LEPTOMENINGEAL METASTASES - EVALUATION BY GADOLINIUM-ENHANCED SPINAL MAGNETIC-RESONANCE-IMAGING

Background: Leptomeningeal metastases are common in patients with meta static systemic cancer or certain primary brain tumors. They may be un suspected clinically and may be missed by cerebrospinal fluid (CSF) cy tology. We undertook a retrospective study of the diagnostic value of gadolinium enhanced spinal MR imaging in patients with known or at hig h risk for leptomeningeal metastases (LM). Material and methods: Ninet y-six gadolinium enhanced MR examinations of the whole spine were perf ormed in 61 patients (26 primary central nervous system tumors, 20 sol id tumors and 15 lymphoproliferative neoplasms). All patients had deta iled neurological evaluation and concomitant CSF examination. Results: Sixty-one MR's (62%) were positive, mostly in the lumbar spine. MR's were positive in 92% of patients with positive initial CSF cytology an d in 60% of patients with negative CSF cytology. The MR examination wa s positive in 49% of those without clinical findings related to the sp inal region. It showed disease beyond the symptomatic level in 42% of patients with spinal symptomatology. Multi-level spinal involvement wa s present in 57% of positive MR exams. Conclusion: Enhanced spinal MR is sensitive for the detection of neoplastic spinal seeding. It detect s LM in about 50% of high risk patients with negative initial CSF cyto logy or no spinal symptoms.