Clinical multifield controlled comparison of the hyperthermia and low dose radiation to full radiation of chest wall recurrences

Because of accessibility and poor response to radiation, chest wall recurrence of breast cancer is ideal for clinical trial of hyperthermia. The authors studied the effect of low dose radiation (2000 or 4000 rd) plus heat compared with 5000 rad alone in an homogeneous tumor and patient population. Seven patients completing this study had disease divided into at least 2 areas, one previously unirradiated receiving 5000 rad alone, the other 10 hyperthermia treatments in 5 weeks, using external microwave applicator, with 2000 rad alone (3 fields) or 4000 rad (9 fields). All fields showed at least 50% tumor regression. 4000 rad with heat proved better than 5000 rad alone, showing less skin reaction. Toxicity of radiation plus heat appeared no greater than expected for the same dose of radiation alone. The authors use full dose radiation plus hyperthermia for previously irradiated disease, 8 of 10 showing complete response. Of a total 31 fields evaluable 2 months following 4000 rad plus heat 74% had complete tumor regression. 2000 rad plus heat has proved less effective with 12 fields showing no normal tissue toxicity but on 57% complete tumor response