title: Computer-assisted delineation of lung tumor regions in treatment planning CT images with PET/CT image sets based on an optimum contour selection method.
abstract: To assist radiation oncologists in the delineation of tumor regions during treatment planning for lung cancer, we have proposed an automated contouring algorithm based on an optimum contour selection (OCS) method for treatment planning computed tomography (CT) images with positron emission tomography (PET)/CT images. The basic concept of the OCS is to select a global optimum object contour based on multiple active delineations with a level set method around tumors. First, the PET images were registered to the planning CT images by using affine transformation matrices. The initial gross tumor volume (GTV) of each lung tumor was identified by thresholding the PET image at a certain standardized uptake value, and then each initial GTV location was corrected in the region of interest of the planning CT image. Finally, the contours of final GTV regions were determined in the planning CT images by using the OCS. The proposed method was evaluated by testing six cases with a Dice similarity coefficient (DSC), which denoted the degree of region similarity between the GTVs contoured by radiation oncologists and the proposed method. The average three-dimensional DSC for the six cases was 0.78 by the proposed method, but only 0.34 by a conventional method based on a simple level set method. The proposed method may be helpful for treatment planners in contouring the GTV regions.
authors: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors: Ze
authors: Z
authors: Jin
authors: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan arimurah@med.kyushu-u.ac.jp.
authors: Hidetaka
authors: H
authors: Arimura
authors: Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors: Yoshiyuki
authors: Y
authors: Shioyama
authors: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors: Katsumasa
authors: K
authors: Nakamura
authors: Medipolis Proton Therapy and Research Center, Higashikata, Ibusuki-shi, Kagoshima, Japan.
authors: Jumpei
authors: J
authors: Kuwazuru
authors: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors: Taiki
authors: T
authors: Magome
authors: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors: Hidetake
authors: H
authors: Yabu-Uchi
authors: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors: Hiroshi
authors: H
authors: Honda
authors: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors: Hideki
authors: H
authors: Hirata
authors: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors: Masayuki
authors: M
authors: Sasaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D049268:Positron-Emission Tomography; D011880:Radiotherapy Planning, Computer-Assisted / Q000706:statistics & numerical data*; D014057:Tomography, X-Ray Computed
keywords: PET/CT images; computer-assisted delineation; gross tumor volume (GTV); level set method; lung tumor