radiotracer trivia Flashcards
thallium-201 is produced in a:
cyclotron
thallium-201 daughter product
mercury 201
mercury 201 parent
thallium 201
thallium behaves like:
potassium
potassium analog
thallium-201
MOA of Thallium
crosses cell membrane via Na/K pump (alive things with working Na/K pumps)
requires active transport (alive cells) to cross the cell membrane
Thallium-201. It’s a potassium analog so it goes into the cell via the Na/K pump
fluciclovine critical organ
liver
excess stannous ion (tin) results in
liver uptake on bone scans or RBC labeling
USP maximum diameter recommendation for macroaggregated albumin
150 μm, with 90% of particles between 10 and 90 μm
radionuclides used to treat painful osseous metastases
Strontium-89, Samarium-153, Rhenium-186
radionuclide used to treat painful osseous metastases that is a pure beta emitter
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
can you image with Strontium-89, Samarium-153, Rhenium-186?
only can image Samarium-153 and Rhenium-186 because along with beta emission (the treatment part) they have gamma emission as well
Effective half-life of a radionuclide is always _____
than either the physical or biologic half-life.
LESS
A becquerel is ___ disintegration per second. A
curie is ________ disintegrations per second.
A becquerel is 1 disintegration per second. A
curie is 3.7 × 1010 disintegrations per second.
Cyclotron-produced isotopes are often _______ because the process involves ______________.
Cyclotron-produced isotopes are often carrier
free (do not contain any of the stable element) because the process involves transmutation.
Isotopes produced by neutron bombardment
are not usually _________ because they involve
bombardment of the same element
Isotopes produced by neutron bombardment
are not usually carrier free because they involve
bombardment of the same element
what is transient equilibrium of a generator
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.
________is used as a reducing agent to allow Tc-99m
labeling of other compounds.
Tin is used as a reducing agent to allow Tc-99m
labeling of other compounds.
Technetium-99m as eluted is in a _________.
Technetium-99m as eluted is in a +7 valence
state.
Molybdenum breakthrough in a generator eluate is detected by:
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
Excessive aluminum in Tc-99m indicates
Excessive aluminum indicates the lack of stability of the generator column.
radiotracers that decay by electron capture
GIT: Gallium, Indium, Thallium
characteristic gamma rays from Tl-201 actually come from
it’s daughter Mercury 201
Gallium’s mechanism of action
acts like lactoferrin
“poor man’s bone scan”
gallium
uptake in the kidneys on gallium scan
kidney problem: acute interstitial nephritis.
critical organ of Tc-99m pertechnetate
colon
critical organ of Tc-99m MAA
lungs
critical organ for Xe-133
trachea
relative contraindication to Tc-99m MAA
pulmonary hypertension
