Ch 30 Fundamental Principles of Radiobiology Flashcards

1
Q

What are the different names for Stem Cells?

A
  • Immature Cells
  • Precursor
  • Undifferentiated Cells
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2
Q

What type of cells are sensitive to Radiation?

A

Immature cells

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3
Q

What does proliferation mean?

A

The splitting/ dividing of cells

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4
Q

What happens to cells the more mature they are?

A

They become more resistant to radiation

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5
Q

What is the law needed to understand the biologic effects of radiation?

A

The Law of Bergonie and Tribondeau

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6
Q

What are the Laws of Bergonie and Tribondeu?

A
  • Stem cells are radiosensitive, the more mature a cell, the more resistant to radiation
  • The younger the tissue, the more radiosensitive
  • When metabolic activity is high, radio sensitivity is high
  • As proliferation increases, so does radio sensitivity
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7
Q

What is the radiosensitvity of cells proportional to?

A

Their reproductive activity

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8
Q

The radio sensitivity is inversely proportional to:

A

Their degree of differentiation

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9
Q

When does the most pronounced radiation effects in cells occur?

A

When they have the least maturity and specialization or differentiation

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10
Q

What law mainly has application in Radiation Therapy?

A

The law of Bergoine and Tribondeau

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11
Q

What type of cell is more sensitive to radiation, immature or mature cells?

A

Immature cells

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12
Q

What does LET stand for?

A

Linear Energy Transfer

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13
Q

What does RBE stand for?

A

Relative Biologic Effectiveness

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14
Q

What does OER stand for?

A

Oxygen Enhancement Ratio

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15
Q

What are the (3) attributes that determine the extent to which radiation energy is transferred into biologic tissue?

A

LET
RBE
OER

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16
Q

What is the rate radiation energy is transferred into soft tissue in diagnostic x-rays?

A

3 keV

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17
Q

What is an important factor in assessing potential tissue and organ damage from exposure to ionizing radiation?

A

LET

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18
Q

What two categories, can LET be divided into?

A

High and Low

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19
Q

What attribute is a method of expressing radiation quality?

A

LET

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20
Q

What are examples of Low- LET radiation?

A

External Electromagnetic Radiations

  - X-rays
  - Gamma rays
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21
Q

Does low LET relinquish their energy quickly or over a sustained amount of time?

A

Over time

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22
Q

How does low LET cause damage?

A

Primarily through indirect action; involves free radicals

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23
Q

What does High LET radiation include?

A

Particles that possess substantial mass and charge.

24
Q

What are some examples of High LET radiation?

A
  • Alpha particles
  • Ions of heavier nuclei
  • Beta radiation
25
Q

How well does High LET radiation penetrate?

A

Not very well,

It gives up energy quickly

26
Q

What type of LET causes the most damage?

A

High

27
Q

What increases as LET increases?

A

The ability of ionizing radiation to produce a biologic response

28
Q

Does beta radiation have more energy than x-rays?

A

No, beta particles just lose their energy into the tissue faster

29
Q

What escalates as the LET of radiation increases?

A

Biologic damage produced by radiation

30
Q

What are some Biologic Factors that Affect Radiosensitivity?

A
  • Oxygen effect (OER)
  • Age (consistent with the law of B&T)
  • Recovery
  • Chemical agents
  • Hormesis
31
Q

What does Hormesis mean?

A

A little bit of radiation is good for you

32
Q

What is OER?

A
  • Oxygen Enhancement Ratio
  • The ratio of the radiation dose required to cause a particular biologic response of cells in an oxygen deprived environment
33
Q

What is more sensitive to radiation, a fetus or a newborn?

A

A fetus

34
Q

Who is more sensitive to radiation, a newborn or a young child?

A

A newborn

35
Q

What happens to radiosensitivity in teens?

A

It decreases

36
Q

At what age specifically in teens does radiosensitivity decrease the most?

A

18 y/o

37
Q

Radiosensitivity stabilizes as we age. At what age does it begin to increase again?

A

70 y/o

38
Q

When are breast cancer rates increased?

A

When children are exposed to radiation at a time when breast tissue is developing

39
Q

What are growing children 2-3 times more radiosensitive than adults in developing?

A

Leukemia

40
Q

What does Dose Protraction mean?

A

Continuous dose of radiation at a lower rate, Bigger dose in a smaller amount of time

41
Q

Define Dose Fractionation:

A

Divided doses of radiation given at a low rate, more of a treatment plan over time

42
Q

Define Nonthreshold:

A

Small dose could cause an effect

43
Q

Define Threshold:

A

Level is reached below, which no effects are observed

44
Q

Curves are either:

A

Linear or non linear

45
Q

As dose increases:

A

So do the effects

46
Q

What is another name for Deterministic radiation responses?

A

Nonstochastic

47
Q

What is a Hematologic disorder?

A

Blood

48
Q

What does Epilation mean?

A

Loss of hair

49
Q

What does Erythema mean?

A

Redness of skin

50
Q

What does Desquamation mean?

A

Shedding of outer layer of skin

51
Q

Following a high dose exposure to radiation that appeared within minutes, hours, days or weeks after exposure would be an example of:

A

Deterministic/ Nonstochastic

52
Q

What are some examples of Deterministic/ Nonstochastic effects?

A
  • Cytogenetic damages
  • Hematologic depression
  • Skin damage
    • Epilation
    • Desquamation
    • Erythema
53
Q

What is another name for a Stochastic response?

A

Probabilistic

54
Q

What is the name for responses that appear years later:

A

Stochastic/ Probabilistic

55
Q

What are some examples of Stochastic/ Probabilistic responses?

A
  • Cancers
  • Leukemia
  • Genetic Disorders