A constrained non-rigid registration algorithm for use in prostate image-guided radiotherapy. Academic Article uri icon


MeSH Major

  • Imaging, Three-Dimensional
  • Prostatic Neoplasms
  • Radiographic Image Interpretation, Computer-Assisted
  • Radiotherapy, Computer-Assisted
  • Subtraction Technique
  • Tomography, X-Ray Computed


  • 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.

publication date

  • December 2008



  • Academic Article



  • eng

PubMed Central ID

  • PMC2790815

PubMed ID

  • 18979817

Additional Document Info

start page

  • 780

end page

  • 8


  • 11


  • Pt 1