Lung cancer is a disease caused by rapid growth and division of cells that make up the lung. Normally, lung cells reproduce in an orderly fashion to maintain health and to repair injuries. But when the growth control is lost and the cells start dividing too much and too fast, it forms a mass of cells which is called as tumor. If the tumor remains confined to a few layers and does not invade the surrounding tissues or other organs, it is called a benign tumor. But if the tumor cells spread to the surrounding tissues and organs, it is called as malignant or cancerous.
Management of Lung Cancer
The management of lung cancer depends on a number of factors. These factors are as follows:
- Stage of the cancer
- Type of the cancer
- Patient’s general health
- Medical conditions that can affect treatment like chemotherapy
The different modalities of treatment for lung cancer include:
- Surgical removal of the tumor
- Radiation therapy
- Photodynamic therapy
Radiation therapy for lung cancer is a method of treatment that uses high energy ionizing radiation like gamma rays to kill cancer cells. Ionizing radiation is produced by a number of radioactive substances like cobalt, radium, iodine, radon, cesium, phosphorous, gold and yttrium.
The indications of lung cancer radiation therapy are:
- It may be used to shrink a tumor that may be later removed by surgery.
- To relieve symptoms.
- To kill malignant cells in a tumor that cannot be removed surgically.
- To treat lung cancer that has spread to the brain or other organs of the body.
- After surgery to eliminate any cancer cells that may remain in the treated area.
Mechanism of Action of Radiation Therapy
Cancer cells multiply very rapidly as compared to other normal tissues of the body. Radiation prevents cell division and formation of DNA which is human genetic material. Hence it prevents the multiplication of cancer cells. It usually does not affect the cell division in other tissues of the body as they don’t multiply so fast. But certain tissues like hair and skin, which multiply very rapidly are also vulnerable to the effects of radiotherapy.
Lung cancer radiation therapy is usually given as external beam technique in which a beam of X-rays is aimed directly at the tumor. Treatment is given in a series of sessions or fractions which is usually given over a period of six weeks.
Side Effects of Radiation Therapy
Radiation therapy can cause the following side effects:
- Hair loss
- Skin disorders like redness, itching, pain, shrinking, peeling of skin, swelling and increased pigmentation
- Anorexia (loss of appetite)
- Changes in taste perception
- Damage to the fetus in women who are pregnant
- Increase in heart rate (tachycardia)
- Increased risk for infection
It is also known as radiation surgery. It is used to treat inoperable lung cancer. In this, a single large dose of radiation is administered precisely to the tumor causing little damage to healthy tissue. The CyberKnife is a type of radiosurgery that can be used in lung cancer.
Thus, radiation therapy may be used either as a primary treatment or as an adjunctive therapy for lung cancer.
- Updates in Advances in Lung Cancer, 1997 by Schiller Joan
- Advances in Radiation Oncology in Lung Cancer, 2005