title: Positron-emission tomography CT to identify local recurrence in stage I lung cancer patients 1 year after stereotactic body radiation therapy.
abstract: OBJECTIVE
  To evaluate the diagnostic value of positron-emission tomography/computed tomography (PET/CT) in stage I lung cancer patients treated with stereotactic body radiation therapy (SBRT), who have suspicious or unclear local recurrence findings in CT 1 year after treatment.
  
  
  METHODS
  A group of 29 patients with unclear or suspicious CT findings 1 year after SBRT were examined with PET/CT. The ability of standard uptake values (SUVmax, SUVmean and posttherapeutic reduction in SUV) to detect local failure and identify patients at a high risk of disease-specific death was evaluated using logrank statistics. Histology and clinical follow-up were the gold standards for local recurrence.
  
  
  RESULTS
  SUVmean greater than 3.44 (p = 0.001); SUVmax greater than 5.48 (p = 0.009) or a relative reduction in SUVmean or SUVmax of less than 43 (p = 0.030) or 52 % (p = 0.025), respectively, was indicative of local recurrence. These parameters also correlated with an increased risk of disease-specific death: SUVmean greater than 2.81 (p = 0.023); SUVmax greater than 3.45 (p = 0.007) or a relative reduction in SUVmean or SUVmax of less than 32 (p = 0.015) or 52 % (p = 0.013), respectively, was indicative of an increased risk of disease-specific death.
  
  
  CONCLUSIONS
  PET/CT performed 1 year after SBRT can reliably identify local recurrence and therefore help to clarify unclear CT findings. As posttherapeutic glucose metabolism also correlates with disease-specific survival, PET/CT may help to stratify lung cancer patients for additional treatment 1 year after SBRT.
authors.affiliation: Department of Nuclear Medicine, Klinikum rechts der Isar, Ismaningerstrasse 22, Munich, Germany. Markus.Essler@tum.de
authors.forename: M
authors.initials: M
authors.lastname: Essler
authors.forename: J
authors.initials: J
authors.lastname: Wantke
authors.forename: B
authors.initials: B
authors.lastname: Mayer
authors.forename: K
authors.initials: K
authors.lastname: Scheidhauer
authors.forename: R A
authors.initials: RA
authors.lastname: Bundschuh
authors.forename: B
authors.initials: B
authors.lastname: Haller
authors.forename: S T
authors.initials: ST
authors.lastname: Astner
authors.forename: M
authors.initials: M
authors.lastname: Molls
authors.forename: N
authors.initials: N
authors.lastname: Andratschke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D016634:Radiosurgery; D016879:Salvage Therapy; D014057:Tomography, X-Ray Computed