Diagnostic Performance of Post-Treatment F-18 FDG PET/CT for Detecting Recurrent Cervical Cancer

Background/Objectives: Cervical cancer recurrence after definitive treatment remains a major clinical challenge, and early detection may improve patient outcomes. This study evaluated the diagnostic performance of fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) for detecting recurrent cervical cancer according to clinical context. Methods: We retrospectively reviewed 1727 post-treatment PET/CT examinations obtained from 659 patients who achieved a complete response after definitive treatment between 2005 and 2024. After excluding 15 examinations that detected second primary malignancies, the recurrence-specific analysis included 1712 examinations from 654 patients. PET/CT findings were classified as true positive, true negative, false positive, or false negative based on histopathology or serial imaging follow-up. Generalized estimating equations were used to account for within-patient clustering. Subgroup analyses were performed according to histology, International Federation of Gynecology and Obstetrics (FIGO) 2009 stage, interval from treatment completion to PET/CT, and clinical context. Results: Of the 1712 examinations, 136 (7.9%) were true positive, 1525 (89.1%) were true negative, 43 (2.5%) were false positive, and 8 (0.5%) were false negative. Overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 94.4%, 97.3%, 76.0%, 99.5%, and 97.0%, respectively. Diagnostic performance was similar across histologic subtypes and FIGO stages. In routine follow-up settings without clinical suspicion of recurrence, PET/CT showed a high NPV (100.0%), whereas examinations performed for clinically suspected recurrence showed a high PPV (96.5%). Conclusions: These findings suggest that the diagnostic interpretation and clinical utility of post-treatment PET/CT may vary according to the clinical setting.