Bonus - Numbers to Know

Question 1

Probability of hereditary disorder in the first generation after RT

Answer 1

0.002/Sv or 0.2%/Sv

Question 2

Increased risk of prenatal xray on childhood cancer rates

Answer 2

40%

Question 3

Risk of radiation induced fatal cancers

Answer 3

5%/Sv

Question 4

Risk of radiation induced cancers

Answer 4

10%/Sv

Question 5

Genetic doubling dose for humans

Answer 5

1-2 Sv

Question 6

Percent of fatal cancers induced by TBI that are leukemia

Answer 6

15-20%

Question 7

General public equivalent dose limit

Answer 7

1 mSv / year

Question 8

NCRP max annual dose limit for eye of radiation workers

Answer 8

50 mSv

Question 9

NCRP max annual dose limit for skin of radiation workers

Answer 9

500 mSv

Question 10

NCRP max annual dose limit for radiation workers

Answer 10

50 mSv
Age x 10 mSv
(whichever is lower)

Question 11

NCRP limit for pregnant patients

Answer 11

0.5 mSv/month after declared

Question 12

Fetal dose at which abortion should be considered

Answer 12

0.1 Gy

Question 13

Average annual natural background radiation dose

Answer 13

3 mSv

Question 14

Average annual effective dose total (background)

Answer 14

6 mSv
(3 mSv from natural, 3 mSv from manmade)

Question 15

Limit for non-occupational exposure to radiation for educational and training purposes

Answer 15

1 mSv / year

Question 16

Negligible individual dose

Answer 16

0.01 mSv / year

Question 17

General public radiation limit for continuous exposure

Answer 17

1 mSv / year

Question 18

General public radiation limit for infrequent exposure

Answer 18

5 mSv / year

Question 19

Genetically significant dose (GSD) for radiation exposure from imaging procedures

Answer 19

0.3 mSv

Question 20

DSBs per Gy per cell

Answer 20

40

Question 21

Ionizations per Gy per cell

Answer 21

100,000

Question 22

Minimum TBI dose for detection of dicentrics in peripheral lymphocytes

Answer 22

0.25 Gy

Question 23

Dose rate range over which SLD most contributes to dose rate effect for x-rays

Answer 23

0.01-1 Gy/min

Question 24

For n, Dq, D0

Answer 24

ln(n) = Dq/D0

Question 25

Multitarget survival fraction

Answer 25

SF = Ne^-(D/D0)

Question 26

Survival fraction without SLD

Answer 26

SF = e^-α/D

Question 27

Linear quadratic survival fraction

Answer 27

SF = e^-(α/D + β/D^2)

Question 28

Dose for one lethal kill per cell on average

Answer 28

D0
aka radiosensitivity

Question 29

Total SLD before lethality

Answer 29

Dq
aka width of the shoulder

Question 30

Solve for D10

Answer 30

D10 = D0 x 2.3

Question 31

BED

Answer 31

= nd (1 + d/ α/β)

Question 32

Tpot

Answer 32

= Tc/GF

Tc ~ 2-5 d
GF ~ 0.2-0.5

Question 33

Cell loss factor

Answer 33

ϕ = 1 - Tpot/Td

Question 34

Labeling index

Answer 34

LI = λTs/Tc
Tpot = λTs/LI

Question 35

Mitotic index

Answer 35

MI = LI = λTm/Tc

Question 36

Therapeutic ratio

Answer 36

BED tumor ratio / BED normal tissue ratio
(experimental vs normal)

Question 37

Tumor control probability

Answer 37

TCP = e^-(# surviving cells)

= e^-M(SF)
M: # tumor clonogens

= e^-pVS
p: density
V: volume
S: SF

Question 38

TCP for 2.3 remaining cells

Answer 38

10% (0.1)
= e^-2.3

Question 39

TCP for 1 remaining cell

Answer 39

37% (0.37)
= e^-1

Question 40

TCP for 0.7 remaining cells

Answer 40

50% (0.5)
= e^-0.7

Question 41

TCP for 0.1 remaining cells

Answer 41

90% (0.9)
= e^-0.1

Question 42

TCP for 0.01 remaining cells

Answer 42

99% (0.99)
= e^-0.01