Clinical Value of Combining 18 F-FDG PET/CT and Routine Serum Tumor Markers in The Early Detection of Recurrence Among Follow-up Patients Treated for Cervical Squamous Cell Carcinoma.

Objective: The purpose of this retrospective study was to investigate the role of 18F-Fluorodeoxyglucose Positron Emission Tomography (18 F-FDG PET/CT) and evaluate if combined elevated serum tumor markers levels improve the accuracy of 18 F-FDG PET/CT in detecting recurrence of cervical squamous cell carcinoma. Methods: A total number of 42 patients who were treated for cervical squamous cell carcinoma and had underwent 18 F-FDG PET/CT for suspected recurrence of cervical cancer were retrospectively reviewed in this study and their clinical, pathological and serological data were collected and analyzed. The clinical value of combining 18 F-FDG PET/CT with serum tumor markers was investigated. Results: Among the 42 patients, 18 F-FDG PET/CT was true positive in 25 (59.5%), false positive in 5 (11.9%), true negative in 12 (28.5%) and false negative in none. The overall patient-based sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 18 F-FDG PET/CT in detecting recurrent cervical cancer were 100%, 70.6, 88.1%, 83.3%, and 100%, respectively. The accuracy of 18 F-FDG PET/CT with combined squamous cell carcinoma antigen (SCC Ag) and carcinoembryonic antigen (CEA) elevation was 100% compared to only SCC Ag elevation and only CEA elevation, 90% and 33.3%, respectively. The positive predictive value of a positive 18 F-FDG PET/CT with combined SCC Ag and CEA elevation was 100% for detection of recurrent cervical cancer. Also, the negative predictive value of a negative 18 F-FDG PET/CT combined with normal SCC Ag and CEA levels was 100%. Conclusion: 18 F-FDG PET/CT is highly sensitive in the diagnosis of recurrent cervical cancer. When 18 F-FDG PET/CT is associated with both SCC Ag and CEA elevation or only SCC Ag elevation, the accuracy is increased but not when associated with only CEA elevation. Positive 18 F-FDG PET/CT associated with both tumor markers elevation can precisely predict recurrence. Moreover, normal levels of both tumor markers with a negative 18 F-FDG PET/CT result may clinically reassure that a recurrence is absent.