Thermal dose‐response of magnetic‐induction thermoradiotherapy

Sixty‐three patients with advanced cancer underwent ≥ 5,000 cGy combined with Concentric Coil magnetic‐induction localized hyperthermia. Tumor regression (CR + PR) was compared to thermal dose received, incorporating the premise that hyperthermia response is a function of time as well as temperature. A computer program was developed (after Saparto and Dewey [2]) which stored minimum tumor temperatures recorded spatially and temporally during treatment and correlated response with T43 (equivalent minutes at 43 °C during the first treatment) and CT43 (cumulative T43, computed by multiplying T43 by the actual number of identical subsequent treatments received during the course of therapy). Those who responded—N = 46 (73%)—had significantly higher median thermal doses than those who did not respond. Comparison of T43 and CT43 thermal dose values between responders and nonresponders was significantly different at p values of 0.05 and 0.04, respectively. The data indicate that magnetic‐induction hyperthermia and high‐dose XRT was an effective treatment combination in advanced disease and that tumor response improved as thermal dose increased.