Utility of 18F-FDG PET/CT in follow-up of patients with low-grade serous carcinoma of the ovary

• PET/CT may impact clinical management in the setting of low-grade serous carcinoma in approximately 30% of patients.
• PET/CT may be a useful tool in the detection of low-grade serous carcinoma recurrence.
• Total lesion glycolysis may predict poorer overall survival after recurrence.

ObjectiveOvarian low-grade serous carcinoma (LGSC) is a rare and indolent tumor. The utility of 18F-FDG PET/CT in monitoring patients with LGSC has not been established. We assessed the accuracy and clinical impact of 18F-FDG PET/CT in patients with ovarian LGSC after initial treatment.MethodsA retrospective analysis was performed on patients with ovarian LGSC who had undergone 18F-FDG PET/CT scans during follow-up after primary treatment. The impact of 18F-FDG PET/CT on the management plan was assessed. The sensitivity, specificity, and accuracy of 18F-FDG PET/CT findings in the detection of recurrence were calculated. Total lesion glycolysis (TLG) was determined to assess metabolic activity of tumors. Potential prognostic factors for disease-free and overall survival after recurrence were assessed.ResultsForty-eight patients were included in the analysis, 39 with recurrent disease and 9 without recurrence. A total of 91 18F-FDG PET/CT scans were performed, and 30% of these (27/91) had an impact on the management plan. Sensitivity, specificity, and accuracy in the detection of LGSC recurrence were 94%, 100%, and 97%, respectively, for 18F-FDG PET/CT; 89%, 95%, and 93%,respectively, for CT; and 68%, 89%, and 73%, respectively, for serum CA-125. There was no significant difference in sensitivity between PET/CT and CT. Survival after recurrence was poorer in patients with a TLG value greater than 67.7 g.Conclusions18F-FDG PET/CT may provide useful information during the follow-up of patients with LGSC after initial treatment. TLG may be a predictor of survival after recurrence.