Radiobiology Ch. 33 (Fundamental Principles Of Radiobiology)

Front 1

LET stands for

Back 1

Linear Energy Transfer

Front 2

LET is another way of expressing radiation ____

Back 2

quality

Front 3

Tissues with high metabolic activity are ( radio-resistant / radio-sensitive )

Back 3

radiosensitive

Front 4

The LET of diagnostic x rays is approximately _____

Back 4

3keV/ micro meter

Front 5

RBE stands for

Back 5

Relative Biologic Effectiveness

Front 6

The RBE of diagnostic X-rays is ___

a. 0.3
b. 1
c. 3
d. 5

Back 6

b.1

Front 7

If dose is delivered continuously but at a lower dose rate, it is said to be _____
a. Protracted
b. Fractionated

Back 7

Protracted

Front 8

As the LET increases, the ability to produce biological damage _____
a. increases
b. decreases

Back 8

a. Increases

Front 9

The standard radiation, by convention, is orthovoltage x-radiation in the range of _____
a. 50 to 100kVp
b. 100 to 150kVp
c. 150 to 200kVp
d. 200 to 250kVp

Back 9

d. 200 to 250 kVp

Front 10

5 MeV alpha particles have a LET of ___ and an RBE of ____

Back 10

100 keV / micrometer

20 RBE

Front 11

Dose fractionation is used routinely in ______
a. interventional radiology
b. radiation oncology
c. fluoroscopic radiology
d. mobile radiology

Back 11

b. Radiation oncology

Front 12

Oxygenated tissue is ____ sensitive. (more or less)

Back 12

More

Front 13

Radiosensitivity of living tissues varies with:
a. maturation
b. metabolism
c. metaphysis
d. a and b
e. all of the above

Back 13

d. a and b

Front 14

Based on age, which of the following is most radiosensitive?
a. fetus
b. adolescent
c. adult
d. elderly

Back 14

a. fetus

Front 15

The Law of Bergonie and Tribondeau states:
1. Stem cells are radiosensitive
2. Younger tissue is more radiosensitive
3. When there is high metabolic activity, radiosensitivity is also high
4. As proliferation rate and growth rate for cells and
tissues increase, radiosensitivity also increases
A. 1 & 4
B. 1 & 3
C. 2, 3 and 4
D. All of the above

Back 15

D. All of the above

Front 16

Oxygen enhances the effects (OER) of ionizing radiation on biologic tissue by ___ tissue radiosensitivity.
a. decreasing
b. increasing

Back 16

b. increasing

Front 17

Cells may be able to “recover” and “repopulate” if the radiation dose is:
a. lethal
b. sub-lethal

Back 17

b. sub-lethal

Front 18

Linear energy transfer is the measure of:
a. The amount of energy deposited per unit mass
b. RAD exposure
c. The rate at which energy is transferred from ionizing
radiation to soft tissue
d. An organ being radiated and shrinking in size

Back 18

c. The rate at which energy is transferred from ionizing radiation to soft tissue.

Front 19

With irradiation of the reproductive cells, one is concerned
with ___ mutations.
a. genetic
b. somatic

Back 19

a. genetic

Front 20

Energies that are slow moving, highly charged, and which deposit large amounts of energy in the tissues through which they pass possess a/an _____ LET.

a. high
b. low

Back 20

a. high

Front 21

Which of the following is not considered a physical factor affecting tissue radiosensitivity?
a. LET
b. RBE
c. fractionation
d. oxygen effect

Back 21

d. oxygen effect

Front 22

The more specialized (mature) the cell, the __ radiosensitive.
a. less
b. more

Back 22

a. less

Front 23

X-rays with a quality factor of 1 have a/an ___ LET as compared to alpha, which has a quality factor of 20.
a. higher
b. lower

Back 23

b. lower

Front 24

Radiation therapy is delivered in ___ doses, which allows recovery time for the healthy cells.
a. protracted
b. fractionated

Back 24

b. fractionated

Front 25

Which of the following relates to quality of the radiation and radiation-weighting factor?
a. LET
b. RBE

Back 25

a. LET

Front 26

The concept of radiation “hormesis” is that a little radiation may be “good for you”.
The radiation is said to stimulate __ responses to other toxic environmental agents.
a. hormonal
b. immune
c. age
d. a and b
e. b and c

Back 26

d. a and b


a. hormonal &
b. immune

Front 27

Diagnostic radiology is primarily concerned with __ effects of radiation exposure.
a. early
b. Late

Back 27

b. Late

Front 28

The S-type (sigmoid-type) radiation dose-response relationship is used to describe:
a. sigmoid colon effects from fluoroscopic studies
b. skin effects from high dose fluoroscopy
c. somatic cells effects from long exposure times
d. sensitizing agent effects on somatic cells

Back 28

b. skin effects from high dose fluoroscopy

Front 29

To “extrapolate” may be compared to developing a/an __________________.

Back 29

hypothesis

Front 30

While we do not consider it “the” safe dose, the author of the text indicates that “no human
radiation responses have been observed following doses of less than 10 rad (100 mGy). To have no response below 10 rad would indicate what kind of dose-response relationship?
a. non-threshold
b. threshold

Back 30

b. threshold

Front 31

When an irradiated cell dies before the next mitosis, it is called:
a. clonal death
b. cytogenetic death
c. interphase death
d. metaphase death
e. mitotic death

Back 31

c. interphase death

Front 32

Ionization of a K-shell electron results from the:
a. Compton effect
b. Photoelectric effect

Back 32

b. Photoelectric effect

Front 33

Using a shorter SID increase the ___ dose of the patient.
a. organ
b. skin

Back 33

b. skin

Front 34

Which of the following does not follow a linear-nonthreshold dose-response relationship?
a. cancer
b. leukemia
c. genetic effects
d. cataracts

Back 34

d. cataracts

Front 35

For cancer patients, doses of radiation may be used to shrink tumors as a means of palliative treatment.
The shrinking of the tumor corresponds to :
a. acromegaly
b. cardiomegaly
c. atrophy
d. dystrophy

Back 35

c. atrophy

Front 36

If an individual was exposed to 1 Rad of each of the following types of radiation, which one would deliver
the greatest dose in Rems?
a. diagnostic x-rays
b. 200 keV x-rays
c. Beta radiation
d. Alpha radiation

Back 36

d. Alpha radiation

Front 37

A group of cells with a high mitotic rate will also possess:
a. high radiosensitivity
b. low radiosensitivity
c. the rate of mitosis does not affect radiosensitivity

Back 37

a. high radiosensitivity

Front 38

Which of the following would result in the least tissue damage?
a. fractionated dose, highly oxygenated tissue
b. fractionated dose, adult tissue
c. non-protracted dose, fetal tissue
d. non-protracted dose, highly oxygenated tissue

Back 38

b. fractionated dose, adult tissue

Front 39

Somatic effects of radiation will be manifested in the:
a. reproductive cells of the individual exposed
b. future generations of the individual exposed
c. lifespan of the individual exposed
d. both the individual exposed and future generations

Back 39

c. lifespan of the individual exposed

Front 40

Which of the following cells demonstrate a low degree of radiosensitivity?
a. muscle
b. sperm
c. lymphocytes
d. leukocytes

Back 40

a. muscle

Front 41

When a linear, nonthreshold dose-response relationship intersects the response axis at zero dose (RN), it means that:
a. there is a natural incidence of the response
b. there is no natural incidence of the response
c. recovery and repair have occurred
d. it is not linear

Back 41

a. there is a natural incidence of the response