Tolerability of long-term temperature controlled whole-body thermal treatment in advanced cancer-bearing dogs

Abstract Aim: In oncology, thermal therapy is the application of external heat to fight cancer cells. The goal of whole-body thermal treatment (WBTT) is to raise the patient’s core temperature to 39–42 °C, and represents the only thermal treatment modality that can act on both the primary tumor and distant metastases. However, WBTT carries potential risks for toxicity when applied without accurate thermometry and monitoring. Methods: ElmediX has developed a medical device, HyperTherm, to deliver long-term controlled and accurate WBTT (41.5 °C, up to 8 h). The safety of the device and thermal treatment protocol was initially evaluated in minipigs, and we present the confirmation of tolerability of WBTT in dogs with advanced cancer, in combination with a reduced dose of radiotherapy or chemotherapy. Results: Thermometry in liver, rectum, and tumor confirmed a homogeneous heating of these body parts. Monitoring of clinical parameters showed acceptable and reversible changes in liver, cardiac, muscle and coagulation parameters, as was expected. Combination of WBTT with both radiotherapy and chemotherapy only caused some low-grade adverse events. Conclusion: We conclude that our findings support the safe use of HyperTherm-mediated WBTT for canine patients with advanced malignancies. They also tend to support a genuine therapeutic potential for long-term WBTT which needs to be confirmed on a larger dog patient population. Combined with previously reported safety results in minipigs, these contribute to support the ongoing clinical evaluation of WBTT in advanced human cancer patients.