Clinical evaluation of hyperthermia equipment: the University of Arizona Institutional Report for the NCI Hyperthermia Equipment Evaluation Contract.

Two-hundred and fifteen independent sites in 203 patients were treated with hyperthermia at the University of Arizona from 10/81 through 3/86 under the auspices of this contract. In the head and neck, a site dominated by superficial tumors, air-coupled and water-coupled microwave applicators yielded the best results. Similarly in the thorax, also dominated by superficial tumors, water-coupled microwave applicators were best. In the abdomen and pelvis, sites dominated by deep tumors, only interstitial radiofrequency (RF) heating, an invasive technique useful only in selected cases, was capable of consistently producing therapeutic temperatures. Toxicity appeared to be site-related, and treatment discomfort was especially common in abdominal and pelvic sites. In conclusion, while superficial sites were readily heated using propagative electromagnetic devices, these devices were ineffective and poorly tolerated at deeper sites. Effective deep hyperthermia was best produced with interstitial techniques, and further development of these techniques using RF electrodes, implantable microwave antennas and thermoregulating ferromagnetic seeds, as well as scanned, focussed-ultrasound techniques, holds promise for effective heating of deep visceral sites.