Therapeutic hyperthermia is a procedure to fight tumors in the body by overheating the affected part of the body. The procedure achieves good results but is not yet fully developed. Side effects of the treatments are rare if there are no other physical impairments.
What is therapeutic hyperthermia?
Therapeutic hyperthermia is a method of fighting tumors in the body by overheating the affected part of the body. Therapeutic hyperthermia characterizes the overheating of specific body parts to treat cancer. Here, the main effect is based on an indirect influence on the tissue. The local heating increases the blood flow to the affected tissue, so that the chemotherapy can work more effectively. A direct effect exists in the sense that the treated tissue dies when exposed to heat for a longer period of time. However, these effects are small in therapeutic hyperthermia, because a higher temperature would have to be applied, which would also damage the neighboring tissue. There are three forms of application of artificial hyperthermia. These are local hyperthermia, regional hyperthermia and whole-body hyperthermia. In the past, the so-called fever therapy was still used, in which heat-generating agents were used to stimulate the metabolism. Due to poor control and significant side effects, this method is no longer used today. Today, therapeutic hyperthermia is based on the application of external heat, whereby the body regions to be treated are warmed up to a temperature of 40 to 45 degrees.
Function, effect and goals
Therapeutic hyperthermia is used for the treatment of malignant tumors. Its use has proven effective for breast cancer, rectal cancer, head and neck tumor, soft tissue tumor, esophageal cancer, skin cancer, brain tumor or cervical cancer. Which procedure is used depends on the location of the tumor. Superficial tumors such as breast cancer or skin cancer can be treated with local hyperthermia. For this purpose, the affected area is heated with needle-shaped probes by electromagnetic radiation. Regional hyperthermia works on the same principle as local application. However, larger areas of the body are treated here. For example, rectal cancer can be treated in this way. Whole-body thermotherapy can also be performed using special probes. This is necessary if deeper tumors are to be treated. For this purpose, the entire body is warmed up to 42 degrees from the outside for 60 minutes. In addition, internal heating is performed with special probes. In principle, hyperthermia can be performed invasively or non-invasively. In the invasive procedure, probes are inserted into the body through body orifices, which irradiate the diseased tissue area from the inside. In the non-invasive form of treatment, heat is applied from the outside. Superficial tumors can thus be treated non-invasively, while the invasive method is used for deeper-lying cancers. The effect of hyperthermia works mainly indirectly. The heated tissue section is better supplied with blood as a result of the warming. This allows the active substances used in chemotherapy to work more effectively and accelerate the killing of cancer cells. Furthermore, when heated, the cells’ own repair mechanisms for DNA repair no longer function. This makes these tumor cells even more vulnerable to radiation therapy. The accumulation of serious mutations in the diseased cells cause them to die more quickly. Overall, therapeutic hyperthermia can therefore support chemotherapy and radiation therapy in cancer treatment. Of course, there is also a direct heating effect on the cells. Cells that are heated too much are damaged in the long term and die already for this reason. However, the direct heat effect is too weak to fight the tumor. For this, higher temperatures would have to be applied for a longer period of time, which would affect the neighboring tissue. Prior to therapeutic hyperthermia, the patient’s general physical situation must of course be clarified in a consultation. During treatment, the affected area is observed using imaging techniques, the temperature distribution is calculated and, of course, the temperature is measured using probes.The heat is mostly generated by radiation of electromagnetic energy. The whole treatment lasts about 60 to 90 minutes. It can be carried out for up to twelve weeks, with one or two treatments a week. The procedure shows good effects. However, the exact mode of action is not yet known. Current scientific research is still clarifying the possibilities for even more effective use.
Risks, side effects, and dangers
Therapeutic hyperthermia proves to be a very gentle procedure in cancer therapy. Thus, serious side effects occur very rarely. However, these mostly relate to redness and swelling of the treated tissue. Burns also occur rarely. The main side effects are caused by chemotherapy and radiotherapy. Because whole-body thermotherapy is sometimes performed under anesthesia, any effects of anesthesia should be noted. Severe burns may cause pain. These signs should be observed in order to reduce their consequences. However, gentle application is only guaranteed for persons who do not otherwise have any other medical conditions. This is especially true for the application of whole-body thermotherapy. Pregnant women, patients with metallic joint prostheses, patients with pacemakers or with defibrillators are to be excluded from the treatment. Implanted material can heat up very strongly and thus be damaged. In pregnant women, the effect of heat treatment on the growing embryo cannot be foreseen. In principle, therapeutic hyperthermia must also not be used on patients with certain pre-existing physical conditions. These include such conditions as cardiac insufficiency, lung disease, bone marrow damage, immune deficiency, severe infections, thrombosis, epilepsy, lymphedema, renal insufficiency or hyperthyroidism. The burdens of hyperthermia are, however, less than with the use of chemotherapy and radiotherapy. However, as these therapies become more effective through its use, the overall burden on the patient usually decreases.
