Comprehensive neuraxis imaging in leptomeningeal metastasis: a retrospective case series

AIM: Quantify imaging abnormalities in a retrospective case series of patients with leptomeningeal metastasis (LM). METHODS: A total of 240 adult patients with LM (125 nonbrain solid tumor patients with positive cerebrospinal fluid [CSF] cytology; 40 nonbrain solid tumor patients with negative CSF cytology and positive MRI; and 50 lymphoma and 25 leukemia patients with positive CSF-flow cytometry) underwent brain and entire spine MRI and radioisotope CSF-flow studies prior to treatment. RESULTS: MRI was more often abnormal in solid tumors (40 CSF defined and 100% in MRI defined) compared with hematologic cancers (16-20%; p = 0.03). Similarly, CSF-flow studies was more often abnormal in solid tumors (25-28%) compared with hematologic cancers (10-20%; p = 0.04). MRI and flow-study abnormalities altered therapy in a third of solid tumors and 15% of hematologic cancers. CONCLUSION: Although imaging abnormalities are less often seen in hematologic cancers compared with solid tumor LM, imaging abnormalities frequently result in treatment alteration.