Implementation of MR image-guided adaptive brachytherapy for cervix cancer

  • Author / Creator
    Ren, Jiyun
  • Currently, the Cross Cancer Institute uses CT imaging in conjunction with the traditional Manchester system, which prescribes dose to a defined point, for cervix cancer brachytherapy. To take advantage of MRI for enhanced definition of soft tissue including the cancerous tissue itself, this thesis focuses on a study of MR image-guided cervix brachytherapy. Firstly, the geometric distortions of an applicator in an MR image and the accuracy of CT-MRI registration were quantitatively evaluated with a custom-made phantom, which provides one measure of the MRI distortion and indicates a CT-MRI registration method for cervix brachytherapy. The remaining part of the thesis describes an optimization method - simulated annealing (SA) - for automatically determining the dwell time configuration based on a set of specified dose-volume constraints. Application to a computer simulation model showed that SA was effective when the model structure sizes and distances are in a normal range. The effects on the optimization of different initial dwell times and a different initial number of dwell positions were also investigated. In general, optimization conformed dose to the target and significantly reduced dose to surrounding normal tissue.

  • Subjects / Keywords
  • Graduation date
    Fall 2011
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.