title: A pilot trial of serial 18F-fluorodeoxyglucose positron emission tomography in patients with medically inoperable stage I non-small-cell lung cancer treated with hypofractionated stereotactic body radiotherapy.
abstract: OBJECTIVE
  Routine assessment was made of tumor metabolic activity as measured by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in Stage I non-small-cell lung cancer (NSCLC). This report describes PET correlates prospectively collected after stereotactic body radiotherapy (SBRT) for patients with medically inoperable NSCLC.
  
  
  METHODS
  14 consecutive patients with medically inoperable Stage I NSCLC were enrolled. All patients received SBRT to 60-66 Gy in three fractions. Patients underwent serial planned FDG-PET/computed tomography fusion imaging before SBRT and at 2, 26, and 52 weeks after SBRT.
  
  
  RESULTS
  With median follow-up of 30.2 months, no patients experienced local failure. One patient developed regional failure, 1 developed distant failure, and 1 developed a second primary. The median tumor maximum standardized uptake value (SUV(max)) before SBRT was 8.70. The median SUV(max) values at 2, 26, and 52 weeks after SBRT were 6.04, 2.80, and 3.58, respectively. Patients with low pre-SBRT SUV were more likely to experience initial 2-week rises in SUV, whereas patients with high pre-SBRT SUV commonly had SUV declines 2 weeks after treatment (p = 0.036). Six of 13 patients had primary tumor SUV(max) >3.5 at 12 months after SBRT but remained without evidence of local disease failure on further follow-up.
  
  
  CONCLUSIONS
  A substantial proportion of patients may have moderately elevated FDG-PET SUV(max) at 12 months without evidence of local failure on further follow-up. Thus, slightly elevated PET SUV(max) should not be considered a surrogate for local treatment failure. Our data do not support routine serial FDG-PET/computed tomography for follow-up of patients receiving SBRT for Stage I NSCLC.
authors.affiliation: Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202, USA. mahender@iupui.edu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Henderson
authors.forename: David J
authors.initials: DJ
authors.lastname: Hoopes
authors.forename: James W
authors.initials: JW
authors.lastname: Fletcher
authors.forename: Pei-Fen
authors.initials: PF
authors.lastname: Lin
authors.forename: Mark
authors.initials: M
authors.lastname: Tann
authors.forename: Constantin T
authors.initials: CT
authors.lastname: Yiannoutsos
authors.forename: Mark D
authors.initials: MD
authors.lastname: Williams
authors.forename: Achilles J
authors.initials: AJ
authors.lastname: Fakiris
authors.forename: Ronald C
authors.initials: RC
authors.lastname: McGarry
authors.forename: Robert D
authors.initials: RD
authors.lastname: Timmerman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D019583:Dose Fractionation, Radiation; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18