title: [A study on the application of 18F-FDG-PET-CT for the radiotherapy of patients with stage III non-small cell lung cancer].
abstract: OBJECTIVE
  PET-CT have emerged as powerful imaging tools in radiotherapy to add information that might lead to a change in GTV definition in patients with non-small cell lung cancer (NSCLC). The aim of this study was to investigate the impact of co-registering 18F-FDG-PET-CT images on the gross tumor volume (GTV), the planning target volume (PTV), and critical organ dose in radiation therapy planning of NSCLC.
  
  
  METHODS
  Thirty patients with stage III NSCLC, referred for radical radiation therapy, underwent PET-CT scanning. GTV was delineated on the CT imaging and PET-CT fused imaging respectively. The two images were used to develop the radiotherapy planning at the GE Advantage Sim 6.0 workstation. Dose-volume histograms (DVH) parameters were selected to be paralleled to compare the quality of the two plans and the impact of PET-CT on radiation plan (RP) was further analyzed.
  
  
  RESULTS
  (1) PET-CT image changed the clinical stage: 3 patients (10%) upstaged and 3 patients (10%) downstaged. (2) PET-CT image altered GTV and PTV: GTV and PTV was decreased by PET-CT image fusion in 18 patients (60%) and was increased in 12 patients (40%). A significant (> 25%) treatment volume modification was observed in 17 patients (56.67%). (3) PET-CT image changed the parameters of DVH: to deliver the same target dose of 60 Gy in 30 fractions, all dose-volume characteristics decreased in treatment planning for the 18 patients with decreased PTV based on PET-CT; the issue was the contrary for the 12 patients who had enlarged PTV based on PET-CT.
  
  
  CONCLUSIONS
  The use of the co-registration of PET-CT significantly reduced inaccurate outlining of the GTV and/or to geographic misses.
authors.affiliation: Department of Radiation Oncology, First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
authors.lastname: Shandan
authors.forename: Bo
authors.initials: B
authors.lastname: Han
authors.forename: Huiying
authors.initials: H
authors.lastname: Pan
authors.forename: Lijuan
authors.initials: L
authors.lastname: Yu
authors.forename: Ruizhi
authors.initials: R
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D047368:Tumor Burden / Q000528:radiation effects
chemical_list: D019788:Fluorodeoxyglucose F18