Significance of chest computed tomography findings in the evaluation and treatment of persistent gestational trophoblastic neoplasia.

OBJECTIVE To evaluate whether chest computed tomography (CT) findings in patients with persistent gestational trophoblastic neoplasia (GTN) and a negative chest roentgenogram (CXR) significantly influence clinical outcome and to determine potential clinical predictors of pulmonary micrometastasis STUDY DESIGN The charts of 201 patients with nonmetastatic GTN (International Federation of Gynecology and Obstetrics [FIGO] stage I) receiving primary treatment with methotrexate (MTX) infusion between December 1985 and December 2000 were reviewed, and data were collected on age, gravidity and parity, FIGO stage, histologic diagnosis, metastatic disease, radiologic findings, surgery, presenting human chorionic gonadotropin (hCG) level, total number of chemotherapy courses and chemotherapeutic agents required to reach remission, and time to remission. The chi2, regression, Kaplan-Meier and log-rank tests were utilized to evaluate the correlation of chest CT with CXR findings, histology of antecedent pregnancy, presenting hCG level, chemotherapeutic requirements and time to remission. RESULTS Of 30 patients with a negative CXR, 13 (43.3%) had chest CT positive for micrometastasis. Histology of the antecedent pregnancy and mean presenting hCG did not correlate with the chest CT result. There was no significant difference between patients with positive or negative chest CT results in the requirement for > 1 dose of MTX or for additional chemotherapeutic agents. There also was no significant difference in time to remission by chest CT status. Regression analysis using histologic diagnosis, presenting hCG level, age, gravidity and parity as covariates did not reveal any clear risk factors for pulmonary micrometastasis. CONCLUSION It has been suggested that GTN patients with micrometastases identified on chest CT only are at increased risk of requiring > 1 dose of MTX or of requiring additional chemotherapeutic agents. Our data suggest that chest CT alone is not predictive of clinical outcome. Furthermore, the presence of micrometastases does not correlate with hCG level or histologic diagnosis, and there are no clear risk factors for pulmonary micrometastases.