title: US-US Fusion Imaging in Radiofrequency Ablation for Liver Metastases.
abstract: OBJECTIVE
  Radiofrequency ablation (RFA) induces gas bubbles in ablation zones, and the ablative margin cannot be evaluated accurately on ultrasound (US) during and immediately after RFA. This study assessed the usefulness of US-US fusion imaging to visualize the ablative margin of RFA for liver metastasis.
  
  
  METHODS
  RFA guided by US-US fusion imaging was performed on 12 targeted tumors in 10 patients. Secondary hepatic malignancies included patients with colorectal cancer (n = 4), breast cancer (n = 2), lung cancer (n = 1), gastrointestinal stromal tumor (n = 1), pancreatic neuroendocrine tumor (n = 1), and adrenocortical carcinoma (n = 1). The maximal diameter of the tumors ranged from 0.8 to 4.0 cm (mean ± SD 1.6 ± 0.9 cm).
  
  
  RESULTS
  The mean number of electrode insertions was 1.6 per session (range 1-3). Technically, effective ablation was achieved in a single session in all patients, and safety ablative margins were confirmed on contrast-enhanced CT for early assessment of tumor response. There were no serious adverse events or procedure-related complications. During the follow-up period (median 220 days, range 31-417 days), none of the patients showed local tumor progression.
  
  
  CONCLUSIONS
  US-US fusion imaging could show the tumor images before ablation and the ablative area on US in real time. The image overlay of US-US fusion imaging made it possible to evaluate the ablative margin three dimensionally according to the US probe action. Therefore, US-US fusion imaging can contribute to RFA therapy with a safety margin, that is, the so-called precise RFA.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Minami
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Minami
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Chishina
authors.forename: Masashi
authors.initials: M
authors.lastname: Kono
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Arizumi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takita
authors.forename: Norihisa
authors.initials: N
authors.lastname: Yada
authors.forename: Satoru
authors.initials: S
authors.lastname: Hagiwara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ida
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Ueshima
authors.forename: Naoshi
authors.initials: N
authors.lastname: Nishida
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kudo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019412:Anatomy, Cross-Sectional / Q000379:methods; D017115:Catheter Ablation / Q000379:methods*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000473:pathology; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007479:Iopamidol / Q000031:analogs & derivatives; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol