Random board questions/equations
1/2 C-12
1 amu =
hinge angle equation
180 - 2(wedge angle)
100 keV/µm
optimal LET
0.1%
shield the linac head to what percent of dose at isodose
pythagorean thereom
to calculate setup error uncertainty
late
which tissue shows less survival for high doses?
acute
which tissue shows less survival for low doses?
betatron is changing microtron is constant
betatron vs microtron magnetic fields?
reproductive death
cell death for reproductive cells
1/r^2
dose falls off as
1/r
dose of a line source falls off as
wedge factor formula
dose with wedge/dose without wedge
1/Tb + 1/Tp = 1/Teff
effective half life equation
E/2
electron practical range (Rp)
Independent
exposure -> Gy in air independent or dependent of energy?
Restoring electrons in the crystal lattice to the ground state
Annealing of TLDs
focal spot - sin∅
Apparent focal spot equation
nd x (1+d/α/β)
BED equation
Charge liberated in the gas of an ion chamber
Bragg-Gray relationship
loss of function
Cell death for static cells
at least dmax
How big does the buildup cap distance need to be
Blocks
Do blocks or MLCs have a higher primary beam transmission?
H=DxQ
Dose equivalent formula
BED/(1+2/α/β)
EQD equation
Farmer chamber
Example of a thimble type chamber
Free-air chamber
Example of absolute dosimeter
cGy
KERMA is measured in
3.5 - 4 Gy
LD5-/60 without medical care
on film/on skin
Magnification factor
(PDD2/PDD1) = ((SSD2+dmax)(SSD1+d)/(SSD2+d)(SSD1+dmax))^2
Mayneord F factor
Dhypoxic/Daerobic
OER
2-3
OER for most cells types for photons/electrons
log(Io/It)
Optical density formula
s(SSD+d-SDD)/SDD
Penumbra equation
3%
Precision of TLDs?
938 MeV
Proton rest mass
PDD at 10cm
Quality of MV photon beam
Dstandard radiation/Dtest radiation
RBE
Sv
SI unit for dose equivalent
SMR = TMR(fs) - TMR (0x0)
SMR and TMR relationship
(voxel activity/mass)/(decay corrected injected activity/body mass)
SUV equation
((273+T)/293)(760/P)
T/P correction
it doesn't require calibration
What does an absolute dosimeter mean?
beam energy density of absorber atomic number of absorber
What does linear attenuation coefficient depend on?
surface dose
What is a use of thin window parallel plate chambers?
gold/lead
What is scattering foil made of
512 kB
What is the size of a CT image?
Establish electronic equilibrium
What's the purpose of a buildup cap?
early responding tissues
alpha/beta large for
late responding tissues
alpha/beta small for