octreotide (octreoscan) Flashcards
what is octreotide
-aka pentetreotide
-somatostatin-peptide-14-amino acid
peptide is…
portion of amino acid that naturally binds to recpetors on cell surface
somatostatin is…
a growth hormone release inhibiting factor that is concentrated in the hypothalamus, cerebral cortex, brain stem, gi tract, and pancreas
what is octreotide used for
peptide not a MoAb
-scan + treatment
reduces diarreha in therapy pt sometimes
functions
prevents release of GH from pituitary gland and releases several other hormones affecting GI system
how do somatostatins help sympotms
treat symptoms when tumors oversecretes hormones- tumors have incr # of somatostatin receptors so octreotide binds to receptors
what receptor sites does octeotride have
somatostatin sites
what can octreotide localzie
primary and mets originating for neuroendocrine tumorsar
carcinoid
hormone producing cell
neuroblastomas
tumor on heme tissue
pheochromocytomas
adrenal glands (heart rate BP)
how to make
6 mCi In-111 chloride solution to penetreotide vial
-kit
-30 min incubate
when do inject and make kit
make kit upon pt arrival bc expensive, scan following day
-inject IV
what does kit come in and why
kit comes in glass and syringe in plastic
-x-rays attenuated by glass vial but not syringe so calibrator measurement high in syringe vs glass vial
pt prep
laxatives to clear GI tracts and off octeotride therpay for 24 hours bc those cells bound to nonradioactive substance already
at how many hours do we scan
at 24 hours
what cam do we use for WB
670
how long is WB
10 min mid thigh-> top of head
do we SPECT and how long if so
SPECT 40 sec/frame. 1,2, or 3 FOV depening on ROI
what collimator
medium
energies used
173 keV and 247 keV
total time pt is on camera
2-3 hours
biodistribution/ excretion
rapidly leaves blood after injection
-excretion by kidneys exclusively
normal places itll show up on scan
pituitary, thyroid gland, liver, spleen, kidneys, bladder, and gallbladder
what line should never be injected
TPN line
