The effectiveness of intra-arterial chemotherapy is dependent on a high tumour to normal blood flow ratio (T/NT). This report demonstrates the use of a vasoconstrictor (NE) to improve the relative blood flow to head and neck tumours by causing vasoconstriction and decreased blood flow to normal soft tissue. Five quantitative planar Tc-MAA perfusion studies were performed on three patients with increasing dose rates of norepinephrine (NE) to determine the optimal dose in each patient that would produce the best T/NT. All patients demonstrated a change in perfusion pattern with increasing dose rates (0.1 to 15 μg min-1), although there was considerable variation between patients. Quantitative SPECT was performed on two patients. In one, there was a 35% increase in the T/NT and a 16% decrease in arteriovenous (A-V) shunting to the lung.