Intraoperative Regional Thermography during Surgery for Brain Tumors

Abstract

Progress has been made in hyperthermia research, but the thermal microenvironment of human brain tumors has received little attention. In six patients with brain tumors located in the cortex or subcortex, the thermal variations of the cortical surface in both the steady and dynamic states were scanned by infrared thermography, which is essentially a noninvasive technique. Hypothermal area was observed on the surfaces of cystic and necrotic lesions, which were delineated with intraoperative sonography. Recovery of surface temperature after thermal loading was delayed in these hypothermal areas. Blood flow in brain tumors, which was estimated by means of the new imageprocessing technique of thermography, was lower than that in surrounding normal tissue. Knowledge of the differences in thermal microenvironments and blood flow patterns between tumor and normal tissue will provide a theoretical framework for the use of regional hyperthermia in the management of brain tumors.