice similarity
coefficients were 0.93{\textpm}0.01 and 0.87{\textpm}0.05 while the 95\% Hausdorff
distance was 2.2{\textpm}0.3 and 4.2{\textpm}1.0 mm. MRI volumes obtained after the rigid
and deformable registration were not statistically different (p\>0.05)
from reference TRUS volumes. For the deformable and rigid registration
respectively, 3D distance error between centroid positions were 0.4{\textpm}0.1
and 2.1{\textpm}1.0 mm while registration errors between common points were
2.3{\textpm}1.1 and 3.5{\textpm}3.2 mm. Deformable registration was found significantly
better (p\<0.05) than rigid registration in all parameters.

Conclusions: An open-source MRI to TRUS registration platform was
validated for integration in the brachytherapy workflow.

}, author = {Eric Poulin and Karim Boudam and Csaba Pinter and Samuel Kadoury and Andras Lasso and Gabor Fichtinger and Cynthia Menard} } @conference {Poulin2017, title = {Validation Of MRI To US Registration For Focal Hdr Prostate Brachytherapy Treatment}, booktitle = {Annual Scientific Meeting of the American Brachytherapy Society}, volume = {16}, number = {3}, year = {2017}, pages = {S56-S57}, publisher = {Elsevier}, organization = {Elsevier}, address = {Boston, MA, USA}, keywords = {Brachytherapy, contour propagation, MRI, Ultrasound}, issn = {1538-4721}, doi = {http://dx.doi.org/10.1016/j.brachy.2017.04.093}, url = {http://www.brachyjournal.com/article/S1538-4721(17)30154-X/fulltext}, author = {Eric Poulin}, editor = {Karim Boudam and Csaba Pinter and Samuel Kadoury and Andras Lasso and Gabor Fichtinger and Cynthia Menard} }