OC23.04: Does spherical sample size affect the performance of 3D power Doppler indexes for predicting malignancy in vascularized adnexal masses?

Abstract

Methods: Patients with persistent adnexal mass with a risk of major malignancy of 3%, based on ultrasound examination were included in this prospective study. Predefined ultrasound morfological and Doppler characteristics were used by an expert sonologist to determine the nature (benign o malignant) of the mass. Border-line masses were considered as malignant. All patients underwent combined PET/CT with F-fluorodeoxyglucose (FDG). The ultrasound and PET/CT findings were correlated with final hystological diagnosis. Results: Sixty one patients were included in this series. Hystologically there were 25 benign, 27 malignant and 9 border-line masses. All malignant masses were correctly classified at transvaginal sonography, while at PET/CT 25 of those demonstrated metabolic activity and 2 lesions resulted false negative. Among hystologically benign lesions transvaginal ultrasound was accurate in 21 (4 false positive), the same as PET/CT. The borderline tumours were correctly identified at sonography as suspected malignant, though PET/TC was predictive in only 1 of 9. Moreover, 2 malignant and 7 border-line masses revealed silent at PET/CT were mucinous tumours. Conclusions: These data show that PET/CT does not provide additional information compared with expert transvaginal ultrasound. It is likely that some malignant mucinous lesions and especially border-line tumours do not show FDG uptake.