Retrospective analysis of hyperthermia for use in the palliative treatment of cancer: a multi-modality evaluation

Forty-two patients with local or superficial metastatic or recurrent malignant tumors were treated in a non-randomized Phase I/II study to assess the tumoricidal effects of heat combined with radiation and/or chemotherapy. Radiation doses administered averaged 3130 +/- 350 cGy; chemotherapeutic agents employed included bleomycin, mitomycin-C, adriamycin, and cis-platin, heat was induced by radiative or interstitial microwave applicators operating at frequencies ranging from 95 to 900 MHz. Forty-one of the forty-two patients were evaluated for initial therapeutic effects yielding the following response distributions: local hyperthermia with radiation--42% complete response (CR), 44% partial response (PR), and 15% no response (NR); local hyperthermia with chemotherapy--0% CR, 50% PR and 50% NR. Long-term response duration was evaluated for local hyperthermia with radiation, yielding mean time to recurrence of 9.4 months for CR's and mean time to progression of 3.4 months for PR's. In retrospective analysis, we examined the correlations of previously established response-predictor variables of tumor volume and minimum thermal dose with both initial and long-term response rates. Initial complete response rates were correlated directly with non-site-specific minimum thermal dose, varied inversely with tumor volume and exhibited a positive correlation for a limited histologic type/treatment site combination. Surprisingly, long-term response did not correlate either with tumor volume or thermal dose. The frequency of thermally induced complications, which did not correlate with any measured thermal parameters, was found to be 42%, expressed on a per-patient basis.