Prognostic relevance of F-18 fluorodeoxyglucose positron emission tomography and computed tomography in molar pregnancy before evacuation.

OBJECTIVE

To assess prognostic significance of tumor metabolic activity of molar tissue by preevacuation F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) in patients clinically diagnosed with molar pregnancy.

STUDY

DESIGN

A total of 11 consecutive patients with clinical diagnosis of molar pregnancy before evacuation were enrolled. After evacuation of molar tissue, histopathologic findings and clinical follow-up were used as reference standards for the study.

RESULTS

Six patients, 5 with complete and 1 with partial hydatidiform mole, had good outcome and normalization of beta-human chorionic gonadotropin (beta-hCG) levels within 5-7 weeks of evacuation. In the other 5 patients, serial measurements showed persistently and/or progressively elevated beta-hCG serum levels. These patients were treated with first-line single methotrexate or second-line etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine (EMA/CO) chemotherapy regimen. Standardized uptake value of molar tissue within the uterus in patients with persistently/progressively elevated beta-hCG levels was significantly higher than that in patients whose serum beta-hCG levels normalized after evacuation of molar tissue.

CONCLUSION

Preliminary results suggest that F-18 FDG uptake within the uterus assessed by preevacuation PET/CT is predictive for probability of high-risk features of gestational trophoblastic disease or choriocarcinoma in patients with molar pregnancy.