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. 2007 Jun 7:5:64.
doi: 10.1186/1477-7819-5-64.

FDG-PET scan in patients with clinically and/or radiologically suspicious colorectal cancer recurrence but normal CEA

Affiliations

FDG-PET scan in patients with clinically and/or radiologically suspicious colorectal cancer recurrence but normal CEA

Ismet Sarikaya et al. World J Surg Oncol. .

Abstract

Background: Although frequently used for tumor surveillance, the sensitivity of carcinoembryonic antigen (CEA) to detect recurrent colorectal cancer (CRC) is not optimal. Fluorine 18-fluoro-2-deoxy-glucose-positron emission tomography (18F FDG-PET) scans promise to improve recurrent CRC detection. We aimed to review PET scans of patients with clinically and/or radiologically suspicious tumor recurrence but normal CEA.

Methods: A retrospective review of an electronic database of 308 patients with CRC who had PET scans was performed. Only PET studies of patients with normal CEAs and suspected tumor recurrence who had pathological verification were selected for further analysis. Thirty-nine patients met the inclusion criteria.

Results: PET was positive in 26 patients (67%) and normal in 13 (33%). Histopathologic evidence of tumor recurrence was seen in 27 of the 39 patients (69%). When correlated with histopathology, PET was true positive in 22 patients, false positive in 4, true negative in 8 and false negative in 5. Overall, the accuracy of PET was 76.9%, negative predictive value (NPV) was 61.5%, and positive predictive value (PPV) was 84.6%. PPV value of PET for liver metastases was 88.8% compared to 73.3% for local recurrence. In two patients with confirmed recurrence, CEA became positive 2 months after PET scan indicating earlier detection of disease with PET. The false positive PET findings were mainly in the bowel and were secondary to acute/chronic inflammation and granulation tissue. In 3 patients with false negative PET, histopathology was consistent with mucinous adenocarcinoma.

Conclusion: PET yields high PPV for recurrent CRC, particularly for liver metastases, in spite of normal CEA levels and should be considered early in the evaluation of patients with suspected tumor recurrence.

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Figures

Figure 1
Figure 1
PET scan and final pathology results of the patients who have clinically and/or radiologically suspicious tumor recurrence but normal CEA.
Figure 2
Figure 2
Transaxial, sagittal, and coronal PET/CT fusion images in a patient with prior left lobectomy. PET scan demonstrated a focal hypermetabolic activity within the liver at resectin margin with SUVmaxof 3.1 (arrow). Pathology demonstrated focal foreign body reaction with necrosis, organizing inflammation and fibrosis secondary to prior surgery.
Figure 3
Figure 3
Transaxial, sagittal, and coronal PET/CT fusion images demonstrating a ring-shaped liver lesion (arrow) with increased metabolic activity (SUVmax:5.5) surrounding a photopenic center in a patient previously treated with Yittrium-90 microspheres. CEA became positive two months after PET and subsequent pathology demonstrated tumor recurrence as well as nodal metastasis.

References

    1. Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin. 2007;57:43–66. - PubMed
    1. Zervos EE, Badgwell BD, Burak WE, Jr, Arnold MW, Martin EW. Fluorodeoxyglucose positron emission tomography as an adjunct to carcinoembryonic antigen in the management of patients with presumed recurrent colorectal cancer and nondiagnostic radiologic workup. Surgery. 2001;130:636–643. doi: 10.1067/msy.2001.116919. - DOI - PubMed
    1. Flamen P, Hoekstra OS, Homans F, Van Cutsem E, Maes A, Stroobants S, Peeters M, Penninckx F, Filez L, Bleichrodt RP, Mortelmans L. Unexplained rising carcinoembryonic antigen (CEA) in the postoperative surveillance of colorectal cancer: the utility of positron emission tomography (PET) Eur J Cancer. 2001;37:862–869. doi: 10.1016/S0959-8049(01)00049-1. - DOI - PubMed
    1. Maldonado A, Sancho F, Cerdan J, Lozano A, Mohedano N, Jimenez J, Moya F, Zomeno M. 16. FDG-PET in the Detection of Recurrence in Colorectal Cancer Based on Rising CEA Level. Experience in 72 Patients. Clin Positron Imaging. 2000;3:170. doi: 10.1016/S1095-0397(00)00082-0. - DOI - PubMed
    1. Flanagan FL, Dehdashti F, Ogunbiyi OA, Kodner IJ, Siegel BA. Utility of FDG-PET for investigating unexplained plasma CEA elevation in patients with colorectal cancer. Ann Surg. 1998;227:319–323. doi: 10.1097/00000658-199803000-00001. - DOI - PMC - PubMed