title: Computed tomography follow-up for the detection of hepatocellular carcinoma recurrence after initial radiofrequency ablation: a single-center experience.
abstract: OBJECTIVE
  Recurrence of hepatocellular carcinoma (HCC) is very common even after curative resection or ablation. This retrospective study compared the radiologic features of recurrent HCC seen by computed tomography (CT) to evaluate our empirical protocol of CT surveillance using 4-month intervals.
  
  
  METHODS
  A total of 113 patients who were diagnosed with a first HCC recurrence after radiofrequency (RF) ablation between January 2005 and December 2006 were enrolled at a single center. Definite HCC was defined as hyperattenuation in the arterial phase with washout in the portal venous phase, and a diagnosis of naive and recurrent HCC was based on dynamic CT findings. Recurrent nodules were classified according to the enhancement patterns of previous CT images. The treatment modality for recurrent HCC and survival were evaluated.
  
  
  RESULTS
  One hundred seventy-seven nodules were diagnosed as recurrent HCC: 31 (17.5%) had already been diagnosed on previous CT images as typical HCC, 72 (40.6%) had arterial hypervascularity without washout in the portal venous phase, 21 (11.9%) showed portal venous phase washout without arterial hypervascularity, and no lesions were noted in the remaining 49 (27.7%). Tumor size at recurrence was smaller than 2 cm in diameter in 98 (86.7%) cases. One hundred four patients were treated for recurrent HCC with RF ablation. The 5-year survival rate after recurrence was 49.8%. There was no significant difference in survival among groups divided by the enhancement pattern on the previous CT examination.
  
  
  CONCLUSIONS
  Dynamic CT in 4-month intervals is an acceptable recurrence-monitoring strategy because it detects most recurrent nodules at a stage at which RF ablation is still feasible.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Mikami
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tateishi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kondo
authors.forename: Tadashi
authors.initials: T
authors.lastname: Goto
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Shiina
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome