title: Single-projection based volumetric image reconstruction and 3D tumor localization in real time for lung cancer radiotherapy.
abstract: We have developed an algorithm for real-time volumetric image reconstruction and 3D tumor localization based on a single x-ray projection image. We first parameterize the deformation vector fields (DVF) of lung motion by principal component analysis (PCA). Then we optimize the DVF applied to a reference image by adapting the PCA coefficients such that the simulated projection of the reconstructed image matches the measured projection. The algorithm was tested on a digital phantom as well as patient data. The average relative image reconstruction error and 3D tumor localization error for the phantom is 7.5% and 0.9 mm, respectively. The tumor localization error for patient is approximately 2 mm. The computation time of reconstructing one volumetric image from each projection is around 0.2 and 0.3 seconds for phantom and patient, respectively, on an NVIDIA C1060 GPU. Clinical application can potentially lead to accurate 3D tumor tracking from a single imager.
authors.affiliation: Department of Radiation Oncology, University of California San Diego 3855 Health Sciences Dr. 0843, La Jolla, CA 92037, USA. ru1002@ucsd.edu
authors.forename: Ruijiang
authors.initials: R
authors.lastname: Li
authors.forename: Xun
authors.initials: X
authors.lastname: Jia
authors.forename: John H
authors.initials: JH
authors.lastname: Lewis
authors.forename: Xuejun
authors.initials: X
authors.lastname: Gu
authors.forename: Michael
authors.initials: M
authors.lastname: Folkerts
authors.forename: Chunhua
authors.initials: C
authors.lastname: Men
authors.forename: Steve B
authors.initials: SB
authors.lastname: Jiang
mesh_terms: D000465:Algorithms; D003199:Computer Systems; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D010363:Pattern Recognition, Automated / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity