Radiation Protection- Unit 2- 6/10

ICRP acronym

• international commission on radiologic protection

Organizations for radiation protection purpose:

• evaluates relationship between radiation equivalent dose & induced biological effects

  • Formulates somatic & genetic effects of irradiation

ICRP purpose

• does not enforce

• Evaluates information on biologic effects of radiation

• Provides radiation protection guidance through general recommendations on occupational & public dose limits

NCRP purpose

• does not enforce

• Nongovernmental, nonprofit, private corporation in US

• Reviews ICRP recommendations & how to incorporate into US criteria

• Assembles guidelines & publishes into NCRP reports

NAS/ NRC-BEIR purpose

• does not enforce

• Formed by NRC (national research council)

• Organized by (NAS)

• Advisory group that reviews studies of biology effects of radiation & risk assessment

• BEIR reports list studies of biological effects & associated risk group of people who were routinely or accidentally exposed:

  • Radiation workers

  • Hiroshima & Nagasaki victims

  • Chernobyl victims

  • Fukushima

NRC purpose

• formerly atomic energy commission

• Controls atomic energy for national security

• Controls the manufacture & use of radioisotopes formed in nuclear reactors

• Oversees nuclear energy industries

• Can enforce radiation protection standards & write rules that are published to Title 10 of US CFR

• Supervises:

  • Design & working mechanics of nuclear power stations, production of nuclear fuel, handling expended fuel, hazardous radioactive waste material

Thallium- 201

• NM heart stress tests

Palladium- 103

• prostate seeds

Agreement states

• US states that agree w/ NRC to enforce regulations through health depts. (licensing, inspection, regulation)

• Non-agreement states NRC retains control

  • will come into facilities to inspect

• States may have their own regulations above & beyond NRC mandates

• NUCLEAR REACTORS MUST BE INSPECTED BY NRC

When did PA become an agreement state?

• March 31st, 2008

EPA purpose

• responsibility for protecting health of humans & safeguarding natural environment

• Oversees development & enforcement regulations for radiation in the environment

• Determines levels of radon

FDA purpose

• Conducts ongoing radiation control program

• Regulates design & manufacturing of electronic products & x-ray equipment

• On-site inspections of equipment

  • MQSA= mammography quality standards act of 1992

  • Compliance ensures protection to use & patient from fault manufacturing

  • Radiopharmaceuticals fall under FDA regulations

OSHA purpose

• agency monitoring places of employment

• Regulates occupational exposures

• Regulates employees “right to know”, provide training, & written info about:

  • Hazardous substances

  • Infectious agents

  • Ionizing/ non-ionizing radiation

NCRP acronym

National Council on Radiation Protection and Measurements

NAS/NRC-BEIR acronym

National Academy of Sciences/National Research Council Committee on the Biological Effects of Ionizing Radiation

NAS/NCR-BEIR Examples:

• early radiation workers

• Atomic bomb victims of Hiroshima & Nagasaki (1945)

• Victims from Chernobyl disaster (1986)

• Fukushima (2011)

Code of federal regulations

• is the codification of the general & permanent rules published in the federal register by the departments & agencies of the federal government

CFR 10; part 20

• standards for protection against radiation

  • Includes:

    • Occupational dose limits for adults

    • Dose equivalent to an embryo/fetus

    • Radiation dose limits for individual members of the public

CFR 21

• Food & drug administration

• Minimum source-to-skin distance

• Guidelines for fluoroscopy & mobile units

US regulatory agencies

• Enforces of protection standards for the general public, patients, & personnel

DEP acronym

Department of environmental protection

DOH acronym

• department of health

DEP purpose

• directs statewide radiation protection program w/ goal of protecting from unnecessary exposure; performs hospitals visits

DOH purpose

• responsible for licensing & oversights of PA hospitals, imaging depts; onsite inspections

PA patient safety authority

• adverse PT events are reported

Department of transportation purpose (DOT)

• works w/ NRC to set safety rules for shipping radioactive materials

• NRC oversees design of packaging for shipment of radioactive materials

• DOT oversees the safety during the shipment

Radiation control for health & safety act of 1968

• Public Law 90-602

  • Protects public from uncessary hazardous exposure

    • Microwaves, TVs, x-ray equipment

  • Restricts equipment performance, not user!!

NCRP Report #102

• 1989

• Recommendations on equipment design, shielding, & use of equipment

  • Guidelines for:

    • Lead equivalent for shields

    • Minimum filtration

    • Exposure rates for mobile & fluoro

NRCP report #116

• 1993

• Basic radiation protection criteria

• Limitations of Exposure to ionizing radiation examples:

  • Effective dose limits

  • Occupational

  • Non occupational

  • Cumulative effective dose

NRCP report #160

• Published in 2009, regarding 2006 exposures

• Due to increasing radiation (7x) from 1980s-2006

  • Mainly CT & NM

    • Reduction from 2006-2016

Radiation safety program

• facilities w/ imaging services must have effective & detailed program to ensure appropriate safety of patients & technologists

  • Begins with administration

    • Delegate funds

    • Oversees development of policies

    • Provide equipment

Radiation safety committee (RSC)

• required by NRC

• Provides guidance, operations, & ensures compliance based on regulations from CFR10 part 20

Radiation safety officer (RSO)

• develop & oversee program

• Ensure everyone is protected

• Maintains radiation records & counsels after high readings

• Day-to-day supervision

Who’s is RH’s RSO?

Jay Yoder

Qualifications of RSO

• usually a medical or health physicist, radiologist, or individual deemed qualified

• Is approved by NRC & State

ALARA

• as low as reasonably achievable

• 1954- NCRP

  • Optimization

  • Linear, non-threshold

  • Effects are DIRECTLY proportional

    • Archived by proper safety procedures & qualified workers

Consumer patient radiation health & safety act of 1981

Also known as public law 97-35

• minimize unnecessary exposure to potentially hazardous radiation due to medical & radiology procedures

Radiation induced responses

Tissue response/non-stochastic/deterministic

1. Cell killing effects

2. Effects of radiation that become more severe at higher levels of exposure

3. Do not typically occur below a certain threshold

4. As dose increases, severity increases

5. Usually in higher areas that’s diagnostic areas

Examples of radiation induced responses (Early)

• erythema

• Decreased WBC (leukopenia)

• Epilation

Radiation induced responses (more severe early)

• hematopoietic syndrome, GI syndrome, & CVA syndrome

Radiation induced responses (late) examples

• cataracts

• Fibrosis

• Organ atrophy

• Reduction of fertility

• Sterility

Stochastic

1. no threshold, randomly occurring

2. Chance of occurrence increases w/ each exposure, probability increases

3. Random effects

4. No dose is safe

Examples of stochastic

• cancer

• Genetic alterations

  • Teratogenesis (radiation of the fetus in utero)

  • Mutagenesis (radiation of reproductive cells before conception)

Radiation induced malignancy

1. Chance increases w/ an increased dose to the somatic cells

2. Severity is not dose related, but chance increases as dose increases

Objective of radiation protection

1. Prevent non-stochastic effects from happening by keeping doses below threshold

2. Limit risk of somatic effects to a conservative level as compared to the benefit of the exposure

Philosophy of radiation

1. Linear, nonthreshold

2. Chance of occurrence increases with each exposure; probability also increases

3. Chance of biologic damage & amount of damage are directly proportional to

4. Smallest dose has potential to cause harm

5. Radiation has benefits but also potential for destruction

6. Must weigh the benefit of exposure against the risk

Organ sensitivity examples (Critical organs)

1. Gonads

2. Blood forming organs

3. Lung

4. Thyroid

Organ sensitive examples (medium sensitivity)

1. Osteoblast (bone forming)

2. Fibroblast (connective tissue)

Organ sensitivity examples (low sensitivity)

1. Muscle cells

2. Nerve cells

Law of Bergonie and Tribondeau

• cells are more sensitive when they are immature & rapidly dividing

NCRP recommendations: Occupational dose limits (Effective dose)

• Annual= 50 mSv (whole body)

• Cumulative= 10mSv x age in years

NCRP recommendations: Occupational dose limits (Lens of eye)

• 150 mSv

NCRP recommendations: Occupational dose limits (localized area of skin)

• 500 mSv

  • Hands, skin, feet

ICRP has lowered the effective dose to ___, but it has not been adapted by the US

20 mSv

NCRP recommendations: Occupational dose limits (Cumulative Effective Dose- CumEfD)

• persons age in years x 10 mSv

  • Pertains to WHOLE BODY

  • Ensures lifetime risk for radiation workers is no greater than public

NCRP recommendations: Non-occupational dose limits (Public exposed)

1. Continuous exposed= 1 mSv

2. Infrequent exposed= 5 mSv

   • these limits are set for those accompanying a patient to the department (spouse, parent, guardian)

3. Non radiology hospital workers= 1 mSv

4. Patient dose limits

• There is not a specific dose limit for patients that are being imaged!!!!

NCRP recommendations: Non-occupational dose limits (Embryo-Fetus limits)

• not exceeding 0.5 mSv in any 1 month

• Not exceeding 5 mSv in entire gestation period

NCRP recommendations: Non-occupational dose limits (Students under age 18)

• 1 mSv

NID

• negligible individual dose

  • Annual dose of 0.01 mSv/ source determine negligible

  • At this level, a reduction of individual exposure is unnecessary