title: Limitation for performing ultrasound-guided radiofrequency ablation of small renal masses.
abstract: OBJECTIVE
  To evaluate which factor is involved in limiting ultrasound (US)-guided radiofrequency (RF) ablation of small renal masses.
  
  
  METHODS
  Twenty-five patients with 31 renal masses underwent image-guided RF ablation. If a lesion was visible on US, US-guided RF ablation was performed. If a lesion was invisible on US or if the lesion was incompletely ablated or recurred following US-guided RF ablation, CT-guided RF ablation was performed. We analyzed the various factors which were involved in US-guided RF ablation.
  
  
  RESULTS
  Of 31 masses, thirteen were US-visible lesions and underwent US-guided RF ablation whereas thirteen were US-invisible lesions and thus underwent CT-guided RF ablation. The remaining five lesions were US-visible but needed additional CT-guided RF ablation, due to incomplete ablation (n=4) or recurrence (n=1); these renal masses (3.1+/-1.0 cm) were significantly larger than those (1.8+/-0.6 cm) ablated with US alone (p<0.05). Steam bubbles (4.4 cm+/-0.7 cm) of the masses requiring additional CT-guided RF ablation were significantly larger than those (2.9 cm+/-0.7 cm) of the tumors completely ablated with US alone in size (p<0.05).
  
  
  CONCLUSIONS
  US-invisibility, lesion size, and steam bubbles may limit to perform US-guided RF ablation of small renal masses.
authors.affiliation: The Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 135-710 Seoul, Republic of Korea. rapark@skku.edu
authors.forename: Byung Kwan
authors.initials: BK
authors.lastname: Park
authors.forename: Chan Kyo
authors.initials: CK
authors.lastname: Kim
authors.forename: Han Yong
authors.initials: HY
authors.lastname: Choi
authors.forename: Hyun Moo
authors.initials: HM
authors.lastname: Lee
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Jeon
authors.forename: Seong Il
authors.initials: SI
authors.lastname: Seo
authors.forename: Deok Hyun
authors.initials: DH
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018084:Ultrasonography, Interventional; D055815:Young Adult