Radiotherapy or Radiation oncology or Radiation therapy is an alternative treatment for cancer. Cancer is uncontrolled growth of cells in any part of the body. Radiotherapy uses high-energy radiations such as x-rays, gamma rays, or protons to control the growth of malignant or cancer cells. It does not provide cure for the disease but controls the progression of disease. It is usually combined with chemotherapy, surgery, or hormone therapy for better results.

Indications for Radiotherapy

    Cancerous or malignant tumors

  • Non-cancerous or benign tumors

  • Some blood disorders

  • Trigeminal neuralgia

  • Acoustic neuromas

  • Heterotopic ossification

Methods of radiotherapy:

There are basically two methods that are usually used to give radiotherapy to a patient. The choice of method depends upon the type, size and location of cancer. The two methods are:

  • External radiotherapy: The radiotherapy that is given from outside through an external source is termed as external radiotherapy. A machine called linear accelerator which consists of high-energy radiation beams is used in external radiotherapy. The radiations are externally aimed on the cancer and surrounding areas. The surrounding areas are focused because there are high chances of spread of cancer to these tissues. It is a painless process. It involves continuous treatment for few days or weeks.

  • Internal radiotherapy: In this method, a radioactive source that can be solid or liquid is temporarily placed inside the body near the cancer. Although the insertion of radioactive source may sometimes cause a little discomfort but the emission process is completely painless.

Procedure of Radiotherapy:

During radiotherapy, the high-energy radiations are directed to the cancerous cells either externally or internally. The radiations permanently damage the DNA of the cancerous cells leading to their death. These radiations may temporarily damage the nearby normal cells as normal cells have the ability to repair the DNA damage themselves. This results in the normal growth of these cells. If the requirement is to reduce the pain or size of tumor then small doses of radiation is recommended.


Radiotherapy is an important part of cancer treatment and can be a highly effective treatment for cancer as well as other disorders. Although it doesn’t cause immediate shrinking of cancerous tumours but can subsequently give beneficial effects. It may cause side-effects in some patients that are easily manageable and go away on their own within few months of the therapy.