dosimetry

Question 1

hazards

Answer 1

radiation exposure of friends, family
contamination
childbearing
postmortem

Question 2

theranostics

Answer 2

combination of therapeutics and diagnostics
The use of one radioactive drug to identify (diagnose) and a second radioactive drug to deliver therapy.
Ideally using the same drug but different radiolabels

Question 3

comparison w xray

Answer 3

nm
Radiation Source within the Patient
Radiation Exposure determined by
Physical Half-life of Radionuclide
Biological Half-life of Pharmaceutical
Low intensity emission of ionising radiation
difficult to establish radiation dose

xray
External Radiation Source
Radiation exposure can be turned on/off
Intense short ‘burst’ or ionising radiation
easy to establish radiation dose

Question 4

radiation dose and absorbed dose
effective dose

Answer 4

Radiation Dose
Radiation energy absorbed per unit mass of absorber material (Joules / kg)

Absorbed Dose
Gray (Gy)

Effective dose combines organ dose with the biological effect of the radioactive emissions and the radiobiological sensitivity of the organ

Question 5

measuring cumulated activity

Answer 5

imaging
find effective half life
area under graph

Question 6

S value

Answer 6

S is the absorbed dose per unit accumulated activity for a particular isotope and organ (units: Grays/MBq∙s)

Question 7

limitations of MIRD

Answer 7

Based on standard models of human anatomy
Shape, size and location of organs
Assumption that activity is distributed uniformly in an organ
Assumption that energy is deposited uniformly in an organ

Question 8

effective dose assumptions

Answer 8

A population measure (not for the individual)
Rapid/slow exposure (X-ray vs NM)
….

Question 9

tissue weighting factor

Answer 9

high relative organ sensitivity
high weighting factors
eg lung

eg of low is thyroid