Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pelvis and Abdomen: R&O > Nuclear Med > Flashcards

Nuclear Med Flashcards

1
Q

what are the types of targeted radionuclide therapy

A

radionuclide itself
radioimmunotherapy: monoclonal antibodies
radio labelled microspheres: introduced into arterial circulation od tumours and provides localised radiation
small molecules which carry radionuclide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

malignant pheochromocytoma

A

highest incidence 30-50
hereditary diagnosis: 24.9 years
sporadic diagnosis: 43.9 years
25% is hereditary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the symptoms for malignant pheochromocytoma

A

high blood pressure
headaches
sweating
forceful palaptations
temor
facial pallor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

MP, NETS have:

A

specific receptors at membrane
specialist neuroamine uptake mechanisms

In the adrenal medulla, some cells produce catecholamines. MIBG concentrates in the secretory granulose of the cells. Tumours which produce catecholamines are eager to metabolise this
High doses of I-131, MIBG are used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does PRRT used

A

radioactive labelled analogue therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the physiology of the RSAT

A

somatostatin is a hormone in the body, which binds to receptors which slows down hormone production, controls gastric and bowel emptying
if there is an abnormal increase treatment might be suitable
must be symptomatic with unresectable or met progressive disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the treatment for PRRT

A

as some NETS overexposes surface receptors, the somatostatin analogue is taken, the radionuclide with a beta radionuclide. A therapeutic dose must be delivered to the tumour
Yttitrium-90 and Lu-177 most common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does SIRT stand for

A

selective internal radiation therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

SIRT

A

for primary and secondary inoperable tumours in the liver
last resort
normal liver draws 80% of blood from portal vein
tumours draw more than 80% of their blood from the hepatic artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is TARE

A

Trans-arterial Radioemoblisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

who is TARE for

A

functioning live with a primary unresectable tumour, HCC
not suitable for TACE
secondary liver tumour with colorectal injury
options discussed in MDT
selected by hepatobillary cancer MDT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what happens during the planning angiogram for SIRT

A

takes 1-2hours
identify blood supply to the liver
local anaesthetic
contrast injected
small blood vessels are blocked so the microspheres can be located
150MBq radioactive tracer [Tc-99] injected into the catheter
SPECT-CT picks up the radioactive tracer, locating the liver
recover overnight in hospital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens after the planning angiogram

A

1-2 weeks after it is repeated
when the catheter is in the liver the microspheres are injected in which takes approx 1 hour
catheter is removed and wound is dressed
pain meds and antiemetics
scan checks the beads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the SE for SIRT

A

nausea
abdominal discomfort
chills
raised temp
stomach pain
diarrhoea
fatigue
cholecystitis: pain, nausea, fever
microspheres in lung = cough and SOB
microspheres in GI tract = nausea, pain, pancreatitis, stomach ulcer and bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

hazards with SIRT

A

wash hands thoroughly
avoid contact with pregnant women and children for the first week after
sleep alone for first 1-2 nights
microspheres remain in the liver
CT scan 2-3 months post treatment
regular liver and kidney tests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is refractory myeloproliferative disease/ PRV

A

over production of RBC, uncommon in bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the symptoms of PRV

A

hyper viscosity
headaches
dysponea
blurred vision
sweating
weightloss
2/3 have enlarged spleen
pruritis
flushed complexion
anaemia due to poor flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where is PRV seen

A

50-60
male
main cause of death is haemorrhage, or thrombosis, due to increased blood flow
raised RBC increases WBC and platelets
median survival: 9-13 years
if not treated 50% die within 18 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the treatment for PRV

A

venesection: one pint of blood is taken at regular intervals, repeated at 24 hours and then 48 until packed cell volume <0.5 [temporary solution]

Chemo- chlorambucil or busulphan (every 4-6 weeks)

P32: sodium phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe P-32 as a treatment option

A

neutron irradiation of P-31
half life = 14.3 days
emits beta particle: 3-8mm range
decays to non radioactive sulphur
usual dose = 150-250MBq
initial dose = 74-111 MBq
further treatments = max 260MBq

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is there rapid uptake of P-32

A

in rapidly dividing cells
it is selectively uptakes into haemopietic tissue
it is incorporated into DNA of rapidly dividing cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does P-32 inhibit

A

marrow, therefore blood production
highest conc is in bone marrow and trabecular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

administration of P-32

A

oral or IV
syringe has perspex casing for shielding
20 minutes through butterfly to avoid extravasations
check circulation
average response time is 7 days
administrator must wear film badge, gloves, mask etc
caution with taking a blood sample as it will be radioactive
effective dose is 465mSv

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the hazards of P-32 sodium phosphate

A

long term will cause leukaemia in 10-15%
GI absorption causes symptoms similar to irritable bowel
don’t give to pregnant, breast feeding women and children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
clinical applications for unsealed sources
orally via capsule radioactive gas IV
26
nuclear med
diagnostic imaging: diagnosis or localisation in vivo studies: patient injected with radioactivity samples taken to measure the level in blood, urine and faeces in vitro: in glass, radioactivity is injected into blood, faeces and urine outside the body i.e radioimmunoassay uses antibodies to detect and quantitate the amount of an antigen treatment: molecular RT or radio-immunotherapy
27
how is a tumour localised
1. a pharmaceutical is elected which will seek out the tumour 2. label the pharamacuetical use a radionuclide which won't interfere with the uptake of the pharmaceutical but allows for easy detection 3. detects the pattern of distribution of gamma rays emitted by the radiopharmaceutical with a gamma emitter 4. use the smallest activity practicable to minimise hazard, as staff will be irradiated
28
advantages with localising
looks at function and position
29
disadvantages with localising the tumour
limited to small masses <10mm in diameter, if larger multiple treatments might be needed location is hard to define
30
diagnostic: gastric
looks at motion of food through the oesophagus into the stomach and its transit time water, eggs, toast and Tc-99M ant and post dynamic images at regular intervals for up to 4 hours (stomach emptying takes 3/4 hours) draws ROI around stomach, GI tract and creates decay corrected curves for activity
31
diagnostic: gall bladder ejection function
Tc-99m hydroxy iminodiacetic acid after excretion by the liver into bile which travels through the gall bladder + bile duct GB contrast and empties due to the cholecystokinin injection images are taken at intervals
32
IN VIVO
CR51 EDTA = radioactive substance doesn't break down by body components/processes GFR is recorded to indicate whether the kidneys can filter and process chemo so won't experience renal failure a curve is plotted for GFR allows the function to be visible rather than the anatomical definition it detects issues early
33
principles of radionuclide therapy
RP are chosen for their selective uptake doses are delivered internally via physiological processes aim: deliver high doses to specific organs and tissues to deliver sufficient dose internally but spare normal tissue, resulting in cell damage
34
what is the radionuclide criteria
physical properties: sufficient dose to TV type and energy of radiation emitted range of emission physical half life chemical characteristics: viability of tumour cell radiosensitivty proliferation rate specificity of targeting - preferential uptake binding to the radioactive label to pharmaceutical effective half life
35
what cells are radiosensitive
spermatogonia erthyroblasts lymphocytes
36
what cells are radioresistant
muscle cells neural cells
37
what is T-90 used for
treating benign tumours
38
what increases biological effectiveness
high dose rate
39
what rate does radionuclide therapy have
variable the initial dose rapidly decreases due to physical decay and biological clearance
40
LET
the amount of energy deposited for a given distance by a particle moving through an absorber
41
low dose =
low LET = SSB
42
high LET =
DSB
43
how much greater is alpha LET to beta
10-1000x
44
I-131
decays by beta particle emission cheap and accessible readily attaches to the MIBG pharmaceutical to form a stable, non toxic radiopharmaceutical, remains couples to the radionuclide and is not metabolised. cells local to the site of despot achieve a higher dose so normal tissue is spared
45
prep for I-131
stop any drugs which might interfere scan first = iodine -123m MIBG block thyroid with potassium iodate at least three days prior continue for a period after treatment improve hydration consent blood test pregnancy test antiemetics
46
procedure for I-131
6000-8000MBq via IV isolated unit infusion takes 2 hours monitor signs drink plenty 1-5 doses administered at 3-6 month intervals
47
hazards with I-131
remain in isolation for 4-7 days, to get to safe level visiting restrictions non children, breastfeeding or pregnant women scanned before uptake liver receives highest dose avoid getting pregnant for the first 6 months or fathering a children for 4 months nausea and vomiting first 2 days bone marrow suppression (4-6 weeks) hypothyroidism may occur
48
beta particle emitter
different range of energies, variable speed and ranges must match what is needed tumour size is important with the range
49
why is a medium range good
great therapeutic effect, delivers dose to the target, but can have less dose homogeneity to the tissue due to gaps in the tissue
50
higher dose =
high homogenous dose to large target
51
when should a long range not be used
if near healthy tissue
52
what should be considered when selecting a emitter for therapeutic effect
effective range relative biological effectiveness to tumour mass size radiosensitivity homogeneity
53
what are the ideal therapeutic properties
high localised dose to TV minimal uptake to distant tissues remain attaches to parent carrier drug and excreted by a simple route half life long enough to accumulate in TV for effective treatment but short enough to avoid non beneficial radiation dose
54
phosphorous - 32
high local dose long range no gamma rays P-31 (n, gamma) -> P-32 neutron bombardment, making it more unstable so it is radioactive ideal §
55
Yttritium-90
high beta emitter 64 hour half life 0.94 MeV 3.6mm range can affect tumour cells up to 11mm length in soft tissue
56
Iodine-131
emits a low beta particle only for small tumours 364 and 606 KeV energy gamma ray emitted so significant irradiation to surrounding tissues
57
what is planned during radiation uptake
the organ which will receive the uptake, so that it complies the dose received from the RP depends on amount of energy deposited by the radiation.
58
what is the cumulative activity dependent on
radiopharmaceutical, the patient and the half life
59
what must be known
the targeting organs, uptake and clearance
60
absorbed dose depends on...
organ involvement, distance apart, how long it remains in the blood stream and the individual
61
dose equivalent =
absorbed dose X factor takes into account the energy distribution in the tissues 1Gy of alpha is more harmful than 1Gy of beta
62
what does dose equivalent enable
comparison of all ionising radiations regarding the potential cause of harm
63
what have a factor of 1
gamma, x-rays and beta
64
what is the factor for alpha particles
20
65
what LET does alpha have
high, so effective but needs to be bonded to the cell due to the short range
66
alpha emitter
hard to dispose safely pure emitters don't have an external hazard risk negative effects: cancer induction, genetic diseases, congenital malformations and degenerative changes
67
what are the target tissues for alpha
respiratory tract, bone, liver, reticuloendothelial
68
what treats hormone relapsed prostate cancer with bone mets
Ra-223 dichloride delivers alpha radiation without affecting normal bone marrow
69
I-131
half life: 8 days beta kev: 182 range: 3mm max gamma kev: 364, 606 uses: thyrotoxicosis
70
T-90
half life: 2.7 days beta kev: 935 range: 3.6mm avg gamma kev: - uses: arthritis, functioning NET
71
P-32
half life: 14.3 days beta kev: 695 range: 8mm max gamma kev: - uses: PRV
72
Lu-177
half life: 6.6 days beta kev: 497 range: 1.7mm max gamma kev: 208 max uses: functioning NETs, advanced prostate cancer
73
Sr-89
half life: 50-55 days beta kev: 580 range: 2.4mm avg gamma kev: 909 uses: bone mets
74
Sm- 153
half life: 1.9 days beta kev: 220 range: 0.6mm avg gamma kev: 103 uses: bone mets
75
Ra-223
half life: 11.4 days alpha 5-7.5 MeV range: <1mm gamma kev: - uses: bone mets CRPC

Pelvis and Abdomen: R&O (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions