title: Treatment of renal tumors by percutaneous ultrasound-guided radiofrequency ablation using a multitined electrode: effectiveness and complications.
abstract: BACKGROUND
  Radiofrequency ablation (RFA) is a minimally aggressive, therapeutic alternative for renal tumors. It can be an alternative to nephrectomy in patients with previous nephrectomy, bilateral tumors, von Hippel-Lindau disease, or small renal carcinomas and in those with contraindications for surgery.
  
  
  OBJECTIVE
  To assess the effectiveness of the treatment of renal tumors by RFA in the short and medium term and to identify the possible complications and the factors that determine therapeutic success.
  
  
  METHODS
  A retrospective review of patients with renal tumors treated with RFA between May 2005 and December 2008 was performed in a tertiary academic hospital. Patients were selected among those with previous nephrectomy, bilateral neoplasms, von Hippel-Lindau disease, surgical risk, comorbidity, advanced age, or patient's refusal to surgery. Tumors with evidence of extrarenal extension were excluded. Patients were followed up for 10-50 mo using computed tomography and magnetic resonance imaging.
  
  
  METHODS
  Ultrasound-guided RFA was performed on 65 tumors (range: 1.2-5.3 cm) of 58 patients using multitined electrodes.
  
  
  METHODS
  Incomplete ablation rate, therapeutic success rate, and complications rate.
  
  
  CONCLUSIONS
  Therapeutic success was achieved in 59 of 65 tumors (91%): 53 in a single session, 5 in two sessions, and 1 in three sessions. A significant relationship was observed between size and growth pattern of the tumor and both therapeutic success and incomplete ablation rates. Therapeutic success in tumors >5 cm was 60%. Complications were detected in 10 patients (13%); 5% were considered major complications. Limitations include the lack of pathologic studies to confirm a complete ablation and the lack of a control group to compare with the results of those who underwent nephrectomy.
  
  
  CONCLUSIONS
  RFA is safe and effective in renal tumors. Corticomedullary lesions and tumors >3 cm have greater possibility of incomplete ablation. In tumors >5 cm, RFA has a significant failure rate.
authors.affiliation: Radiology Department, Basurto University Hospital, Bilbao, Spain. joseluis.delcurarodriguez@osakidetza.net
authors.forename: Jose L
authors.initials: JL
authors.lastname: del Cura
authors.forename: Rosa
authors.initials: R
authors.lastname: Zabala
authors.forename: Jose I
authors.initials: JI
authors.lastname: Iriarte
authors.forename: Miguel
authors.initials: M
authors.lastname: Unda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes / Q000009:adverse effects; D004867:Equipment Design; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D014463:Ultrasonography