Imaging practices in the diagnosis and management of gestational trophoblastic disease: an assessment.

This article discusses several of the problems associated with imaging in gestational trophoblastic disease based on critical assessment of the literature. (1) Ultrasound scanning has revolutionized the diagnosis of abnormalities of the first trimester of pregnancy. Fetal death can now be diagnosed as early as 6 weeks of gestation, resulting in uterine evacuation. Histologic and genetic analysis of the conceptus therefore becomes essential as otherwise the diagnosis of hydatidiform mole and other chromosomal anomalies of the fetus may be missed. If such investigation is not performed, human chorionic gonadotropin should be measured after early pregnancy loss to make sure it is negative. (2) The routine use of ultrasound or Doppler flow to follow hydatidiform mole regression is clinically and fiscally counterproductive. (3) To diagnose lung metastases and assess the FIGO risk factor score, chest X-ray is mandated. However, CT scanning may show lung micrometastases indicative of possible chemotherapy resistance. (4) positron emission tomography scanning in trophoblastic neoplasia needs to be validated. Previous studies have been small, with some 30% false positive and false negative findings. The International Society for the Study of Trophoblastic Disease should undertake carefully designed prospective studies to validate imaging practices in the management of trophoblastic disease.