What is hyperthermia?
By hyperthermic therapy, or hyperthermia, we mean the heating of biological tissues with a temperature higher than the physiological one. Tissue heating has a wide clinical application today:
- orthopedic rehabilitation
The use of hyperthermia in medical practice dates back to the late 70s thanks to the studies observed by the doctor Harry Le Veen in the United States. Given the excellent results obtained, it was also introduced in Italy.
How does hyperthermia work?
The heating of the tissues is carried out by electromagnetic fields which have the advantage of arriving on tissues located in depth. The electromagnetic waves used are those included in the frequency range that goes from microwaves to short waves, up to long waves. Currently, for the treatment of tissues located in depth, the frequency of 13.56 MHz is used which allows to obtain a deep, non-invasive heating without causing burns on the surface of the skin. To treat surface areas, electromagnetic waves with a frequency of 300-900 MHz are used.
The temperature of the surrounding tissues is kept unchanged because the frequency of the electromagnetic waves is such as to heat precisely the area to be treated, without dissipating to other areas of the body.
Hyperthermia in oncology
Oncological hyperthermia is based on the principle that by heating the tumor tissue, the cancer cells weaken, become irreversibly damaged, are no longer able to replicate and go to cell death. The temperature that causes the apoptosis of the tumor cells and to which the diseased tissue is then brought is around 41 – 45 ° C.
This was made possible by the characteristics of the tumor vascularization: the blood vessels of the tumor, in fact, lacking the muscular scaffold, do not allow, due to lack of elasticity, physiological vasodilation which allows adequate heat dissipation. In other words, the heat remains trapped, the damage that occurs inside the cancer cell leads to the increased production of caspase (proteins involved in the cell death process) and apoptosis is triggered.
Hyperthermia shows greater efficacy in association with traditional cancer therapy:
- by weakening with heat, cancer cells become easily attacked by chemotherapy drugs or other drug therapies
- heat has a radiosensitizing effect and enhances the effects of radiation therapy on the tumor
- performing it before surgery can help reduce tumor mass and allow the surgeon to remove it completely more easily.
Hyperthermia and traditional therapies, without increasing the side effects, have a synergistic effect and allow a significant improvement in the control of tumor growth.
In addition to the reduction of the tumor mass, another important effect of oncological hyperthermia is that analgesic (pain reliever).
The treatment, i.e. the heating of the neoplasm site area, can be performed several times, according to the protocols, but not more than three times a week, to avoid the phenomenon of thermotolerance, i.e. the greater cellular resistance to heat in the 48 hours following the therapy.
Each single treatment lasts about 60 minutes
Types of hyperthermia
Oncological hyperthermia can be carried out mainly in different ways:
- classical hyperthermia: it is carried out by positioning the electromagnetic wave emitting instrument directly in the area of the body where the tumor mass is present.
- total body hyperthermia: the whole body is heated. The aim is not to directly destroy the tumor mass but to induce a feverish state in order to stimulate the immune system and strengthen it against the tumor. Thermal chambers are used in this type of hyperthermia.
- interstitial hyperthermia: tumor lesions are directly heated by introducing special needles, under ultrasound guidance, transcutaneously.
- Infusion hyperthermia: it is based on the use of peritoneal washes with a heated solution
For which types of tumors is hyperthermia indicated?
Hyperthermia is indicated in all types of solid cancer of anybody district, including hematological tumors in the case that lymph node aggregates have formed.
Contraindications and side effects
Hyperthermia is a painless treatment with no side effects.
It is contraindicated in people with pacemakers, plaques or metal stents.