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Radiation Physics/Safety/ Regulations/Common Acronyms

Terms in this set (77)

physical half life
the time required for 50% of the radioisotope to decay of its original value
biological half life
the time required for the body to eliminate half of administered substance
effective half life
time required for an administered dose to be reduced to one half due to both physical and biological half lives
ALARA
As Low As Reasonably Achievable
nonionizing radiation
Low energy radiation
Has enough energy to move atoms, but not enough to remove electrons
(sound waves, visible light, microwaves)
ionizing radiation
form of radiation that can remove elections, thus creating ions
Too much exposure can cause damage
(xray, gamma)
Regulations for professionals working with radiation
Professionals are allowed to receive up to 50 mSv per year
Central nervous system (CNS) syndrome
a whole body dose over 3000 rad.
immediate signs will include convulsions, ataxia, tremor, and lethargy
Deterministic effects
effects that are understood to occur when dose reaches a given threshold or amount
Gastrointestinal (GI) Syndrome
800 to 1000 rad
severe nausea, vomiting, diarrhea very soon after exposure
Hemopoietic syndrome
200 rad
systemic illness caused by high dose, acute exposure to ionizing radiation, vomiting may occur
High radiation area
radiation levels from sources external to the body could result in an individual receiving a dose equivalent in excess of .1 rem in 1 hour at 30 cm from source
International Council on Radiation Protection (ICRP)
advisory body made of representatives that issues recommendations and guidance in radiation protection
Medical event
administration of byproduct material that results in any of the following:
a dose given that differs from prescribed dose
a dose that exceeds .05 SV(5 rem)
a dose to the skin or organs other than treatment site exceeds by .5 Sv (50 rem)
National Council on Radiation Protection (NCRP)
nonprofit corporation that provides information and recommendations concerning radiation protection to members of the public
Nuclear Regulatory Commission (NRC)
federal governing body that has primary mission of protecting public health and safety. Also regulates nuclear materials and facilities to promote common defense and security
Quality management program (QMP)
program that establishes a set of policies and procedures that ensure proper administration of radiopharmaceuticals to patients
Radiation area
area in which radiation levels could result in an individual receiving a dose equivalent in excess of .005 rem in 1 hour at 30 cm from radiation source
Radiation safety committee (RSC)
purpose is to set policy for the entire institution and is responsible for the use of all radioactive materials
Radiation safety officer (RSO)
individual responsible for the day to day operation of the institution's radiation safety program
Stochastic effects
effects that are considered random in nature. For example, cancer is a stochastic effect of radiation exposure
Very high radiation area
area in which radiation levels from radiation sources could result in an individual receiving an absorbed dose in excess of 500 rad in 1 hour at 1m from source
Written directive
authorized user's written order for the administration of radiation to a specific patient
inverse square law
intensity of radiation is inversely proportional to the square of the distance from the source of radiation
example, doubling the distance decreases exposure to 1/4 original rate
bremsstrahlung radiation
x-rays that are produced as the result of rapid decceleration of electrons that pass near the atomic nucleus
main stream of CT x-ray
Compton scattering
one process by which a photon loses energy through collision with electrons
electron volt (eV)
measurement of kinetic energy gained by an electron
frequency
number of cycles per unit time normal unit is Hertz or cycles per second
Half Value Layer (HVL)
thickness of absorbing material necessary to reduce the intensity of radiation by half
isobars
nuclides that have the same total number of neutrons and protons but are different elements
isomers
two compounds with the same molecular formulas and different structural formulas
isotones
nuclides having the same number of neutrons but a different number of protons
isotopes
nuclides of the same element with the same number of protons but different number of neutrons
What are the two types of Radioactive materials used in nuclear medicine?
1) Electromagnetic Radiation:
-Gamma rays
-xrays
-annihilation photons

2) Particulate radiation
-Alpha
-Beta
- Positrons
-Auger electrons
-Compton electrons
- Photoelectrons
absorbed dose
energy deposited in a given mass.
Traditional unit is rad and SI unit is Gy.
4 stages of Acute radiation syndrome
Prodromal- nausea, vomiting, diarrhea, can occur minutes to days following exposure

Latent- patient looks/ feels healthy for a few hours or weeks

Manifest illness- symptoms can last from hours up to several months

Recovery or death- most patients who don't recover die within days- months
Other effects of radiation exposure include
Cataracts- exposure of 500 rem can cause opacities in the lens within a year

Fertility- 400 rem can cause temporary amenorrhea (lack of menstrual cycle) or sterility

Developmental- .25 Sv can cause growth, congenital abnormalities, prenatal or neonatal death; cases are below 6% of live births
Summary of Radiation Units
Units of exposure= Roentgen (R)

Units of quantity= Curie (Ci) or Becquerel (Bq)

Units of absorbed dose = rad or gray (gy)

Units of effective dose= rem or sievert (sV)
Radiation Unit Conversions
1 Gray= 100 rads

1 sievert= 100 rems
Maximum Permissible Dose
Whole body= 5,000 mrem/year

Lens of eye= 15,000 mrem/ yearExtremities= 50,000 mrem/year

Extremities= 50,000 mRem/year

Total organ deep dose= 50,000 mrem/year

Embryo/ Fetus over 9 months= 0.5 rem/ declared gestation
DOT packaging labels
White I = doesn't exceed .5mrem/hr

Yellow II= doesn't exceed 50 mrem/hr

Yellow III= exceeds 50 mrem/hr
Hematopoietic Syndrome dose and symptoms
> 70 rads, some symptoms may occur as low as 30 rads

prodromal- nausea, vomiting
latent- appears to feel well, but stem cells are dying
manifest illness- fever, anorexia, drop in blood cell counts, infection, hemorrhaging
recovery- full recovery or death
Gastrointestinal Syndrome dose and symptoms
>1000 rads, some symptoms can occur as low as 600 rads

prodromal- anorexia, severe nausea and vomiting, cramps, diarrhea
latent, cells in lining of GI tract are dying, but patient feels well
manifest illness- malaise, anorexia, severe diarrhea, fever, dehydration
recovery or death- LD100 is 1000 rads
CV/CNS syndrome dose and symptoms
5000 rads, some symptoms can occur as low as 2000 rads

prodromal- extreme nervousness and confusion, severe nausea, vomiting, diarrhea, loss of consciousness, burning of the skin
latent- patient may return to partial functionality
manifest illness- watery diarrhea, concussions, coma
recovery or death- no recovery is expected
ACLS
Advanced Cardiac Life Support
ACR
American College of Radiology
ARRT
American Registry of Radiologic Technologists

Certification for Nuclear Medicine
CCK
cholecystokinin:
hormone that is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas
CDC
Centers for Disease Control and Prevention
CPR
Cardiopulmonary Resusitation
CVA
Cerebrovascular Accident (stroke)
DNR
Do not resuscitate
DOT
Department of Transportation
FDA
Food and Drug Administration
FERPA
Family Educational Rights and Privacy Act
federal legislation in the US that protects the privacy of students personally identifiable information
HIDA scan
hepatobiliary iminodiacetic acid scan
radioactive imaging of the liver, gallbladder, and intestine

Takes 1 to 4 hours
Radiopharmaceuticals: chopetec, hepatolite
HIPAA
The Health Insurance Portability and Accountability Act

Provides federal protection for the privacy of health information
HOCM
High osmolarity contrast media
HVL
Half Value Layer:
thickness of absorbing material necessary to reduce the intensity of radiation by half
JCAHO
The Joint Commission

Develops standards, awards accreditation, and provides education to hospitals and health care organizations
LEP
Limited English Proficiency
LOCM
low osmolarity contrast media
MPI Scan
Myocardial Perfusion Imaging - Several scans are done to provide thin slices of the entire heart from all angles

1 or 2 days protocol
Rest / stress doses
15 min per image
up to 4 hours from start to finish
radiopharmaceuticals: sestamibi, myoview, Ti201
MUGA scan
Gated cardiac blood pool
A procedure that images the motion of heart wall muscles using radioactive chemicals.
Uses tagged red blood cells
Scan takes up to 1 hour
NMTCB
Nuclear Medicine Technology Certification Board

Certification for Nuclear Medicine
NRC
Nuclear Regulatory Commission

Ensures protection of the public health and environment in the use of nuclear materials in the United States. NRC has control over medical uses of nuclear materials, the transport, storage, and disposal of nuclear materials and waste.
OSHA
Occupational Safety and health Administration
Sets national safety standards of operation
PEEPS
Patient
Environment
Equipment
Posture
Safety
PET scan
positron emission tomography scan
Radiopharmaceuticals: F18- FDG, F18, Rb-82, N-13, O-15
Scan takes 1 to 1.5 hours
PHI
Protected health information

name, dob, social security number, medical record number, address, phone number, etc
A technologist states there is an unknown radionuclide spilled on the countertop. which of the following devices could be utilized to identify what radionuclide was spilled ?
GM
ionization survey chamber
dose calibrator
well counter
well counter
How often should the uniformity flood images be acquired?
daily
weekly
biweekly
monthly
quarterly
yearly
daily
should be obtained daily to e3valuate both the intrinsic function of the camera and the extrinsic function of the collimators. All cameras have some degree of field inhomogeneity, which can usually be corrected by performing a flood and subsequent correction. Use of a camera with an inhomogeneous field could result in misinterpretation of scan findings.
how often should the spatial resolution be tested?
daily
weekly
biweekly
monthly
quarterly
annually
weekly
spatial resolution refers to the ability of the system to discern discrete but contiguous sources of radioactivity. inherent spatial resolution in the ability of the crystal, photomultiplier tube detector, and accompanying electronics to record the exact location of the light pulse on the sodium iodide crystal. overall spatial resolution in the resolution capacity of the entire system including camera, collimator resolution, septal penetration, and scatter radiation. this can be tested with bar phantoms or with full width at half maximum.
what is the maximum allowable molybdenum-99 breakthrough limit in Mo-99/Tc-99m generator eluate?
.15uCi/mCi
1.5uCi/uCi
1.5mCi/mCi
1.5mCi/uCi
1.5uCi/mCi
.15 uCi/mCi
this is an example of radionuclide impurity. excess Mo-99 leads to unnecessary increase in patient radiation dose. with time, the amount of Mo-99 breakthrough increases in a sample secondary to its longer half life of 2.8 Days. One can test for Mo-99 breakthrough by placing the eluate in a 6mm thick lead container to stop
what is the maximal allowed exposure to other members of the public from a patient who has received an outpatient I 131 therapy ?
.5 mSv
1 mSv
5 mSv
10 mSv
50 mSv
5 mSv
under the current regulations a patient may be released of the effective dose does not exceed 5 mSv from a single radioisotope treatment.
What is the dose limit to the fetus/embryo over the gestation period for a declared pregnant worker?
.5 mSv
1.5 mSv
5 mSv
15 mSv
5 mSv (.5 rem)
there is no fetal dose limit if the pregnancy is not declared to the employer
what is the occupational whole body dose limit?
.5 mSv
5 mSv
50 mSv
500 mSv
50 mSv (5 rems)
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