title: 18F-FDG PET/CT Is an Immediate Imaging Biomarker of Treatment Success After Liver Metastasis Ablation.
abstract: The rationale of this study was to examine whether (18)F-FDG PET/CT and contrast-enhanced CT performed immediately after percutaneous ablation of liver metastases are predictors of local treatment failure at 1 y.
  
  
  
  This Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved retrospective study reviewed 25 PET/CT-guided thermal ablations performed from September 2011 to March 2013 on 21 patients (11 women and 10 men; mean age, 56.8 y; range, 35-79 y) for the treatment of liver metastases (colorectal, n = 23; breast, n = 1; and sarcoma, n = 1). One to 3 tumors (mean size, 2.3 cm; range, 0.7-4.6 cm; mean SUVmax, 22.7; range, 9.5-77.1) were ablated using radiofrequency (n = 16) or microwave (n = 9) energy in a single session. Immediate-postablation enhanced CT and PET/CT scans were qualitatively evaluated by 2 reviewers independently, and the results were compared with clinical and imaging outcome at 1 y. The PET/CT scans were also analyzed to determine tissue radioactivity concentration (TRC) from 3-dimensional regions of interest in the ablation zone, the margin, and the surrounding normal liver to calculate a TRC ratio, which was then compared with outcome at 1 y. Receiver operating characteristics (ROC) were used, and the maximal-accuracy threshold in predicting recurrence was calculated.
  
  
  
  Eleven (44%) of the 25 tumors recurred within 1 y. Enhanced CT did not significantly correlate with recurrence (P = 0.288). Accuracy was 64% (16/25), and the area under the ROC curve was 0.601 (95% confidence interval [95% CI], 0.387-0.789). The accuracy of the qualitative analysis of (18)F-FDG PET was 92% (23/25) (P < 0.001), and the area under the ROC curve was 0.929 (95% CI, 0.740-0.990). The mean TRC ratio was 40.6 in the recurrence group (SD, 9.2; range, 29.3-53.9) and 15.9 in the group without recurrence (SD, 7.3; range, 3-27.3). A TRC ratio of 28.3 predicted recurrence at 1 y with 100% accuracy (25/25) (P < 0.001), and the area under the ROC curve was 1 (95% CI, 0.863-1).
  
  
  
  Immediate PET/CT accurately predicts the success of liver metastasis ablation at 1 y and is superior to immediate enhanced CT.
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York Department of Radiology, Pellegrin Hospital, Bordeaux, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Cornelis
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Vlasios
authors.initials: V
authors.lastname: Sotirchos
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Elena
authors.initials: E
authors.lastname: Violari
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Constantinos T
authors.initials: CT
authors.lastname: Sofocleous
authors.affiliation: Department of Radiology, Molecular Imaging and Therapy Service, Memorial Sloan Kettering Cancer Center, New York, New York; and.
authors.forename: Heiko
authors.initials: H
authors.lastname: Schoder
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Durack
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Siegelbaum
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Majid
authors.initials: M
authors.lastname: Maybody
authors.affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: John
authors.initials: J
authors.lastname: Humm
authors.affiliation: Department of Radiology, Interventional Radiology Service, Memorial Sloan Kettering Cancer Center, New York, New York solomons@mskcc.org.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Solomon
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D000072078:Positron Emission Tomography Computed Tomography; D049268:Positron-Emission Tomography; D015642:Radiology, Interventional; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: PET/CT; imaging biomarkers; interventional radiology; thermal ablation; treatment failure