Leptomeningeal metastasis

Leptomeningeal metastasis occurs in approximately 3-5% of all patients with cancer. A contemporary literature review of methods of diagnosis and treatment of leptomeningeal metastasis was performed.

The single most important aspect to diagnosis of leptomeningeal metastasis is considering and pursuing the diagnosis in a patient with cancer and neurological signs and symptoms. Evaluation of leptomeningeal metastasis includes contrast-enhanced brain and spine magnetic resonance imaging (MRI) and a radionuclide cerebrospinal fluid (CSF) flow study if leptomeningeal metastasis-directed therapy is being considered. Treatment often requires involved-field radiotherapy to bulky or symptomatic disease sites as well as intra-CSF and systemic chemotherapy. The use of high-dose systemic therapy may benefit patients with leptomeningeal metastasis and obviate the need for intra-CSF chemotherapy. Intra-CSF drug therapy primarily utilizes one of three chemotherapeutic agents (i.e. methotrexate, cytosine arabinoside and thio-TEPA) administered by a variety of schedules either by intralumbar or intraventricular drug delivery. Novel and increasingly utilized intra-CSF agents in the treatment of leptomeningeal metastasis are targeted monoclonal antibodies such as rituximab and trastuzumab.

Although treatment of leptomeningeal metastasis is palliative with median patient survival of 2-3 months (15% of patients with leptomeningeal metastasis survive 1 year), treatment may afford stabilization and protection from further neurologic deterioration in patients with leptomeningeal metastasis.