Deck 30: Fundamental Principles of Radiobiology

Question 1

The possible beneficial effect of a small amount of radiation is called ____________.

A) radiosensitizing
B) hormesis
C) radioprotection
D) protraction

Answer 1

hormesis

Question 2

Radiation induced genetic damage follows a ___________________ dose-response relationship.

A) linear-nonthreshold
B) linear-threshold
C) nonlinear-nonthreshold
D) nonlinear-threshold

Answer 2

linear-nonthreshold

Question 3

The law of __________________ states that the radiosensitivity of living tissue is a function of the metabolism and maturation of that tissue.

A) Watson and Crick
B) Roentgen and Plank
C) Hurter and Driffield
D) Bergonie and Tribondeau

Answer 3

Bergonie and Tribondeau

Question 4

A _________ response to radiation is directly proportional to the dose received.

A) linear
B) nonlinear
C) curvilinear
D) non-threshold

Question 5

A dose of 10 Gy given to a patient in 5 doses of 2 Gy per day is a ____________ dose.

A) protracted
B) fractionated
C) diagnostic
D) fatal

Question 6

_________ is a measure of the rate that energy is transferred from ionizing radiation to soft tissue.

A) LET
B) RBE
C) MeV
D) OER

Question 7

Studies of the effects of radiation show that low doses may ________________.

A) stimulate the immune system
B) extend the life span
C) stimulate hormonal responses
D) All of the above

Question 8

As LET ____________, the RBE ______________.

A) increases, remains the same
B) decreases, remains the same
C) increases, increases
D) increases, decreases

Question 9

Human cells cannot recover from radiation damage after there is ________________.

A) cellular repair
B) cellular repopulation
C) interphase death
D) sublethal damage

Question 10

Humans are most radiosensitive during ________________.

A) fetal stages
B) infancy
C) adulthood
D) old age

Question 11

The LET of diagnostic x-rays is _____ keV/mm.

A) 0.2
B) 0.3
C) 3.0
D) 50

Question 12

The human application of radioprotective agents would _____________________.

A) double radiation damage
B) be fatally toxic
C) reduce radiation effects by half
D) reduce radiation effects by one fourth

Question 13

The RBE of diagnostic x-rays is equal to _____.

A) 20
B) 10
C) 5
D) 1

Question 14

Tissue is _______ radiosensitive under high oxygen conditions and _________ radiosensitive under hypoxic conditions.

A) less, equally
B) less, more
C) more, less
D) more, equally

Question 15

Fractionation and protraction are used for radiation therapy because they allow the patient to ______________.

A) recover between doses
B) have higher total doses
C) repair damaged tissues
D) All of the above

Question 16

Tissues that are ____________ with a _______ metabolic rate are more radiosensitive.

A) immature, low
B) immature, high
C) mature, low
D) mature, high

Question 17

The human dose-response relationship at low ranges of radiation is calculated using _______________________.

A) known responses from low doses
B) extrapolation from high ranges
C) human experiments
D) All of the above

Question 18

A protracted dose of radiation is given _______________.

A) over a long period of time
B) all at one short exposure
C) in a series of separate doses
D) in two large doses

Question 19

Which dose-response relationship can follow a sigmoid curve?

A) Linear-nonthreshold
B) Linear-threshold
C) Nonlinear-nonthreshold
D) Nonlinear-threshold

Question 20

If a response to radiation is expected, no matter how small the dose, then that dose-response is _________________.

A) linear
B) nonlinear
C) nonthreshold
D) threshold