Lesson 3 Flashcards
– radioactive drugs used for therapy and diagnostic purposes.
Radiopharmaceuticals
– study of radioactive drugs and their therapeutic and diagnostic uses.
Radiopharmacology
Carrier (chemical) + Radionuclide =
Radiopharmaceutical
– provides for the affinity to special body tissues
Carrier (Ligand)
4 Nuclear Physical properties
Half- life
Decay mode
Energy & range
Gamma energy
Abundance
A shorter half life means there is a higher dose rate and therefore a greater biological effect
This is defined as the interval taken for a given quantity to decrease to halfof its initial value.
Half- life
Particulate radiation with high Linear Energy Transfer (LET) is desirable for maximum exposure and damage to tissues. All approved therapeutic radiopharmaceuticals are Beta emitters. Alpha and Auger electron emitters(Electron Capture decay mode) are also investigated today.
Decay mode
The optimal range and energy depends on the size of
the tumor, with large tumors requiring more range.
ENERGY AND RANGE
It is desirable to have gamma ray of imageable energy to allow in
vivo verification of the localization of the radiopharmaceutical
and possible patient-specific dosimetry calculation with a
gamma camera
GAMMA ENERGY AND ABUNDANCE
Nuclear (Physical) Properties
imaging procedures require an _____
(gamma or x-rays) to produce an image. it is desirable that the
photon be emitted in high abundance and be monoenergetic
electromagnetic photon
Radionuclides that decay by ___ or ___
are the most useful in diagnostic.
Isomeric Transition (IT) or Electron Capture (EC)
use of therapeutic radiopharmaceutical year
1911
was use
ineffectively to treat lupus
radium-226
In 1939, _____was used to treat leukemia in the first
medical use of an artificiallyproduced radionuclide.
P-32 Phosphate
Advantages oftherapeutic radiopharmaceuticals over chemotherapy and external beam radiation:
The carrier-free nature of radiopharmaceuticals allows therapeutic effect to be accomplished
without pharmacological effect
