Retrospective analysis of patients with leptomeningeal disease (LMD) in the MRI era

Abstract

2070 Background: The leptomeninges are an increasingly frequent site of cancer relapse. The traditional gold-standard for diagnosis of LMD is CSF cytology, but MRI is now used routinely as a diagnostic tool; LMD has not been studied in the MRI era. Methods: Cases of metastatic LMD from 2002 through 2004 were obtained by querying a neurology database, as well as reviewing all patients with abnormal CSF cytology. Cases were diagnosed with LMD either by a malignant cytology or by LMD on imaging. Suspicious cases treated as LMD were also included. Results: 186 cases were collected; 149 had solid tumors and 37 hematopoietic. Median age was 56.6 years; median KPS was 70. The most common solid tumors were breast (64 patients), lung (47), GI (11) and melanoma (9). Of the hematopoietic tumors, 21 were lymphoma and 15 were leukemia. 53% of patients were diagnosed via imaging, 22% via cytology, and 25% via both. Cytology established the diagnosis more often in hematopoietic cancers (51% vs. 15%), while imaging identified LMD more often in solid tumors (65% vs. 11%). Of the 47 patients with complete neuraxis imaging and CSF cytology performed, 23% had negative cytology despite definite LMD on imaging, and 31% had negative imaging despite a positive cytology. Treatment included radiation therapy in 54%, intrathecal (IT) chemotherapy in 28%, and systemic chemotherapy in 17%; 21% received supportive care only because they had end-stage disease. Treatment patterns were similar between solid and hematopoietic tumor patients, except patients with hematopoietic tumors more often received IT chemotherapy (46% vs. 24%). Median survival in weeks for patients with hematopoietic tumors was 20.4 and for solid tumors was 9.9 (p =0.0005). Median survival in weeks for leukemia was 25.1, for lymphoma 19.9, for breast cancer 11.3, for lung cancer 9.7, and for melanoma 7.4. Conclusions: Diagnosis of LMD remains challenging, and a negative cytology or MRI does not exclude the disease. LMD remains a disease with very poor prognosis, though less so in hematopoietic than in solid tumors. In our series, there was no difference in survival between types of solid tumor, method of diagnosis, or type of treatment given. No significant financial relationships to disclose.