Tumor thermotherapy mainly refers to the use of non-ionizing radiation physical factors of bio-thermal effect, so that biological tissues are heated to warm up (usually 40 ~ 44 ℃) to kill tumor tissues or promote apoptosis, so as to achieve the therapeutic purpose of the treatment method. It is the fifth major means of tumor treatment after surgery, radiotherapy, chemotherapy and biotherapy. In recent years, many studies have found that thermotherapy and certain chemotherapeutic drugs have obvious synergistic effects when they are used in combination, and have achieved remarkable results. Thermotherapy and chemotherapeutic drugs can play a synergistic anti-tumor effect The theoretical basis is: (1) cell membrane proteins are damaged during thermotherapy, and permeability increases, which is conducive to the entry and accumulation of chemotherapeutic drugs in cancer cells to reach the effective concentration of the drugs; (2) heating denatures proteins and inhibits the repair of chemotherapeutic drug damage by tumor cells, which reverses the resistance of tumor cells to the drug. (3) The center of the tumor body is mostly anaerobic cells, but due to the low pH value is sensitive to heat therapy; on the contrary, the peripheral cells of the tumor body are sensitive to chemotherapy, so the two combine to play a complementary role. Intracellular pH also plays an important role in regulating the thermal sensitivity of cells. Selection of Thermal Chemotherapeutic Drugs Not all drugs are thermosensitizing, and the results of different authors vary due to the different cell lines and test conditions used. Drugs recognized by most authors and proven to act synergistically with thermotherapy include platinum and adriamycin. (1) Platinum is a commonly used clinical antitumor drug, which occupies an important position in the first-line treatment regimen of common tumors in the digestive tract and gynecology. Platinum drugs play a cytotoxic role by binding to DNA, causing internal or inter-DNA cross-links and/or cross-links between DNA and proteins. Among them, cisplatin is one of the earliest drugs found to have a synergistic effect with hyperthermia, and it is also the most commonly used intraperitoneal perfusion drug in clinical practice. (2) Adriamycin is still one of the main antitumor drugs with strong cytotoxicity, and it is a specific blocking drug for S phase of mitosis of tumor cells, and S phase is the most sensitive to heat; therefore, the combination of heat and chemotherapy can not only improve the sensitivity of chemotherapeutic drugs, but also enhance the killing and wounding of tumor cells and improve the therapeutic efficacy; also, it can reduce the dosage of the drug, which can alleviate the immediate and long-term adverse effects of chemotherapy. Adriamycin has a sensitizing effect on thermotherapy. (3) Other more studied and considered effective drugs are paclitaxel, hydroxycamptothecin, cyclophosphamide, mitomycin, etc. By combining with thermotherapy, intracellular drug concentration can be improved, tumor cell resistance can be reduced, and cytotoxicity can be enhanced to reduce the adverse effects of chemotherapy. Selection of thermo-chemotherapy modality With the development of thermotherapy equipment and technological progress as well as the change of the concept of tumor thermobiology, regional deep thermotherapy and systemic thermotherapy have been gradually promoted both at home and abroad, and the combination of thermotherapy and chemotherapy for treating tumors has gained great development, and thermo-chemotherapy has been applied to clinical applications in various ways: (1) Combination of local thermotherapy and systemic chemotherapy: for the focal site of the area of the combination of regional thermotherapy and systemic chemotherapy There are many reports at home and abroad on the role of regional thermotherapy and systemic chemotherapy in the treatment of middle and late-stage tumors, which has certain efficacy for some primary or metastatic tumors. (2) Local hyperthermia and body cavity perfusion chemotherapy: for malignant tumors in abdomen and pelvis, even after radical surgery, there may still be extensive planting and metastasis of tumor cells. In the case of intraperitoneal perfusion chemotherapy, the drug concentration in serum and intraperitoneal fluid can differ by 100 to 1,000 times. It is the combination of heat therapy, local chemotherapy and abdominal lavage that is utilized in abdominal thermal perfusion chemotherapy, thus it has better curative effect on middle and advanced abdominal tumors. At present, the therapeutic effect of late-stage cancer is unsatisfactory, extracorporeal microwave thermotherapy is internationally known as the “green therapy” for tumor, and thermal chemotherapy is a new integrated anti-tumor method. In recent years, there has been rapid progress in the molecular biology of tumor thermochemotherapy, as well as in cellular and animal experimental research, which has provided a theoretical basis and guidance for us to further carry out the clinical trials of combined thermotherapy and chemotherapy. Through the deepening of the basic research on tumor thermo-chemotherapy, combined with the successful experience of clinical application of thermo-chemotherapy in foreign countries, our clinical design and application of thermo-chemotherapy will be more standardized and rational, so that more tumor patients will benefit from it.