Regulations and legal responsibilities Flashcards
What is ionising radiation?
Has the ability to knock electrons (free radicals) out of cells in our body which can go on to cause further damage etc. to our DNA
e.g. xrays, gamma rays etc.
In which two ways does ionising radiation damage DNA?
- Indirect = generation of free radicals
- Direct = interaction with DNA
What are the two types of effects of ionsing radiation?
- Stochastic effects
- Non-stochastic effects
What are stochastic effects?
Those for which the probability increases with dose, without threshold (every exposure carries the possibility of causing damage and the severity is not dependent on the size fo exposure)
E.g cancer induction & heritable effects
What are non-stochastic effects?
Those where the incidence and severity are proportional to dose (i.e. definitely occur from a specific high dose of radiation) = has a threshold dose
e.g. Mucositis, loss in taste, dry mouth, ‘radiation caries’ -> by gingival margin due to dry mouth, tooth defects if irradiated while teeth developing, atrophic mucosa, cataracts, radiation burns, sterility
N.b. DOSES USED IN DENTISTRY ARE TOO LOW TO CAUSE THIS KIND OF EFFECT
What does the International Commission on Radiological protection (ICRP) do?
Produce advice for the creation of national legislation to govern the use of ionising radiation
e.g. consider how we can reduce harm to the environment from xrays
Radiography in dentistry:
Whats the dose and volume like?
Low dose but high volume (overall population dose high)
2008 - estimated 17,800,000 intraorals & 2,700,000 DPT’s were taken
What % of radiographs submitted to the dental practice board (DPB) audit were of unacceptable quality?
18%
What is the problem of unacceptable quality radiographs?
= ineffectual = needs repeating
(increases exposure to patient)
What is the risk benefit ratio?
If something causes harm (i.e. exposure to ionising radiation) then the good must outweigh the bad
What is the UK background dose of radiation?
Approx. 2.5 mSv
What is the radiation dose of a DPT?
Approx 0.002 Sv
n.b. this depends on technique and machine being used
What is the radiation dose of a single periapical?
Approx 0.001mSv
What are the different UK legislations of radiography?
- Ionising radiation regulations IRR (1999)
- Ionising radiation [Medical exposure] regulations IR[ME]R (2000)
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What are the legal obligations of an individual taking radiographs etc.?
To keep:
- The general public safe (IRR)
- Staff safe (IRR)
- Patietns dose as lower as reasonably possible [ALARP] (IR[ME]R)
What does the Ionising Radiation Regulations (IRR) relate to?
The workplace, employees and the public
= the responsibility of the employer
= A framework ensuring exposure to ionising radiatin arising from work activities is as low as reasonably practicible (ALARP) and does not exceed specified limits
What 10 things does the Ionising radiation regulations (IRR) require?
- Risk assessment
- Employers written procedures
- Appointment of radiation protections advisor (RPA) & radiation protection supervisor (RPS)
- Local rules (contingency plans)
- Controlled areas
- Restriction of exposure (design, systems of work and PPE)
- Quality assurance programme (routine inspections & testing of equipment)
- Dose limits
- Dose constraints for comforters and carers
- Notification of equipment related incidents
What happens in a risk assessment (5 steps)?
- Identify the hazards (i.e. dose)
- Decide who may be harmed & how they may be affected
- Evaluate the risks (i.e. likelihood) and implement control measures
- Record the findings
- Periodoic review and revision of risk assessment = Standard operating procedures (SOPs)
Who is a radiation protection adviser?
Each dental practice MUST have one - this appointment must be in writing (not neccessarily on site all the time)
Must be consulted on for:
- Requirements for controlled areas
- Prior examination of plans for new equipment and rooms
- Regular calibration of dose monitoring equipment
- Periodic testing of safety features and warning devices
- Risk assessment and contingency plans
- Involved in staff training on safe use
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Who is a radiation protection supervisor (RPS)?
Usually a dentist/dental nurse who must be on site
Each practice must have one
Need adequate training & sufficient authority to implement their responsibilities = ensure local rules are followed
What are local rules?
= How to work safely in a controlled area
MUST BE READ AND SIGNED BY ALL EMPLOYEES
Must contain:
- RPS & RPA name and contact number
- identification of the controlled area
- summary of working instructiooms
- contingencies for forseeable accidents
When is a controlled area neccessary?
- To follow special procedures to restrict significant exposure
- Any area where dose > 6mSv/y
- Or any area where a dose 3/10ths of the dose limit is likely
(anywhere staff may be exposed to radiation dose = keep out unless you have to be in it! Red do not enter sign is only on when the ray beam is on)
What is a classified person?
Someone who’s profession means they are likely to recieve a dose of more than 6mSv per year (i.e. nuclear power station worker)
Who does a dose limit apply to?
Staff, trainees & other persons EXCLUDING the patient exposed
n.b. must NOT be exceeded!
What is a dose constraint?
A recommended level that should not be exceeded with standard practice = NOT A LIMIT!
For dental radiography:
- Operators directly involved with radiography = 1mSv
- Employees not directly involved, comforters & carers = 0.3 mSv
What is a quality assurance programme?
A regular programme of testing and review of equipment, procedures and training to ensure optimal diagnostic results at minimal level of radiation dose
What is the ionising radiation [medical exposures] regulations aimed towards?
Patient protection
= to minimise risk to patients undergoing medical exposures
Who enforces IR[ME]R?
Care quality commission England
and
Healthcare inspectorate wales
= check that sterilisers are working properly and the correct equipment is being used etc
What does IR[ME]R require?
- Guidelines for referral criteria for radiographic examinations
- Written protocols for every type of standard radiographic examination
- Correct identifiation of the patient
- Identification of referrers, practicioners and operators
- Ensuring quality assurance programmes are followed (i.e. images are of diagnostic quality)
- Assessment of patient dose
- Use of diagnostic referencing levels
- Carrying out and recording evaluation of the outcome of each exposure
- Medical physics expert
- Clinical audit
What are the 4 classes of IR[ME]R duty holder?
- Referrer
- Practitioner
- Operator
- Employer (legal person)
N.b. can be all/ more than 1
(not simultaneously but sequentially)
What is the role of the referrer?
= Requests the radiograph (authorised person)
- Supplies practitioner with sufficient clinical details relevant to the exposure to enable the practitioner/operator to justify the procedure (i.e. caries)
- Must take and docuent history and examination
N.b. appropriately trained hygieniss/ therapists msy now refer for radiographs
What is the role of the practitioner?
= Justification of the procedure
- Use selection criteria i.e. risk-benefit ratio
- Is the radiograph going to change the way you manage the patient?
- Utilisation of previous films
- Authorisation = the recording that justification has been carried our prior to patients exposure
What is the role of the operator?
= carrying out the investigation and activities associated with it & optimisation (ALARP)
- Exposing test obejects as part of QA programme (ensure its working properly)
- Responsible for each and eveery aspect of image production: Identifying the patient (address & DOB); positioning the film, x-ray tube & patient; settting the exposure parameters; processing the films; evaluate the quality of the films
What is optimisation?
Patients have no dose limit = to reduce exposure we optomise
- Justification
- Use selection criteria
- All practical means of reducing dose used to produce images (i.e. use modern eqipment)
- Sensitive image detector systems
- Field reduction (expose minimum required)
- Rectangular collumation for intra-orals
- Effective quality assurance & equipment maintenance programme
What is the role of the employer?
- Responsible for implemeting IRR and IR[ME]R
- Notification of health safety executive
- Appoint RPS & RPA
- Risk assessment
- Training (inc. record)
- Dose limits (dignostic reference levels)
- Ensures written procedures for medical exposures (local rules) are in place and complied with by staff
- Quality assurance programme (legal requirement)
- Ensure written protocols are in place for every type of standard radiological practice (exposure chart)
When does the health and safety executive need to be informed?
On the installation of equipment:
- When new ownership of the practice
- Change of address
- (NOT WHEN EQUIPMENT IS CHANGED OR RENEWED)
= inform in writing
What are the duties of the employee?
Must:
- NOT knowngly expose himself/ anyone else to ionising radiation more than neccessary
- use & take care of PPE provided
- Report equipment defects
- Keep updated (training)
What is the role of the Medical Physics Expert required by IR[ME]R?
- Comes from a number of different sources (Public health england radiation protection division, local medical physics department, independent company specialisin in radiation protection)
- Should give advice on: Patient dosimetry, development and use of new &/or complex techniques & other matters relating to radition protection concerning dental exposures
- Must obtain all recommendations in writing
What is the advice for pregnant patients in dentistry?
- Normally unneccessary to worry as low dose and beam aimed at patients head
- If patient worried explain this, on occasion we may provide a lead gown for patient if it doesn’t interfere with the procedure (i.e. high necked in way of mandible)
Whats a diagnositic reference level (DRL)?
= Doses for typical examinations for groups of adverage sized patient = based on entrance surface dose (skin entry dose)
Regular monitoring is required = test film put in unit and sent to local radiography department to be examined
EMPLOYERS MUST TAKE ACTION IF THESE ARE EXCEEDED
What was the diagnostic reference level for dental radiography in 1999?
6334 intraoral units tested = range of 0.14 -45.7 mGy
387 panoramic sets tested = range 1.7 -328 mGy
=HUGE!! SHOULD NOT BE THIS AMOUNT OF DIFFERENCE
At what level is the DRL set?
1/3rd quartile of dose
1999 mandibular molar intraoral = 4 mGy/mm
standard adult panoramic 65mGy/mm
2007 mandibular molar intraoral - 2.5 mGy/mm
standard adult panoramic 60 mGy/mm
= decrease by 1.6 mGy/mm & 5mGy/mm
What dose is reached for a patient to be said to have had excessive exposure?
A patient percieved to recieve >20 X intended dose or unintended dose
Whar has to happen if a patient is exposed to excessive exposure?
- Employer must consult RPA and inform the patient of the incident
- Employer and RPA investigate to see if incident really occured and if it did… contact health and safety executive and MDA if due to equipment fault & the care quality commision (CQC) if due to human error
How can you report an IR[ME]R incident?
Online … on CQC website search ionising radiation & select reporting incidents
What must staff taking radiographs be trained in?
Know the risks from xrays, neccessary precautions & the importance of complying with legislation
Undertake continuing education & training (recommended do a 1 day course every 5 years for dentists and dental care practitioners)
Who can be operators?
Dental nurse
Hyguenusts
Therapists
(must possess NEBDN certificate in radiography)
What qualifications does a film processing and quality assurance possess?
The certificate of dental nursing or equivalent
What about pregnant female operators?
They should kow risks to the feotus and they are required to notify their employer of the pregnancy (only really a problem if work load v. high i.e. > 100 intraoral/50 DPT exposures per weel (consult RPA)
How are the radiological regulations enforced?
The Health and Safety at work act 1974
IRR 99 -> health and safety executive HSE)
IR[ME]R 2000 -> care quality commission (CQC)
Failure to comply to legislation = prosecution under criminal law and sanction from GDC
