Photodynamic therapy - a method of treating cancer, which uses a combination of special preparations (photosensitizers) and light with certain wavelengths. Photosensitizers that tend to accumulate in the tumor injected or given orally to the patient. When exposed to light with specific wavelengths photosensitizers produce a special form of oxygen that destroys cancer cells.

Each photosensitizer is activated by light of a specific wavelength. Wavelength depends on how deep in the body can penetrate light. Thus, physicians may use different photosensitizers to treat tumors in various parts of the body.

How does photodynamic therapy

Primarily in the patient administered photosensitizer. This substance absorbs all body cells, but in cancer cells it is longer than all the others. Approximately 24-72 hours after entering the drug when in normal cells have almost no photosensitizer, a tumor begin to affect light of a specific wavelength. Photosensitizers accumulated in the tumor, absorb light and produce a special form of oxygen that destroys the surrounding cells.

In addition to killing cancer cells, photodynamic therapy destroys cancer in two other ways. Firstly, photosensitizers may damage the blood vessels in the tumor, thus breaking the flow of nutrients thereto. Secondly, photodynamic therapy may activate the immune system, causing it to attack the cancerous cells.

A light source for photodynamic therapy are most often the lasers. Laser light via a fiber optic cable can be routed directly to a tumor within the body. For example, fiber optic cable can be inserted through the endoscope into the lungs or esophagus for the treatment of cancer in these organs. Other light sources, such as light emitting diodes, are used for the treatment of superficial tumors, such as skin cancer Skin cancer - a full recovery possible .

Photodynamic therapy can be used in conjunction with other treatments - surgery, radiotherapy and radiotherapy Radiotherapy in cancer treatment: irradiation aid .

Extracorporeal photopheresis - a type of photodynamic therapy. During this procedure, a special device collects blood cells by the patient outside the body processes the photosensitizer, light and then returns to the patient.

Restrictions apply

Light needed to activate most photosensitizers can not pass through the tissue deeper than one centimeter. For this reason, photodynamic therapy is commonly used for the treatment of tumors located just below the skin or membrane of the internal organs or cavities. Photodynamic therapy is less effective in the treatment of large tumors, since light can not properly act on them. Finally, in most cases, this method can not be used for the treatment of metastatic cancer.

Complications

Photosensitizers increase the sensitivity of the skin and eyes to light; This effect lasts for about six weeks after the end of treatment.

Furthermore, the use of this method of treatment can cause burns, edema, pain and scarring of healthy tissue adjacent to the place where the tumor is located. Depending on where the tumor is located, photodynamic therapy can cause side effects such as cough, difficulty swallowing, stomachache Pain in the stomach when the body asks for help Pain when breathing, shortness of breath. Typically, these side effects are temporary.

The order of the procedure

• The photosensitizing agent is administered by injection into the bloodstream.
• The drug is absorbed by cells throughout the body. In cancer cells, as compared to unaltered cells of the body is longer agent: drug leaves normal cells for 24-72 hours, remain in cancer cells.
• The tumor is exposed to radiation. A photosensitizing agent absorbs light of tumor cells by generating reactive oxygen species destroy cancer cells.
• The photosensitizing agent destroys blood vessels in the tumor, preventing the entry into the affected area of ​​nutrients. Moreover, therapy stimulates the immune system The immune system - how it works? , Begins to suppress cancer cells.

Benefits

• Less aggressive compared with surgery
• The procedure is limited to only the area requiring treatment
• When used correctly, there is no long term side effects
• Depending on the requirements of photodynamic procedure can be repeated as many
• After photodynamic therapy remains scars

Restrictions photodynamic therapy

• With this procedure it is possible to cure only those entities that may be subjected to irradiation. Even if the photosensitizing agent penetrates into the cells of any organ, the light does not reach all parts of the body.
• Patients undergoing an injection of a photosensitizing agent, need to guard against the sun and glare for six weeks after the injection.
• Patients with allergies to porphyrins can not prescribe photodynamic therapy

Cancer - is the uncontrolled growth of abnormal cells in the body. The cells are a type of building blocks from which to "build" all living things. Cancer begins to increase in healthy cells. Normally, cells multiply when the body needs them, and die when the need for them disappears. Cancer occurs when cell growth goes out of control of the body, and they multiply too quickly. It also occurs when cells "forget" how to die and that they all need to do.

There are many types of cancer. It can start to develop in almost all organs and tissues, such as lung, colon, breast, bone, or nervous tissue.

The causes of cancer are also very many, among them:

• Exposure to benzene and other chemicals
• The ingestion of certain poisons and poisonous mushrooms vegetable
• Certain types of viruses
• Radiation
• sunlight
• Tobacco

However, the causes of many types of cancer remain unknown. At the moment, most of the deaths from cancer accounts for lung cancer.

In total there are more than 100 types of cancer.

Normal body cells

The human body consists of one billion living cells that grow, divide, and die in a certain way and in due time. In the early years of life is faster cell reproduction to ensure the growth of the organism; an adult human, this process slows down and the majority of the cells divided only to replace the old or dying cells, or to restore the damaged areas of the body.

How cancer begins

Cancer of any kind begins with the fact that the cells in any part of the body start to grow in an uncontrolled manner. The process of cell growth at this differs from the normal. Rather than to die, cancer cells continue to grow and form new abnormal cells. Cancer cells may also infiltrate (invade) into other tissue to healthy cells that are not capable. Uncontrolled growth and penetration into other tissues - the two main features which make the cell a cancer cell.

Cells become cancerous because of damage to DNA. DNA is found in all cells and directs their actions. DNA damage in the normal cells or these cells is restored or die. In cancer cells, the damaged DNA is not restored, and the cells do not die, not only, but also generate new cells in which the body does not need. These new cells will be the same damaged DNA.

Defective DNA can be inherited, but most of the damage or are the result of errors that occur during normal cell division, or are due to environmental factors. Sometimes it causes DNA damage apparent, such as lung cancer Lung cancer - prevention is better than cure   a smoker, but in many cases you can not figure out what caused the cancer. Most cancers form a tumor cell; However, for some types of cancer, such as leukemia Leukemia - it is not a sentence This does not happen.

In the later stages of cancer can pass from the body, where it began to develop in other tissues and parts of the body and form new tumors there that replace normal tissue. This process is called metastasis. It begins when the cancer cells get into the bloodstream and lymphatic vessels of the body.

Cancer is always named according to the place where he began to develop. Even if the cancer started in the mammary glands, and passed to the liver, it will be called breast cancer, not liver, only already metastatic.

Between different types of cancer, there are huge differences. For example, breast cancer Breast cancer - the verdict?   and lung cancer - a very different diseases that develop differently, and lend themselves to different Metolit treatment.

Noncancerous tumor

Tumors that are not cancerous, called benign. They may also become a problem, for example, if made very large, and will press on healthy organs and tissues. However, they can not spread to other parts of the body remain where they were formed, and are almost never life threatening.