principles of radiation protection and legislation Flashcards
What 3 things determine the effective dose?
- the amount of energy absorbed in tissue (absorbed dose)
- type of radiation (equivalent dose)
- organs irradiated and their sensitivity to radiation
Define somatic and genetic effect
somatic effect - if individual is effected
genetic effect - if effects damage reproductive cells
state the effective dose in mSv of chest, pelvis, lumbar spine, barium enema and CT abdomen
chest PA- 0.02
pelvis- 1
lumbar- 2.4
barium enema- 5.0
CT abdomen- 8.0
What is the intensity of a beam of electromagnetic radiation?
the total energy per second flowing through that point when normalised to a unit area
What are the 3 types of examinations?
non-significant, low dose, high dose
What is classified as a non-significant dose examination?
(pregnancy check not required for non-significant dose examinations)
- any radiography not near uterus
- chest x-ray
- C/T spine, skull
Maximum foetal dose<0.01 mGy
What is classified as low dose examinations?
- CT chest
- fluoroscopy of chest and limbs or barium meal/swallow
- plain film AXR, pelvis, femur
- mammography
Maximum foetal dose< 10mGy
What is classified as high dose examination?
- CT abdomen/pelvis
- fluoroscopic process e.g barium enema
- ## check for any chances of being pregnant
When is the 10 and 28 day rules applied?
during low radiation procedures
What is the 10 and 28 day rule?
if period is within last 28 days then proceed vice versa
if period is within last 10 days the proceed vice versa
What are the areas and checks required for non significant, low and high dose examinations?
NS:
-projection radiography below knees and above diaphragm
-no need to check pregnancy
LD:
-examinations between knees and diaphragm
- apply 28 day pregnant rule
HD:
-CT fluoroscopy examinations between knees and diaphragm
- apply 10 day pregnancy rule
What does ICRP stand for and what do state?
international commission on radiological protection
all radiation is harmful
What are 2 types of radiation and give examples?
natural: cosmic, diet, terrestrial
artificial: medical, occupational, fallout
What are the 3 principles of radiation protection?
Justification : risk vs benefit
Optimisation : as low as reasonably practicable
Limitation : limit individual doses
Give a few of the general duties of IRR 2017
- arrangements for management of radiation protection
- controls over areas
- controls relating to people
- controls over substances and equipment
- accident preparedness
overall its notification of work, restriction of exposure and PPE
How do you notify work according to IRR2017?
- notified, small amounts of radioactive material used
- registered, includes diagnostic and radiotherapy
- consent to be obtained for nuclear medicine including manufacturers
What is consists of a controlled area?
- local rules
- physically demarcated (boundaries)
- warning signs
- warning light
- restricted access
What must be included in local rules of a controlled area?
- dose investigation levels
- summary of contingency arrangements
- name of radiation protection supervisor
- identification and description of areas covered
- summary of working instruction for entry and working in a controlled area
When will an employer designate and 18+ employee as classified?
- their effective dose is likely to exceed 6mSv annually OR equivalent dose is greater than 3/10 of any other relevant dose limit
What are the requirements to a classified person?
- annual medical surveillance
- assessment and record of doses recieved
- records kept for 50 years
What is the dose limit in mSv annually for 18+, 18- and others?
18+ = 20mSv (whole body)
18- = 6mSv (whole body)
others = 1
What must be done by an employer when a patient is overexposed?
- immediate investigation to confirm exposure
- inform Health and safety executive/CQC
- arrange for more detailed investigation of particular circumstance and dose received by patient
What is included in a contingency arrangement?
- issue arises
- pinpoint the issue
- take notes of ppl involved
- estimate affected area
- report to RPA and RPS
- dont use equipments until checked by engineer and authorised for reuse
What does RPA and RPS stand for?
radiation protection adviser
radiation protection supervisor
What are the 4 different duty holders and what are their roles?
Employer - provide framework of radiation protection of patient through standard operating procedures
Referrer - provide sufficient clinical information
Practitioner - justify each individual exposure, adequately trained, theoretical knowledge and practical training expected
operator - undertake practical aspects of medical exposure and adequately trained
