title: Diagnostic and staging impact of radiotherapy planning FDG-PET-CT in non-small-cell lung cancer.
abstract: OBJECTIVE
  To evaluate whether FDG-PET performed for radiotherapy (RT) planning can detect disease progression, compared with staging PET.
  
  
  METHODS
  Twenty-six patients with newly-diagnosed non-small-cell lung cancer underwent planning PET-CT for curative RT within 8 weeks (mean: 33±14days) of staging PET-CT. Progressive disease (PD) was defined as >25% increase in tumour size (transaxial) or volume, as delineated by SUV threshold of 2.5, or new sites (SUV>2.5).
  
  
  RESULTS
  The planning PET detected PD in 16 patients (61%), compared to four patients (15%) by CT component of PET-CT. The mean scan interval was longer in patients with progression: 40±12days, compared to 22±11days without progression. Planning PET detected PD in 13/17 (76%), 12/14 (86%) and 7/7 patients if the interval was ≥4, 5 and 6 weeks, respectively, compared with 3/9 patients if interval <4 weeks. Planning PET detected PD in primary metabolic volume in seven patients, 20 new nodal sites in 12 new nodal stations and nine patients, five extra-nodal sites in five patients. This resulted in upstaging in nine patients (35%): stage IIIA in three, IIIB in three and IV in three.
  
  
  CONCLUSIONS
  RT-planning FDG-PET can provide incremental diagnostic information and may impact on staging in a significant number of patients.
authors.affiliation: Department of Nuclear Medicine and PET, Liverpool Hospital, Liverpool, NSW 1871, Australia. peter.lin@sswahs.nsw.gov.au
authors.forename: Peter
authors.initials: P
authors.lastname: Lin
authors.forename: Eng-Siew
authors.initials: ES
authors.lastname: Koh
authors.forename: Michael
authors.initials: M
authors.lastname: Lin
authors.forename: Shalini K
authors.initials: SK
authors.lastname: Vinod
authors.forename: Ivan
authors.initials: I
authors.lastname: Ho-Shon
authors.forename: June
authors.initials: J
authors.lastname: Yap
authors.forename: Seu
authors.initials: S
authors.lastname: Som
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D011880:Radiotherapy Planning, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D051598:Whole Body Imaging
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18