The response of tissues to combined hyperthermia and X rays

Three normal tissues in mice and rats (skin, intestine and cartilage) have been used to investigate the effects of combined hyperthermia and radiation. The heating time was kept constant at one hour and X rays were given either immediately before or after heating. Thermal enhancement ratios were measured as a function of temperature up to 43 degress C and were compared with data for other normal tissues and tumours taken from the literature. The variation from tissue to tissue was found to be fairly small within this temperature range, but there is some indication of a greater response of tumours.