**3. Rational of tissue necrosis (ablation) in hyperthermia medicine**

Modern research in thermal medicine aims to understand molecular, cellular and physiological effects of temperature manipulation and the "stress" response, as well as to develop effective and safe equipment for clinical application and temperature monitoring. Multiple facets of tumor growth and the tumor microenvironment, including vascular perfusion, heat shock protein expression, endothelial/stromal cells, hypoxia, immune cells, pro-inflammatory cytokines, are impacted by heat and these effects may underlie remarkable successes being obtained in a surge of clinical trials throughout the world. Thermal ablation whereby tissue is destroyed by localized heating or freezing, is now used worldwide for treatment of many benign and malignant tumors and several other important medical applications (2-4).

The main actions of hyperthermia in the neoplastic tissues are the following:


146 Hyperthermia

**Figure 1.** Technique of Cauterization by fire for a patient with neck swelling (1)

generation of clinical trials of heat-activated drug delivery.

**2. Various energy sources of hyperthermia** 

minimally invasive procedure that significantly reduces risks and speeds recovery. So, it provides an excellent safe alternative to major surgery. The primary advantage of percutaneous radiofrequency thermal ablation is a reduction in the need for post-operative hospitalization and a reduced duration of convalescence. In this chapter, we will review the recent application of hyperthermia medicine in treatment of different disease under the guidance of different radiological modalities. In this chapter, we will provide a clearer picture of the intimate relation between hyperthermia, radiology and medical imaging. We will discuss the multiple facets of tumor growth and the tumor microenvironment that can be impacted by heat during hyperthermia medicine. We will emphasize the approved clinical application of hyperthermia in management of growing number of patients with a variety of diseases. We also discuss other experimental and investigational trial studies that can be used effectively in the future for management of other clinical conditions. Also we will emphasize the adjuvant role of thermal therapy in combination with radiotherapy and chemotherapy in management of cancer. Finally, we will elaborate the exciting new

Various energy sources including laser, ultrasound, microwaves, and radiofrequency electric current are being investigated as minimally invasive, and potentially non-invasive therapies. There are two types of thermal ablation: radiofrequency (RFA) and microwave.
