Radiation Biology Flashcards
What is radiobiology?
Study of effects of ionizing radiation on living systems.
What is direct effects vs indirect effects? which is more common?
Direct= On DNA Indirect= Ionizing water.
Indirect more common (2/3)
Free radicals lead to?
Dissociations and cross-linking of the DNA
Indirect effects lead to the formation of what?
Peroxide, Peroxyl radicals…
Which cell cycle is more/less sensitive to radiation? Why?
G2>G1>S
G2 =already done editing
S= Still making repairs
Frequency of mutations increase in proportion to what?
Dose.
What is the law of Bergonie and Tribondeau?
Most radiosensitive=
- Rapidly dividing cells
- Longest mitotic potential
- Undifferentiated cells
What is deterministic effects?
Effects that occur once threshold is reached.
What is stochastic effects?
Effects occur independent of dose (probability).
Why is cancer treated with radiation therapy?
It kills cancer cells (and normal cells), but cancer cells can’t repair themselves.
Radiation causes irreversible damage to what in the oral cavity?
Salivary glands.
What is radiation caries?
Rampant form of dental decay.
What happens to teeth if they are exposed to radiation therapy during development.
Odontoblast and meoloblasts effected.
What does radiotherapy do to bone?
Leads to osteonecrosis of bone. Most important clinical feature.
What should be done before radiotherapy? After?
- Before= Restore teeth, remove teeth, let heal.
2. After= Flouride gel daily, tooth removal should be avoided.
