What is RBE in radiation?
RBE (relative biological effectiveness) is a relative measure of the damage done by a given type of radiation per unit of energy deposited in biological tissues.
What type of radiation is used as a standard for determining the RBE?
Although 250 kVp X-ray was the common standard radiation to determine the RBE, the International Commission on Radiation Protection (ICRP) recommended in their 92th report to use gamma rays of 60Co as reference radiation (3) and therefore was chosen as reference in this study.
Which type of radiation has the largest RBE?
We say that α particles have a greater relative biological effectiveness (RBE) than low-energy X rays. Compared to 200-keV X rays (which are defined to have an RBE of 1), the RBE of α particles is approximately 20.
Why is RBE important?
Such beams (particularly light ions) are associated with an increased relative biological effectiveness (RBE) which, when viewed alongside the more favourable physical distributions of radiation dose available with all forms of particle beams, makes them especially attractive for treating tumours which are associated …
What effect does RBE have?
Factors That Influence RBE RBE is highly variable and depends on several parameters including the type of radiation, total dose, dose rate, dose fractionation pattern, and the biological effect being assayed. Therefore, when quoting an RBE value the exact experimental conditions used to measure it must be stated.
How is RBE measured?
RBE is calculated as a ratio of the reference radiation dose to the dose of the test radiation (ICRP, 2003): 3. However, the value of RBE varies depending on the level of effect being considered (Fig 1). The ratio Dγ High/Dn High may be different from Dγ Low/Dn Low.
What is RBE in medical?
Page 1. AbstractID: 11865 Title: Biological aspects of heavy charged particle radiation therapy. The relative biological effectiveness (RBE) is defined as the ratio of the doses required by two radiations to cause the same level of effect.
What factors govern cell radiosensitivity?
Radiosensitivity depends on several factors. These factors include the ability to repair damage, hypoxia, cell cycle position, and growth fraction. In addition, the volume of the initial tumor has been demonstrated to influence the ability to eradicate tumors.
What is radiosensitive cell?
Radiosensitivity is the relative susceptibility of cells, tissues, organs, organisms, or other substances to the injurious action of radiation. In general, it has been found that cell radiosensitivity is directly proportional to the rate of cell division and inversely proportional to the degree of cell differentiation.
Which body part is most sensitive to radiation?
Lymphocytes (white blood cells) and cells which produce blood are constantly regenerating, and are, therefore, the most sensitive. Reproductive and gastrointestinal cells are not regenerating as quickly and are less sensitive.
Which organ is the most sensitive to radiation?
As noted previously, the most sensitive organs are the blood forming organs and the gastrointestinal system. The biological effects on the whole body from exposure to radiation will depend upon several factors.
Does radiation destroy DNA?
Radiation damages the genetic material (DNA) causing single strand breaks (SSB) or double strand breaks (DSB) in the cells, thus blocking their ability to divide and proliferate further.