Crib sheet data Flashcards
Tech 99
Energy?
Half Life?
Low - 140
6 hours
Iodine 123
Energy?
Half Life?
Low - 159
13 hours
Xenon
Energy?
Half Life?
Low 81 125 hours (bio t1/2 is 30 seconds)
Thallium 201
Energy?
Half Life?
Analogue of?
Low 135
73 hrs
Potassium
Indium 111
Energy?
Half Life?
Medium 173 and 247
67 hours
Gallium 67
Energy?
Half Life?
Analogue of?
93/184/300/393
78 hours
Iron
Iodine 131
Energy?
Half Life?
High 365 8 days (192 hours)
Fluorine 68
Energy?
Half Life?
Analogue of?
High - 511
110 min
Glucose
Cobalt 57
Energy?
Half Life?
Low 122/136
270.9 days
Germanium 68
Energy?
Half Life?
High 511
270 days
Gallium 68
Energy?
Half Life?
High 511
68 min
Field Uniformity Flood testing - how often is Extrinsic (with collimator) testing performed?
Daily
Field Uniformity Flood testing - how often is Intrinsic (without collimator) testing performed?
Weekly
How often is energy window testing performed?
Daily
What is this?
What are the components?
Max count/sec?
Good for wipe test?
What other nucs device is similar?
- Well Counter
- refer to diagram
- 5,000 count/sec
- Yes, is good for wipe test
- Thyroid probe
What is this?
What is it good for?
What do you do if dose higher than expected?
detection range?
Problem with it?
- geiger muller counter
- low level surveys (good for this)
- Ion chamber used when dose is higher than expected
- 0.1 - 100 R/hour
- Problem is dead time when dose is >100 mR/hour
Gamma camera QC
- Field Uniformity
“Flood”
- Extrinsic (with collimator) - DAILY
- Intrinsic (without collimator) - WEEKLY - Energy window - DAILY (For Tc, 20% window centered at 140 keV)
- Image linearity and spatial resolution - WEEKLY
- Center of rotation - WEEKLY
QA on dose calibrator (ionizing chamber)
CLAG
- Consistency - DAILY
- Linearity - QUARTERLY
- Accuracy - INSTALLATION and ANNUALLY
- Geometry - INSTALLATION and ANY TIME DEVICE IS MOVED
Annual dose limit to public
1 mSV (100 mrem)
Dose to be considered “restricted area” (public)
0.02 mSV/hr (2 mrem/hr)
Signs must be placed for the following with what doses (public):
- Radiation area
- High radiation area
- Very high radiation area
- 0.05 mSv/hr (0.005 rem/hr) at 30 cm
- 1 mSV/hr (0.1 rem) at 30 cm
- 5000 mSV/hr at 1 m
Total body dose per year (occupational)
50 mSv or 5 rem
Dose to ocular lens per year (occupational)
20 mSV or 2 rem
Total equivalent organ dose (including skin) (occupational)
500 mSv or 50 rem
Total equivalent extremity dose per year
500 mSv or 50 rem
Total dose to embryo/fetus over entire 9 months
5 mSv or 0.5 rem
SUV (formula)
(Tissue radioactivity concentration at time point 1 x Pt weight) / Injected dose activity
PET QA
- Blank scan - DAILY
- Normalization scan - MONTHLY
What is this?
What kinds of radiopharmaceuticals can it be used for?
Syringe Shield
Gamma emitters
What is this?
What can you put in it (general)?
What specifically can you put in it?
How does this type of decay work and why use plastic?
Plastic syringe shield
Beta emitters
I-131, MO-99, Xe-133 (produced in nuclear reactor)
Beta minus decay is ejection of an electron from the nucleus.
Would cause bremsstrahlung radiation in a metallic shield.
What is going on here?
How often should it be done?
wipe test
weekly and if recent contamination in excess of roughly 22,000 dpm/100cm^2 (probably low yield)
What does this label indicate regarding the package contents?
White I: Almost no radiation
Maximum allowable radioactivity is 0.005 mSv/hr on package surface.
What does this label indicate about the contents?
- Yellow II: low radiation levels - max radioactivity is:
- 50 mrem/hr (0.5 mSv) on package surface.
- 1mrem/hr (0.01 mSv/hr) at 1 M from package
Imagine if you will that this said Radioactive III instead of radioactive II… what would that tell you about the contents?
- Yellow III: higher levels of radiation
- surface: 200 mrem/hr (2 mSv/hr)
- 1 m from package: 10 mrem/hr (0.1 mSv/hr)
What constitutes a reportable medical event?
Whole body dose >50 mSv
Single organ dose > 500mSv
Delivered dose 20% or more than expected dose
When must a reportable medical event be reported?
By telephone no later than next calendar day.
and
In writing within 15 days
Dose limit for the eye lens per year
150 mSv
When is a pregnant radiation worker required to declare their pregnancy?
They aren’t. It’s voluntary.
(#embryonic lives matter)
Dose limit to embryo/fetus?
- Entire pregnancy 5 mSV
- If already received this dose by time of declaration, then + 0.5 mSv more is ok
What are recordable but not reportable medical events?
How long must records be retained?
Event resulting in a dose below the NRC limits. It may caused by
Administered dose falls 10% outside the prescribed dose range, or
Wrong patient, or
Wrong radiopharmaceutical, or
Wrong route of administration
Need to be recorded locally and kept for 10 years
E.g. 10 mCi of In-111 octreotide is 66.7% more than the usually prescribed dose of 6 mCi. This is a recordable event for the hospital and nuclear medicine department but does not meet the NRC definition of medical event.
Muaz says 5 yrs, Jerry Allison says 10 years
What doses constitute a major spill for the following:
- Tc-99m
- Tl-201
- Ga-67
- In-111
- I I-131
100 mCi Tc-99m or Tl-201
10 mCi Ga-67 or In-111
1 mCi I-131
Stochastic effects are?
Stochastic: The frequency of effects in a
population depends on dose without
threshold (e.g. cancer).
Nonstochastic effects?
Non-stochastic: The severity of effects varies with dose above threshold (e.g. cataracts).
In nuclear medicine what is the relationship between sensitivity and resolution?
sensitivity and resolution are inversely related.
formula for effective half life?
1/Te = 1/Tp + 1/Tb
PET QA
How often to perform blank scan?
How often to do normalization?
How often to do image linearity and spatial resolution using parallel lead bar phantom?
- Daily
- Monthly
- weekly
What kind of scan is this?
Radiotracer half life?
Indium 111 tagged WBC
Bones visible > hot spleen
67 hour
What kind of scan?
Half life?
Tc-99 Sulfur colloid
Bones visible > spleen = liver
6 hours
What kind of scan (all 4 are same scan with slightly different but still normal biodistributions)
Halflife?
Gallium 67
bones visible > light splenic uptake
78 hours
What scan?
half life?
Indium 111 octreotide
67 hrs
What scan?
Half life?
Tc 99 sestamibi (MIBI)
No bones > heart uptake seen > Kidneys seen
6 hours
What scan?
Half life?
I 123 - MIBG (metaiodobenzylguanidine )
13 hours
What scan?
Halflife?
Iodine
I-123 T½ is 13 hours
I-131 T½ is 8 days (192 hours)
Radionuclides that decay by electron capture?
GIIT
- Gallium 67
- Indium 111
- Iodine 123
- Thallium 201
3 radionuclides that undergo beta minus decay?
- I-131
- MO-99
- Xe-133
What are the cardiac radionuclides?
- Thallium 201
- Tc 99 sestamibi
- Rubidium 82
- Nitrogen 13
- F18 FDG
What does Thallium 201 show in the heart?
Half life?
Perfusion with redistribution
73 hours
What does Tc99 sestamibi show in the heart?
Half life?
Perfusion without redistribution
6 hours
Rubidium 82 shows what in the heart?
Perfusion
Nitrogen 13 shows what in the heart?
perfusion
F18 FDG gives what information regarding the heart?
Viability
Radionuclides that are produced in a cyclotron have charged particles and are neutron deficient. So, decay occurs by one of what two ways?
- Positron emission
- Electron capture
What are 4 things that decay by positron emission?
- C-11
- N-13
- O-15
- F-18
What are the things that decay by electron capture again?
GIIT Co (colorado? Company? I dunno)
Gallium 67
Indium 111
Iodine 123
Thallium 201
oh, and also Cobalt 57
Typical IR thrombin dose range?
100 - 1000 IU
Usually 300 IU
List the stages of the cell cycle in order of decreasing susceptibility to radiation.
M > G2 > G1 > S
General population risk of cancer is what %?
4- 5 %/ SV
Fetal risk of cancer doubles if exposed to > ?
> 25 mGy
Half value layer for:
- CR
- CT
- Mammo
- CR: 3 cm
- CT 3-4 cm
- Mammo: 1 cm (lower energy beam quality)
CT dose reference values for:
- CT head:
- Pediatric CT head:
- CT abd/pelv:
- Ped CT abd/pelv:
- CT head: 75 mGy
- Pediatric CT head: 35 mGy
- CT abd/pelv: 25 mGy
- Ped CT abd/pelv: 20 mGy
What size are the pediatric abdomen phantoms?
Reference values for each?
16 cm: 7.5 mGy
32 cm: 10 mGy
Formula for relative biological effectiveness?
RBE = (Dose of 250 Kv of xrays)/(Dose in Gy of test radiation)
What things have high linear energy transfer (LET)?
Alpha particles
Heavy ions
Neutrons
Protons
What things have low LET?
Positrons
photons
gamma rays
electrons