SINCE the publication of a previous paper on this subject1 we have treated 97 patients with metastatic cerebral malignancy and 2 postoperative primary ones in addition to those previously recorded. This group of cases consisted of 31 squamous cell cancers of the lung in males whose ages ranged from 43 to 68 years, the average age being 55 years. The interval between total pneumonectomy and cerebral metastases was between 4 and 15 months, averaging 8 months. All of these patients were unconscious when first seen. We established a uniform method of treatment which was used on all patients, namely injection of 100 mg. of triethylenethiophosphoramide (Thio-TEPA) directly into the carotid artery on that side which seemed to indicate the greatest amount of metastatic disease by neurological and physical examination. The patients became conscious and lucid between 6 hours and 4 days after the injection. The injection of triethylenethiophosphoramide in