title: Impact of FDG-PET on lung cancer delineation for radiotherapy.
abstract: OBJECTIVE
  The purpose of this study is to assess the impact of fused diagnostic F-18 2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) and planning FDG-PET/CT scans on voluming of lung cancer for radiotherapy.
  
  
  METHODS
  Five radiation oncologists (ROs), five radiation oncology trainees and a radiologist contoured five cases of non-small cell lung cancer. The CT alone, the diagnostic FDG-PET/CT and planning FDG-PET/CT each registered to the CT, were used to contour three volumes. The concordance index (CI) was used to compare each volume with a reference RO.
  
  
  RESULTS
  Although there was considerable inter-observer variability in CT contouring, there was no significant difference between mean volumes of the gross tumour volume for the RO and radiation oncology trainees using any technique. There was no increase in CI with the addition of PET/CT, either diagnostic or planning, for the RO. However, the volumes of the radiation oncology trainees showed a significant increase in CI from 65.8% with CT alone to 68.0% and 72.3% with diagnostic PET/CT and planning PET/CT, respectively (P = 0.028). Mean variation at the tumour/mediastinum interface was significantly reduced with addition of registered PET/CT.
  
  
  CONCLUSIONS
  The concordance of RO with the reference RO did not significantly increase with use of integrated FDG PET/CT images. However, the contouring of radiation oncology trainees' became more concordant with the reference.
authors.affiliation: Cancer Therapy Centre, Liverpool Hospital, Locked Bag 7103, Liverpool BC, NSW 1871, Australia. kmorarji@hotmail.com
authors.forename: Kavita
authors.initials: K
authors.lastname: Morarji
authors.forename: Allan
authors.initials: A
authors.lastname: Fowler
authors.forename: Shalini K
authors.initials: SK
authors.lastname: Vinod
authors.forename: Ivan
authors.initials: I
authors.lastname: Ho Shon
authors.forename: Jerome M
authors.initials: JM
authors.lastname: Laurence
mesh_terms: D000465:Algorithms; D000704:Analysis of Variance; D003287:Contrast Media; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D064847:Multimodal Imaging; D015588:Observer Variation; D049268:Positron-Emission Tomography; D011880:Radiotherapy Planning, Computer-Assisted; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C054871:ioversol