Go to  Advanced Search

Towards intra-operative dosimetry for prostate brachytherapy : improved seed detection and registration to ultrasound using needle detection

Show full item record

Files in this item

Files Size Format Description   View
ubc_2012_fall_lobo_julio.pdf 2.744Mb Adobe Portable Document Format   View/Open
 
Title: Towards intra-operative dosimetry for prostate brachytherapy : improved seed detection and registration to ultrasound using needle detection
Author: Lobo, Julio
Degree Master of Applied Science - MASc
Program Electrical and Computer Engineering
Copyright Date: 2012
Publicly Available in cIRcle 2013-04-30
Abstract: Errors in seed placement during low dose rate prostate brachytherapy can result in over-treating healthy tissue and/or under-treating cancer cells. In a standard treatment procedure, seeds are implanted according to a planned seed distribution. This pre-operative plan (pre-plan) is created using an ultrasound volume scan taken about two weeks earlier. Errors in seed placement can occur due to changes in prostate structure during those two weeks, and from seed displacement during and after the actual operation. This thesis presents methods of seed localization that are suitable for both postoperative and intra-operative use. The techniques can be applied to the imaging modalities used in the current operation setup to implement a method of intraoperative planning. This involves using Transrectal Ultrasound (TRUS) and C-arm X-ray Fluoroscopy (fluoro) data to monitor the seed positions relative to the current target volume during an operation. Towards this goal, an automatic method of assigning seeds to their corresponding insertion needle tracks has been developed to match seeds between modalities so that seed displacements can be computed. This method can be applied to measure intra-operative misplacement, by comparing the desired positions to the actual positions computed from fluoro data, or post-implant movement, comparing the fluoro seed positions to those from post-implant Computed Tomography (CT) data. For the intra-operative and post-implant data, 99.31% and 99.41% of the seeds were correctly assigned, respectively. An average intra-operative seed displacement of 4.94±2.42 mm and a further 2.97±1.81 mm of post-implant movement is measured. This information reveals several directional trends and can be used to preemptively correct the pre-operative plan (pre-plan).
URI: http://hdl.handle.net/2429/43524
Scholarly Level: Graduate

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893