PHYSICS/QC HIGH YIELD NUMBERS, BIOSTATS, AND CANCER STAGING TRIVIA
Terms in this set (51)
OCCUPATIONAL DOSE LIMITS
total body per year?
total body per year for worker under 18 years old?
dose to lens per year?
dose to embryo/fetus over 9 months?
extremity dose per year?
BODY: 50mSv per year (5 rem)
-10% of this for under 18 years old (5 mSv or 0.5 rem)
LENS: 150 mSv per year (15 rem)
FETUS: 5mSv over 9 months (0.5 rem)
EXTREMITY 500 mSv per year (50 rem)
UNIT CONERSION (NUCS)
1 rad = ____ rem
1 rad = ____ Gy
1 mSv = ____ mrem = ____ rem
1 Curie = ____ Bq = ____ GBq
1 rad = 1 rem
1 rad = 0.01 Gy
1 mSv = 100 mrem = 0.1 rem
(for conversion purposes, 1 Gy= 1 Sv = 100 rad or rem)
1 Curie = 3.7 x 10 to the tenth Bq = 37 GBq
what is a curie?
what is a Becquerel?
curie = 3.7 x 10 to the tenth disintergrations per second
Becquerel is a newer unit
describes on disintegration per second
what constitutes a MAJOR vs. MINOR spill?
"100 for the T's"
-100 mCi or more of Thallium or Tc99m
-10 mCi or more of indium, I-123, or gallium
-1mCi or more of I-131
anything less is a minor spill
nuclear dose limits to general public
rate limit in "unrestricted area"
100 mrem to the public
UNRESTRICTED RATE LIMIT
2mrem per hour
NUCLEAR MED SIGNAGE
when do these signs need to be placed ...
high radiation area?
very high radiation area?
0.005 rem (0.05 mSv) per hour at 30cm
0.1 rem (1mSv) per hour at 30cm
500 rads (5 Gy) per hour at 1 meter
when must a new nuclear delivery be inspected
within 3 working hours
geiger counter at 1 meter must be less than 6600 dpm / 300 square cm
Shipping labels on nuclear deliveries
what is the transportation index?
WHITE 1: no special handling
surface rate <0.5 mRem/hr
T.I. is about 0 mRem/hr at 1 meter
YELLOW 2: special handling needed
surface rate < 50 mRem/hr
T.I. is <1 mRem/hr at 1 meter
YELLOW 3: special handling needed
surface rate <200 mRem/hr
T.I. is >1 mRem/hr at 1 meter
T.I. is the max dose at 1 meter (actual measured dose)
what is the limit for Moly contamination in Tc99 from the generator?
limit is ...
0.15 microCi of Mo per 1 milliCi of Tc99m (note units differences)
NEEDS TO BE KNOWN AT TIME OF ADMINISTRATION (NOT THE ELUTION)
what is the K-shell binding energy of Tungsten
binding energies of Mo and Rho
Mo - 18 keV
Rho - 20 keV
automatic exposure control limits by law
87 mGy/min or 10 R/min
IF patient is way too obese, you can activate "high level control" which requires audible alarms
limit is: 176 mGy/min or 20 R/min
Mammo tasks, when are these performed?
localization/accuracy for stereo?
what are the MQSA line pair requirements for analog mammo
12 lp/mm average
characteristics of mammo ghost phantom
4.2 cm thick
dose less than 3mGy per image (+grid)
to pass image quality, an image must show how many fibers, microcalcs, masses?
4 fibers (F is for 4)
above which threshold for fluoro skin dose do symptoms occur? when must action be taken?
above 2 Gy
less than 2 Gy : do nothing
2-5 Gy: advise patient to watch for burns for 10 days
above 5 Gy: physicist review
skin symptoms of radiation by dose
2 Gy: transient erythema
3 Gy: temporary epilation
6 Gy: chronic erythema
7 Gy: permanent epilation
10 Gy: telangiectasia
13 Gy: dry desquamation
18 Gy: ulceration
24 Gy: secondary ulceration
what are the classic window and level settings on CT for ...?
BRAIN W 80 L 40
LUNG W 1500 L -400
ABDOMEN W 500 L 50
SUBDURAL/LIVER W 150 L 50
BONE W 1500 L 500
what is CTDIvol
what are ACR reference values of CTDI vol for head, adult abd, peds abd?
CT dose index per unit volume
HEAD: 75 mGy
ADULT ABD: 25 mGy
PEDS ABD: 20 mGy
ultrasound machine assumes what speed of sound in tissues?
FDA limits for SAR for MRI
4 W/kg for 15 mins
3 W/kg for 10 mins
precision vs. accuracy
precise is reproducible close results
accuracy is at the actual desired target
Type 1 vs. Type 2 errors
TYPE 1 (false positive)
TYPE 2 (false negative) - the bad kind of error
Incidence vs. Prevalence
incidence is number of new cases per unit time (ex. per year)
prevalence is total number of cases present at any given point in time (regardless of when first diagnosed)
sensitivity vs. specificity
SENS = TP / (TP+FN)
SPEC = TN/(TN+FP)
how is accuracy calculated
(TP+TN) / (TP+FP+TN+FN)
how does prevalence affect pos/neg predicitve values
higher prevalence makes PPV better (ex. only screen smokers for nodules ... nodules in smokers probably higher PPV for cancer than nonsmokers)
what is statistical power?
ability to prevent a type 2 error (a false negative)
increase power with larger sample size
how is number needed to treat calculated
NNT = 1/ absolute risk reduction
ex. ARR = (control event rate - experimental event rate)
which employees need dosimeters?
those expectied to receive a dose greater than or equal to 10% of max dose annually
(so expected dose > 5mSv - which is 10% of the annual 50mSv limit)
per NRC guidelines, how long should written directives be kept (for nucs studies/treatments)
EFFECTS of radiation on the fetus at ...
100 mGy in first two weeks? at 3-8 weeks? at 9-15 weeks?
10mGy during first trimester?
maximum allowable aluminum ion in Tc99m generator eluate?
10 micrograms per mL
GAMMA CAMERA QC
center of rotation
uniformity - "flood"
-daily (extrinsic) with collimator
-weekly (intrinsic) without collimator
-test energy peak windowing with set source
-cobalt57 sheet with lines
center of rotation (for SPECT)
-use small sources of Tc99m
dose calibrator QC
-should be within 5% accuracy of dose amount
accurate readout of different energy over a large range (comes as a kit with varying lead thickness with Tc99 to simulate different energies)
-at installation or annually
-at installation or relocation of device
energy and half life?
critical organ of ...
rectal cancer MRI staging
cervical cancer staging
stage 2A: beyond cervix with intact parametrium (gets surgery)
stage 2B: invades parametrium (gets chemo/XRT)
stage 3: into pelvic wall
stage 4: invades other stuff
endometrial cancer staging
stage 1A: <50% of myometrium
stage 1B: >50% of myometrium
stage 2: invades cervix
(stage 2 increases risk for lymph node mets and likely requires pre-op radiation)
colon cancer staging
lung cancer staging
what stage becomes unresectable? what makes it that stage?
what stages are ...
1. two tumors in same lobe?
2. two tumors in ipsilateral lobes?
3. tumors in each lung?
unresectable at stage 3B
-supraclav or contralateral media/hilar LAD
-tumor in more than one lobe (same lung)
two tumors in same lobe? T3
two tumors in ipsilateral lobes? T4
tumors in each lung? M1a
1 - in kidney, < 7 cm
2 - in kidney > 7 cm
3 - in gerotas fascia (renal vein or IVC also ok)
4 - ipsilateral adrenal or mets
ALSO HAVE A STAGE FIVE (for bilateral tumors - would stage each independently)
4S has better prognosis
most are stage 4 at diagnosis
bladder cancer staging
T2 - confined to bladder
T3 - hazy perivesicle fat
T4 - invades stuff
prostate cancer staging
-barely through capsule
-seminal vesicles and adjacent nerves invaded
by how much can a nuclear diagnostic and therapuetic dose differ from the prescribed dose?
20% for diagnostic
10% for therapuetic
a 10% variation is recordable. 20% is reportable.
when releasing an I-131 patient, you must ensure that no other member of the public will receive ______ dose before releasing the patient
0.5 rem or 5 mSv
COMMON CHROMOSOME DISORDERS ...
Polycystic kidney disease?
BRCA 1 and 2?
VHL - 3
Hemochromatosis - 6
Cystic fibrosis - 7
Wilms - 11
Retinoblastoma - 13
Polycystic kidney disease - 16
NF-1 - 17
Down syndrome - trisomy 21
Edward syndrome - trisomy 18
Patau syndrome - trisomy 13
NF-2 - 22
Digeorge syndrome - 22
BRCA 1 - 17
BRCA 2 - 13
CADASIL - 19
YOU MIGHT ALSO LIKE...
Nucs - Safety, QA, Regulations
Chapter 8 Pre-Test (EMS 105)
OTHER SETS BY THIS CREATOR
THIS SET IS OFTEN IN FOLDERS WITH...
Chest and Cardiac