Radiation Biology

Question 1

How many rads is 1 Gy?

Answer 1

1 Gy = 100 rads

Question 2

How does absorbed does get converted mathematically into equivalent dose?

Answer 2

radiation weighting factor

Question 3

How does equivalent does get converted mathematically into effective dose?

Answer 3

tissue weightig factor

Question 4

If all dose is absorbed, how many gray is 1 Sievert?

Answer 4

if all absorbed, 1 gray = 1 sievert

Question 5

Are tissue doses generally a little bit higher or a little bit lower than KERMA?

Answer 5

little bit higher

Question 6

What does KERMA stand for?

Answer 6

kinetic energy released per unit mass

Question 7

What dose parameter is totally independent of distance?

Answer 7

KAP

Question 8

What is the equation for Relative Biological Effectiveness (RBE)?

Answer 8

dose of 250 kV Xrays/test dose

Question 9

What does Direct Ionizing Radiation act on?

Answer 9

direct = DNA

Question 10

What does Indirect Ionizing Radiation act on?

Answer 10

water

Question 11

Xray or gamma ray of what dose will kill a large number of cells in a few seconds?

Answer 11

1,000 gray

Question 12

In what cell cycle phase are cells MOST susceptible to radiation?

Answer 12

M

Question 13

In what cell cycle phase are cells LEAST susceptible to radiation?

Answer 13

S

Question 14

Surviving Cell Synchonization

Answer 14

yes

Question 15

What is the most radiosensitive part of the GI tract?

Answer 15

small bowel

Question 16

Greater than what dose is needed to effect bone marrow?

Answer 16

> 2 Gy

Question 17

Greater than what dose is needed to effect the GI tract?

Answer 17

> 8Gy

Question 18

Greater than what dose is needed to effect the CNS?

Answer 18

> 20

Question 19

What is LD 50/30?

Answer 19

radiation dose that will kill 50% of people in 30 days

Question 20

What is the typical LD 50/30?

Answer 20

3-4 Gy (whole body) WITHOUT treatment

Question 21

What weeks of gestation are most susceptible to radiation?

Answer 21

weeks 8-15

Question 22

The fetal thyroid does not take up iodine prior to what week of gestation?

Answer 22

week 8

Question 23

What is the annual dose limit for cataract exposure?

Answer 23

150 mSv

Question 24

What is the onset of epilation?

Answer 24

21 days

Question 25

What is the dose for temporary epilation?

Answer 25

3 Gy

Question 26

What is the dose for permanent epilation?

Answer 26

7 Gy

Question 27

What is the dose for male sterility?

Answer 27

5 Gy

Question 28

What is the dose for female sterility at age 12?

Answer 28

10 Gy

Question 29

What is the dose for female sterility at age 45?

Answer 29

2 Gy

Question 30

What is the minimum age for occupational exposure?

Answer 30

18

Question 31

What dose will typically trigger additonal patient care/follow up?

Answer 31

15 Gy

Question 32

What is the annual exposure maximum to an occupational worker for a single extremity?

Answer 32

500 mSv

Question 33

What is the maximum allowable dose to the fetus in a post-declared pregnancy?

Answer 33

0.5 mSv/month

Question 34

In regards to a mammo room, what is the drywall thickness?

Answer 34

two layers of 5/8th inch thick drywall

Question 35

In regards to a mammo room, how thick of steel do the doors need to be equivalent to?

Answer 35

1 mm

Question 36

Which organ can have radiation induced benign and malignant lesions?

Answer 36

thyroid