Effectiveness of microwave hyperthermia combined with ionizing radiation: clinical results on neck node metastases

Sequential regional hyperthermia: a possible answer for the treatment of cancer

A therapeutic rationale for the treatment of metastatic cancer is presented which incorporates the use of deep regional hyperthermia of major body areas such as the thorax and abdomen. These body areas would be treated sequentially with the goal of eliminating the problems inherent to whole-body hyperthermia. To achieve this goal, a tri-modality approach is considered which combines regional deep heating with regional x-ray therapy and with drug therapy using agents which are heat as well as radiation hypoxic cell sensitizers (Nitroimidazoles or glucose analogues). The rationale for such an approach is well founded at the basic research level. The benefit of the tri-modality approach is that therapeutic levels of drug, X-rays and heat can be reduced significantly and hopefully be non-toxic.

Microwave-induced hyperthermia and ionizing radiation. Preliminary clinical results

The combination of microwave-induced (2450 MHz) hyperthermia and ionizing radiation was used in 7 patients with superficial malignant tumours, which were considered refractory to other therapy. A newly developed heating system was used, allowing for a maintained temperature at the master probe of 42.5 degrees C +/- 0.5 degrees C during 45 min, but temperature measurements at multiple sites showed a marked variation. This preliminary series indicates that the combination of hyperthermia and ionizing radiation may be useful, the response rate (complete or partial) being 8 of 8 evaluable lesions. Even previously heavily irradiated sites responded. Technical improvements are highly needed to allow for controlled heating of any tissue volume.

Results of a phase I/II clinical trial of fractionated hyperthermia in combination with low dose ionizing radiation

This paper addresses, in part, the current status of hyperthermia as a new clinical modality and reports the results of a large, prospective clinical trial employing microwave hyperthermia in combination with low doses of ionizing radiation. In the protocol employed, each treated area received 8 hyperthermia treatments of 1.5 hour combined with 1600 rad over a total period of 5 weeks. Patients were heated with microwaves of 915 or 300 MHz employing external applicators or internal intracavitary antennas. The results of this fractionation scheme are encouraging since in 121 fields that were treated completely according to protocol and were available for follow-up for at least 2 months, complete responses were observed in 65% of all cases, partial response in 30% and no response in only 5%. It is also important to note that toxicity was minimal throughout the study.

Local hyperthermia and irradiation in cancer therapy

The preliminary experience at the Mallinckrodt Institute of Radiology with hyperthermia and irradiation is reported and current issues in clinical application of heat are reviewed. Twenty-nine lesions were treated with 400 rad fractions given every 72 hr (twice weekly) for a total dose of 2400 to 4000 rad followed by hyperthermia (1450-MHz or 915-MHz microwaves, 42.0 degrees -43 degrees, 90 min, every 72 h). Eight of 12 recurrent epidermoid carcinomas of the head and neck showed complete regression (67%) and one more than 50% response. Of 5 metastatic melanoma nodules treated with irradiation an hyperthermia, 4 (80%) showed complete regression of the tumors an 1 almost complete response. Of 9 recurrent adenocarcinoma of breast nodules in the chest wall treated with 3200 to 4000 rad 5 lesions exhibited complete regression and 2 others about 80%. Of 6 lesions treated with 1500 rad and hyperthermia (RTOG protocol), 2 metastatic melanomas showed complete regression (CR) and 3 tumors exhibited partial regression. Of the 35 sites treated, 4 (11%) developed blisters, 7 (20%) erythema only, 3 (8%) moist desquamation and 27 (77%) dry desquamation. Additional clinical trials are in progress to assess the potential value of hyperthermia alone or combined with irradiation in the treatment of selected cancer patients.