Radiopharmacy

Question 1

What do isotopes have?

Answer 1

same number of protons

but different number of neutrons

Question 2

at what form does isotope wants to be in?

Answer 2

in the most stable form

Question 3

What results in radioactivity?

Answer 3

the rearrangement within the nuclue

Question 4

What are the types of radiation?

Answer 4

alpha particles, beta particles, gamma rays, x-rays

Question 5

Which radiation is used for diagnosis?

Answer 5

gamma radiation

- imaging, non-imaging

Question 6

What makes gamma radiation a good diagnostic tool

Answer 6

it has a very good fast penetration

Question 7

Which radiation is used for therapy?

Answer 7

beta radiation (esp for brain/thyroid cancer)

Question 8

What are the examples of radiopharmaceuticals?

Answer 8

Technetium 99m- based
others
for PET scan

Question 9

What is technetium 99m?

Answer 9

it decays by isomeric transition
with physical half life of short, 6 hours
They are readily available from a generator

Question 10

Is technetium 99m chemically versatile?

Answer 10

yes

so it is easy to stick it with many chemicals like ligands

Question 11

What is the use of technetium-99m?

Answer 11

TC-radiopharmacetual ‘cold’ kits

The kit allows them to make radioactive ligands

Question 12

What does the kit include?

Answer 12

inert gas, reducing agent, stabiliser, ligand

Question 13

What are the kits used for?

Answer 13

We have many kits for different purposes
eg. bone/brain/heart/liver imaging, kidney function/structure, hepatobiliary imaging, lymph node imaging, RBC/WBC labelling

Question 14

What beta emitters are used in what treatments?

Answer 14

iodine - thyroid (also gamma)

Question 15

What are positron emitters?

Answer 15

18F, 11C, 15O

unusual isotope for carbon, oxygen

Question 16

What is PET used for?

Answer 16

imaging cellular and molecular events (proliferation, oxygen metabolism, tumour receptor density, bone remodelling)

Question 17

What do you need for PET?

Answer 17

close access to CYCLOTRON
it accelerates charged particles for collision to make radioactive isotopes
15O, 13N, 11C, 18F

Question 18

What are the tracers in PET?

Answer 18

FDG = glucose
FLT = thymidine (nucleic acid)
18F

Question 19

What is FDG used for?

Answer 19

targets GLUT
tumour marker (increased glucose transporter)

Question 20

What is FLT used for?

Answer 20

Targets DNA synthesis, thymidine kinase

Visualisation of cells undergoing DNA replication

Question 21

What is 18F used for?

Answer 21

Targets hydroxyapatite crystals
(fluorine is for bones)
Visualisation of bone reaction to tumours

Question 22

Increase in FDG in which part of the body may indicate cancer?

Answer 22

head, neck

liver, kidney, urinary tract, bladder, heart and brain always have glucose

Question 23

Increase in FLT in which part of the body may indicate cancer?

Answer 23

Brain, heart

Question 24

What is the new technique for screening?

Answer 24

PET + MRI (both structural and functional)

AA tracer for PET –>AMT (identify which cells are making proteins)

Question 25

What are the Radiopharmaceutical quality controls

Answer 25

Radionuclidic/radiochemical/chemical.biological purity, radioactivity administered (accuracy of dose calibrator units)

Question 26

Drug ineractions

Answer 26

TPN
decreases gall bladder activity

Aluminium (e.g antacids)

Question 27

Safety - limiting exposure

Answer 27

ALARA, dose monitoring, spill kits, limit expose