Diagnostic value of integrated ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography in recurrent epithelial ovarian cancer: accuracy of patient selection for secondary cytoreduction in 134 patients

The aim of this study was to evaluate the diagnostic value of integrated ¹⁸F-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) for suspected recurrence of epithelial ovarian cancer (EOC) with non-disseminated lesions. We retrospectively reviewed the medical records of recurrent EOC patients who underwent secondary cytoreduction from January 2000 to December 2013. A total of 134 patients underwent secondary cytoreduction after imaging with either ¹⁸F-FDG-PET/CT or contrast-enhanced computed tomography (CECT). In a patient-based analysis of 134 patients, 124 (92.5%) were confirmed to be positive for malignancy. Among 72 patients with suspected non-disseminated recurrence on ¹⁸F-FDG-PET/CT, 65 (89.0%) were confirmed to have recurrence, giving 98.5% sensitivity, 87.7% accuracy, and 88.9% positive predictive value (PPV). In the 65 patients with recurrence, residual tumor remained in 14 patients, giving an accuracy of patient selection for secondary cytoreduction of 69.4% (50/72) and it is higher than that of CECT (64.0%). In 169 lesions removed from patients who underwent preoperative ¹⁸F-FDG-PET/CT, 135 (79.9%) were confirmed to be positive for malignancy and 124 were accurately detected by ¹⁸F-FDG-PET/CT, giving 91.9% sensitivity, 81.1% accuracy, and 85.5% PPV. Foreign body granuloma was found in 33.3% of 21 lesions with false-positive ¹⁸F-FDG-PET/CT findings (7/21). The mean preoperative cancer antigen 125 (CA-125) level in false-positive patients was 28.8 U/mL. Compared with CECT, ¹⁸F-FDG-PET/CT shows higher sensitivity in lesion-based analysis and better accuracy of patient selection for secondary cytoreduction. However, there is still a need for integration of the results of ¹⁸F-FDG-PET/CT, CECT, and CA-125 levels to aid treatment planning.