NM 3

Question 1

what does an isotopes half life allow us to determine

Answer 1

• how long a sample of a useful isotope will be available
• how long a sample of undesirable/ dangerous isotope must be stored before it decays to low enough radiation level (safe)

Question 2

what is physical half life

Answer 2

period of time required to reduce radioactivity level of source to exactly half of its original value solely to radioactive decay

Question 3

what is biological half life

Answer 3

period of time required to reduce amount of a drug in an organ/ body to half of it’s value due to biological elimination

Question 4

what is effective half life

Answer 4

period of time required to reduce radioactivity level of internal organ due to biological elimination

Question 5

what is effective half life

Answer 5

period of time required to reduce radioactivity level of internal organ/ whole body to half of its original value due to elimination AND decay

Question 6

what is the decay law

Answer 6

describes decay of a quantity over time
- exponential

Question 7

what are radionuclides

Answer 7

radioactive isotopes/ isomers of an element

Question 8

what are radiopharmaceuticals a combination of

Answer 8

• radioactive molecule that permits external detection
• biological active molecule/ drug that acts as a carrier and determines localisation

Question 9

nuclear reactors

Answer 9

• where radionuclides are produced
• produced using target materials with neutrons
• ## neutrons cause nuclear reactions in target material

Question 10

what is the proces by which nuclides are made in nuclear reactors

Answer 10

nuclear fission

Question 11

advantages of nuclear reactors

Answer 11

• produce useful and important radionuclides
• produce nuclides with long enough half lives to be transported

Question 12

disadvantages of nuclear reactors

Answer 12

• expensive to build and maintain
• production of radioactive waste
• expensive to run
• few and far

Question 13

how do cyclotrons work

Answer 13

• produce a beam of charged alpha particles which are used to bombard target material
• resulting nuclide will have excess charge so will decay by emission of positively charged particle

Question 14

what are the radionuclides produced from cyclotrons used in

Answer 14

• PET
• production of fluorine (F18)

Question 15

advantages of cyclotrons

Answer 15

• cleaner production than reactors
• wide range of nuclides producible
• wide range of possible techniques

Question 16

disadvantages of cyclotrons

Answer 16

• expensive to install and maintain
• very large
• radionuclides have to be ordered in advance
• radioactive waste
• not energy efficient

Question 17

what are generators

Answer 17

• used to produce steady supply of isotopes by allowing precursor to decay over time
• separates parent and daughter nuclides as some cases; daughter nuclides have shorter half life

Question 18

elution

Answer 18

separating parent and daughter nuclide

Question 19

how is the generator eluted

Answer 19

• using saline
• atm will force saline out of generator
• pouring saline through column of immobilized 99Mo elutes the soluble 99mTc
• resulting saline solution contains 99mTc
• salien is them extracted and placed directly in a sterile evacuated vial

Question 20

radionuclides for RNI ideal properties

Answer 20

• physical half life short enough to reduce patient dose but long enough for scanning
• short biological half life
• emits gamma rays that are energetic enough to leave body
• not toxic
• cheap

Question 21

what does product labelling include

Answer 21

• statement that productive is radioactive
• name of pharmaceutical preparation
• if prep is for diagnostic or therapeutic use
• route of administration
• expiry date
• batch number ]
• total radioactivity present

Question 22

common PET pharmaceutical

Answer 22

FDG - F18
- goes anywhere that is metabolising glucose
- used for oncology, cardiac and brain imaging

Question 23

common pharmaceutical of GAMMA/SPECT bone scans

Answer 23

pertechnetate - 99m TC
- easily to produce

Question 24

common pharmaceutical of PET prostate imaging

Answer 24

PSMA - 68Ga
- newer PET tracer for prostate imaging

Question 24

common pharmaceutical of GAMMA/SPECT for cardiac stress scans

Answer 24

sestamibi - 99mTc
taken up by heart muscle