The intent of this application is to perform preclinical toxicologic and pharmacologic studies in dogs of intrathecal drugs of potential applicability to the treatment of human meningeal neoplasia. Acute, subacute, and chronic drug toxicity on the nervous system will be evaluated during and after 8 weeks of intraventricular therapy. CSF pharmacokinetics, in conjunction with in vitro pharmacokinetics and related tumor cell kill, will be used to determine in vivo dose ranges and to anticipate the benefit of therapy and maximal non-toxic doses.