Does chest CT matter in the staging of GTN?

The term gestational trophoblastic neoplasia (GTN) encompasses a variety of uncommon neoplastic conditions arising from the placental trophoblast. Staging of GTN using the FIGO 2000 system divides patients into low and high risk groups and treatment of these patients depends on the risk score achieved. Chest x-ray (CXR) is recommended to assess lung metastases; however the significance of lung metastases seen on computed tomography (CT) scan of the chest is uncertain. The aim of this study is to determine whether or not CT scan significantly influences outcome of patients with GTN in terms of a need to change to second line chemotherapy or time to remission.

96 patients with low risk metastatic GTN and 102 patients with low risk non-metastatic GTN who had been staged at Weston Park Hospital, Sheffield were identified. Staging according to the FIGO 2000 system was retrospectively calculated to assess what impact using CT scan would have had on the scores of those patients. Rates of first line treatment failure and time to remission were assessed and comparisons made.

There was no significant difference in the need to change to second line chemotherapy or in time to remission in those patients with metastatic GTN whose score or risk was changed when CT scan was used in place of CXR. Low risk patients with metastatic disease were, however, significantly more likely to need to change to second line chemotherapy than patients with non-metastatic GTN although there was no significant difference in time to remission between these groups.

CT scan of the chest used instead of CXR in the staging of GTN does not alter outcome.