Paper Info
Title
Automatic registration of portal images and volumetric CT for patient positioning in radiation therapy.
Abstract
The efficacy of radiation therapy treatment depends on the patient setup accuracy at each daily fraction. A significant problem is reproducing the patient position during treatment planning for every fraction of the treatment process. We propose and evaluate an intensity based automatic registration method using multiple portal images and the pre-treatment CT volume. We perform both geometric and radiometric calibrations to generate high quality digitally reconstructed radiographs (DRRs) that can be compared against portal images acquired right before treatment dose delivery. We use a graphics processing unit (GPU) to generate the DRRs in order to gain computational efficiency. We also perform a comparative study on various similarity measures and optimization procedures. Simple similarity measure such as local normalized correlation (LNC) performs best as long as the radiometric calibration is carefully done. Using the proposed method, we achieved better than 1mm average error in repositioning accuracy for a series of phantom studies using two open field (i.e., 41cm2) portal images with 90° vergence angle.
Year
DOI
Venue
2006
10.1016/j.media.2005.06.002
Medical Image Analysis
Keywords
Field
DocType
Patient positioning,Radiation therapy,2D–3D registration,DRR generation
Radiometric calibration,Computer vision,Similarity measure,Pattern recognition,Computer science,Imaging phantom,Radiation treatment planning,Radiation therapy,Artificial intelligence,Radiography,Graphics processing unit,Calibration
Journal
Volume
Issue
ISSN
10
1
1361-8415
Citations 
PageRank 
References 
40
3.10
15
Authors
5
Name
Order
Citations
PageRank
Ali Khamene146938.63
Peter Bloch2403.10
Wolfgang Wein346138.75
Michelle Svatos4403.10
Frank Sauer514511.04