Proton Irradiation with Hyperthermia in Unresectable Soft Tissue Sarcoma

Purpose: Unresectable soft tissue sarcomas (STSs) do not usually exhibit significant tumor downstaging with preoperative radiotherapy and/or chemotherapy due to their limited radiosensitivity/chemosensitivity. Limb amputations for tumors of the extremities inevitably lead to considerable loss of function and impairment in quality of life. Local hyperthermia at 39°C to 43°C and proton irradiation combine thermoradiobiological and physical dose distribution advantages, possibly mimicking those of a 12C ion therapy. We report the first 2 patients treated with this unique approach of proton thermoradiotherapy.