What is the linear energy transfer of X-rays?
Linear energy transfer is the average (radiation) energy deposited per unit path length along the track of an ionizing particle. Linear energy transfer describes the energy deposition density of a particular type of radiation, which largely determines the biological consequence of radiation exposure.
Do X-rays transfer energy?
X-rays are a form of electromagnetic radiation similar to radio waves, microwaves, visible light and gamma rays. X-ray photons are highly energetic and have enough energy to break up molecules and hence damage living cells. When X-rays hit a material some are absorbed and others pass through.
How do you calculate linear energy transfer?
Linear energy transfer (LET) is defined for charged particles in any medium as the quotient of dEL divided by dl, where dEL is the average energy locally imparted to the medium by a charged particle of specific energy transversing a distance dl.
What is the concept of linear energy transfer?
The term “linear energy transfer (LET)” is used to indicate the average amount of energy that is lost per unit path-length as a charged particle travels through a given material.
What is OER in radiotherapy?
The OER is traditionally defined as the ratio of radiation doses during lack of oxygen compared to no lack of oxygen for the same biological effect. This may give varying numerical values depending on the chosen biological effect.
What is low linear energy transfer?
Radiation with low linear energy transfer (LET), normally assumed to comprise photons (including X rays and gamma radiation), electrons, positrons and muons. High energy (>4 MeV) protons are considered to be a low LET radiation.
What is the difference between linear energy transfer and stopping power?
While mean stopping power refers to the energy lost by the particle beam traversing the surrounding media, linear energy transfer (LET) refers to the energy absorbed by the media per unit of distance travelled by the ionizing radiation.
Why does OER decrease as LET increases?
Linear energy transfer (LET) is the density of ionizations deposited by each radiation type along its track. As LET increases, OER decreases until it becomes 1 (e.g., there is no oxygen effect). As LET increases, RBE increases up to a point (100 KeV/μm), and then declines due to the “overkill effect.”
What is the law of Bergonie and Tribondeau?
The law of Bergonie and Tribondeau is that the radiosensitivity of a biological tissue is directly proportional to the mitotic activity and inversely proportional to the degree of differentiation of its cells.
What is the relationship between OER and LET?
Why is oxygen enhancement ratio OER different from high and low LET radiation?
The Oxygen Enhancement Ratio (OER) or oxygen enhancement effect in radiobiology refers to the enhancement of therapeutic or detrimental effect of ionizing radiation due to the presence of oxygen. Radiation with higher LET and higher relative biological effectiveness (RBE) have a lower OER in mammalian cell tissues.
What is the law of Ancel and Vitemberger?
What is the law of Ancel and Vitemberger? All cells will be damaged to the same degree for a given dose of radiation, BUT damage will only be expressed if and when a cell divides. Cells that divide quickly appear to be sensitive; cells that divide slowly appear resistant.