title: The diagnostic performance and added value of (18)F-FDG PET/CT in the detection of liver metastases in recurrent colorectal carcinoma patients.
abstract: OBJECTIVE
  The aim of this study was to assess the value of (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT in detection of liver metastases in patients with suspected recurrent colorectal carcinoma, as well as to compare diagnostic performance of (18)F-FDG PET/CT with conventional imaging methods (MDCT).
  
  
  METHODS
  This study included 73 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013, with suspicion of recurrence. The patients underwent (18)F-FDG PET/CT examination on a 64-slice hybrid PET/CT scanner (Biograph, TruePoint64, Siemens Medical Solutions, Inc. USA). Prior to (18)F-FDG PET/CT all patients underwent contrast-enhanced MDCT. Findings of (18)F-FDG PET/CT and MDCT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up over at least six months. Final diagnosis of liver metastases of colorectal cancer was made either by histopathological examination of specimen after biopsy or surgery, or based on clinical, laboratory and imaging evaluation during first six months after PET/CT scan.
  
  
  RESULTS
  In detection of liver metastases (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 83.3%, 95.3%, 92.6%, 89.1% and 90.4%, respectively. In addition, MDCT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy in detection of liver metastases of 60%, 88.4%, 78.3%, 76% and 76.7%, respectively. There was significant difference in sensitivity (83.3% vs 60%; P=0.045) between these two methods. In addition, significant difference was observed in accuracy between PET/CT and MDCT (90.4% vs 76.7%; P=0.016). The higher specificity in visualization of liver metastases was also achieved by (18)F-FDG PET/CT compared to MDCT (95.3% vs 88.4%), but this difference was not significant (P=0.37).
  
  
  CONCLUSIONS
  (18)F-FDG PET/CT was highly sensitive, specific and accurate method in detection of liver metastases in patients with suspected recurrent colorectal carcinoma in our study. This hybrid imaging showed superior diagnostic performance in evaluation of suspected colorectal cancer liver metastases compared to conventional imaging.
authors.affiliation: Center of Nuclear Medicine, Clinical Center of Serbia, Visegradska 26, 11000 Belgrade, Republic of Serbia. cale_odl@yahoo.com.
authors.forename: Strahinja
authors.initials: S
authors.lastname: Odalovic
authors.forename: Vera
authors.initials: V
authors.lastname: Artiko
authors.forename: Dragana
authors.initials: D
authors.lastname: Sobic-Saranovic
authors.forename: Milica
authors.initials: M
authors.lastname: Stojiljkovic
authors.forename: Milorad
authors.initials: M
authors.lastname: Petrovic
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Petrovic
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Kozarevic
authors.forename: Isidora
authors.initials: I
authors.lastname: Grozdic-Milojevic
authors.forename: Vladimir
authors.initials: V
authors.lastname: Obradovic