title: Therapeutic response assessment of percutaneous radiofrequency ablation for hepatocellular carcinoma: utility of contrast-enhanced agent detection imaging.
abstract: OBJECTIVE
  To assess the utility of contrast-enhanced agent detection imaging (ADI) in the assessment of the therapeutic response to percutaneous radiofrequency (RF) ablation in patients with hepatocellular carcinoma (HCC).
  
  
  METHODS
  Ninety patients with a total of 97 nodular HCCs (mean, 2.1+/-1.3 cm; range, 1.0-5.0 cm) treated with percutaneous RF ablation under the ultrasound guidance were evaluated with contrast-enhanced ADI after receiving an intravenous bolus injection of a microbubble contrast agent (SH U 508A). We obtained serial contrast-enhanced ADI images during the time period from 15 to 90 s after the initiation of the bolus contrast injection. All of the patients underwent a follow-up four-phase helical CT at 1 month after RF ablation, which was then repeated at 2-4 month intervals during a period of at least 12 months. The results of the contrast-enhanced ADI were compared with those of the follow-up CT in terms of the presence or absence of residual unablated tumor and local tumor progression in the treated lesions.
  
  
  RESULTS
  On contrast-enhanced ADI, technical success was obtained in 94 (97%) of the 97 HCCs, while residual unablated tumors were found in three HCCs (3%). Two of the three tumors that were suspicious (was not proven) for incomplete ablation were subjected to additional RF ablation. The remaining one enhancing lesion that was suspicious of a residual tumor on contrast-enhanced ADI was revealed to be reactive hyperemia at the 1-month follow-up CT. Therefore; the diagnostic concordance between the contrast-enhanced ADI and 1-month follow-up CT was 99%. Of the 94 ablated HCCs without residual tumors on both the contrast-enhanced ADI and 1-month follow-up CT after the initial RF ablation, five (5%) had CT findings of local tumor progression at a subsequent follow-up CT.
  
  
  CONCLUSIONS
  Despite its limitations in predicting local tumor progression in the treated tumors, contrast-enhanced ADI is potentially useful for evaluating the early therapeutic effect of percutaneous RF ablation for HCCs.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-gu, Seoul 135-710, South Korea.
authors.forename: Chan Kyo
authors.initials: CK
authors.lastname: Kim
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Kim
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Lee
authors.forename: Yong Hwan
authors.initials: YH
authors.lastname: Jeon
authors.forename: Jongmee
authors.initials: J
authors.lastname: Lee
authors.forename: Soon Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011134:Polysaccharides; D011237:Predictive Value of Tests; D011379:Prognosis; D036542:Tomography, Spiral Computed / Q000379:methods; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color / Q000379:methods*
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508