title: Multi-institutional Validation Study of Commercially Available Deformable Image Registration Software for Thoracic Images.
abstract: To assess the accuracy of the commercially available deformable image registration (DIR) software for thoracic images at multiple institutions.
  
  
  
  Thoracic 4-dimensional (4D) CT images of 10 patients with esophageal or lung cancer were used. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomic landmarks (300 bronchial bifurcations) that had been manually identified. Deformable image registration was performed between the peak-inhale and -exhale images. Deformable image registration error was determined by calculating the difference at each landmark point between the displacement calculated by DIR software and that calculated by the landmark.
  
  
  
  Eleven institutions participated in this study: 4 used RayStation (RaySearch Laboratories, Stockholm, Sweden), 5 used MIM Software (Cleveland, OH), and 3 used Velocity (Varian Medical Systems, Palo Alto, CA). The ranges of the average absolute registration errors over all cases were as follows: 0.48 to 1.51 mm (right-left), 0.53 to 2.86 mm (anterior-posterior), 0.85 to 4.46 mm (superior-inferior), and 1.26 to 6.20 mm (3-dimensional). For each DIR software package, the average 3-dimensional registration error (range) was as follows: RayStation, 3.28 mm (1.26-3.91 mm); MIM Software, 3.29 mm (2.17-3.61 mm); and Velocity, 5.01 mm (4.02-6.20 mm). These results demonstrate that there was moderate variation among institutions, although the DIR software was the same.
  
  
  
  We evaluated the commercially available DIR software using thoracic 4D-CT images from multiple centers. Our results demonstrated that DIR accuracy differed among institutions because it was dependent on both the DIR software and procedure. Our results could be helpful for establishing prospective clinical trials and for the widespread use of DIR software. In addition, for clinical care, we should try to find the optimal DIR procedure using thoracic 4D-CT data.
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan. Electronic address: kadoya.n@rad.med.tohoku.ac.jp.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kadoya
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Nakajima
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Radiation Oncology and Image-Applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Miyabe
authors.affiliation: Department of Radiation Oncology, Kanagawa Cancer Center, Yokohama, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurooka
authors.affiliation: Department of Radiotherapy, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kito
authors.affiliation: Department of Radiation Oncology, Tokai University School of Medicine, Hachioji, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: Department of Radiological Technology, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Motoharu
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Department of Radiation Physics and Technology, Southern Tohoku Proton Therapy Center, Koriyama, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Arai
authors.affiliation: Department of Radiation Oncology, St Luke's International Hospital, Tokyo, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Tani
authors.affiliation: Department of Carbon Ion Radiotherapy, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yagi
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Wakita
authors.affiliation: Department of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic Makuhari, Chiba, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tohyama
authors.affiliation: Department of Radiation Oncology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Jingu
mesh_terms: D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D012986:Software Validation; D013382:Subtraction Technique; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*