title: Evaluating Treatment Response of Radioembolization in Intermediate-Stage Hepatocellular Carcinoma Patients Using 18F-Fluoroethylcholine PET/CT.
abstract: The aim of this study was to evaluate (18)F-fluoroethylcholine PET/CT as a metabolic imaging technique for the assessment of treatment response to (90)Y radioembolization in patients with locally advanced hepatocellular carcinoma (HCC).
  
  
  METHODS
  Thirty-four HCC patients undergoing 78 (18)F-fluoroethylcholine PET/CT scans were identified for this study. Patients with initial or follow-up metastastic disease (n = 9) were excluded at the time point of the metastatic occurrence as well as patients with negative α-fetoprotein (AFP; n = 1), resulting in 24 patients and 57 scans that were eligible. All patients were scheduled for radioembolization and underwent 1 pretherapeutic and at least 1 posttherapeutic (18)F-fluoroethylcholine PET/CT scan. Volume-of-interest analysis and volume-of-interest subtractions were performed. Maximum, mean, and peak standardized uptake value (SUV) analysis was performed, and the total intrahepatic (18)F-fluoroethylcholine positive tumor volume (FEC-PTV) and tumor-to-background ratio were assessed. Statistical analysis was performed using a decreasing AFP of at least 20% as a standard of reference for therapy response including receiver-operating-characteristic analyses as well as descriptive and correlation analyses and multiple logistic regression.
  
  
  RESULTS
  Fourteen follow-up examinations were categorized as responder and 19 follow-up examinations as nonresponder. Absolute AFP values did not correlate with SUV parameters (P = 0.055). In receiver-operating-characteristic analyses, the initial mean SUV, Δmaximum SUV, and Δtumor-to-background ratio demonstrated the highest area under the curve, 0.84 (P = 0.009), 0.83 (P = 0.011), and 0.83 (P = 0.012), respectively, resulting in a positive prediction of 82%, 83%, and 91% at the respective cutoff points. When multiple logistic regression analysis was applied, this resulted in an area under the curve of 0.90 (P = 0.001), with a positive prediction of 94% and a sensitivity of 94%. The FEC-PTV did not reach significance in the presented dataset.
  
  
  CONCLUSIONS
  (18)F-fluoroethylcholine PET/CT demonstrates a high potential for follow-up assessment in the context of radioembolization in patients with locally advanced, but nonmetastatic, HCC and initially elevated AFP, possibly enabling early therapy monitoring independent of morphology.
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Hartenbach
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Nathalie L
authors.initials: NL
authors.lastname: Albert
authors.affiliation: Institute of Pathology, German Armed Forces Hospital Ulm, Ulm, Germany; and.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Hartenbach
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Albert
authors.initials: A
authors.lastname: Hirtl
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Mathias J
authors.initials: MJ
authors.lastname: Zacherl
authors.affiliation: Department of Clinical Radiology, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Paprottka
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Tiling
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria.
authors.forename: Marcus
authors.initials: M
authors.lastname: Hacker
authors.affiliation: Division of Nuclear Medicine, Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany alexander.haug@meduniwien.ac.at.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Haug
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000628:therapy*; D002794:Choline / Q000031:analogs & derivatives*; D004621:Embolization, Therapeutic / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D016896:Treatment Outcome; D000509:alpha-Fetoproteins
chemical_list: D019275:Radiopharmaceuticals; D000509:alpha-Fetoproteins; C448902:fluoroethylcholine; D002794:Choline
keywords: FEC; GI; PET; PET/CT; hepatocellular carcinoma; oncology; radioembolization; radionuclide; therapy