title: A constrained non-rigid registration algorithm for use in prostate image-guided radiotherapy.
abstract: A constrained non-rigid registration (CNRR) algorithm for use in updating prostate external beam image-guided radiotherapy treatment plans is presented in this paper. The developed algorithm is based on a multi-resolution cubic B-spline FFD transformation and has been tested and verified using 3D CT images from 10 sets of real patient data acquired from 4 different patients on different treatment days. The registration can be constrained to any combination of the prostate, rectum, bladder, pelvis, left femur, and right femur. The CNRR was tested with 5 different combinations of constraints and each test significantly outperformed both rigid and non-rigid registration at aligning constrained bones and critical organs. The CNRR was then used to update the treatment plans to account for articulated, rigid bone motion and non-rigid organ deformation. Each updated treatment plan outperformed the original treatment plan by increasing radiation dosage to the prostate and lowering radiation dosage to the rectum and bladder.
authors.affiliation: Department of Biomedical Engineering, Yale University, New Haven, CT, USA. william.h.greene@yale.edu
authors.forename: W H
authors.initials: WH
authors.lastname: Greene
authors.forename: S
authors.initials: S
authors.lastname: Chelikani
authors.forename: K
authors.initials: K
authors.lastname: Purushothaman
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: J P S
authors.initials: JP
authors.lastname: Knisely
authors.forename: L H
authors.initials: LH
authors.lastname: Staib
authors.forename: X
authors.initials: X
authors.lastname: Papademetris
authors.forename: J
authors.initials: J
authors.lastname: Duncan
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D010363:Pattern Recognition, Automated / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*