Results of a preliminary study of the potential of vasodilators for improving thermotherapy of deep-seated tumours

Abstract

Administration of the vasodilator hydralazine to a single mongrel dog with a transplanted, superficial transmissible venereal tumour in the abdomen permitted tumour-adjacent normal tissue temperature differences produced in local hyperthermia to be enhanced by nearly 2°C. A preliminary study of tumour and normal tissue perfusion rate in the dog, employing the ¹⁵O-labelled water-positron emission tomography technique, suggested that administration of the vasodilator led to a significant reduction in the tumour perfusion rate, consistent with the observed tumour temperature enhancement. Computational studies with a multi-layer, one-dimensional cylindrical model of deep-tumour heating suggest that vasodilator-induced reductions of tumour perfusion rates could significantly increase deep tumour-superficial normal tissue temperature differences produced in deep-tumour thermotherapy.

Keywords::

• deep-tumour hyperthermia
• vasodilators
• perfusion rate