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For such purposes, doses should be evaluated in terms of absorbed dose (in gray, Gy), and where high-LET radiations (e.g., neutrons or alpha particles) are involved, an absorbed dose, weighted with an appropriate RBE, should be used" Radiation weighting factors are largely based on the RBE of radiation for stochastic health risks. However, for ...
The RBE is generally independent of LET for any LET less than 10 keV/μm, so a low LET is normally chosen as the reference condition where RBE is set to unity. Above 10 keV/μm, some systems show a decline in RBE with increasing LET, while others show an initial increase to a peak before declining.
The detailed RBE vs. LET relationship that was found for total exchanges is similar to that of earlier studies of mutation [11] [12] and in vitro neoplastic transformation. [13] For all of these endpoints, RBE peaks at around 100 to 200 keV/μm before it decreases at very high-LET. However, the quality of chromosome damage is different when ...
Relative biological effectiveness (RBE) quantifies the ability of radiation to cause certain biological effects, notably either cancer or cell-death, for equivalent radiation exposure. Alpha radiation has a high linear energy transfer (LET) coefficient, which is about one ionization of a molecule/atom for every angstrom of travel by the alpha ...
Heavy ion therapy (e.g. carbon ions) makes use of the similarly high LET of 12 C 6+ ions. [5] [6] Because of the high LET, the relative radiation damage (relative biological effect or RBE) of fast neutrons is 4 times that of X-rays, [7] [8] meaning 1 rad of fast neutrons is equal to 4 rads of X-rays. The RBE of neutrons is also energy dependent ...
Radiation with higher LET and higher relative biological effectiveness (RBE) have a lower OER in mammalian cell tissues. [2] The value of the maximum OER varies from about 1–4. The maximum OER ranges from about 2–4 for low-LET radiations such as X-rays, beta particles and gamma rays, whereas the OER is unity for high-LET radiations such as ...
The primary advantage of alpha particle (α) emitters over other types of radioactive sources is their very high linear energy transfer (LET) and relative biological effectiveness (RBE). [5] Beta particle (β) emitters such as yttrium-90 can travel considerable distances beyond the immediate tissue before depositing their energy, while alpha ...
It is unknown whether high-LET radiation could cause the same types of tumors as low-LET radiation, but differences should be expected. [9] The ratio of a dose of high-LET radiation to a dose of x-rays or gamma rays that produce the same biological effect are called relative biological effectiveness (RBE) factors. The types of tumors in humans ...