Doppler Ultrasound in Post-Molar Gestational Trophoblastic Neoplasia

Objectives: To evaluate the role of Doppler ultrasound in prediction and follow up during management of gestational trophoblastic neoplasia (GTN). Methods: The study was performed at Oncology Unit, Maternity Hospital, Ain Shams University in the period from November 2015 to December 2018. Forty cases of complete mole, after evacuation and follow up of serum human chorionic gonodotrophin (β-hCG) titre until it reached zero level (group I) and forty post molar GTN cases (group II) were included in the study. Doppler ultrasound of the subendometrial and intramural blood flow was done for all cases of group I and II. Doppler included two dimensional and three dimensional power Doppler indices. Group II received Methotrexate (MTX) and folinic acid in a dose of 8-day MTX-FA regimen. Doppler follow up for six months of group II concurrently with the chemotherapy regimen was done. Results: A statistically significant difference was found between group I and II regarding initial readings of all Doppler parameters. Follow up for 6 months of GTN cases revealed progressive statistically significant decrease of intramural and subendometrial three dimensional power Doppler (3DPD) indices, while there was a significant increase in two dimensional (2D) Doppler parameters. Four cases were resistant to Methotrexate chemotherapy. Cut off values were determined for prediction of GTN. Multivariate analysis revealed that the most predictive parameter was the subendometrial pulsatility index (PI), odds ratio = 10.63 (95% CI: 1.30 - 86.89). The cut-off point for sub-endometrial PI was: 2.05 (AUC, 90%; sensitivity, 88%; specificity, 76%, PPV 78%, and NPV 86%) with a diagnostic accuracy of 87%. To and Fro sign may be considered a pathognomonic intramural ultrasound sign for prediction of GTN chemo-resistance or choriocarcinoma. Conclusion: Cut off values for Doppler parameters can be used for early predication of GTN. Doppler ultrasound indices can be used during follow up of GTN cases concurrently with serum β-hCG to monitor the response to treatment.