Bonus - Numbers to Know Flashcards
Probability of hereditary disorder in the first generation after RT
0.002/Sv or 0.2%/Sv
Increased risk of prenatal xray on childhood cancer rates
40%
Risk of radiation induced fatal cancers
5%/Sv
Risk of radiation induced cancers
10%/Sv
Genetic doubling dose for humans
1-2 Sv
Percent of fatal cancers induced by TBI that are leukemia
15-20%
General public equivalent dose limit
1 mSv / year
NCRP max annual dose limit for eye of radiation workers
50 mSv
NCRP max annual dose limit for skin of radiation workers
500 mSv
NCRP max annual dose limit for radiation workers
50 mSv
Age x 10 mSv
(whichever is lower)
NCRP limit for pregnant patients
0.5 mSv/month after declared
Fetal dose at which abortion should be considered
0.1 Gy
Average annual natural background radiation dose
3 mSv
Average annual effective dose total (background)
6 mSv
(3 mSv from natural, 3 mSv from manmade)
Limit for non-occupational exposure to radiation for educational and training purposes
1 mSv / year
Negligible individual dose
0.01 mSv / year
General public radiation limit for continuous exposure
1 mSv / year
General public radiation limit for infrequent exposure
5 mSv / year
Genetically significant dose (GSD) for radiation exposure from imaging procedures
0.3 mSv
DSBs per Gy per cell
40
Ionizations per Gy per cell
100,000
Minimum TBI dose for detection of dicentrics in peripheral lymphocytes
0.25 Gy
Dose rate range over which SLD most contributes to dose rate effect for x-rays
0.01-1 Gy/min
For n, Dq, D0
ln(n) = Dq/D0
Multitarget survival fraction
SF = Ne^-(D/D0)
Survival fraction without SLD
SF = e^-α/D
Linear quadratic survival fraction
SF = e^-(α/D + β/D^2)
Dose for one lethal kill per cell on average
D0
aka radiosensitivity
Total SLD before lethality
Dq
aka width of the shoulder
Solve for D10
D10 = D0 x 2.3
BED
= nd (1 + d/ α/β)
Tpot
= Tc/GF
Tc ~ 2-5 d
GF ~ 0.2-0.5
Cell loss factor
ϕ = 1 - Tpot/Td
Labeling index
LI = λTs/Tc
Tpot = λTs/LI
Mitotic index
MI = LI = λTm/Tc
Therapeutic ratio
BED tumor ratio / BED normal tissue ratio
(experimental vs normal)
Tumor control probability
TCP = e^-(# surviving cells)
= e^-M(SF)
M: # tumor clonogens
= e^-pVS
p: density
V: volume
S: SF
TCP for 2.3 remaining cells
10% (0.1)
= e^-2.3
TCP for 1 remaining cell
37% (0.37)
= e^-1
TCP for 0.7 remaining cells
50% (0.5)
= e^-0.7
TCP for 0.1 remaining cells
90% (0.9)
= e^-0.1
TCP for 0.01 remaining cells
99% (0.99)
= e^-0.01
