title: Response assessment of colorectal liver metastases with contrast enhanced CT/18F-FDG PET.
abstract: OBJECTIVE
  Evaluate the diagnostic performance of contrast enhanced CT/PET (ceCT/PET) in the response assessment of patients with colorectal cancer liver metastases.
  
  
  METHODS
  33 ce CT/PET studies of 19 patients with colorectal liver metastases were prospectively evaluated. All of them, 13 (68.4%) were males and 6 (31.6%) females. Mean age and range were 63 [42-78]. All patients were treated with neoadjuvant chemotherapy. In all cases post-therapy diagnostic confirmation of liver lesions was obtained. A ce CT PET/was obtained 1h after the injection of 370 MBq of 18F-FDG. Metabolic and morphologic studies were evaluated by two blinded nuclear physicians and radiologists respectively to assess the location, size and suspected diagnosis of lesions (benign or malignant). A combined assessment of both techniques was performed. The final diagnosis was established by histopathology or clinical/radiological follow-up greater than 6 months.
  
  
  RESULTS
  A total of 120 liver lesions were identified, 115 were malignant and 5 benign. From the malignant lesions, 105 were identified with the ceCT, 44 with the PET and 109 with ceCT/PET. All of the benign lesions were correctly classified with any of the three imaging techniques. The sensitivity of PET, ceCT and ceCT/PET were of 38%, 91% and 95% respectively and the specificity was 100% in all three of the diagnostic studies.
  
  
  CONCLUSIONS
  Administration of intravenous contrast in the PET/CT is mandatory to evaluate treatment response rate of liver metastases due to the limitations of isolated metabolic images in these cases.
authors: Department of Nuclear Medicine, University General Hospital, Ciudad Real, Spain. angarvice@yahoo.es
authors: Ana María
authors: AM
authors: García Vicente
authors: Esther
authors: E
authors: Domínguez Ferreras
authors: Victoria
authors: V
authors: Sánchez Pérez
authors: Víctor Manuel
authors: VM
authors: Poblete García
authors: José Carlos
authors: JC
authors: Villa Guzmán
authors: Fátima
authors: F
authors: Jiménez Aragón
authors: Maria Dolores
authors: MD
authors: Pineda Pineda
authors: Ceferino
authors: C
authors: Molino Trinidad
authors: Ángel
authors: Á
authors: Soriano Castrejón
mesh_terms: D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007479:Iopamidol / Q000031:analogs & derivatives*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary / Q000628:therapy; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013030:Spain; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C057937:iomeprol; D007479:Iopamidol