Diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions and staging ovarian cancer:: Correlation with transvaginal ultrasonography, computed tomography, and histology

Aims To (a) assess the accuracy of F-18-FDG PET/CT in distinguishing malignant from benign pelvic lesions, compared to transvaginal ultrasonography (TVUS) and (b) to establish the role of whole-body F-18-FDG PET/CT, compared to contrast enhanced computed tomography (CT), in staging patients with ovarian cancer. final pathological staging in 22/32 (69%) patients while CT results were concordant in 17/32 (53%) patients. CT incorrectly down-staged four out of six stage IV patients by missing distant metastasis in the liver, pleura, mediastinum, and in left supraclavicular lymph nodes, which were correctly detected by F-18-FDG PET/CT. Patients Fifty consecutive patients with a pelvic lesion, already scheduled for surgery on the basis of physical examination, TVUS, and serum Ca125 levels, were enrolled in the study. Patients' age ranged between 23 and 89 years (mean 64). All patients underwent TVUS including a colour Doppler study followed by a thorax and abdominal CT scan, and whole-body F-18-FDG PIET/CT within 2 weeks prior to surgery. Histological findings obtained at surgery were taken as the 'gold standard' to compare F-18-FDG PET/CT and TVUS, and F-18-FDG PET/CT vs. CT. When tissue analysis showed ovarian cancer, the accuracy of F-18-FDG PET/CT and CT were compared for the purpose of obtaining a precise staging. Results At surgery, the ovarian lesions were malignant in 32/50 patients (64%) and benign in the remaining 18/50 patients (36%). The sensitivity, specificity, NPV, PPV and accuracy of F-18-FDG PET/CT were 87%,100%, 81 %, 100% and 92%, respectively, compared with 90%, 61%, 78%, 80% and 80%, respectively, for TVUS. In staging ovarian cancer, 18F-FDG PET/CT results were concordant with Conclusion PET/CT with 18F-FDG provides additional value to TVUS for the differential diagnosis of benign from malignant pelvic lesions, and to CT for the staging of ovarian cancer patients. Nucl Med Commun 28:589-595 (c) 2007 Lippincott Williams & Wilkins.