What is radiotherapy?
Radiotherapy is the treatment of disease, but predominantly cancer, which uses forms of radiation. It uses high-energy rays to treat disease and it works by destroying cancer cells in the area that's being treated.
With external radiotherapy a carefully controlled beam of radiation targets the area where the cancer cells are found. A team of radiation therapists, cancer specialists and physicists try to work out the best way to target the cancer whilst minimising the damage to other tissue. For curing cancer the radiation needs to be very carefully targeted and controlled, so the radiation is produced by a powerful X-ray machine.
With internal radiation therapy, a small amount of radioactive …show more content…
Doctors take potential damage to normal cells into account when planning a course of radiation therapy. the amount of radiation that normal tissue can safely receive is known for all parts of the body. Doctors use this information to help them decide where to aim radiation during treatment.
Physics of the electromagnetic radiation used
Electromagnetic radiations can be considered as a stream of photons. Photons are particles of zero mass and charge that travel in a wave like pattern at the speed of light. Each photon has a certain quantity or pattern of energy.
Gamma rays have the smallest length wave and their photons have the most energy of all the waves in the electromagnetic spectrum. They are generated by the decay of radioactive atoms and nuclear explosions. The high energy of gamma ray photons means they can pass through most things. Gamma rays are a form of ionising radiation, which means that when they pass through matter they pass on their energy to electrons in the atoms they hit. This makes them dangerous as they can ionise atoms in the body thereby damaging killing cells. If the DNA in a cell is damaged by gamma radiation it can mutate and cause