Cancer is a class of diseases characterized by out of control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected. Cancer is a potentially fatal genetic disease that is caused mainly by environmental factors. The cancer causing agents (carcinogens) can be present in food & water, in the air, in chemicals and sunlight that people are exposed to. Cancer begins when cells in a part of the body start to grow out of control. Cancer cell growth is different from normal cell growth. Instead of dying, cancer cells continue to grow and form new abnormal cells. Cancer cells can also invade other tissues. Growing out of control and invading other tissues are what makes a cell a cancer cell. Humans have been fighting against cancers past hundreds years. During that period, many clinical modalities have been proposed to treat cancers. Among them, the clinical procedures known as cryosurgery and hyperthermia.
Cryosurgery employs very low temperatures (freezing) to destroy undesirable and diseased tissues, in order to kill it. Applications of this treatment are used quite widely in superficial diseases such as tumors, warts and some other dermatological conditions. The advantages of cryosurgery treatment are minimally invasive, repeatable, has less side effects and can be operated at different targets in the same organ at the same time.
Hyperthermia may be defined more precisely as raising the temperature of a part of or the whole body above normal for a defined period of time. The extent of temperature elevation associated with hyperthermia is on the order of a few degrees above normal temperature (41 - 45°C). Because of the results that high temperature may produce in tissues, one can refer to use of temperatures (>50°C) as coagulation, (60 to 90°C) as thermal ablation and (>200°C) as charring. Hyperthermia is a type of cancer treatment in which body tissue is exposed to high temperatures, using external and internal heating devices. Hyperthermia is almost used with other forms of cancer therapy such as radiation and chemotherapy. Research has shown that high temperatures can damage and kill cancer cells, usually with minimal injury to normal tissues. It is proposed that by killing cancer cells and damaging proteins and structures within the cells, hyperthermia may shrink tumors making the cells more sensitive to radiation therapy (RT) or chemotherapy.
The aim of present study, design and construct a Cryosurgery-Hyperthermia device using thermoelectric effect using simple national materials. This device was used to destroy a superficial tumor and to study the effect of the combined cryosurgery and hyperthermia treatments using Peltier effect on the malignant tissues.
Cryosurgery-Hyperthermia device was constructed and developed. The constructed device consists of the following four main parts: power supply, freezing-heating system, thermometer and controlling part. The freezing-heating system is the most important part of device that actually produces freezing and heating, which consists of freezing-heating head, thermoelectric (Peltier) module, heat sink and water pump. The freezing-heating head designed to meet a wide range of heating and freezing needs to quicker and less invasive treatment for some cancer patients. The freezing-heating head contacts with a thermoelectric (Peltier) module coupled to a water flow based heat sink, which dissipates heat to water when the head is cooled and absorbs heat from water while the head is heated. The polarity of the DC power supply can be reversed by the switch to achieve the conversion between freezing and heating mode.
The present work was carried out in 60 male Swiss albino mice injected with (2 x 106) Ehrlich ascites carcinoma cells, mammary in origin, diluted approximately (1-4) in 0.9% saline. A week later, the tumor reached approximately a size of about 0.5-1 cm in diameter. The tumor bearing mice were divided into five main groups:
Group 1 deals as control (20 mice): mice bearing tumor without treatment.
Group 2 (10 mice): mice bearing tumor exposed to cryosurgery treatment at –20°C for 5 minutes followed by hyperthermia treatment at 45°C for 5 minutes every day for 10 days.
Group 3 (10 mice): mice bearing tumor exposed to cryosurgery treatment at –20°C for 7.5 minutes followed by hyperthermia treatment at 45°C for 7.5 minutes every day for 10 days.
Group 4 (10 mice): mice bearing tumor exposed to cryosurgery treatment at –20°C for 10 minutes followed by hyperthermia treatment at 45°C for 10 minutes every day for 10 days.
Group 5 (10 mice): mice bearing tumor exposed to cryosurgery treatment at –20°C for 12.5 minutes followed by hyperthermia treatment at 45°C for 12.5 minutes every day for 10 days.
For all groups, the length and width of the tumor were measured every day with a slide caliper before subjected to Cryosurgery-Hyperthermia therapy and tumor growth volume was calculated. At the end of ten days, all animals were killed and the tumors were dissected out, their volumes were measured. Tumor volume inhibition ratio was calculated.
In the present work dielectric measurements were performed on control group (untreated), group 3 exposed to cryosurgery treatment at –20°C for 7.5 minutes followed by hyperthermia treatment at 45°C for 7.5 minutes and Group 4 exposed to cryosurgery treatment at –20°C for 10 minutes followed by hyperthermia treatment at 45°C for 10 minutes every day for 10 days.
The Experimental Results Showed That:
• A homemade Cryosurgery-Hyperthermia device was developed and constructed with simple and available materials. By examining the constructed cryosurgery-hyperthermia device, we found a device can easily reach (–20°C) during freezing and above (100°C) during heating.
• It showed that the combination treatment of both cryosurgery and hyperthermia therapies were effective to destroy the tumors by exposed with freezing and heating energy at different treatment conditions and the higher temperature applied immediately after freezing might reinforce the tumor destruction.
• Tumor growth rate increases in untreated control group. Tumor growth rate decreased in treated group with cryosurgery and hyperthermia therapy.
• A clear inhibition ratio in tumor volume was observed in treated group than untreated.
• Dielectric measurements performed on control group (untreated), group 3 and group 4 showed variation in real conductivity with frequency, the imaginary and real conductivity, the relative permittivity with frequency and the imaginary and relative permittivity between untreated and treated groups, using cryosurgery and hyperthermia therapy with different exposure times.
• Dielectric measurements can be used to monitor the changes that occur in cells due to the Cryosurgery-Hyperthermia therapy