Prognostic significance of 111indium-DTPA CSF flow studies in leptomeningeal metastases.

We assessed the clinical significance of interruption of CSF flow documented by radionuclide ventriculography (111Indium-DTPA CSF flow study) in patients with leptomeningeal metastases. Forty patients (25 men and 15 women) ranging in age from 6 to 70 years (median 38.5 years) with cytologically documented leptomeningeal metastases were demonstrated to have interruption of CSF flow by radionuclide ventriculography. All patients were treated with radiotherapy (30 Gy in 10 fractions) to the site of CSF obstruction after which intra-CSF chemotherapy (methotrexate or cytarabine followed by cytarabine or thio-TEPA if clinically indicated) was administered. Twenty patients (group 1) after radiotherapy to the site of CSF flow block demonstrated reestablishment of normal CSF flow. By contrast, 20 patients (group 2) treated in a similar manner had persistent CSF flow obstruction. All patients were treated with intraventricular chemotherapy. Median survival was 6 months in group 1 (range 3 to 15 months) compared with 1.75 months in group 2 (range 1 to 4 months) (p < 0.0001). Cause of death differed between groups with 20% of group 1 patients dying of progressive leptomeningeal disease compared with 70% of group 2 patients (p < 0.0006). In patients with leptomeningeal metastases and CSF flow obstruction, 111Indium-DTPA CSF flow studies predict patient survival and are useful in determining which patients would be candidates for intra-CSF chemotherapy administration.