Capacitive radiofrequency hyperthermia in the treatment of cutaneous murine melanoma

We have evaluated localized capacitive radiofrequency hyperthermia in the treatment of murine S91 melanoma. Two hundred and ten DBA/2J male mice were implanted with 1 X 10(6) S91 murine melanoma cells innoculated into a noninflammatory upper dermal suction blister cavity. Two tumors were implanted per animal, so that each animal served as its own control in evaluating the effects of temperature, treatment duration, and tumor size on tumor growth following radiofrequency hyperthermia treatment. The data supported the following conclusions: (1) capacitive radiofrequency hyperthermia is effective in the treatment of murine S91 melanoma; (2) duration of treatment between 10 and 60 seconds at 52 degrees C does not influence effectiveness; and (3) treatment temperatures greater than 49 degrees C are needed for maximal effectiveness in the treatment of these tumors. Based on these preliminary findings, high temperature, short duration capacitive radiofrequency hyperthermia may prove to be a useful modality in the treatment of certain cutaneous malignancies.