title: Radiofrequency ablation of medically inoperable stage IA non-small cell lung cancer: are early posttreatment PET findings predictive of treatment outcome?
abstract: OBJECTIVE
  The purpose of this study was to evaluate initial experience with (18)F-FDG PET/CT after pulmonary radiofrequency ablation of stage IA non-small cell lung cancer to determine whether treatment success or residual disease can be predicted with early postablation PET.
  
  
  METHODS
  Thirty patients with medically inoperable stage IA non-small cell lung cancer (12 men, 18 women; median age, 76 years; range, 60-87 years) underwent outpatient CT-guided radiofrequency ablation over a 33-month period. Mean tumor size was 2.0 cm (range, 1.3-2.9 cm). PET/CT was performed within 60 days before radiofrequency ablation (RFA), within 4 days after RFA, and 6 months after RFA. Metabolic response was categorized as complete response or partial or no response at early post-RFA PET/CT and complete response, partial response, or progressive metabolic disease at 6-month post-RFA PET/CT and was compared with the 1-year clinical event rate (death, disease progression at contrast-enhanced CT, or repeat ablation).
  
  
  RESULTS
  Early PET/CT images, obtained within 4 days of RFA, were evaluable for 26 patients (23 at 6 months). Patients with a complete metabolic response at early PET/CT had a 1-year event rate of 43%, whereas those with partial or no response or disease progression had a 1-year event rate of 67% (p = 0.27). Patients with a complete metabolic response at 6-month PET/CT had a 1-year event rate of 0%. Those with a partial response and those with disease progression had an overall event rate of 75% (p = 0.001).
  
  
  CONCLUSIONS
  Early post-RFA PET/CT is not necessary and 6-month post-RFA PET/CT findings correlate better with clinical outcome at 1 year.
authors.affiliation: Department of Diagnostic Imaging, Warren Alpert Medical School, Rhode Island Hospital, 593 Eddy St, Providence, RI 02903, USA. dyoo@lifespan.org
authors.forename: Don C
authors.initials: DC
authors.lastname: Yoo
authors.forename: Damian E
authors.initials: DE
authors.lastname: Dupuy
authors.forename: Shauna L
authors.initials: SL
authors.lastname: Hillman
authors.forename: Hiran C
authors.initials: HC
authors.lastname: Fernando
authors.forename: William S
authors.initials: WS
authors.lastname: Rilling
authors.forename: Jo-Anne O
authors.initials: JA
authors.lastname: Shepard
authors.forename: Barry A
authors.initials: BA
authors.lastname: Siegel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011859:Radiography; D019275:Radiopharmaceuticals; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18