title: Repeat radiofrequency ablation for local progression of lung tumors: does it have a role in local tumor control?
abstract: OBJECTIVE
  To retrospectively evaluate the role of repeat radiofrequency (RF) ablation for local progression of lung tumors in local tumor control.
  
  
  METHODS
  From June 2001 to February 2007, the authors treated 797 lung tumors (primary lung cancer, n=66; metastatic lung neoplasm, n=731; mean tumor size, 1.7 cm) in 295 patients with RF ablation. After RF ablation, patients were followed-up with contrast-enhanced chest computed tomography at 1, 3, 6, 9, and 12 months and thereafter at 6-month intervals. Local progression was observed in 117 of the 797 lung tumors. Fifty repeat RF ablation sessions were performed for 56 tumors (primary lung cancer, n=9; metastatic lung neoplasm, n=47; mean tumor size, 2.7 cm) in 46 patients (33 men, 13 women; mean age, 59.6 years). Repeat RF ablation was not performed for the remaining 61 locally progressing tumors because it was not presumed to provide survival benefit. For all 797 tumors, the overall primary and secondary technique effectiveness rates (TERs) after the first RF ablation were compared with each other. To determine the risk factors for local control with repeat RF ablation, multiple variables were analyzed. Next, local control with repeat RF ablation was evaluated for tumors with and tumors without risk factors.
  
  
  RESULTS
  The overall secondary TERs were significantly higher than the overall primary TERs (P<.00001). Tumor size of at least 2 cm at the first RF ablation (P=.045) and contact with bronchi (P=.045) or vessels (P=.048) were risk factors for local control with repeat RF ablation. The secondary TERs after the first RF ablation were 94% at 1 year, 68% at 2 years, and 55% at 3 years for tumors without risk factors and 60% at 1 year and 40% at 2 years for tumors with at least one risk factor. Among the 50 repeat RF ablation sessions, pneumothorax occurred in 13 sessions (26%), one of which necessitated chest tube placement; pleural effusion occurred in nine sessions (18%), all of which resolved spontaneously. Thermal injury of the brachial plexus occurred after one session.
  
  
  CONCLUSIONS
  Repeat RF ablation improved the overall local control outcomes. In particular, it offered an opportunity to salvage tumors that had no risk factors but nevertheless progressed locally after the first RF ablation. Conversely, tumors with risk factors were not controlled sufficiently even after repeating the procedure.
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Shikatacho, Okayama 700-8558, Japan. takaoh@tc4.so-net.ne.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Hiraki
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Mimura
authors.forename: Hideo
authors.initials: H
authors.lastname: Gobara
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Sano
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Date
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019233:Retreatment; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media