Final

Question 1

1 Gray = ? Rads

Answer 1

100 rad = 1 Gray

Question 2

What are rad and gray a measure of?

Answer 2

The dose (energy imparted) to a specific tissue

Question 3

What does rem stand for?

Answer 3

Roentgen equivalent in man

Question 4

QF x rad = ?

Answer 4

Rem

Question 5

QF x Gy = ?

Answer 5

Sievert

Question 6

1 Sievert = ? Rem

Answer 6

100 rem = 1 Sv

Question 7

100 rem = ? Sv

Answer 7

1 Sv = 100 rem

Question 8

What are rem and sievert used to measure?

Answer 8

Occupational dose and population dose

Question 9

T/F Relative biological effectiveness (RBE) does not vary with different TYPES of radiation?

Answer 9

False

Question 10

Which unit is useful when several types of radiation are involved?

Answer 10

Rem (it takes into account the QUALITY FACTOR for different types of ionizing radiations)

Question 11

What is LET?

Answer 11

Linear Energy Transfer

How much energy an ionizing particle transfers to a material per unit distance

Question 12

T/F LET depends only on the energy of the radiation and not on the material traversed

Answer 12

False

Question 13

For x-ray energies in the diagnostic x-ray range: 1 R = ? Rad = ? Rem?

Answer 13

1 R = 1 rad = 1 rem

Question 14

Organ dose

Answer 14

Probability of stochastic effects (mainly cancer creation) as the absorbed dose averaged over an organ

Question 15

Absorbed dose

Answer 15

Energy absorbed per unit mass at a given point

Question 16

Equivalent dose

Answer 16

Organ dose corrected by a radiation weighting factor that takes into account the relative biological effectiveness of the incident radiation in producing stochastic effects

Question 17

Effective dose

Answer 17

Weighted sum of equivalent doses to all relevant tissues + organ w/the purpose “to indicate the combo of different doses to several different tissues in a way that’s likely to correlate well w/the total of the stochastic effects”

Question 18

Where is patient dose usually calculated from?

Answer 18

The skin

Question 19

Readings obtained from Focus to Skin Dose graph (F2S Dose Graph) are usually measured in what units?

Answer 19

Mrad ESE (Entrance Skin Exposure)

Question 20

What are the direct effects radiation can have on cells?

Answer 20

• Point mutations in DNA

Question 21

What are the indirect effects of radiation on cells?

Answer 21

• Ionization of water in the cell produces free radicals that may damage DNA directly or produce toxic substances that affect DNA

Question 22

T/F: DNA repair is more successful when only a single strand is broke

Answer 22

True!

Question 23

What are the 4 factors of cell sensitivity, according to the laws of Bergonie and Tribondeau

Answer 23

• Age (young cells)
• Differentiation (simple cells)
• Mitotic rate (rapidly dividing cells)
• Metabolic rate (energy-devouring cells)

Question 24

A baby has mutations from mother being irradiated prior to pregnancy. Is this somatic or genetic radiation effects?

Answer 24

Genetic

Question 25

What are non-stochastic radiation effects?

Answer 25

• Relatively high doses of radiation with severe effects that are proportional to the amount of radiation received – effects are predictable
• non-stochastic = “non-survivors”

Question 26

What is stochastic radiation effect?

Answer 26

Likelihood of the effects is proportional to dose, but the severity is unrelated to the dose (X-rays are this kind!)
– effects are random and unpredictable!

Question 27

What does rad stand for?

Answer 27

Radiation Absorbed Dose