title: Diagnostic accuracy of serial CT/magnetic resonance imaging review vs. positron emission tomography/CT in colorectal cancer patients with suspected and known recurrence.
abstract: OBJECTIVE
  This study examined the sensitivity and specificity of CT/magnetic resonance imaging serial review compared to fluoro-2-deoxy glucose positron emission tomography-CT scanning to optimize colorectal cancer follow-up.
  
  
  METHODS
  Using standardized proformas, three blinded radiologists reviewed serial CT and magnetic resonance imaging in suspected cases of colorectal cancer recurrence in patients undergoing fluoro-2-deoxy glucose positron emission tomography-CT imaging.
  
  
  RESULTS
  Fifty eligible patients were included in the review. On follow-up, 23 patients had positive and 27 patients had negative diagnoses for colorectal cancer recurrence. Serial imaging review reduced the number of equivocal studies from 20 to 4 and unexplained carcinoembryonic antigen elevations from 17 to 10. Using fluoro-2-deoxy glucose positron emission tomography-CT, the number of equivocal studies reduced from 20 to 6 and unexplained carcinoembryonic antigen elevations reduced from 17 to 10. Fluoro-2-deoxy glucose positron emission tomography-CT altered management in 8 percent of patients (4/50, 95 percent CI, 0-16 percent). No significant differences were found between accuracy, sensitivity and specificity upon comparison of serial imaging review and fluoro-2-deoxy glucose positron emission tomography-CT in detecting recurrent disease. Extra information was demonstrated on 18 fluoro-2-deoxy glucose positron emission tomography-CT compared to serial imaging review in 8 of 50 patients and one patient had a positive incidental finding.
  
  
  CONCLUSIONS
  With suspected recurrence, we recommend undertaking serial imaging review with careful correlation of suspicious findings with previous studies. Fluoro-2-deoxy glucose positron emission tomography-CT imaging was useful when findings remain equivocal after serial imaging review for colorectal cancer recurrence.
authors.affiliation: The Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom.
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Potter
authors.forename: Janet E
authors.initials: JE
authors.lastname: Husband
authors.forename: Sasha L
authors.initials: SL
authors.lastname: Houghton
authors.forename: Karen
authors.initials: K
authors.lastname: Thomas
authors.forename: Gina
authors.initials: G
authors.lastname: Brown
mesh_terms: D002272:Carcinoembryonic Antigen / Q000032:analysis; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000175:diagnosis; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D002272:Carcinoembryonic Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18