title: Assessment of liver ablation using cone beam computed tomography.
abstract: OBJECTIVE
  To investigate the feasibility and accuracy of cone beam computed tomography (CBCT) in assessing the ablation zone after liver tumor ablation.
  
  
  METHODS
  Twenty-three patients (17 men and 6 women, range: 45-85 years old, mean age 65 years) with malignant liver tumors underwent ultrasound-guided percutaneous tumor ablation [radiofrequency (n = 14), microwave (n = 9)] followed by intravenous contrast-enhanced CBCT. Baseline multidetector computed tomography (MDCT) and peri-procedural CBCT images were compared. CBCT image quality was assessed as poor, good, or excellent. Image fusion was performed to assess tumor coverage, and quality of fusion was rated as bad, good, or excellent. Ablation zone volumes on peri-procedural CBCT and post-procedural MDCT were compared using the non-parametric paired Wilcoxon t-test.
  
  
  RESULTS
  Rate of primary ablation effectiveness was 100%. There were no complications related to ablation. Local tumor recurrence and new liver tumors were found 3 mo after initial treatment in one patient (4%). The ablation zone was identified in 21/23 (91.3%) patients on CBCT. The fusion of baseline MDCT and peri-procedural CBCT images was feasible in all patients and showed satisfactory tumor coverage (at least 5-mm margin). CBCT image quality was poor, good, and excellent in 2 (9%), 8 (35%), and 13 (56%), patients respectively. Registration quality between peri-procedural CBCT and post-procedural MDCT images was good to excellent in 17/23 (74%) patients. The median ablation volume on peri-procedural CBCT and post-procedural MDCT was 30 cm(3) (range: 4-95 cm(3)) and 30 cm(3) (range: 4-124 cm(3)), respectively (P-value > 0.2). There was a good correlation (r = 0.79) between the volumes of the two techniques.
  
  
  CONCLUSIONS
  Contrast-enhanced CBCT after tumor ablation of the liver allows early assessment of the ablation zone.
authors.affiliation: Mohamed Abdel-Rehim, Maxime Ronot, Annie Sibert, Valérie Vilgrain, Department of Radiology, APHP, University Hospitals Paris Nord Val de Seine, 92110 Clichy, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdel-Rehim
authors.affiliation: Mohamed Abdel-Rehim, Maxime Ronot, Annie Sibert, Valérie Vilgrain, Department of Radiology, APHP, University Hospitals Paris Nord Val de Seine, 92110 Clichy, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Ronot
authors.affiliation: Mohamed Abdel-Rehim, Maxime Ronot, Annie Sibert, Valérie Vilgrain, Department of Radiology, APHP, University Hospitals Paris Nord Val de Seine, 92110 Clichy, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Sibert
authors.affiliation: Mohamed Abdel-Rehim, Maxime Ronot, Annie Sibert, Valérie Vilgrain, Department of Radiology, APHP, University Hospitals Paris Nord Val de Seine, 92110 Clichy, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Vilgrain
mesh_terms: D061605:Administration, Intravenous; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation / Q000379:methods; D054893:Cone-Beam Computed Tomography; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media; C093233:iobitridol; D007472:Iohexol
keywords: Ablation; Cone beam computed tomography; Liver; Malignancies; Radiofrequency