1. Patients receiving other therapy (either intrathecal or systemic) designed specifically to treat their leptomeningeal disease are not eligible for this study. However, patients receiving concomitant non-cytotoxic therapy (hormonal or cytostatic therapy) to control systemic disease or bulk CNS disease will be eligible, provided the therapy is not a phase I agent, an agent which significantly penetrates the CSF or an agent known to have serious unpredictable CNS side effects.