Title
Accurate tracking of tumor volume change during radiotherapy by CT-CBCT registration with intensity correction.
Abstract
In this paper, we propose a CT-CBCT registration method to accurately predict the tumor volume change based on daily cone-beam CTs (CBCTs) during radiotherapy. CBCT is commonly used to reduce patient setup error during radiotherapy, but its poor image quality impedes accurate monitoring of anatomical changes. Although physician's contours drawn on the planning CT can be automatically propagated to daily CBCTs by deformable image registration (DIR), artifacts in CBCT often cause undesirable errors. To improve the accuracy of the registration-based segmentation, we developed a DIR method that iteratively corrects CBCT intensities by local histogram matching. Three popular DIR algorithms (B-spline, demons, and optical flow) with the intensity correction were implemented on a graphics processing unit for efficient computation. We evaluated their performances on six head and neck (HN) cancer cases. For each case, four trained scientists manually contoured the nodal gross tumor volume (GTV) on the planning CT and every other fraction CBCTs to which the propagated GTV contours by DIR were compared. The performance was also compared with commercial image registration software based on conventional mutual information (MI), VelocityAI (Varian Medical Systems Inc.). The volume differences (mean+/-std in cc) between the average of the manual segmentations and automatic segmentations are 3.70+/-2.30 (B-spline), 1.25+/-1.78 (demons), 0.93+/-1.14 (optical flow), and 4.39+/-3.86 (VelocityAI). The proposed method significantly reduced the estimation error by 9% (B-spline), 38% (demons), and 51% (optical flow) over the results using VelocityAI. Although demonstrated only on HN nodal GTVs, the results imply that the proposed method can produce improved segmentation of other critical structures over conventional methods.
Year
DOI
Venue
2016
10.1117/12.2217047
Proceedings of SPIE
Keywords
Field
DocType
Tumor volume tracking,CBCT,deformable registration
Computer vision,Segmentation,Computer science,Histogram matching,Image quality,Image segmentation,Artificial intelligence,Mutual information,Graphics processing unit,Optical flow,Image registration
Conference
Volume
ISSN
Citations 
9786
0277-786X
0
PageRank 
References 
Authors
0.34
0
9
Name
Order
Citations
PageRank
Seyoun Park1534.88
Adam Robinson200.34
Harry Quon341.44
Ana P. Kiess400.34
Colette Shen500.34
John Wong663.26
William Plishker700.34
Raj Shekhar828232.08
Junghoon Lee9387.21