title: (18)F-FDG PET-CT simulation for non-small-cell lung cancer: effect in patients already staged by PET-CT.
abstract: OBJECTIVE
  Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition.
  
  
  METHODS
  A total of 28 patients with Stage IA-IIIB NSCLC were enrolled. All patients had undergone staging PET-CT to ensure suitability for radical RT. Of the 28 patients, 14 received induction chemotherapy. In place of a RT planning CT scan, patients underwent scanning on a PET-CT scanner. In a virtual planning study, four oncologists independently delineated the GTV on the CT scan alone and then on the PET-CT scan. Intraobserver and interobserver variability were assessed using the concordance index (CI), and the results were compared using the Wilcoxon signed ranks test.
  
  
  RESULTS
  PET-CT improved the CI between observers when defining the GTV using the PET-CT images compared with using CT alone for matched cases (median CI, 0.57 for CT and 0.64 for PET-CT, p = .032). The median of the mean percentage of volume change from GTV(CT) to GTV(FUSED) was -5.21% for the induction chemotherapy group and 18.88% for the RT-alone group. Using the Mann-Whitney U test, this was significantly different (p = .001).
  
  
  CONCLUSIONS
  PET-CT RT planning scan, in addition to a staging PET-CT scan, reduces interobserver variability in GTV definition for NSCLC. The GTV size with PET-CT compared with CT in the RT-alone group increased and was reduced in the induction chemotherapy group.
authors: Centre for Cancer Research and Cell Biology, Queen's University of Belfast, Belfast, Northern Ireland, United Kingdom. Gerry.Hanna@googlemail.com
authors: Gerard G
authors: GG
authors: Hanna
authors: Jonathan
authors: J
authors: McAleese
authors: Kathryn J
authors: KJ
authors: Carson
authors: David P
authors: DP
authors: Stewart
authors: Vivian P
authors: VP
authors: Cosgrove
authors: Ruth L
authors: RL
authors: Eakin
authors: Ashraf
authors: A
authors: Zatari
authors: Tom
authors: T
authors: Lynch
authors: Peter H
authors: PH
authors: Jarritt
authors: V A Linda
authors: VA
authors: Young
authors: Joe M
authors: JM
authors: O'Sullivan
authors: Alan R
authors: AR
authors: Hounsell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D012074:Remission Induction; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18