Laser photoradiation therapy of cancer: Possible role of hyperthermia

Two patients were treated at 20 different tumor sites by hematoporphyrin derivative (HPD) photoradiation therapy (PRT). An infrared detector was used to record changes in surface temperature during laser exposure. A temperature rise of up to 4.9 °C was recorded for a total energy of 15–30 J/cm2 and less than 150 mW/cm2. For 508 mW/cm2 and 15–20 J/cm2 a temperature rise of 7.0 °C was detected. The results suggest a possible role of hyperthermia in HPD‐PRT.