The value of [18F]FDG PET/CT examination in the detection and differentiation of recurrent ovarian cancer

Background: The exact role of positron emission tomography with fluorine-18-deoxyglucose ([18F]FDG PET/CT) in an early diagnosis of relapsed ovarian cancer is not clearly defined. The aim of the study was to assess the value of [18F]FDG PET/CT in the detection and differentiation of recurrent ovarian cancer. Material and methods: Eighty-four patients with suspected recurrent ovarian cancer underwent [18F]FDG PET/CT examination. Results of PET/CT were analyzed taking into account clinical data of the patients, histological diagnosis, and 6-month follow-up. Results: The [18F]FDG PET/CT examinations showed abnormal findings in 67 patients (79.76%). There were 63 true positive results (75.00%), 14 true negative (16.67%), 4 false positive (4.76%), and 3 false negative (3.57%) results. Sensitivity, specificity, positive and negative predictive values of [18F]FDG PET/CT were 95%, 78%, 94%, and 82%, respectively. In patients with elevated serum Ca 125 concentration (n = 43), sensitivity and specificity of [18F]FDG PET/CT was 95.00% and 66.67%, respectively. Recurrence was confirmed in 22 (88.00%) of 25 patients referred for [18F]FDG PET/CT due to suspected relapse in imaging tests. Conclusions: A high frequency of recurrent ovarian cancer detected in the [18F]FDG PET/CT examinations due to increased Ca 125 concentration in patients without clinical symptoms and without changes in other imaging tests confirmed the usefulness of [18F]FDG PET/CT in such cases. In patients with suspected recurrent ovarian cancer implied in radiological findings, [18F]FDG PET/CT results in most cases differed from the original results of imaging examination. Our results showed high accuracy of [18F]FDG PET/CT in the evaluation of recurrent ovarian cancer and presented this diagnostic method as a useful tool in detecting and differentiating suspected lesions in this group of patients.