Rad protection Ch 6

1.

1 point

________________ is the dose necessary to produce a certain biologic response under anoxic conditions compared to the dose necessary to produce the same response under aerobic conditions.

LET

Oxygen enhancement ratio

Relative biologic effectiveness

2.

1 point

OER is higher for _____________

high LET radiation

Low LET radiation

3.

1 point

The unit of measure for LET is:

Rads

keV/µm

keV/mm

Rem

4.

1 point

The delivery of a dose of radiation over an extended period of time is ____________

Protraction

Linear Energy Transfer

Relative biologic effectiveness

Fractionation

5.

1 point

Fast neutrons have an OER of ___

1.5

1.1

3

2.5

6.

1 point

Protons have an OER of _____

1.5

3

1.1

2.5

7.

1 point

The oxygen effect is dependent on the ____

HLR

LET

RBE

OER

8.

1 point

If 600 RADS is delivered to the whole body in one dose given within a few minutes, the patient will probably die but, if the same dose is given as 100 RADS per treatment for several days, the patient is likely to survive. This is an example of ____________

relative biologic effectiveness

linear energy transfer

fractionation

protraction

9.

1 point

Diagnostic x-rays have an OER of ____

1.5

1.1

2.5

3

10.

1 point

Biological factors affecting radiosensitivity includes:

Cross linking

Chemical agents

Oxygen effect

Height

Weight

Age

Point lesion

Recovery

11.

1 point

Recovery is assisted by ________ by the surviving cells

Repair

Repopulation

death

12.

1 point

As LET increases, RBE increases proportionally

True

False

13.

1 point

Irradiation of water molecules causes the molecule to ionize and form new substances. this is called _______

Hydrolysis

Radiolysis

Cross-links

abberation

14.

1 point

______________ have less chance to interact with the DNA directly

high LET radiations

Low LET radiations

15.

1 point

If 600 RADS is delivered to the whole body in one dose given within a few minutes, the patient will probably die in a few days but, if the same dose is delivered as 1 RAD/hr for 600 hours, the patient will probably live. This is an example of _________

linear energy transfer

protraction

relative biologic effectiveness

fractionation

16.

1 point

The Radiosensitivity/age pattern reverses around the age of

70

80

90

60

17.

1 point

X-rays and gamma rays are _________

Low LET radiation

High LET radiation

18.

1 point

The formation of new substances through radiolysis requires what two processes?

Cross-linking

Point lesion

Dissociation

Ionization

19.

1 point

1 MEV electrons have an OER of ___

2.5

3

1.1

1.5

20.

1 point

The delivery of a total dose of radiation broken down into several smaller intermittent doses given over a period of several days is _______________

relative biologic effectiveness

protraction

linear energy transfer

fractionation

21.

1 point

Examples of radiosensitizers:

Hydrogen

Vitamin K

Actinomycin D

Sulfur

Cysteine

Methotrexate

Cysteamine

Hydroxyurea

22.

1 point

Water makes up _____ of body composition

90%

80%

70%

98%

23.

1 point

Radioprotectors have not found human application because they would have to be administered in levels that would be toxic.

True

False

24.

1 point

Characteristics of low LET radiation include:

More destructive to biologic matter

Slow to relinquish energy

Sparsely ionizing

Produce more ionizations per unit of track

Lose energy more rapidly

Interacts randomly

25.

1 point

_____________ have less travel range but higher probability of interacting with the DNA of a cell

Low LET radiation

High LET radiation

26.

1 point

The LET for x-rays is:

1 KeV/mm

20 KeV/µm

10 KeV/µm

3 KeV/µm

27.

1 point

H2O + x-ray photon =

HOH+ & e-

HOH+ & e+

HOH- & e-

HOH- & e+

28.

1 point

___________ causes less exposure effects to the organism as a whole because intracellular repair and recovery occur between doses.

fractionation

protraction

29.

1 point

The ratio of the dose of standard radiation needed to produce an effect to a dose of test radiation needed to produce the same effect

Relative biological effectiveness

Protraction

Fractionation

Linear Energy Transfer

30.

1 point

Because of the limitations with RBE, we use the ______________________ to calculate the dose equivalent and determine the ability of a dose of ionizing radiation to cause biologic damage.

Radiation weighting factor

Testing factor

Equivalent dose

Effective dose

31.

1 point

Chemicals that reduce the effect of radiation damage

Radiolysis

Radioprotectors

Radiosensitizer

32.

1 point

Living tissue is more sensitive to the biologic effects of ionizing radiation when the tissue is saturated with ________

Chemicals

Oxygen

Nitrogen

Hydrogen

33.

1 point

When solving for RBE, the "standard dose" refers to an x-ray photon with the energy range of ____________

200 to 250 kVp

70 to 75 kVp

90 to 100 kVp

100 to 125 kVp

34.

1 point

Chemicals that enhance the effect of radiation damage

Radioprotectors

Radiosensitizers

Vitamins

Minerals

35.

1 point

Characteristics of high LET radiation include:

Sparsely ionizing

Produce more ionization per unit of track

Lose energy more rapidly

More destructive to biologic matter

Slow to relinquish energy

Interacts randomly

36.

1 point

If the ion pair does not regroup, the electron can attach to another water molecule and produce ____

HOH+

HOH-

37.

1 point

_______________ results in a reduced response by the organism due to the lower dose rate which gives any damaged tissue time to repair itself.

protraction

fractionation

38.

1 point

Radiosensitivity decreases with ____

altitude

age

Increased melanin

39.

1 point

Humans are most sensitive to ionizing radiation _________

as a child

before birth

as a teenager

as an adult

40.

1 point

Alpha particles are _____________

Low LET radiation

High LET radiation

41.

1 point

If the ion pair regroups during radiolysis, no damage occurs.

True

False

42.

1 point

OER decreases to about 1.0 for _______________

low LET radiation

high LET radiation

43.

1 point

The measure of the rate at which energy is transferred from the ionizing radiation to the object it penetrates

Relative biologic effectiveness

Linear Energy Transfer

Fractionation

Protraction

44.

1 point

As LET increases, RBE _________

increases

does not change

decreases

45.

1 point

It is estimated that _____________ of all radiation damage is not repaired.

25%

5 to 10%

10 to 20%

15%

46.

1 point

Because human cells vary in absorbed dose, RBE is not practical for radiation protection dose levels in humans.

True

False

47.

1 point

Gamma rays have an OER of _____

1.5

1

2.5

3

48.

1 point

The ability of ionizing radiation to produce a biologic response increases as the LET _______

Increases

Decreases

49.

1 point

Irradiation is most likely to occur with ________

macromolecules

water

cysteine

cysteamine