title: DIAGNOSTIC ROLE OF FLUORINE-18 (18F) FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY COMPUTED TOMOGRAPHY IN DETECTING RECURRENT DISEASE IN PATIENTS WITH COLORECTAL CANCER AND ELEVATED CARCINOEMBRYONIC ANTIGEN.
abstract: BACKGROUND
  Early detection of recurrence is an important factor for long term survival of patients with colorectal cancer. Measurement of serum levels of carcinoembryonic antigen has been commonly used in the postoperative surveillance of colorectal cancer. The purpose of this study was to evaluate the ability of positron emission tomography-computed tomography to detect pathological substrate of elevated serum carcinoembryonic antigen in patients with colorectal cancer.
  
  
  METHODS
  The patients with colorectal cancer who underwent curative surgical resection and/ or chemotherapy, who were found in our database, were analyzed retrospectively. Forty-eight 18F-fluorodeoxyglucose positron emission tomography-computed tomography studies including 45 patients (14 women, 31 men; mean age: 62.93 years) with elevated serum, carcinoembryonic antigen levels, which had been performed between January 2011 and January 2014, were evaluated. Serum levels of carcinoembryonic antigen were measured within 3 months after positron emission tomography-computed tomography examination. Final diagnosis of recurrence was made by histopathological findings, radiology studies or clinical follow-up.
  
  
  RESULTS
  Recurrences were diagnosed in 37 patients, the prevalence being 77.1%. Liver metastases were found in 18 patients, abdominal, pelvic and/or mediastinal lymph nodes were positive in 19 patients, 11 patients had loco regional recurrences and 4 patients had pulmonary metastasis, and bone metastases were found in one patient. One patient was diagnosed with metastasis in scar tissue. The overall sensitivity and specificity of positron emission tomography-computed tomography was 90.24% and 71.42%, respectively. The positive and negative predictive values were 94.87% and 55.56%, respectively.
  
  
  CONCLUSIONS
  18F-fluorodeoxyglucose positron emission tomography-computed tomography is a powerful tool that could be used in determining colorectal cancer recurrence in patients with elevated carcinoembryonic antigen levels and could have an important clinical impact on the management in patients with suspected recurrent colorectal cancer.
authors.forename: Emil
authors.initials: E
authors.lastname: Matovina
authors.forename: Jasna
authors.initials: J
authors.lastname: Mihailović
authors.forename: Katarina
authors.initials: K
authors.lastname: Nikoletić
authors.forename: Dolores
authors.initials: D
authors.lastname: Srbovan
mesh_terms: D000328:Adult; D000368:Aged; D002272:Carcinoembryonic Antigen / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D002272:Carcinoembryonic Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18