Download
radiation protection in radiotherapy n.
Skip this Video
Loading SlideShow in 5 Seconds..
Radiation Protection in Radiotherapy PowerPoint Presentation
Download Presentation
Radiation Protection in Radiotherapy

Radiation Protection in Radiotherapy

117 Views Download Presentation
Download Presentation

Radiation Protection in Radiotherapy

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Radiation Protection inRadiotherapy IAEA Training Material on Radiation Protection in Radiotherapy Part 13 Accidents and Emergencies Lecture 2: Emergencies

  2. Emergencies • Some overlap with previous lecture • Emergencies can occur, therefore it is essential to be prepared • Important reference: IAEA TECDOC 1162: Generic procedures for assessment and response during a radiological emergency, 2000 Part 13, lecture 2: Emergencies

  3. Clarification of terms • BSS glossary: • Accident: Any unintended event, including operating errors, equipment failures or other mishaps, the consequences or potential consequences of which are not negligible from the point of view of protection or safety. • Emergency plan: A set of procedures to be implemented in the event of an accident. Part 13, lecture 2: Emergencies

  4. BSS Appendix V: EMERGENCY EXPOSURE SITUATION • “RESPONSIBILITIES V.1. It is presumed that the State will have determined in advance the allocation of responsibilities for the management of interventions in emergency exposure situations between the Regulatory Authority, national and local Intervening Organizations and registrants or licensees.” • The responsibility starts at the very top... Part 13, lecture 2: Emergencies

  5. Objectives • To understand the need to plan for an emergency in radiotherapy • To be able to respond adequately to an emergency in a radiotherapy department • To identify the information which needs to be reported in case of an emergency Part 13, lecture 2: Emergencies

  6. Contents 1. Planning for an emergency 2. Emergency response and mitigation 3. Investigations and reporting Part 13, lecture 2: Emergencies

  7. 1. Planning for an Emergency • Consider what could happen • Try to prevent it • Prepare for the emergency situation • internal (overdose of patients, malfunction of equipment) • external (exposure of public and/or contamination of the environment) Part 13, lecture 2: Emergencies

  8. Need to differentiate type of emergency plan for • Accidents involving the exposure of patients (previous lecture) • Accidents involving the environment outside the hospital • Radioactive sources used in radiotherapy are released into public • Radiological emergencies of different origin may require radiotherapy staff to supply expertise and monitoring equipment Part 13, lecture 2: Emergencies

  9. Accidents involving the exposure of patients • Considered in BSS in the context of medical exposure (appendix II 28,29) • Discussed in detail in the previous lecture • Panama accident an example Part 13, lecture 2: Emergencies

  10. Accidents involving sources from a radiotherapy department causing exposure of general public • Covered in BSS in appendix V: Emergency Exposure Situations • Includes also brachytherapy sources leaving the hospital • Covered in more detail in part 15 of the course Part 13, lecture 2: Emergencies

  11. External accidents where equipment and/or expertise from radiotherapy staff is required • Staff in radiotherapy (in particular radiation safety officer and/or qualified expert in radiotherapy physics) have unique expertise which may also be useful in other radiological emergency situations • Assessment of persons suspected of accidental exposure by radiation oncologists may be helpful • Radiotherapy department’s emergency plan may link to hospital or area’s disaster plan Part 13, lecture 2: Emergencies

  12. BSS Appendix V: EMERGENCY EXPOSURE SITUATION • “EMERGENCY PLANS V.2. Emergency plans shall be prepared which specify how the responsibilities for the management of interventions will be discharged on the site, off the site and across national boundaries, as appropriate, in separate but interconnecting plans.” Part 13, lecture 2: Emergencies

  13. Emergency Planning and Preparedness in radiotherapy assessment of the hazards acquisition of emergency equipment development of written procedures training Part 13, lecture 2: Emergencies

  14. BSS appendix V.4 • “Emergency plans shall include, as appropriate: (a) allocation of responsibilities for notifying the relevant authorities and for initiating intervention; (b) identification of the various operating and other conditions of the source which could lead to the need for intervention; (c) intervention levels, based on a consideration of the guidelines in Schedule V, for the relevant protective actions and the scope of their application, with account taken of the possible degrees of severity of accidents or emergencies that could occur; “ Part 13, lecture 2: Emergencies

  15. BSS appendix V.4 (cont.d) • “Emergency plans shall include, as appropriate: ... (d) procedures, including communication arrangements, for contacting any relevant Intervening Organization and for obtaining assistance from fire-fighting, medical, police and other relevant organizations; (e) a description of the methodology and instrumentation for assessing the accident and its consequences on and off the site; (f) a description of the public information arrangements in the event of an accident; and (g) the criteria for terminating each protective action.” Part 13, lecture 2: Emergencies

  16. Examples Can you report an example for an emergency in a radiotherapy department?

  17. Emergency plan - questions one should ask • Is there a written emergency plan? • Is the plan periodically reviewed and updated? • Are staff aware of the plan and do they have training in the response required of them? • e.g.: Are there staff procedures for when a teletherapy or brachytherapy radiation source fails to return to the shielded position? • Are there records of other or similar accidents? Part 13, lecture 2: Emergencies

  18. Please note: • These are also questions the regulatory authority may ask you... Part 13, lecture 2: Emergencies

  19. BSS appendix V.3.: • “The appropriate responsible authorities shall ensure that… (a) emergency plans be prepared and approved for any practice or source which could give rise to a need for emergency intervention; (b) Intervening Organizations be involved in the preparation of emergency plans, as appropriate; (c) the content, features and extent of emergency plans take into account the results of any accident analysis and any lessons learned from operating experience and from accidents that have occurred with sources of a similar type;” Part 13, lecture 2: Emergencies

  20. BSS appendix V.3. (cont.d): • “The appropriate responsible authorities shall ensure that… (d) emergency plans be periodically reviewed and updated; (e) provision be made for training personnel involved in implementing emergency plans and the plans be rehearsed at suitable intervals in conjunction with designated authorities; and (f) prior information be provided to members of the public who could reasonably be expected to be affected by an accident” Test the emergency plan! Part 13, lecture 2: Emergencies

  21. Training personnel should be trained to deal with identified situations drills and exercises should be conducted include feedback from exercises to improve training Part 13, lecture 2: Emergencies

  22. Emergency drills • All relevant actions must be trained and regularly performed to be proficient at the time of an accident • Regular drills are important, e.g. • Manual removal of a source in brachytherapy • Removal of a patient from a treatment couch after power failure Part 13, lecture 2: Emergencies

  23. Emergency drills and exercises • May be planned • May be not announced to test response in a ‘real’ situation • The latter may also be used to audit the emergency preparedness Part 13, lecture 2: Emergencies

  24. Emergency drills and exercises • Documentation important • Planning needs to be done carefully to avoid interference with patient treatment • De-briefing of staff essential • Findings should be public and considered for revision of emergency plan and training programs Part 13, lecture 2: Emergencies

  25. Emergency Equipment • Integral part of the emergency plan • Manual, procedures, documentation • Radiation monitor • Other items as required by the specific application • Only of use if staff is trained to use it Part 13, lecture 2: Emergencies

  26. 2. Emergency response and mitigation • Emergency procedures spell out mitigation measures • Procedures shall be succinct, unambiguous and posted where ever need is anticipated • Responsibilities of individuals shall be identified Part 13, lecture 2: Emergencies

  27. Emergency response - initial actions • Rectify the situation (e.g. stop irradiation, manually retract a source) • Make sure patients are brought into safety • Isolate the area • Notify supervisor and/or radiation safety officer Part 13, lecture 2: Emergencies

  28. Quick question for illustration Consider a patient with a radioactive implant (e.g. 198-Au seeds) has a cardiac arrest - what is to be done?

  29. Some additional suggestions for the answer • The patients welfare is the highest priority therefore resuscitation should be commenced immediately. Also cardiac arrest team and radiation safety officer should be informed and called immediately. The dose for anyone in close contact with a patient having an implant does typically not exceed 1mSv in an hour. The radiation safety officer must try to estimate the dose received by all persons involved. Part 13, lecture 2: Emergencies

  30. Other important points • Any incident should be reported in writing • An accident may need formal investigation • Doses can be reconstructed and should be reported for all persons involved - this includes the patient! • Reporting of an incident outside the hospital may be required by law!!! Part 13, lecture 2: Emergencies

  31. Quick question What is a radiation accident in radiotherapy for you?

  32. 3. Investigation • BSS Appendix II: INVESTIGATION OF ACCIDENTAL MEDICAL EXPOSURES • “II.29. Registrants and licensees shall promptly investigate any of the following incidents: • (a) any therapeutic treatment delivered to either the wrong patient or the wrong tissue, or using the wrong pharmaceutical, or with a dose or dose fractionation differing substantially from the values prescribed by the medical practitioner or which may lead to undue acute secondary effects; • ... • (c) any equipment failure, accident, error, mishap or other unusual occurrence with the potential for causing a patient exposure significantly different from that intended.” Part 13, lecture 2: Emergencies

  33. Investigation • Things for the licensee or registrant to do following BSS II 29: • Calculate or estimate the dose(s) received and their distribution within the patient • Indicate corrective measures to prevent a recurrence of the incident • Implement all corrective measures under their control • Submit a written report to the Regulatory Authority as soon as possible after the investigation or as otherwise specified by the Regulatory Authority How bad was it? What to do to put it right? Part 13, lecture 2: Emergencies

  34. Flow chart may be useful Part 13, lecture 2: Emergencies

  35. Investigation level • BSS IV.18. Registrants and licensees shall conduct formal investigations as specified by the Regulatory Authority if: (a) a quantity or operating parameter related to protection or safety exceeds an investigation level or is outside the stipulated range of operating conditions; or (b) any equipment failure, accident, error, mishap or other unusual event or circumstance occurs which has the potential for causing a quantity to exceed any relevant limit or operating restriction. Did it exceed the level (or might it have)? Part 13, lecture 2: Emergencies

  36. In radiotherapy practice • Investigation levels mainly applicable to occupational exposure • For medical exposure the definition of an incident/accident may be relevant • e.g. “if the total dose delivered is different from the prescribed by more than 10%” • This could be too much but also not enough dose... Part 13, lecture 2: Emergencies

  37. Investigation • Should be done as soon as possible after the incident • Often useful: a written statement of all witnesses before they talk to each other • Incident review meeting including a representative of senior management • Assessment of impact on staff and patient • Information for affected patient(s) Part 13, lecture 2: Emergencies

  38. Investigation • Expertise of other professionals (e.g. Occupational Health and Safety, Environment) can be useful • Could be most effectively lead by an external expert • Feedback important • A written report should be provided Part 13, lecture 2: Emergencies

  39. Report to • Hospital management • Regulatory authority • IAEA? • Professional organizations? Part 13, lecture 2: Emergencies

  40. Help may be available • Radiological accident assistance • e.g. outside assistance after radiological incident in Panama Part 13, lecture 2: Emergencies

  41. The Response • The ION (Hospital) contacted the office of WHO/PAHO who made a calculation with the provided treatment time and other parameters. PAHO also confirmed • The ION requested an expert group from MD Anderson who performed the mission in April 2000 and confirmed the differences in doses • 14 May the ION informed the Ministry of Health and the DSR • 22 May a formal request for assistance was requested from the Agency • The mission started in May 27 Part 13, lecture 2: Emergencies

  42. The terms of reference for IAEA expert team • Ensure that radiation sources are in safe conditions • Evaluate the doses to patients • Perform a medical evaluation, prognosis and advice on treatment • Evaluate issues on which the IAEA can coordinate assistance to minimize the consequences Part 13, lecture 2: Emergencies

  43. Databases • Several data bases exist which allow the comprehensive evaluation of causes for accidents and emergencies in radiotherapy • Examples: IAEA RADEV • These databases rely on accurate and prompt reporting Part 13, lecture 2: Emergencies

  44. Disseminate information within professional community • A chance to learn • Make sure legal investigations are not interfered with • Make sure no one can be identified Part 13, lecture 2: Emergencies

  45. Actions after an accident in radiotherapy • Investigation • Report • Actions to prevent a recurrence of the accident • … not necessarily closure of the radiotherapy facility ... Part 13, lecture 2: Emergencies

  46. A final comment:Radiotherapy can cure cancer • An uncontrolled cancer can look just like a deterministic radiation effect - and can kill a patient in the same way Part 13, lecture 2: Emergencies

  47. Radiotherapy should go on... • A treatment unit may treat hundreds of patients per year - even if only a fraction of them is cured this constitutes a significant contribution to public health • Clearly, an accident • SHOULD be prevented • MUST be investigated and • a recurrence MUST be made impossible, • however, if at all possible: Part 13, lecture 2: Emergencies

  48. Summary It is essential to be prepared for a radiological emergency in radiotherapy Important elements of this are training, written procedures, emergency equipment and regular drills All accidents and emergencies MUST be reported and investigated A report may be required also to regulatory bodies Part 13, lecture 2: Emergencies

  49. Any questions?

  50. Question: ‘Defence in depth’ may be an important part of the preparedness for an emergency. Please discuss the ‘defence in depth’ approach in the context of avoiding a lost source in brachytherapy.