Nukes QA Flashcards
How do you test Uniformity?
Flood test. 2-5% uniformity allowed. 1% for SPECT.
How do you test Extrinsic Uniformity and how often?
Flood test with a collimator. Daily
How do you test Intrinsic Uniformity and how often?
Flood test without a collimator. Weekly.
What are the recommended counts for a flood test?
5-10 million
How often do you test gamma camera linearity? How?
Weekly with a bar phantom.
How often do you test SPECT center of rotation? How?
Monthly. 5 point sources along the axis of rotation. Ring artifact implies uniformity issue.
What is this and what do you use it for?

Well counter. Used for small samples (mainly the Wipe test). Uses a scintiallation detect.
What is this and what is it used for?

Thyroid Probe (scintillation detector, uses a small gamma camera with NaI crystal and single PMT). Calcualtes thyroid uptake values for patients and nuc med workers after I131 doses.
Can give you information about photopeaks.
What is this?
How does it detect radiation?

Gieger-Muller Counter
Gas-filled chamber. Used to detects counts only. Used for spills and packages.
What is this?
When is it used?

Ion Chamber (uses a gas-filled chamber)
Used to detect radiation at higher doses that would overload a gieger muller counter and is able to quantify dose. Dose callibrators are ion chambers.
What mechanism does a dose calibrator use to detect radiation?
Ion Chamber
How often is consistency checked on the dose calibrator?
Daily (should be within 5%)
How often is linearity checked with a dose calibrator?
Quarterly
When is accuracy checked with dose calibrators?
At device installation and annually
When is geometry checked with dose calibrators?
At device intallation and every time the device is moved and annually
What is considered a major spill? (think dose of radioisotope)?
Low Energy Isotopes: >100 mCi
Tc-99m, TI-201
Medium Energy Isotopes: >10 mCi
In-11, I-123, Ga-67
High Energy Isotopes: >1 mCi
I-131
What to in a major spill?
Clear the area
Cover the spill. DO NOT CLEAN IT UP.
Indicate boundaries of spill
Shield Source
NOTIFY THE RSO IMMEDIATELY
Decontaminate persons
Annual Radiation dose limit for the general public?
100 mrem (1 mSv)
No greater than 2 mrem/hr in unrestricted areas
When do you need a radiation area sign?
5 mrem (0.05 mSv) in 1 hr at 30 cm
What is considered a high radiation area?
100 mrem (1 mSv) in 1 hour at 30 cm
What is considered a very high radiation area?
500 rads (5 Gy) in 1 hour at 1 meter.
Note the change in units because we are now measuring deterministic effects, not just stoichiastic
Annual total body occupational radiation dose limit for a person?
5 rem (50 mSv)
Annual occupational dose limit to the ocular lens?
15 rem (150 mSv)
Annual occupational dose limit to a single organ (including skin) or an extremity?
50 rem (500 mSv)
Total pregnancy embyo/fetus dose (over the 9 months)?
0.5 rem (5 mSv)
Fetus can have an additional 0.5 mSv for the remainder of the pregnancy if they are exceeded at time of declaration (or if within 0.5 mSv of limit at time of declaration)”
Radiation conversions:
1 rad = ? rem
1 Gy = ? rad
1 Sv = ? rem
1 rad = 1 rem
1 Gy = 100 rad
1 Sv = 100 rem
What is considered a REPORTABLE nuclear medicine medical event?
(Just considered a medical event with newer NRC rules)
Wrong drug, wrong route, wrong patient, wrong dose (>20% of prescribed dose), or dose to wrong part of body >50% of expected dose to body part)
AND
whole body dose >5 rem (50 mSv) or single organ dose >50 rem (500 mSv)
What needs to be done with a NM Reportable medical event?
- Call NRC within 24 hours
- Send Letter to the NRC within 15 days
- Notify referring physician within 24 hours
- Notify patient
What to do when recieving NM package?
Within 3 hours of package receipt:
- Gieger Muller test at package surface and at 1 meter (only measures counts)
- Wipe test all surfaces of package (>6600 dpm/300cm^2 is not allowed)
- Leave the package in a controllable area
Nuclear medicine white 1 package label implies?
- No special handling
- Surface dose <0.5 mrem/hr, 0 mrem/hr at 1 meter
Nuclear medicine yellow 2 label implies?
-Special handling required
<50 mrem/hr at surface, <1 mrem/hr at 1 m
NM yellow 3 label implies?
-Special handling required
<200 mrem/hr at surface, <10 mrem/hr at 1 meter
How is NM package transportation index (T.I.) determined?
Package dose at 1 meter at time of shipping
- White 1 = Radiactive label 1 -> T.I. = 0
- Yellow 2 = Radioactive label 2 -> T.I. <1 mrem/hr
- Yellow 3 = Radioactive label 3 -> T.I. > 1 mrem/hr
What are the package limits that can be shipped via a common carrier?
Same as yellow 3 limits (surface <200 mrem/hr, <10 mrem/hr at 1 meter)
If multiple packages of radioactive material are shipped together, what is the dose limit at the surface of the group?
50 mrem/hr
The stomach is the critical organ for what radiotracer(s)?
Pertechnetate
The spleen is the critical organ for what radiotracer(s)?
Octreotide
Damaged RBC tracers
In-WBC
The distal colon is the critical organ for what radiotracer(s)?
Gallium
The bladder is the critical organ for what radiotracer(s)?
MAG3
I123 MIBG
TcMDP
The proximal colon is the critical organ for what radiotracer(s)?
Oral Sulfur Colloid
Sestamibi
The renal cortex is the critical organ for what radiotracer(s)?
Thallium
DMSA
The gallbladder wall is the critical organ for what radiotracer(s)?
HIDA
The liver is the critical organ for what radiotracer(s)?
In-Prostascint
I131 MIBG
IV sulfur colloid
What crystal is used in gamma camera scintillators?
NaI doped with thallium (the activator)
What cystal is used in modern PET scintillators?
LSO (Lutetium Oxyorthosilicate)
How is a PET blank scan performed, how often, and why is it performed?
Performed daily
1) using only a positron source (considered having nothing in the FOV) OR 2) using a cylindrical positron phamtom
Checks from gross non-uniformity (damaged crystal/detector)
How is a PET normalization scan performed, how often, and why?
Performed monthly
Performed using either method same as a blank scan (1) using only a positron source (considered having nothing in the FOV) OR 2) using a cylindrical positron phantom)
Checks and CORRECTS for fine non-uniformity
What radioactive isotope is used in PET QA scans?
Gallium 68 eluted from a Germanium 68 generator
How often do you check constancy/sensitivty of a NaI well counter?
Daily
How often do you check consistency of Geiger Muller and ion chambers?
How often are they calibrated?
Daily
On receipt, repair, and annually
When do you need to do Gieger Muller (GM) surveys and wipe tests in nuclear medicine rooms? How often?
Need to do GM surveys and wipe tests in any rooms/areas of where unsealed radioactive materials are used.
GM surveys = daily
Wipe test = Weeky
How much Mo is allowed in the Tc (Moly Breakthrough)?
0.15 microCi of Mo per 1 milliCi of Tc
Test with dose calibrator with a lead shield
How much Al is allowed in the Tc? (Aluminum breakthrough)
< 10 microgram of Al per 1 ml
Tested with paper strip test
How do you test for free Tc?
Thin layer chromotography
What does authorization 35.100, 35.200, and 35.300 mean?
100 - uptake, dilution, and execution of unsealed radiation byproduct material
200 - use any unsealed byproduct material prepared for medical use for imaging and localization studies
300 - use any unsealed byproduct that requires a written directive (I131 therapy)
How often must sealed sources be tested for leaks? and how?
At least every 6 months and with a wipe test.
After administration of I-131, what factors determine if the patient be released?
If less than 33 mCi of I131 was administered, the patient may be released without further monitoring.
Radiation dose cannot excceed 7 mrem (0.07 mSv) per hour at 1 meter from the patient’s chest prior to release.
Effective dose to a member of the patient’s immediate family cannot exceed 5 mSv.
What is the dose limit to the public in the waiting room of a nuc med clinic?
0.002 rem (0.02 mSv) per hour