Neuraxis imaging in leptomeningeal metastasis: A retrospective case series.

Abstract

2046 Background: (and Objective) Leptomeningeal metastasis (LM) is a central nervous system metastatic complication of cancer that affects the entire neuraxis. Quantify imaging (brain and spine MRI and radio-isotope cerebrospinal fluid [CSF] flow study) abnormalities in a retrospective case series of patients with LM. Methods: 240 adult patients with LM (125 non-brain solid tumor patients with positive CSF cytology; 40 non-brain solid tumor patients with negative CSF cytology; 50 lymphoma and 40 leukemia patients with positive CSF flow cytometry) underwent prior to treatment brain and entire spine MRI and radio-isotope CSF flow studies (FS). Results: Neuraxis MRI in pathologically defined patients was more often normal in hematologic tumors (80-84%) compared to solid tumors (60%). Similarly, FS was more often normal in hematologic tumors (90-92%) compared to solid tumors (72-75%). However, neuraxis MRI and FS abnormalities (i.e. CSF flow obstruction; nodular subarachnoid or parenchymal disease; hydrocephalus) altered therapy by requiring CSF diversion, site specific radiotherapy, systemic chemotherapy or recommending no further therapy in one third of CSF cytology positive solid tumors and 15% of CSF flow cytometry positive hematologic tumors. Conclusions: Notwithstanding less frequent imaging abnormalities in hematologic tumors, similar to solid tumors imaging abnormalities frequently result in treatment alteration for patients with LM. Consequently, neuraxis imaging is recommended in both tumor categories in patients being considered for LM-directed and in particular intra-CSF chemotherapy treatment.