A Review of Hyperthermia Combined With Radiotherapy/Chemotherapy on Malignant Tumors

Therapeutic hyperthermia is a procedure that involves heating tissues to a higher temperature level, typically ranging from 41°C to 45°C. Its combination with radiotherapy and/or chemotherapy has been performed for many years, with remarkable success in treating advanced and recurrent cancers. The current hyperthermia strategies generally include local, regional, and whole-body hyperthermia, which can be implemented by many heating methods, such as microwave, radiofrequency, laser, and ultrasound. There are several hyperthermic treatment modalities in conjunction with radiotherapy/chemotherapy. Numerous studies have attempted to explain the mechanisms of thermosensitization from radiation and chemotherapy; however, a generalized standard for determining an optimal hyperthermia modality combined with radiotherapy/chemotherapy has not been established, so more research is needed. Fortunately, phase II/III clinical trials have demonstrated that hyperthermia combination therapy is beneficial for local tumor control and survival in patients with high-risk tumors of different types. The aim of this article is to present a comprehensive review of the latest advances in tumor hyperthermia combined with radiotherapy and/or chemotherapy. We specifically focus on synergistic cellular and molecular mechanisms, thermal dose, treatment sequence, monitoring and imaging, and clinical outcomes of the combination therapy. The role of nanoparticles in sensitization during radio-/chemotherapy is also evaluated. Finally, research challenges and future trends in the related areas are presented.