The role of FDG-PET/CT in the detection of recurrent colorectal cancer

Eur J Nucl Med Mol Imaging. 2006 Jul;33(7):779-84. doi: 10.1007/s00259-006-0072-z. Epub 2006 Mar 25.


Purpose: The conventional diagnostic techniques used to assess recurrence of colorectal cancer (CRCR) often yield unspecific findings. Integrated FDG-PET/CT seems to offer promise for the differential diagnosis of benign and malignant lesions. The aim of this study was to compare the value of FDG-PET and PET/CT in the detection of CRCR subsequent to colonic resection or rectal amputation.

Methods: The population for this retrospective study comprised 84 patients with suspected CRCR. The sensitivity, specificity and accuracy of PET and PET/CT were calculated for (a) intra-abdominal extrahepatic recurrences, (b) extra-abdominal and/or hepatic recurrences and (c) all recurrences, and tumour marker levels were analysed.

Results: The sensitivity, specificity and overall accuracy of PET in detecting intra-abdominal extrahepatic CRCR were 82%, 88% and 86%, respectively, compared with 88%, 94% and 92%, respectively, for PET/CT. The corresponding figures for detection of extra-abdominal and/or hepatic CRCR were 74%, 88% and 85% for PET and 95%, 100% and 99% for PET/CT. Considering the entire population, the sensitivity, specificity and overall accuracy of PET were 80%, 69% and 75%, respectively, compared with 89%, 92% and 90%, respectively, for PET/CT. FDG-PET/CT examination correctly detected 40 out of a total of 45 patients with CRCR. Two of five patients with falsely negative FDG-PET/CT findings had local microscopic recurrences and one had miliary liver metastases. Of 39 patients without CRCR, three showed false positive FDG-PET/CT results. Two of these cases were due to increased accumulation in inflammatory foci in the bowel wall, while one was due to haemorrhaging into the adrenal gland.

Conclusion: FDG-PET/CT appears to be a very promising method for distinguishing a viable tumour from fibrous changes, thereby avoiding unnecessary laparotomy.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / surgery*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnosis*
  • Neoplasm Recurrence, Local / prevention & control*
  • Positron-Emission Tomography / methods*
  • Prognosis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Subtraction Technique
  • Tomography, X-Ray Computed / methods*