NUCS Flashcards
Tc99m (T1/2 and Energy)
6hrs
140 keV
Tc99m (Prod and Decay)
Generator
Isomeric Transition
Xe 133 (T1/2 and Energy)
5.3 days
81 keV
Tl 201 (T1/2 and Energy)
73 hours
69-81 keV
In-111 (T1/2 and Energy)
67 hours
172/247 keV
Ga-67 (T1/2 and Energy)
78 hours
90, 190, 290 keV
I-123 (T1/2 and Energy)
13 hours
159 keV
I-131 (T1/2 and Energy)
8 days
364 (G) and 606 (B)
F18 (T1/2 and Energy)
110 minutes
511
Max Mo in Tc? Term?
0.15 micro Ci per 1 mCi of Tc (UNITS!)
Radionuclide purity
Max Al contamination in Tc? Term?
<10 mcg Al per 1mL
Chemical purity
How can aluminum contamination show up on a
1) free Tc scan
2) Sulfer Colloid scan
1) Liver activity
2) Lung activity
Happens bc Al clumps the tech
How much free Tc in 1) Na99mTc 2) 99mTc Sulfer Colloid 3) All other Tc products Term?
1) 95%
2) 92%
3) 91%
Radiochemical Purity
Formula for effective half life
1/Eff = 1/Phys + 1/Biol
If using two tracers in the same patient/study, what order should they be used in ?
Lower energy tracer first to prevent downscatter from muddying the picture
How often is gamma camera field uniformity (flood) performed for 1)extrinsic and 2)intrinsic evaluation?
Extrinsic is daily and includes the collimator
Intrinsic is weekly and does not use collimator
How often is gamma camera energy window tested?
Daily
How often is gamma camera linearity tested?
Weekly
How often is gamma camera center of rotation tested?
Monthly
How often is gamma camera spatial resolution tested?
Weekly
What is the maximum accurately detectable dose by a Geiger counter?
100mR/h
What is the detectable range for an ionization chamber?
0.1-100R/h (note units, this R/h vs mR/h for Geiger)
What type of instrument is a dose calibrator?
Ionization chamber
What is the consistency tolerance (+/-) for a dose calibrator? How often is it checked?
5%, daily
How frequently is linearity for a dose calibrator checked?
Quarterly
How frequently is accuracy for a dose calibrator checked?
At installation and annually
How frequently is dose calibrator geometry checked?
At installation and anytime the device is moved
What constitutes a major spill of Tc99?
100mCi
What constitutes a major spill of Tl-201?
100mCi
What constitutes a major spill of In-111?
10mCi
What constitutes a major spill of I-123?
10mCi
What constitutes a major spill of Ga-67?
10mCi
What constitutes a major spill of I-131?
1mCi
Gy=rad=rem=mSv
1 Gy = 100 rad/rem = 1 Sv
Annual dose limit for public
100mRem
Unrestricted area max dose
2mRem/hr
Radiation area definition
0.005-0.1 Rem/hr at 30cm (0.05 mSv)
High radiation area definition
0.1-500 Rem/hr at 30cm (1 mSv)
Very high radiation area definition
500 Rem/hr at 1 meter (5 Sv)
NRC Occupational dose limits:
Whole body per year
5 rem (50mSv)
NRC Occupational dose limits:
Ocular lens per year
15 rem (150mSv)
NRC Occupational dose limits:
Total equivalent organ dose per year
50 rem (500mSv)
NRC Occupational dose limits:
Total equivalent extremity dose per year
50 rem (500mSv)
NRC Occupational dose limits:
Dose to embryo over pregnancy
0.5 rem (5mSv), embryo can receive additional 0.5mSv/month post declaration of pregnancy
What variance from expected dose constitutes a reportable event?
20%
What two things are required for a reportable event?
1) Wrong drug/patient/dose(20% off) OR pt receives dose to unintended body part exceeding expected exposure by 50% if it had been administered correctly
2) Harm - defined as whole body dose >5rem or Single organ dose >50rem
What constitutes reporting a reportable event?
Call NRC w/in 24 hours, written notice to NRC w/in 15 days, notify referring doc w/in 24 hours, notify patient
What is required on receipt of radioactive materials?
Within 3 hours: survey package at surface at 1 meter, wipe test
Package label: White 1
<0.5mRem/hr surface, essentially 0 at 1 meter
Package label: Yellow 2
<50mRem/hr surface, <1mRem/hr at 1 meter
Package label: Yellow 3
<200mRem/hr surface, <10mRem/hr at 1 meter
Max yearly public exposure in uncontrolled area
5mSv/year
Genetically significant dose
0.25 mSv
What is the minimum luminance of diagnostic monitors per ACR guidelines?
The ACR has recommended a minimum luminance for grayscale monitors (50 foot-lamberts/171 cd/m^2).
How long do you have to notify the NRC A) by phone and B) in writing of a medical event?
1 day
15 days
When/how often is an ambient radiation exposure survey performed?
At the end of each day
What is an isobar?
Same atomic mass, different number of protons (diff elements)
What is the maximum variance allowed from prescribed dose?
20%
What is cutoff for admission after I131 therapy?
7mR/h at one meter from chest or 33mCi of residual activity
