W/L Ch 4 Overview of Radiobiology Quiz

Question 1

What is the typical oxygen enhancement ratio (OER) value for sparsely ionizing radiation?

a. 0.5 to 1.0
b. 1.0 to 2.0
c. 2.5 to 3.0
d. Greater than 3.0

Answer 1

c. 2.5 to 3.0

Question 2

Which of the following is the most important treatment-related variable for the development of the late-term effects of ionizing radiation?

a. Treatment volume
b. Elapsed days
c. OER
d. Dose

Answer 2

d. Dose

Question 3

To calculate the nominal standard dose (NSD), what factors must be known?
I.   Total dose
II.  Fraction size
III. Elapsed days
a.	I and II
b.	I and III
c.	II and III
d.	I, II, and III

Answer 3

d. I, II, and III

Question 4

A whole-body radiation dose given in a period of seconds to minutes produces a clinical pattern called what?

a. Delayed effects
b. Mortality rates
c. Acute radiation syndromes
d. Clinical body dose

Answer 4

c. Acute radiation syndromes

Question 5

How does oxygen retention affect radiosensitivity?

a. Increases
b. Decreases
c. No change
d. Varies by tissue

Answer 5

a. Increases

Question 6

Isoeffect curves are most closely associated with which of the following?

a. Oxygen enhancement
b. Radiation syndromes
c. Tolerance doses
d. Fractionation

Answer 6

d. Fractionation

Question 7

Which term describes certain chemicals or drugs that enhance the response of cells to radiation?

a. Free radicals
b. Radiosensitizers
c. Radioprotectors
d. NSAIDs

Answer 7

b. Radiosensitizers

Question 8

What does the term interphase death mean?

a. The cell dies prior to entering interphase.
b. The cell dies prior to leaving interphase.
c. The cell dies between mitotic phases.
d. The entire organism dies.

Answer 8

b. The cell dies prior to leaving interphase.

Question 9

Which of the following tissues is least radiosensitive?

a. Bone
b. Kidney
c. Ocular lens
d. Colon

Answer 9

a. Bone

Question 10

Which macromolecule is most radiosensitive?

a. Lipids
b. Carbohydrates
c. Proteins
d. Deoxyribonucleic acid (DNA)

Answer 10

d. Deoxyribonucleic acid (DNA)

Question 11

Which of the following is not a pyrimidine?

a. Adenine
b. Cytosine
c. Thymine
d. Uracil

Answer 11

a. Adenine

Adenine is a purine.

Question 12

Which of the following terms is used to describe radiation damage to a cell that is not sufficient to kill the cell?

a. Relative biological effect
b. Sublethal damage
c. Tumor lethal dose
d. Lethal dose50/40

Answer 12

b. Sublethal damage

Question 13

Which of the following terms describes the separation of water into hydrogen and oxygen following exposure to radiation?

a. Radiolysis
b. Radioactivity
c. Ionization
d. Duplication

Answer 13

a. Radiolysis

Question 14

Which of the following is not an early response to radiation?

a. Breast cancer
b. Erythema
c. Diarrhea
d. Chromosome aberrations

Answer 14

a. Breast cancer

Question 15

To produce the same biological effects seen after a single dose of 5,000 cGy, the total dose of a fractionated dose would be _________.

a. less
b. greater
c. equivalent

Answer 15

b. greater

Question 16

The tolerance dose TD 50/5 for the lens of the eye is __________ to/than the TD 5/5 for the lens of the eye

a. less
b. greater
c. equivalent

Answer 16

b. greater

Question 17

The TD 5/5 for the whole liver is approximately _____ Gy.

a. 15
b. 20
c. 30
d. 40

Answer 17

c. 30

Question 18

The TD 50/5 for the optic nerve is approximately _____ Gy.

a. 25
b. 35
c. 50
d. 65

Answer 18

d. 65

Question 19

Fractionation of radiation dose administration to neoplastic tissues has which of the following effects? (Select three.)

a. Reoxygenation of hypoxic tumor cells, thus promotes their sensitivity to subsequent doses
b. Favors repair of radiation injury in normal cells over that of cancer cells
c. Favors repopulation of normal tissues slightly
d. Reduces or blunts the effects of the radiation injury in early responding normal tissues

Answer 19

a. Reoxygenation of hypoxic tumor cells, thus promotes their sensitivity to subsequent doses
b. Favors repair of radiation injury in normal cells
d. Reduces or blunts the effects of the radiation injury in early responding normal tissues

Question 20

Which of the following cell types are likely to express radiation injury shortly after a D0 dose of radiation is received? (Select two.)

a. VIM
b. DIM
c. RPM
d. FPM

Answer 20

a. VIM
b. DIM

Vegetative intermitotic (VIM) and differentiating intermitotic (DIM) cells are the most and second most radiosensitive types of cells, respectively, and are likely to express radiation injury.