Differential diagnosis of pelvic masses with serum CA-125, ultrasound, and positron emission tomography

Koo, Ja Seong; Kim, Young Tae; Kim, Sung Hoon; Kim, Jae Wook; Kim, Jae Hoon; Park, Yong Won; Kim, Bok Ja; Nam, Eun Ji; Yun, Mi Jin

Abstract

OBJECTIVE
The purpose of this study was to evaluate whether positron emission tomography (PET) is more valid than transvaginal ultrasonography (TVS) or serum CA125 in differentiating malignant ovarian tumor from benign ovarian tumor.
METHODS
Fifty patients with adnexal tumor were evaluated with PET, TVS and serum CA 125 before surgery. PET was used to determine the uptake of FDG (18F-2-fluoro-2-deoxyglucose) for characterization of ovarian tumor. Sassone score was used as sonomorphological scoring system to distinguish from malignant to benign lesion. This scoring system is based on ovarian inner wall structure, wall thickness, septation, and echogenicity. Serum CA-125 levels were measured. After surgery, based on histopathologic findings, sensitivity, specificity, accuracy of each diagnostic modality at each cut-off value were calculated. And the validity of three diagnostic modalities was analysed further with receiver operating characteristics (ROC) curve.
RESULTS
In the sonographic evaluation of adnexal tumors, the sensitivity and specificity were 63% and 76% at the cut off level of 9 of Sassone score. With PET, both sensitivity and specificity was not improved respectively. The ROC curves show that PET does not provide statistically significant benefits to predict ovarian malignancy.
CONCLUSION
Our results suggested that CA-125 has no statistical significance and PET did not provide more significant additional diagnostic information than TVS for differentiation of malignant ovarian tumor from benign ovarian tumor.