Impact of various thermal doses on the oxygenation and blood flow in malignant tumors upon localized hyperthermia.

Upon localized hyperthermia at modest thermal doses an increase in tumor blood flow can be observed in many tumors which is paralleled by an improvement of the oxygenation status of the tissue. At intermediate or high thermal doses a pronounced restriction of the tumor circulation becomes obvious leading to a deterioration of the tumor oxygenation. As a consequence, a further enhancement of the thermal response of tumors relative to normal tissues has to be expected at intermediate or high thermal doses.