What is Radiotherapy?

Radiotherapy, also known as radiation therapy, is the treatment of cancer and other diseases using ionizing radiation. This deposits energy that injures or destroys cells in the area being treated by damaging their genetic material making it impossible for them to continue to grow. Radiotherapy is of 2 types: Internal radiotherapy (brachytherapy) where radioactive material is temporarily placed within the body, and External radiotherapy (teleradiotherapy) where the radiation is given from an external source. The majority of patients require to take external radiotherapy.

Machines like the Linear accelerator supply the radiotherapy in the form of high-energy x-rays. The higher the energy the deeper the penetration.

It is obvious from the above that developing countries, especially India are solely lacking in, up to date radiotherapy facilities.

A Basic Radiotherapy Centre

	A virtual image of the area to be radiated is first obtained. This can be done with a dedicated simulator. It is also possible to do the same with an existing CT scan machine if equipped with virtual simulation package.
	Once a simulated image is obtained treatment planning is done on the treatment planning system. Here decisions are made on how to best deliver the radiotherapy causing maximum benefit with minimal damage to surrounding tissues.
	The treatment planning settings are then conveyed to the linac to deliver the appropriate treatment.

• Radiotherapy is given in divided doses called fraction
• Typically a patient is given between 28-35 fractions
• Each fraction is given on a daily basis, 5 days a week followed by 2 days of rest