title: The impact of PET/CT on the management of hepatic and extra hepatic metastases from gastrointestinal cancers.
abstract: OBJECTIVE
  To investigate the efficacy of positron emission tomography/computed tomography (PET/CT) in detection and management of hepatic and extrahepatic metastases from gastrointestinal cancers.
  
  
  METHODS
  Between February 2008 and July 2010, patients histopathologically diagnosed with gastrointestinal cancer and showing suspected metastasis on CT screening were subsequently evaluated with PET/CT. All patients were subgrouped according to histopathological origin and localization of the primary tumor. Localization of gastrointestinal cancers was further specified as lower gastrointestinal system (GIS), upper GIS, or hepato-pancreato-biliary (HPB). Both accuracy and impact of CT and PET/CT on patient management were retrospectively evaluated.
  
  
  RESULTS
  One hundred and thirteen patients diagnosed histopathologically with gastrointestinal cancers were retrospectively evaluated. Seventy-nine patients had adenocarcinoma and 34 patients other gastrointestinal tumors. Forty-one patients were in the upper GIS group, 30 patients in the HPB group, and 42 patients in the lower GIS group. Evaluation the diagnostic performance of PET/CT for suspected metastasis according to histopathological origin of the tumor, revealed that the sensitivity of PET/CT - although statistically not different - was higher in adenocarcinomas than in non-adenocarcinomas (90% (95% CI, 0.78-0.96) vs. 71.4% (95% CI, 0.45-0.88), P=0.86). The specificity was not significantly different (85.7% (95% CI, 0.70-0.93) vs. 85% (95% CI, 0.63-0.94), P=1.00). In the overall patient group; CT was significantly more sensitive than PET/CT for detection of hepatic metastases (94.7% vs. 78.9%, P=0.042), whereas PET/CT was significantly more specific than CT (48% vs. 98.7%, P<0.001). In subgroup analysis, sensitivity was not significantly different (P>0.05) but specificity was significantly higher in PET/CT than CT (P<0.05). The specificity of PET/CT was highest in upper GIS (100%) and HPB (100%) subgroups. In the overall patient group; for detection of extrahepatic metastasis, the sensitivity of CT (75%) and PET/CT (87.5%) showed no significant difference (P=0.437). However, PET/CT was significantly more specific than CT (88.7% vs. 70.4%, P=0.007). In subgroup analysis, no significant difference was found between CT and PET/CT either in sensitivity or in specificity (P>0.05). The specificity of PET/CT was highest in the lower GIS subgroup (93%). The management of 45 patients (39.8%) was revised after PET/CT evaluation.
  
  
  CONCLUSIONS
  PET/CT has a higher specificity than CT in detecting suspected hepatic and extrahepatic metastases of gastrointestinal cancers, and has an impact of nearly 40% on changing patient management strategies.
authors: Kartal Kosuyolu High Specialty Training and Research Hospital, Department of Gastrointestinal Surgery, Istanbul, Turkey. Electronic address: erdal066@yahoo.com.
authors: Erdal
authors: E
authors: Polat
authors: Sakarya University, Faculty of Medicine, Department of General Surgery, Sakarya, Turkey.
authors: Erdal Birol
authors: EB
authors: Bostanci
authors: Turkiye Yuksek Ihtisas Teaching and Research Hospital, Department of Gastroenterological Surgery, Ankara, Turkey.
authors: Erol
authors: E
authors: Aksoy
authors: Sakarya University, Faculty of Medicine, Department of General Surgery, Sakarya, Turkey.
authors: Kerem
authors: K
authors: Karaman
authors: Ataturk Teaching and Research Hospital, Department of Nuclear Medicine, Ankara, Turkey.
authors: Nilufer Yildirim
authors: NY
authors: Poyraz
authors: Sevket Yilmaz Training and Research Hospital, Department of General Surgery, Bursa, Turkey.
authors: Ugur
authors: U
authors: Duman
authors: Ankara University, Faculty of Medicine, Department of Biostatistics, Ankara, Turkey.
authors: Zeynep Biyikli
authors: ZB
authors: Gencturk
authors: Medeniyet University, Faculty of Medicine, Department of General surgery, Istanbul, Turkey.
authors: Sinan
authors: S
authors: Yol
mesh_terms: D004067:Digestive System Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed tomography; Gastrointestinal cancer; Metastasis; Positron emission tomography