ch 16: radioisotopes and radiation protectin Flashcards
atoms that have the same number of protons within the nucleus but have different numbers of neutrons
isotopes
isotopes of a particular element that are unstable because of their neutron-proton configuration spontaneously undergo changes or transformations to rectify the unstable arrangement
radioisotopes
what types of cells are very sensitive to damage by radiation?
well oxygenated, rapidly dividing
radioactive material must be held for a period of
10 half lives
Iodine-125 (125 I 53) has been used quite extensively in the form of _____________________ to give a tumoricidal radiation equivalent dose (EqD) to cancers that are confined within the _________
titanium-encapsulated cylindric seeds, prostate gland
Treatment goal with _______ is to deliver 145 Gy to at least 90% of the prostate’s volume
Iodine 125
Treatment goal with Iodine is to deliver ______ to at least __% of the prostate’s volume
145 Gy, 90%
Iodine 125 decays by a process called
electron capture
half life of Iodine 125
59.4 days
half life of Iodine 131
8 days
iodine 131 decays by a process called
beta decay
diagnostic nuclear medicine isotopes
Iodine 123, Technetium-99m
what is the most commonly used radioisotope in nuclear medicine?
Technetium-99m
Iodine-123 (123 I 53): When chemically coupled with sodium, it forms the radiotracer compound sodium iodide 123I that preferentially concentrates in the ____________ and achieves levels of concentration that can be directly correlated with the ____________________-
thyroid gland, thyroid gland’s performance status
what is the most common isotope in PET scanning?
Fluorine-18
