Comparing the Effectiveness of Combined Hyperthermia and External Beam Radiation (EBRT) Versus EBRT Alone in Treating Patients With Painful Bone Metastases

The goal of this study is to conduct comparative data on the efficacy of low temperature (40-43℃ range) deep hyperthermia adding on external beam radiation for treatment of metastatic bone tumors. There are 3 reasons of conducting this clinical trial. Firstly, radiotherapy is most effective modality for bony metastases treatment, but only limited radiation dose can be delivered to metastatic bony metastatic sites with relatively short response duration observed clinically. Since it is a palliative treatment for pain relief, some patients develop recurrent pain at the same lesions a few months later. Most patients must accept their hopeless conditions and accept toward the end of their lives due to difficulty of reirradiation. There is urgently need for more effective treatment. Secondly, most combination of hyperthermia and radiation trials were relatively high dose of radiation, with the basic idea of hyperthermic radiosensitization, the combination of hyperthermia and radiotherapy on bone metastasis is warrant. Clinical trials experiences on relatively less deep tumors such as breast, head and neck cancers, extremity sarcoma or melanoma may not be applied on deep seated tumors. Bony metastases are usually deep seated lesions with hard cortex bone surrounded. The real benefit of hyperthermia can be highlighted on bony metastases. Thirdly, metastatic bony microenvironment are critical for the providing of bone marrow-derived immune suppressor cells circulating to systemic tumor microenvironment, mild thermal therapy to metastatic bony microenvironment may have dual immunomodulatory effects: direct enhancement of immune cell activity through thermally sensitive molecular pathways associated with immune cell function/activation, and, indirect enhancement of immunosurveillance through a reduction in hypoxia-induced immune suppressor cells around metastatic foci via improved tumor vascular perfusion. An unexpected survival benefit may demonstrated from this study.

Patients are stratified according to solitary or multiple sites, primary cancer type (Breast or prostate vs others), and severity of pain (i.e., worst pain score in the last 24-hour period) (4-6 vs 7-10). Patients are randomized to 1 of 2 treatment arms.

Treatment protocol A was designed to compare the response of matched tumors in the same patient treated by radiation alone or by radiation combined with hyperthermia when the patient had multiple tumors. Two tumors of comparable size were treated with either protocol A or B, and the responses were compared. The tumor size was computed as the product of maximum length times maximum width.