Abstract
1. The hematologic findings on 21 patients who received fractionated intra-arterial HN2 therapy are presented. The arteries cannulized were the external carotid in 9 cases, the internal carotid in 4 cases, the external iliac in one case and the lower abdominal aorta in 7 cases. The total dose of drug given varied from 0.25 to 3.10 mg./Kg.
2. The effects on bone marrow and peripheral blood were essentially the same in character as those observed after intravenous administration of HN2. Larger doses of HN2 were tolerated when administration was intra-arterial.
3. A consistent early depression of marrow eosinophils was noted in all cases with original differential counts of 2 per cent or more, except in one patient who had Hodgkin’s disease and extensive psoriasis.
4. A differential effect of HN2 on marrow in the region of therapy and the marrow from other sites was demonstrated by simultaneous aspiration studies.
5. Factors reducing hematologic damage include occlusion of venous return from the injected site and prolongation of therapy.
6. Only one patient in this group developed severe hypoplasia of the bone marrow. Studies on this and other patients treated by the lower abdominal aortic route suggest that more than 1.1 mg./Kg. HN2 per course in this region may be hazardous.
7. Four patients died within two weeks following therapy with symptoms suggesting profound electrolyte disturbance. It is probable that limiting factors other than hematologic may occur with localized HN2 therapy.
