how does the degree of specialization affect radiosensitivity?
radiosensitivity decreases with increased specialization.
what is:
the rate of energy deposited per unit track length through an absorber
Linear Energy Transfer (LET)
What is:
defines the ability of aerobic conditions to enhance effectiveness of radiation.
oxygen effect?
what is:
the ability to produce biologic damage
relative biologic effectiveness (RBE)
If blood producing cells are not available as an option, what cells should be considered as most radiosensitive?
stem cells
which cells are more radiosensitive:
stem cells or nerve cells?
1. stem cells are less specialized, and more radiosensitive
2. nerve cells are more specialized, and less radiosensitive.
what does LET describe in terms of radiation traveling through the body?
amount of radiation that in transferred through the body as the x-ray beams travels through it.
how does oxygenation affect radiosensitivity?
increasing oxygenation of a cell will increase a cells radiosensivity
how does LET relate to RBE?
directly related, as LET increases, RBE increases.
What does LD50 mean?
lethal dose of radiation required to kill 50% of a population.
during what phase of the cell cycle is a cell most radiosensitive?
mitosis.
As LET increases, the quality factor for a given form of radiation will ________?
increase
what is the oxygen enhanced ratio (OER)?
numeric description of the oxygen effect
X-rays are considered______?
low LET
what does the 30 represent in LD5030?
"in 30 days"
The more a cell divides, the more _______ it is?
radiosensitive.
which type of radiation has HIGH LET?
particulate radiation (alpha and beta particles)
what is the maximum OER for human tissue?
3.0
arrange the following from least sensitive, to most sensitive:
1. muscle cells
2. stem cells
3. nerve cells
4. lymphoctyes
3,1,2,4
what is:
radiation interaction with water
Radiolysis
what is the most radiosensitive cell in the body?
lymphocytes.
which type of radiation has LOW LET?
x-ray and gamma rays
what does the 3.0 represent in OER?
radiation is three times more effective greater in an aerobic environment than in an anoxic environment.
why might geriatric patients become more radiosensitve?
because their cells breakdown and regenerate again, making them more radiosensitive.
what happens when radiation interacts with water?
ionization of water occurs (HOH+ and e-)