Radiation Safety Flashcards
What are the basic principles of the ICRP system?
International Commission for Radiological Protection (ICRP)
- Justified = The benefits must outweigh the risk of the radiation exposure.
- Optimised = Keep exposure levels As low as Reasonably Practicable.
- Limited = Radiation dose limits ensure no person receives an unacceptable level of radiation exposure.
What are the two laws regarding radiation in th UK?
what act are they under?
The important Legislation in diagnostic radiology is:
* Ionising Radiations Regulations 2017 (IRR17)
* Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER17)
These are enacted under the Health and Safety at Work Act
What does IRR17 deal with?
with occupational exposure of staff and exposure of the general public
What is IRR17 enforced by?
Health and Safety Executive (HSE)
The employer is responsible for putting in place arrangements for compliance
Employees are responsible for following the safety arrangements
What are the implications of IRR17 for dentists?
private and NHS
NHS: NHS is responsible for compliance as the employer
Private practice: Owner(s) responsible as the employer
What is an RPA?
A Radiation Protection Adviser (RPA) is a person meeting HSE requirements to advise on radiation safety
Consulted for safety in design, equipment checks, and risk assessments.
What is the controlled area distance for intra-oral x-rays?
1.5m from x ray tube and within the primary bean
What is the controlled area distance for cone beam cts?
entire room is controlled area
When is signage required?
Where the entire room is a controlled area, or when the entrance leads directly into the controlled area,
What are the annual radiation dose limits for radiation workers and members of the public?
- Radiation Workers: Whole body limit of 6mSv/year
- Members of the public: Whole body limit of 1mSv/year
- (dental staff dose levels should be far below the dose limits)
What does IRMER17 deal with?
with exposure of patients (and some other groups)
Who is IRMER17 enforced by?
from when
Healthcare Improvement Scotland
december 2018
Who does IRMER17 apply to?
Patients as part of diagnosis or treatment
Health Screening
Research
Asymptomatic individuals
Carers and Comforters
Individuals undergoing non-medical imaging using medical equipment
Who are carers and comforters?
individuals who are ‘knowingly and willingly’ exposed to radiation to support and comfort those undergoing exposure - these are not employees and are usually a relative or a friend, such as a parent.
When is imaging used non-medically?
- health assessment for employment purposes
- health assessment for immigration purposes
- health assessment for insurance purposes
- radiological age assessment
- identification of concealed objects within the body.
Who is responsiblle for putting in place arrangements for compliance?
under IRMER17
the employer
employees are responsible for following these arrangements
What do employers have to show to show what procedures they’re going to comply with?
patient identification
entitlement of staff
information provided to patients
What are the types of duty holders and what is their role?
- Referrer = Responsible for providing enough information for patient identification and to enable justification.
- Practitioner = Decides if the exposure is justified and ensures doses are ALARP.
- Operator = Select the right equipment, follow the employer’s procedures and ensure the request is justified and authorised.
- In dentistry, a dentist will perform all these roles.
What is the basic framework for carrying out medical exposures?
- Referral for imaging Requested by a Referrer
- The examination must be justified by a Practitioner who may also authorise it
- The examination may be authorised and will be carried out by an Operator
- The image is assessed and reported by an Operator
- The image and report are provided to the Referrer
When can an exam not legally proceed?
unless justification process is complete
What is a clinical evaluation?
who ensures it
- The Employer must have procedures to ensure that a clinical evaluation of the outcome of each medical exposure is recorded
– Procedures for in-department reporting
– Procedure for images sent externally for reporting. - An exposure cannot be Justified if it is known a Clinical Evaluation will not be performe
What is justification?
This must take into account the objectives of the exposure and the benefits and risks to the individual, as well as the benefits and risks of available alternative techniques.
What is optimisation?
who is responsible for it
IRMER17 requires that all exposures are optimised.
This means that exposures are as low as reasonably practicable, consistent with the intended purpose
This is a responsibility of both the Practitioner and the Operator
ALARP
Who is a medical physics expert (MPE)?
In NHS GG&C, Health Physics MPEs provide advice on exposure factors and equipment-related matters
What is the quality assurance of radiation equipment?
what do the regulations specifiy?
The regulations specify that radiation equipment should be regularly tested to ensure it is working correctly and delivering the expected dose level.
Tests are normally split into:
* Routine local tests, carried out by local staff who normally operate the equipment, and;
* Physics tests, carried out every 1 to 3 years by specialist staff
National guidelines suggest what tests should be carried out
What are diagnostic reference levels?
- DLRs are guideline dose levels for standard sized patients - they can be used as a comparison value to decide whether your exposure levels are appropriate.
- Some equipment, such as CBCT or panoramic unit, displays a ‘dose indicator’ following an exposure - these can be compared against the DRLs.
