title: Evaluation of treatment response after chemoembolisation (TACE) in hepatocellular carcinoma using real time image fusion of contrast-enhanced ultrasound (CEUS) and computed tomography (CT)--preliminary results.
abstract: OBJECTIVE
  To evaluate treatment response of hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) with a new real-time imaging fusion technique of contrast-enhanced ultrasound (CEUS) with multi-slice detection computed tomography (CT) in comparison to conventional post-interventional follow-up.
  
  
  METHODS
  40 patients with HCC (26 male, ages 46-81 years) were evaluated 24 hours after TACE using CEUS with ultrasound volume navigation and image fusion with CT compared to non-enhanced CT and follow-up contrast-enhanced CT after 6-8 weeks. Reduction of tumor vascularization to less than 25% was regarded as "successful" treatment, whereas reduction to levels >25% was considered as "partial" treatment response. Homogenous lipiodol retention was regarded as successful treatment in non-enhanced CT.
  
  
  RESULTS
  Post-interventional image fusion of CEUS with CT was feasible in all 40 patients. In 24 patients (24/40), post-interventional image fusion with CEUS revealed residual tumor vascularity, that was confirmed by contrast-enhanced CT 6-8 weeks later in 24/24 patients. In 16 patients (16/40), post-interventional image fusion with CEUS demonstrated successful treatment, but follow-up CT detected residual viable tumor (6/16). Non-enhanced CT did not identify any case of treatment failure. Image fusion with CEUS assessed treatment efficacy with a specificity of 100%, sensitivity of 80% and a positive predictive value of 1 (negative predictive value 0.63).
  
  
  CONCLUSIONS
  Image fusion of CEUS with CT allows a reliable, highly specific post-interventional evaluation of embolization response with good sensitivity without any further radiation exposure. It can detect residual viable tumor at early state, resulting in a close patient monitoring or re-therapy.
authors.affiliation: Department of Internal Medicine I, University of Regensburg, Regensburg, Germany.
authors.forename: Hella
authors.initials: H
authors.lastname: Wobser
authors.affiliation: Department of Internal Medicine I, University of Regensburg, Regensburg, Germany Department of Internal Medicine, University of Bern, Bern, Switzerland.
authors.forename: Reiner
authors.initials: R
authors.lastname: Wiest
authors.affiliation: Department of Internal Medicine I, University of Regensburg, Regensburg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Salzberger
authors.affiliation: Institute for Radiology, University of Regensburg, Regensburg, Germany.
authors.forename: Walter Alexander
authors.initials: WA
authors.lastname: Wohlgemuth
authors.affiliation: Institute for Radiology, University of Regensburg, Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stroszczynski
authors.affiliation: Institute for Radiology, University of Regensburg, Regensburg, Germany.
authors.forename: Ernst-Michael
authors.initials: EM
authors.lastname: Jung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
chemical_list: D003287:Contrast Media
keywords: CEUS; HCC; Real-time image fusion; TACE; treatment response