Other Metals in Biology Flashcards
what is diagnostic imaging?
exploiting tissue penetration of gamma rays derived from nuclear decay or positron annihilation
what is targeted therapy
exploiting the cellular toxicity of non-penetrating alpha and beta particles and secondary electrons.
what is a cyclotron?
a particle accelerator which is electrically powered to accelerate a beam of charged particles in a spiral path.
how does a cyclotron work?
Ds are electromagnets causing ions to move in a spiral motion. Field switches between + and - to attract and repel ions causing acceleration. ion hits deflecting electrode and the durants as they spiral. ions collected at target point.
how do radioisotopes decay?
by either positron emission or electron capture
why is the most common radiopharmaceutical used 99mTc?
because it is:
- easily available
- has optimal nuclear properties
- it is low cost
what does SPECT stand for and what is it used for?
Single Photon Emission Computerised Tomography
-used to create sectional images from single gamma rays.
what does PET stand for and what does it do?
Positron Emission Tomography
-it is the emission of a positron which annihilates with an electron to produce a pair of identical gamma rays which is then detected to create an image.
how does the positron emitting Leutathera work?
- It’s injected by IV
- its concentration rises in neuroendocrine tumor (NET) site
- Lutathera binds to somatostatin receptors type 2 (ssrt2) which are overly expressed by (NETs)
- it is internalised in the NET cells
- it delivers radiation within the cancerous cell
- the radiation causes DNA strands to break causing tumour cell death
How is Lutathera selective for cancer tells?
the somatostatin receptor type 2 is present on many cells so lutathera can bind to all. However, there’s more of the receptors on NETs so lutathera is more attracted to them killing many cancer cells but only a few healthy cells.
