Effects of radiation on biological tissue

Effects of radiation on biological tissue are Linear Energy Transfer (LET), Oxygen effect, Metabolic effects etc.

Linear Energy Transfer (LET)

Linear Energy Transfer (LET) is a measure of rate at which energy is transferred from ionising radiation to the exposed tissue. Biological damage increases as linear Energy transfer increases.

Oxygen effect

Radiation therapy is more effective in Oxygenated cells. Hyperbaric oxygen and hyperthermia are recommended to increase oxygenation of tissue.

Metabolic effects

Radio sensitivity is a function of the metabolic state of the tissue.  Radio sensitivity is directly proportional to the mitotic activity of cell and indirectly proportional to their level of specialisation. So, permanent cells such as neutrons, skeletal and cardiac muscles are radio-resistant and dividing cells such as germ cells, marrow cells, lymphoid and respiratory cells are radio sensitive.

Complications of Radiotherapy

Complications of Radiotherapy may be immediate, latent or depends on the area to be irradiated.

Immediate complications of Radiotherapy observed with in minutes or days after irradiation. For example, Epilation (loss of hair), desquamation of skin, skin erythema, chromosome aberration, haematological depression etc.

Latent complications of Radiotherapy are not observed within month or years and occur after the long gap of time. Examples are Leukemia, cancer, life span shortening and lethal genes.

Complications of Radiotherapy depend on the area to be irradiated such as ophthalmic neoplasm irradiations and bone complications. In case of ophthalmic neoplasm irradiations, the effects can be in the form of conjunctivitis, keratitis, cataract etc. In case of radiotherapy of bone complications are fractures, septicosteoradio necrosis and sarcoma formation may occur.