radiotracer trivia

Question 1

thallium-201 is produced in a:

Answer 1

cyclotron

Question 2

thallium-201 daughter product

Answer 2

mercury 201

Question 3

mercury 201 parent

Answer 3

thallium 201

Question 4

thallium behaves like:

Answer 4

potassium

Question 5

potassium analog

Answer 5

thallium-201

Question 6

MOA of Thallium

Answer 6

crosses cell membrane via Na/K pump (alive things with working Na/K pumps)

Question 7

requires active transport (alive cells) to cross the cell membrane

Answer 7

Thallium-201. It’s a potassium analog so it goes into the cell via the Na/K pump

Question 8

fluciclovine critical organ

Answer 8

liver

Question 9

excess stannous ion (tin) results in

Answer 9

liver uptake on bone scans or RBC labeling

Question 10

USP maximum diameter recommendation for macroaggregated albumin

Answer 10

150 μm, with 90% of particles between 10 and 90 μm

Question 11

radionuclides used to treat painful osseous metastases

Answer 11

Strontium-89, Samarium-153, Rhenium-186

Question 12

radionuclide used to treat painful osseous metastases that is a pure beta emitter

Answer 12

Strontium-89.

Strontium-89 (89Sr) is essentially a pure beta emitter and poses virtually no hazard to medical staff
or patient families, except for urinary precautions
for a few days.

BUT….cannot image because no gamma rays

Question 13

can you image with Strontium-89, Samarium-153, Rhenium-186?

Answer 13

only can image Samarium-153 and Rhenium-186 because along with beta emission (the treatment part) they have gamma emission as well

Question 14

Effective half-life of a radionuclide is always _____

than either the physical or biologic half-life.

Answer 14

LESS

Question 15

A becquerel is ___ disintegration per second. A

curie is ________ disintegrations per second.

Answer 15

A becquerel is 1 disintegration per second. A

curie is 3.7 × 1010 disintegrations per second.

Question 16

Cyclotron-produced isotopes are often _______ because the process involves ______________.

Answer 16

Cyclotron-produced isotopes are often carrier

free (do not contain any of the stable element) because the process involves transmutation.

Question 17

Isotopes produced by neutron bombardment
are not usually _________ because they involve
bombardment of the same element

Answer 17

Isotopes produced by neutron bombardment
are not usually carrier free because they involve
bombardment of the same element

Question 18

what is transient equilibrium of a generator

Answer 18

In most generators used, there comes a time
when the ratio of the daughter to the parent
becomes constant (transient equilibrium) and
for 99Mo-99mTc generators, the 99mTc activity
slightly exceeds the 99Mo activity. This takes
several days. Once eluted, a 99Mo-99mTc generator will reach 95% of maximal 99mTc activity in
about 24 hours.

Question 19

________is used as a reducing agent to allow Tc-99m

labeling of other compounds.

Answer 19

Tin is used as a reducing agent to allow Tc-99m

labeling of other compounds.

Question 20

Technetium-99m as eluted is in a _________.

Answer 20

Technetium-99m as eluted is in a +7 valence

state.

Question 21

Molybdenum breakthrough in a generator eluate is detected by:

Answer 21

Molybdenum breakthrough in a generator eluate is detected by the penetration of 740- and
780-keV photons through a lead shield that
attenuates the 140-keV photons of technetium

Question 22

Excessive aluminum in Tc-99m indicates

Answer 22

Excessive aluminum indicates the lack of stability of the generator column.

Question 23

radiotracers that decay by electron capture

Answer 23

GIT: Gallium, Indium, Thallium

Question 24

characteristic gamma rays from Tl-201 actually come from

Answer 24

it’s daughter Mercury 201

Question 25

Gallium’s mechanism of action

Answer 25

acts like lactoferrin

Question 26

“poor man’s bone scan”

Answer 26

gallium

Question 27

uptake in the kidneys on gallium scan

Answer 27

kidney problem: acute interstitial nephritis.

Question 28

critical organ of Tc-99m pertechnetate

Answer 28

colon

Question 29

critical organ of Tc-99m MAA

Answer 29

lungs

Question 30

critical organ for Xe-133

Answer 30

trachea

Question 31

relative contraindication to Tc-99m MAA

Answer 31

pulmonary hypertension