ALTHOUGH not widely accepted, systemic chemotherapy in patients with metastatic malignancies of the central nervous system (CNS) is feasible and can offer excellent palliation. Systemic therapy is preferred to regional therapy because most, if not all, of these patients have other metastatic disease. A review of the literature on the treatment of metastatic CNS lesions revealed little information. Three articles on perfusion with alkylating agents (Woodhall et al,1 Mark et al,2 and Perese et al3) were directed primarily to technique. Chu and Hilaris 4 used irradiation for CNS lesions and noted improvement in a variety of malignancies, by means of local therapy. Davis and Shumway 5 reported intra-arterial (carotid) injection of triethylenethiophosphoramide in a series of patients. This study included 31 men with carcinoma of the lung and 66 women with carcinoma of the breast. Triethylenethiophosphoramide was injected into the carotid artery on the involved side at