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Section D

Equipment

Regulation 32(8) of the regulations defines radiation equipment as that which delivers ionising radiation with any additional equipment which directly controls the extent of the radiation exposure (e.g. intensifying screen).

SCoR Guidance
In radiology optimum radiation protection begins with the radiography or radiotherapy equipment used and should be one of the criteria raised in the subsequent procurement process. It is essential that manufacturers are asked specific questions relating to patient and staff doses at the beginning of this process so that the information can be taken into consideration in the selection process. This is especially the case when the equipment is to be utilised in children’s services in order that radiation doses to children be ALARA. Furthermore, it is equally important for equipment used for interventional radiology when new detector technology and equipment functions can significantly reduce patient and staff dose. The SCoR advise that radiographers with appropriate experience are involved in the equipment procurement process.

In 2006, the Health and Safety Executive made available the third edition of PM77 'Equipment used in connection with medical exposure' (HSE, 2006)

This guidance includes advice on:

  • selection, installation, maintenance, calibration and replacement of equipment
  • criteria of acceptability for both new and older equipment
  • quality assurance programmes, including adoption of suspension levels
  • the investigation of incidents involving a malfunction or defect in radiation equipment which results in an exposure much greater than intended.

The Welsh Scientific Advisory Committee have produced a useful publication on the procurement of equipment used for medical exposure to ionising radiation (to include diagnostic x-ray, radiotherapy and nuclear medicine) Good Practice Guidelines for Tender, Supply, Installation and Handover – March 2005 this is available for download via
http://wales.gov.uk/topics/health/cmo/committees/scientific/reports/equi...

i) Design / authorisation / installation of equipment

Design:
 
Diagnostic Radiography
The following information relating to diagnostic radiography x-ray facilities is required when designing rooms for x-ray equipment:
- required thickness of walls as well as electrical + mechanical services
- use of protective screens/shielding - taking account of x-ray attenuation etc
- entrance to the x-ray room/area
- demarcation of controlled + supervised areas
- position of the control panel for the radiographer

Further information is available from the DH website: https://www.gov.uk/government/organisations/government-estates-management

Radiotherapy
Information about the design of a radiotherapy department may be obtained from an NHS Estates guide entitled “Facilities for Cancer Care Centres” (2001). 

Authorisation
Regulation 5 of the IRR’99 has placed a legal duty on radiation Employers to have written permission from HSE before carrying out specified operations. The overwhelming majority of Employers should be able to meet all the conditions in the relevant generic authorisation (GA), in which case, authorisation is automatic: the Employer does not have to apply to the HSE, and no action is required by HSE. The Employer must adhere to the conditions in generic prior authorisation summaries. Prior authorisation for the use of electrical equipment intended to produce X-rays (diagnostic & therapeutic) is available at: http://www.hse.gov.uk/radiation/ionising/authorisation.htm and
www.hse.gov.uk/radiation/ionising/certxray.htm

Regulations 5 of IRR’99 covers the following practices:

  • the use of accelerators (other than electron microscopes);
  • the use of x ray machines for the following specific purposes:
  • industry radiography;
  • the processing of products;
  • research; 
  • x raying of patients for medical treatment.

Radiotherapy
Details about authorisation, prior to the use of accelerators (other than electron microscopes) in radiotherapy is available at: www.hse.gov.uk/radiation/ionising/certacel.htm

Installation

General
Regulation 6 of IRR’99 requires the Employer to notify the HSE of any work relating to ionising radiation at least 28 days in advance of starting any work. A change of name of the Employer or site must also be notified to HSE.
Regulation 31(2) of IRR’99 requires that the installer must ensure that a critical examination is carried out following the installation of x-ray equipment. This is different from the physical tests usually undertaken within a department by the internal medical physics staff.
The critical examination covers verification of the correct operation of all safety features and warning devices and an assessment of the adequacy of the radiation protection for staff and visitors. 

SCoR Guidance
Critical examination is required for new installations, re-installations of equipment and the replacement of parts (e.g. cathode ray tubes), where installation could have implications for the radiation protection of staff and members of the public (as well as individuals undergoing medical exposures) or affect the operation of safety features /  warning devices. 
The critical examination must be performed, before clinical use, in conjunction with either the installer’s Radiation Protection Advisor (RPA) or the RPA of the Employer who has acquired the x-ray equipment.  A written report must be sent to the department to confirm satisfactory completion of this testing.
Arrangements for the critical examination should be made when drawing up contracts with the installer.

Diagnostic Radiography
Further guidance is available in the following publications:
Report 91, Recommended Standards for the Routine Performance Testing of Diagnostic X-Ray Imaging Systems”, Institute of Physics and Engineering in Medicine (IPEM) 2005.This report replaces IPEM Report 77 and provides essential guidance for anyone responsible for diagnostic X-ray equipment.  Available at: ipem.ac.uk/publications/ipemreports/Pages/default.aspx

The Critical Examination of X-Ray Generating Equipment in Diagnostic Radiology, Report 79, written by the Critical Examination Working Party of Institute of Physics and Engineering in Medicine in 1998 is essential guidance for all involved in the critical examination of diagnostic X-ray equipment, as required by Regulation 32 (2) of the Ionising Radiations Regulations 1998

Radiotherapy
Radiotherapy equipment should only be installed in a room designed for the purpose and should include adequate shielding. The equipment must comply with HSG226 (HSE guidance) –
see www.hse.gov.uk/radiation/rpnews/medical.htm#hsg226pm77, and BSEN60601 (electrical standards in healthcare).

The IPEM Report 93 (2006)
“Guidance for Commissioning and QA of a Networked Radiotherapy Department” is particularly informative about the “networking equipment requirements” within a radiotherapy department.

Section 7 of the “Medical and Dental Guidance Notes”, Institute of Physics and Engineering in Medicine (IPEM), 2002 details considerations for practices for photons, electron beams and treatment energies over 10MeV.

Adjacent areas such as roofs, basements, ducting may be considered Controlled or Supervised Areas and appropriate systems of work for these areas should be detailed in the Local Rules.
The RPA (& the RPS if appropriate) should conduct acceptance testing data which should be then used to form a reference baseline for quality control testing.

Further details can be found in the “Report 94, Acceptance Testing and Commissioning of Linear Accelerators” Institute of Physics and Engineering in Medicine (IPEM), 2007

ii)    Prior Risk Assessment (PRA)

Regulation 7 requires Employers who introduce new systems of work or new equipment using ionising radiation to undertake and record a full prior risk assessment (PRA) prior to any new work beginning. The rationale behind any PRA is to restrict exposure to ionising radiation during routine clinical practice and in the event of accidental or unintended incidents. PRA helps to designate areas surrounding sources of ionising radiation into controlled or supervised areas. Keys parts of the PRA are:

  • Source of radiation
  • Estimated / measured doses / dose-rates
  • Control of radiation exposure (i.e engineering controls)
  • Systems of work that are planned / any required training
  • Personal protective equipment requirements
  • Potential accident situations and contingency plans
  • (pp 22-23 of L121, HSE 2000)

Five examples of risk assessment forms (blank & complete) are available (with kind permission of those departments represented by the radiographers on the working party for this handbook) within Appendix I, which covers practices in diagnostic radiography, radiotherapy, interventional radiology and generic practices.

Risk assessments are undertaken to identify potential hazards to staff and patients and should be performed by the RPS in consultation with the RPA. Refer to the “5 steps to risk assessment”, Health & Safety Executive (HSE), Chapters 1 & 19 of “Medical and Dental Guidance Notes”, Institute of Physics and Engineering in Medicine (IPEM), 2002 and Report 95 “Risk Management and its Application to Medical Device Management” (IPEM), 2008. Pages 20 – 26 of L121 (HSE, 2000) provide further guidance and good practice.

SCoR Guidance
SCoR believes that the prior risk assessment (PRA) is the most important aspect of IRR’99 as poor PRA or failure to undertake PRA normally leads to poor compliance with other areas of the regulations. PRAs are the responsibility of the Employer and should be carried out by appropriately trained staff (e.g. the RPS or other radiographers) before the actual clinical practice takes place and must be reviewed and updated when practices change or new practices are introduced and when new equipment is installed. All PRAs should be made available to all staff in the Local Rules of clinical imaging/radiotherapy departments. PRAs should be formally reviewed annually.

iii)  Quality Assurance (QA)

Diagnostic Radiography
Regulation 32 (3)-(4) of IRR’99 requires that every Employer should ensure that suitable quality assurance (QA) programmes are in place for every part of the imaging system to ensure compliance with the intended purpose. Time should be allocated to appropriately trained personnel (i.e radiographers and physicists) to ensure that QA tests are undertaken at regularly scheduled intervals.
It may be that some of the complex tests allocated are carried out periodically by the medical physics dept whilst the more routine tests are part of the daily pattern of work of radiographers.

The Employer should give special attention to equipment used for medical exposure:

  1. of children (also see http://www.imagegently.org/Roles-What-can-I-do/Technologists)
  2. Involving high doses such as interventional radiology and CT and radiotherapy

SCoR Guidance
QA testing is part of the radiographer’s & APs role. It is good practice that QA testing is overseen by one dedicated member of staff to facilitate efficiency and continuity.
Dedicated equipment testing QA files should be kept with each piece of equipment and should contain:-

  • An equipment list,
  • Information regarding the frequency of tests,
  • Descriptions of the tests to be carried out (e.g. regular testing of output, AEC, collimation, fluoroscopy etc)
  • Results sheets and quarterly QA report forms
  • Actions that are required if the tests are “out with agreed limits”

It is also important that regular QA meetings are held to feedback the test results. Interpretation of the results may also be used to analyse trends in order to act in the light of any adverse findings. 

Further guidance is available in the following publications:

  • Recommended Standards for the Routine Performance Testing of Diagnostic X-Ray Imaging Systems, Report 91, Institute of Physics and Engineering in Medicine 2005
  • Assurance of quality in the Diagnostic X-Ray Department, second edition.    
  • British Institute of Radiology (BIR) 2001
    Pages 125 – 127 of L121 (HSE, 2000).

     

Nuclear medicine
The IPEM Report 86 (2003), Quality Assurance in Gamma Camera Systems, and IPEM Report 87 (2004), Radioactive sample counting Principles and Practice are particularly useful reports.

Radiotherapy
A quality assurance (QA) programme should be established and a definitive calibration performed before the equipment is first clinically used following the appropriate Code of Practice for Radiotherapy Dosimetry which is produced by IPEM. All dosimetry calibrations should be fully documented and undertaken by appropriately trained personnel.

SCoR Guidance
Equipment should be recalibrated by appropriately trained personnel following any servicing, maintenance or upgrade procedures that may affect outputs. As radiotherapy equipment is reliant on computer based systems, and delivery is increasingly automated, it is important that all software warnings are recorded, acted upon and reported to the appropriate person in a timely fashion. Responsibilities for QA need to be clearly defined. Examples of equipment QA checks to be carried out are:

  • Daily equipment QA performed at run up
  • Patient information checks prior to treatment
  • Portal imaging taken as protocol
  • Simulator exposures as protocol    
  • Treatment verification checks

The multidisciplinary (SCoR, RCR, IPEM, BIR, HPA & NPSA) 2008 publication entitled “Towards Safer Radiotherapy” written to improve patient safety in radiotherapy, makes 7 recommendations with regards QA systems. These relate to quality management systems, and the reporting of radiotherapy errors and near misses. This publication is available via: https://www.sor.org/learning/document-library?title=towards+safer+radiot...

iv) Servicing and Maintenance

General
Regulation 32(1) of IRR’99 outlines that it is the Employer’s duty to ensure that equipment is maintained so that patient dose may be minimised whilst remaining compatible with the clinical purpose.
It is the Employer’s duty to ensure that the maintenance requirements in respect of mechanical and electrical safety are also addressed. An itemised list of all work done during servicing and maintenance should be recorded by the service engineer at the end of the visit and QA testing should be carried out on the equipment before it is put back into service.

Diagnostic Radiography
Further guidance is available in the following publications

- Recommended Standards for the Routine Performance Testing of Diagnostic X-Ray Imaging Systems, Report 91, Institute of Physics and Engineering in Medicine 2005
- Equipment Used In Connection With Medical Exposure   PM77 Guidance Notes HSE 2006.  Website: www.hse.gov.uk/pubns/guidance/pm77.pdf
- Safe use of work equipment. Provision and use of work equipment regulations, 1998. Approved code of Practice and Guidance HSE 1998

 

Nuclear Medicine
Servicing is carried out by the supplier and the regularity of such activity is dependent upon their recommendations.

Radiotherapy
Radiotherapy departments must maintain an up to date inventory of all radiotherapy equipment - including manufacturer, model and serial numbers, year of manufacture and date of installation.
Equipment should comply with BSEN 60601 – see Appendix 13 of the “Medical and Dental Guidance Notes”, Institute of Physics and Engineering in Medicine (IPEM), 2002 and Regulation 12 of IRR’99.

SCoR Guidance
Records of all servicing, repairs, and fault correction should be kept in a dedicated file for that piece of equipment (with QA results). The QA tests required following a repair or maintenance check may be carried out by the service engineer or by the x-ray/radiotherapy department as part of their QA programme.  Good practice would be to sign the equipment over to the engineer for the service and have it handed back with a declaration that all settings are in the same configuration and the equipment is fit for purpose after the service or repair. A procedure should also be in place to ensure it is clear when a machine is in service use and not suitable for clinical use.

v) Malfunction (Contingency Planning)
Regulation 32 (5) of IRR’99 gives the Employer the responsibility of overseeing the possibility of any malfunction and to limit any consequences of such, especially where this may lead to a radiation dose being delivered greater than intended. Limitation could take the form of failsafe interlocks to prevent exposure if necessary.
Equipment may malfunction, or not perform as intended as a result of misunderstandings between service engineers and users. This can be avoided by clear hand over procedures for equipment that has undergone maintenance.

If it is suspected that an exposure greater than intended has occurred as a result of malfunction or defect in any radiation equipment an immediate investigation must be carried out and the HSE informed (Regulation 32(6&7)).

Regulation 7 of IRR’99 provides the need for an assessment of risk of accidental radiation exposure and 7(3) identifies that if such a risk is identified then the Employer must take reasonable steps to prevent accidents, the consequences of such accidents and provide Employees with information and training to restrict their exposure. Regulation 12 (1) requires the Employer to have contingency plans in place for such risks to restrict radiation exposure and the Health and Safety of anyone affected. This is more likely to occur in Radiotherapy and Nuclear Medicine if any where at all.

SCoR Guidance
It is good practice to report an error or near miss arising from equipment malfunction not only to the manufacturer but also to the Medicines & Healthcare Products Regulatory Agency (MHRA) to allow a national overview of trends which can be acted upon by national alert notices.
Contingency plans should be drawn up for any potential hazards with details being included in the Local Rules and rehearsals practiced at suitable intervals.  Operators should utilise the necessary fault reporting procedures within the local department.

Further guidance is available in the following publications.

SCoR Guidance
Nuclear Medicine
If a camera should fail a QA test, the test should be repeated at least a further two times to confirm the malfunction or to question the initial test. Injections to patients must not take place when a malfunction is suspected. If a malfunction is confirmed, alternative arrangements need to be made for those already injected with a radionuclide to be imaged either on another camera or on a different site. This will depend on the size and capacity of the department.
Should the calibrator fail a test, all injecting on patients must stop until the equipment has been corrected and checked by a physicist.

Radiotherapy
Perhaps the most important contingency would be how to end an exposure that has failed to terminate – all operators should be aware of the location of the emergency stop button and to use it when required. A lot of newer equipment comes with inbuilt safety interlocks which automatically terminate the beam in the event of a malfunction. It is important to have a procedure in place to manage the breakdown to minimise risk of an unintended exposure.

vi) Personal Protective Equipment  (PPE)
Regulation 9 (1)(2) of IRR’99 states that all personal protective equipment (PPE) should be compliant with the 1992 Regulations from the EC directive and in Regulation 9(3) it is stated that it should be maintained and stored appropriately.
Regulation 8(2) itemises that PPE should be adequate and appropriate for the task and Regulation 8(4) calls for a system of work that ensures proper use. All PPE should be stored safely when not in use to minimise the possibility of damage.

Diagnostic Radiography
Each item of protection should be labelled and dated at time of issue, regular checks should be made of the condition of all PPE and records kept of these in the radiation protection file. The best method of checking would include a regular visual survey to look for damage, and an annual screening of aprons by fluoroscopy to ascertain if any cracks or folds have appeared to allow radiation through.

Further guidance is available in the following publication.

  • Pages 43-44 of L121 (HSE, 2000).

SCoR Guidance
Lead (Pb) aprons (of sufficient lead equivalent to absorb all radiations), lead gloves, thyroid shields and lead glasses should be available in all fluoroscopy suites and theatres. The RPS may find it useful to involve the RPA in choosing the appropriate type of PPE, and the local Health and Safety team may advise on how it suits the wearer best.  It is particularly recommended that lead glasses be routinely worn by interventional radiologists and cardiologists due to the potentially high eye doses and subsequent risk of the development of cataracts.  It is also recommended that lead skirts are attached to the table to reduce the dose to the legs and feet and that pull down lead equivalent visors are used to offer additional protection for the eyes and thyroid.

Dental Radiography
Dental radiographs are the most frequently carried out radiographic examination undertaken in Great Britain (NRPB, (now HPA), 2001) and accounts for 25% of all radiological examinations.
Lead aprons do not protect against internal scattered radiation, and can on occasions actually obscure part of the image.

It has been demonstrated that the use of lead protection has minimal effect on gonadal dose, and the UK Guidance Notes for Dental Practitioners (2001) state that there is no justification for the routine use of lead aprons in dental radiography. The current view of the HPA (2008) is that lead aprons give no real radiation protection benefit to the dental patient apart from those rarely used extra oral views where the main x-ray beam passes through the body.  This is due to the fact that the doses arising from scatter are so low.  

Likewise, operators conducting dental radiography under properly controlled conditions as laid down in dental guidance notes again should have no need of wearing lead aprons at normal radiographic workloads.  They should, however, always be used when it is necessary for another person to provide assistance by supporting a patient during radiography. Protective aprons (lead equivalent of not less that 0.25mm) should be provided for any adult who is assisting with holding a patient during the examination. Thyroid collars should only be used in cases where the thyroid is in the primary beam and following advice from an RPA.

As the dose and risk to a fetus is low, there is no contra-indication to the irradiation of women who are and may be pregnant, however, the justification of the exposure should be reviewed in line with IR (ME)R 2000 procedures, and then the examination may be deferred for emotive reasons.
If the examination is undertaken, the fetal dose must be kept as low as reasonably achievable ALARA and in those cases a lead coat should be worn, mainly for the reassurance it provides for the patient.

Further guidance is available in the following publications.

Radiotherapy
PPE for radiotherapy staff in the form of lead (Pb) aprons are utilised in brachytherapy suites and the previously stated guidance in diagnostic radiography should be employed.

Radiotherapy treatments are with the aim of optimising exposure to the target while minimising exposure to normal tissue. The latter is achieved through the use of lead or lead equivalent materials, such as external or internal eye, shields, gum shields, post auricular shields, nasal & gonad shielding (where appropriate). Treatment fields are kept to a minimum size with shielding used to protect areas that are not to be treated (e.g. the use of diaphragms and multi leaf collimators etc).

 

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