Hyperthermia

In studies, the reduction of the tumor mass correlates with the increase in temperature, hypoxia and the reduction of the pH value in the tissue. The following procedures are currently common:

• Local hyperthermia: The affected area is irradiated from the outside using an applicator with ultrasound, radio waves or microwaves. Local hyperthermia can be used for superficial lesions, i.e. tumors or metastases that lie just under the skin (e.g. cervical lymph node metastases).
• Regional hyperthermia: Larger areas of the body, such as the pelvic area or the lower extremities, are heated using electromagnetic waves (radio waves or microwaves). The patient lies on a couch in a ring applicator. In this applicator, antennas that emit the electromagnetic waves are arranged in a ring and generate a power distribution that can be controlled within limits by means of suitable phase and amplitude control. This control option means that overheating in normal tissue can be avoided and sufficiently high temperatures can be achieved in the tumor.
• Whole-body hyperthermia: The whole body is heated, whereby so-called contact methods (e.g. hot water, hot air or heated water blankets) were originally available. However, these methods are hardly used any more due to intolerance. Nowadays, the body is heated from the outside using infrared rays of different wavelengths (so-called radiative methods). During treatment, the patient is placed in a largely thermally insulated chamber.
• Interstitial hyperthermia: "Antennas" or probes are inserted into the tumor to allow heating directly inside the tumor. A treatment similar to this technique is seed application or "spiking". Seeds are capsules containing a radioactive substance (usually radioactive iodine) that are implanted directly into the tumor, where they destroy the tumor cells with their radiation. As the radiation dose in the immediate vicinity of the seeds is very high, but decreases sharply with increasing distance, only the tumor is damaged. The use of fine magnetizable particles, which are injected into the patient in a liquid, is also derived from this principle; such a magnetic liquid can be heated by a strong alternating magnetic field.
• Hyperthermic perfusion (see limb perfusion, hyperthermic): A heated fluid (e.g. a cytostatic solution) is passed through the veins supplying the part of the body affected by cancer. However, to ensure that only the diseased part is flushed, the body part must have its own blood supply (e.g. lower/upper extremity, liver). The flushing of body cavities, for example the abdominal cavity or the bladder, with heated fluids is also used. Whole-body hyperthermia can also be achieved by heating the blood.
• Electrohyperthermia

Reduction of tumor mass in inoperable tumors. As a result, 52% of previously inoperable tumors could be surgically treated in pilot studies. Rarely does hyperthermia alone lead to complete tumor regression. Locally, hyperthermia also reduces or restores individual organ metastases, e.g. liver. Currently, surface hyperthermia is also being used with good success for resistant verrucae vulgares.

Other areas of application include chronic inflammation and infections, painful degenerative diseases, circulatory disorders and tinnitus.

• Whole body hyperthermia: By means of infrared, the body temperature is heated to 42 °C, under central attenuation or even under general anaesthesia.
• Local: The application head (infrared lamp) is positioned directly above the region to be heated and thus overheats a defined area.

At present, hyperthermia is not yet covered by statutory health insurance, but may be reimbursed on application.

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2. Nickolaus B (1996) Hyperthermia: New concepts for an old procedure. German Medical Journal 93: A-1368, B-1068, C-968
3. Richtig E et al (2003) Efficacy of superficial and deep regional hyperthermia combined with systemic chemotherapy and radiotherapy in metastatic melanoma. JDDG 1: 635-642
4. Wehner H et al (2001) Whole body hyperthermia with water-filtered infrared radiation: Technical-physical aspects and clinical experiences. Int J Hyperthermia 17: 19-30
5. Wiedemann GJ et al (1996) Ifosfamide and carboplatin combined with 41.8 °C whole body hyperthermia in patients with refractory sarcoma and malignant teratoma. Cancer Res 55: 5346-5350
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