**2. Microwave thermotherapy**

The first four of the following list of thermotherapeutical applications are just largely used in many countries around the world; the last three instead are at this moment in the phase of very promising projects:

• Oncology (cancer treatment)

Biological principle utilizes the fact that certain tumor cells are very sensitive to a temperature higher than 41°C, while normal cells generally survive elevated

temperatures up to 45°C. And so heating of the tumor region at temperatures of 41– 45°C can selectively destroy tumor cells.

• Physiotherapy (treatment of rheumatic and skeletal diseases)

Like in hyperthermia, therapeutic effect is caused by the principle of heating biological tissue, but to lower temperatures—usually only up to 41°C. It is used for treating pain in certain rheumatic and degenerative diseases and the treatment of chronic inflammations resistant to antibiotics, often used in rehabilitation and physical therapy.

• Urology (BPH treatment)

Microwave thermocoagulation—heating up to temperatures much higher than 45°C, usually around 70°C. An example can be given the microwave treatment of Benign Prostate Hyperplasia, which can replace a complicated surgery.

• Cardiology (arrhythmia and fibrillation treatment, microwave angioplasties)

Cardiac catheter thermal ablation is now the standard of care for various cardiac arrhythmia types (irregular heartbeat rhythm). The method uses a catheter terminated with a microwave antenna, which is introduced into either heart of the patient or into partially or totally blocked blood vessels. Heat gained by microwave energy either safely removes the cells inside the human heart causing arrhythmia and/ or fibrillation or removes sclerotic plaques deposited on the walls of blood vessels.


For here mentioned thermotherapy treatments, it is important to mention that frequencies from the frequency band started approximately at 1 MHz and going up to 10 GHz are mostly used. This frequency range is given by the optimal depth of penetration of EM waves into biological tissue. Thus, this frequency band can achieve the needed depth of effective treatment.
