Overview of tumor thermotherapy on March 1, 2003

Overview of tumor thermotherapy on March 1, 2003

More than a century ago, someone accidentally discovered that high fever could treat malignant tumors. Case reports show that cancer patients suffering from erysipelas experienced high fevers of 40°C for several days, ultimately benefiting from the ordeal and achieving complete remission. In 1973, Palzer found that high fever at 42°C for 60–120 minutes had the greatest impact on the S phase and G2 phase of cell division; in 1976, Dveryand proved that the fundamental principle of heat killing cancer lies in promoting lysosomal changes, while also discovering that blood flow within tumors is only 1%–15% of that in surrounding tissues. Due to the low blood flow, heat penetrates deeply without dissipating easily, resulting in temperatures 8–10°C higher than in adjacent normal tissues, which is conducive to killing cancer cells. In 1984, combining radiotherapy, chemotherapy, and high fever for cancer treatment created better outcomes than either radiotherapy or chemotherapy alone. In 1985, Storm tested radiofrequency thermal therapy combined with chemotherapy for 3,790 cancer cases, achieving satisfactory results. In recent years, advances in electronic technology have provided unprecedented prospects for thermotherapy, collectively referred to as thermobiology, cellular thermobiology, vascular thermobiology, and thermal dosimetry.

1. Heating technologies ① Radiofrequency thermal therapy: a. Capacitive electric method (surface and cavity); b. Inductive method: superficial tumors on the body surface; c. Interstitial thermal therapy. ② Microwave thermal therapy: a. Surface radiation; b. Cavity radiation; c. Insertion radiation (radiators inserted), the combination of the two is called high-frequency thermal therapy.

2. Common thermal therapy machines Radiofrequency thermal therapy machine, microwave thermal therapy machine, ultrasonic thermal therapy machine, extracorporeal circulation thermal therapy machine, multi-head radiofrequency device.

3. Classification of thermal therapy Whole-body thermal therapy (WBH), regional thermal therapy (RHT), local thermal therapy (LHT).

4. Several terms ① Radiofrequency (also known as high frequency): electromagnetic waves in the frequency range of 300 MHz to 100 kHz. Domestic SR-100 model radiofrequency thermal therapy machine (40.68 MHz radiofrequency thermal therapy system). ② Heat sensitizers: commonly used heat sensitizers include Tween 80, theoretically capable of increasing cancer cells’ sensitivity to heat, thereby reducing the temperature required for thermal therapy and protecting normal tissues. ③ Fat barrier: as radiofrequency increases, temperature rises relatively, but when it reaches 40 MHz, fat temperature no longer increases, nor does muscle temperature.