[Intensification of the oncolysis by clostridia by means of radio-frequency hyperthermy in experiments on animals--dependence on dosage and on intervals (author's transl)].

The effect of a local pretreatment by radio-frequency hyperthermy upon the capability of germination and, hence, upon the oncolysis by intravenously given spores of oncolytic clostridia (M55) was tested with 2305 NMRI-mice carrying neck tumors. Using two different experimental tumors (Ehrlich adenocarcinoma and Harding-Passey-melanoma) it is possible to show the dependence of the intensification on the thermic dose. Additionally, there is a distinct dependence of the extent of oncolysis on the time interval between the hyperthermy treatment and the administration of clostridia. The intensification effect in both the tumors is mostly marked twelve hours after hyperthermy. The rapidly growing Ehrlich adenocarcinoma regenerates more quickly than the slowly growing Harding-Passey-melanoma. A period of 12 hours between hyperthermy and injection of clostridia represents a favourable interval for the timing of slowly as well as of rapidly growing tumors.