Efficiency of whole-body positron emission tomography/computed tomography using 18 F-Fluorodeoxyglucose in detecting the cause of elevated cancer antigen 125 serum level in treated ovarian cancer patients

Background Ovarian cancer is one of the leading causes of death in females worldwide. Early diagnosis and accurate staging are mandatory for proper management. Anatomic imaging and serum cancer antigen 125 (CA 125) measurement have been widely used for follow up of treated ovarian cancer patients to detect residual or recurrent neoplasia. The aim of this study was to assess the value of whole-body positron emission tomography/computed tomography using 18 F-Fluorodeoxyglucose ( 18 F-FDG PET/CT) in follow up of ovarian cancer patients presented with elevated CA 125 serum level. Results The current study was performed over a period of 2 years between March 2019 and March 2022. Seventy-six patients were included with history of treated ovarian cancer (underwent either surgical resection and/or received radio/chemotherapy) but were subsequently presented rising tumor marker CA-125 serum level (more than 35 U/ml). All patients underwent a 18 F-FDG PET/CT scanning on whole body. The FDG-PET results were correlated with histological findings, radiological or tumor marker/clinical follow-up. The patients with inconsistent findings were followed up with U/S, post contrast pelviabdominal CT, MRI or PET/CT 3–6 months later. The 18 FDG PET/CT scan was positive in 62 patients, and it was negative in 14 patients. Specificity, sensitivity, negative predictive value, as well as positive predictive value and diagnostic accuracy of integrated PET/CT, were found to be 92.3%, 96.3%, 96.1%, 85.7% and 98.4%, respectively. Conclusions 18 F-FDG PET/CT is a valuable imaging tool for assessment of ovarian cancer patients presented with elevated CA-125 tumor marker serum level.