Radiopharmacy Flashcards
What is radiopharmacy?
Radiopharmacy is the study of the science and art of preparing, compounding, quality control and dispensing of radiopharmaceuticals and radioisotopes for use in nuclear medicine for diagnosis, therapy and also for use in research and industries.
What is a radiopharmaceutical?
Radiopharmaceutical (or radioactive drug) is any substance defined as a drug that exhibits spontaneous transformation of unstable nuclei with the emission of nuclear particles or photons and includes any nonradioactive reagent kit or nuclide generator that is intended to be used in the preparation of any such substance.
Classes of radiopharmaceuticals
Diagnostic (rad Dx)
Therapeutic (rad Rx)
Research radiopharmaceuticals.
What is a radioisotope?
Radioisotope (or radionuclide) is an isotope which is not in a stable energy state and can gain stability by the emission of radiation which can be particulate (α or β emission) or electromagnetic (γ radiation).
Who are radiopharmacists?
Radiopharmacists are responsible for the filling and dispensing of prescriptions for radioactive tracers and for the clinical aspects of radiopharmacy.
Required training for radiopharmacists
(1) Radioactive tracer techniques
(2) Safe handling of radioactive materials
(3) Preparation and quality control of drugs prepared for administration to humans.
What is a nuclide?
A unique atom characterized by its atomic number and its atomic mass number and having stability such that its lifetime is measurable.
All atoms sharing the same atomic number are not the same element. True or false?
False
What is radioactivity?
The property of certain nuclides whereby they emit radiation due to the spontaneous
transformation of their nuclei into those of other nuclides as a result of disintegration due to instability.
What is radioactive decay?
Radioactive decay is the property of unstable nuclides during which they undergo a spontaneous transformation within the nucleus. This change results in the emission of energetic particles or electromagnetic energy from the atoms and the production of an altered nucleus.
The term radioactivity was actually coined by…
…Marie Curie
Who discovered polonium and radium as radioactive elements?
Marie and Pierre Curie
Who discovered radioactive emissions and when?
Antoine Henri Becquerel in 1896
What was Becquerel working with when he discovered radioactive emissions?
Naturally fluorescent minerals called pitchblende
Who won the Nobel Prize in Physics in 1903?
Becquerel - for discovery
Pierre and Marie - for contribution
What influences the stability of an atom?
The relative numbers of protons and neutrons present.
An atom is said to be radioactive if…
…it contains unstable nuclei and is able to naturally release energy in the process of shedding high speed charged particles, in an attempt to reach a stable state.
When does transmutation of a radioactive substance stop?
When stability is achieved. A daughter nuclide will continue to be formed spontaneously until this happens
What are radioisotopes?
They are unstable isotopes of an element whose nuclei emit radiation spontaneously to achieve a more stable nuclear configuration
Radioactive isotopes are identified by…
…their mass numbers, used as a superscript in front of the symbol of the isotope or it is written after the symbol or name of the isotope, eg, iodine-123
What is natural radioactivity?
When radioactivity occurs spontaneously without external forces
How many naturally occurring radioactive series are there?
There are three naturally occurring radioactive series among the elements in the periodic table.
What are the natural radioactive series?
The uranium series
The actinium series
The thorium series
NOTE: Each named after the element at which the series start (except the actinium series which starts with a different uranium isotope).
When does the radioactive decay of the natural radioactive series stop?
Each one ends when it reaches a different stable isotope of lead.
What is a radioactive series?
A series of elements that are formed by disintegration of a long-lived parent (as actinium, thorium, or uranium) through the successive loss of alpha or beta particles, sometimes by alternative routes and that are all radioactive, except the end products which are stable isotopes of lead or bismuth.
All members of a radioactive series are unstable except…
…the end products which are stable isotopes of lead or bismuth.
What is artificial radioactivity?
It is a method of inducing a nuclear reaction in a stable isotope by bombarding it with particles such as neutrons.
What are transuranium elements?
Since about 1940, a set of new elements with atomic numbers over 92 (the atomic number of the heaviest naturally occurring element, Uranium) have been artificially made.
Types of radiation
- Alpha particle emission (α-particle)
- Beta-particle emission (β-particle)
- Gamma-ray emission (γ)
- Positron emission
- Proton and neutron emission
- Electron capture
- X-rays
Artificial transmutation is usually
carried out in…
…either a particle accelerator such as a cyclotron or in a nuclear reactor.
The rate of decay depends on the radioactive material and varies widely from material to
material. True or false?
True
Some physical or chemical processes can alter or affect the rate at which the disintegration of
atoms proceeds
False
The activity (A) of a radionuclide is…
…the rate at which it is decaying, i.e. the rate at which the nuclei in a sample are decomposing. It is recorded as the number of nuclei disintegrating per seconds.
S.I. unit of activity
Becquerel (Bq)
The activity of a nucleus does not depend on…
- the type of decay
- the energy of the decay products
- the biological effects of the radiation.
The activity of a nuclei only depends only on…
…the number of decays per second
What is the value of 1 Curie (Ci) in Becquerel?
3.7 x 10^10 becquerel
The activity of 1 gram of radium
What is the specific activity of a nuclide?
The specific activity of a radioactive material is the activity per unit mass or volume of that sample.
The activity of a radionuclide is inversely proportional to the mass of the isotope. True or false?
False
Simple radioactive decay
Here, radionuclides produce only one daughter isotope with radiation, even though it may exist in several different energy states, exhibiting first order kinetics.
What is the decay constant?
It represents the probability of a nucleus disintegrating in a given time t.
What is the half-life of radionuclide?
Half-life (t1/2) of a radionuclide is the time taken for half the nuclei in a sample to disintegrate.
