title: Percutaneous radiofrequency ablation of renal tumors: midterm results in 16 patients.
abstract: OBJECTIVE
  To evaluate the outcome of 16 patients after percutaneous radiofrequency ablation of renal tumors.
  
  
  METHODS
  Sixteen patients (nine women, seven men; mean age, 61+/-9 years) with 24 unresectable renal tumors (mean volume, 4.3+/-4.3 cm3) underwent CT-guided (n=20) or MR imaging-guided (n=4) percutaneous radiofrequency ablation using an expandable electrode (Starburst XL, RITA Medical Systems, Mountain View, CA) with a 150-W generator. The initial follow-up imaging was performed within 1-30 days after RF ablation, then at 3-6 month intervals using either CT or MRI. Residual tumor volume and coagulation necrosis was assessed, and statistical correlation tests were obtained to determine the strength of the relationship between necrosis volume and number of ablations.
  
  
  RESULTS
  Overall, 97 overlapping RF ablations were performed (mean, 3.5+/-1.5 ablations per tumor) during 24 sessions. Five or more RF ablations per tumor created significant larger necrosis volumes than 1-2 (p=.034) or 3-4 ablations (p=.020). A complete ablation was achieved in 20/24 tumors (primary technical success, 83%; mean volume of coagulation necrosis: 10.2+/-7.2 cm3). Three of four residual tumors were retreated and showed complete necrosis thereafter. Three major complications (one percuatneous urinary fistula and two ureteral strictures) were observed after RF ablation. No further clinically relevant complications were observed and renal function remained stable. During a mean follow-up of 11.2 months (range, 0.2-31.5), 15/16 patients (94%) were alive. Only one patient had evidence of local recurrent tumor.
  
  
  CONCLUSIONS
  The midterm results of percutaneous RF ablation for renal tumors are promising and show that RF ablation is well-suited to preserve renal function.
authors.affiliation: Division of Angiography and Interventional Radiology, Department of Radiology, General Hospital of Vienna, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. mazda.memarsadeghi@meduniwien.ac.at
authors.forename: Mazda
authors.initials: M
authors.lastname: Memarsadeghi
authors.forename: Theresia
authors.initials: T
authors.lastname: Schmook
authors.forename: Mesut
authors.initials: M
authors.lastname: Remzi
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Gerda
authors.initials: G
authors.lastname: Pötscher
authors.forename: Johannes
authors.initials: J
authors.lastname: Lammer
authors.forename: Joachim
authors.initials: J
authors.lastname: Kettenbach
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000601:surgery*; D012086:Reoperation; D015898:Tomography Scanners, X-Ray Computed; D016896:Treatment Outcome