Radiation Protection- Cath lab

Transcription

1 Radiation Protection- Cath lab Dr. Mawya A Khafaji Associate Prof. Medical Physics, Faculty of Medicine, KAU Head of Medical Physics Unit Dept. of Radiology -KAUH Head, Volunteer Office -KAUH

2 Outline: Ionizing Radiation Effects of Ionizing Radiation Radiation Protection and reducing risk Updates in radiation protection.

3 Ionizing Radiation: Energy high enough to change atomic structures and DNA, NOT detected by our senses High utilization (on daily basis) Staff (i.e. cardiologists, cardiac technicians, radiographers, nurses and trainees) exposure is highest In room Beam on time

4 Ionizing Radiation: Source of radiation is fluoroscopy unit (beam on) and scatter from patient When x-ray beam photons enter patient: absorbed, pass straight through (responsible for image formation), and many photons bounce off the tissues atoms and exit body in different directions. Even if personnel is not in main radiation beam path, susceptible to scatter radiation: Main source of occupational radiation exposure Concentrated at table level

5 Ionizing Radiation: For every 1000 photons reaching the patient: scatter 20 reach image detector Remaining are absorbed (patient dose) Scatter is higher near the area where beam enters patient

6 Ionizing Radiation: Equipment configuration Number of cases/day Time Modes of use: Fluoroscopy - involves 95% total x-ray operation time, only causes 40% of total radiation exposure to staff and patients, due to pulsed screening. Cine - diagnostic images and permanent record of procedure (5% of total x-ray tube operation time), 60% of total exposure to staff and patients, due to use of high dose rapid sequence screening required to record.

7 Effects of Ionizing Radiation: Death Cancer Skin Burns Cataract Infertility Genetic effects

8 Effects of Ionizing Radiation Radiation is proven to have side effects that can be severe: Deterministic effects? severity of effect is dose-related, has a dose threshold hair loss, skin burns, cataracts, diminished fertility, and bone marrow suppression Stochastic effects? probability (not severity) of an effect increases with dose severity of effect is not dose related, no dose threshold cancer and genetic effects ICRP guidelines : prevent deterministic effects and limit probability of stochastic effects

9 Effects of Ionizing Radiation Radiosensitivity - young and rapid growing cells are more sensitive to radiation than mature cells Sensitivity Low Muscle, Joints, Central nerves, Fat Skin, Inner-layer of intestines, Eyes Lens of the eye is radiosensitive will be affected if un-shielded Bone marrow, Lymph system, Reproductive High organs

10 ICRP in 2011 reduced lens threshold value of absorbed dose for cataracts from 5.0 Gy to 0.50 Gy based on the following: Vano et al interventional cardiology personnel (93 unexposed control) 38 % cardiologists, developed cataracts 21% other medical personnel, radiation-associated lens changes Ciraj-Bjelac et al 2010, 56 interventional cardiologists and 11 nurses (22 age/gender matched controls) 52% cardiologists and 45% nurses developed posterior lens opacities concluded that without proper eye protection, users are at higher risk of developing cataracts.

11 Chest x-ray 0.02 msv * Mammo (4 views) 0.7 msv Barium Enema (10 images, 137 sec fluoroscopy) 7.0 msv Computed Tomography (CT) 2 to 30 msv: Abdomen 10 msv Coronary angiography 19 msv Coronary artery calcium scoring 2 msv NM Investigations 0.3 to 18.5 msv Cathlab, 4 to 30 msv Coronary angiography 4 to 21 msv PCI effective doses 9 to 29 msv Depending on area, equipment settings, technique and specs

12 Common Examination Doses: Reference of both slides : /content/informationfor/health professionals/5_interventionalc ardiology/index.htm; Einstein Einstein et al 2007; Hausleiter et al 2009; Kim et al 2009

13 Occupational & Public Dose Limits Application Effective Dose Annual equiv. dose for Lens of the eye The skin Hands and feet Occupational 20 msv/year, averaged over 5 years 20 msv (used to be 150 msv) 500 msv 500 msv Public 1 msv/year, averaged over 5 years 15 msv 50 msv Source: International Commission on Radiological Protection, ICRP

14 Principles of Radiation Protection 1 Justification 2 Optimization 3 Limitation

15 Justification All exposures must be justified No use of ionizing radiation is justified if no benefit Even the smallest exposures are potentially harmful and risk must have a benefit 15

16 Optimization: Any use of radiation must be optimized to minimize harm and damage Doing the best you can under the prevailing conditions to decrease the dose Need to be familiar with techniques and options to optimize application of ionizing radiation 16

17 Limitation: 1. Exposure of radiation workers and individuals of public must not exceed dose limit ( as per ICRP, NCRP, etc.) International Commission on Radiological Protection National Council on Radiation Protection 2. Are there limits for patients? NO! Guidelines Reference Values Dose reduction techniques

18 Radiation Protection - Actions Time Distance Shielding

19 Regulations In Cath-lab Local guidelines and rules for radiation safety Radiation safety coordinator Strict adherence to protection measures Evaluates daily practice Monitors staff dose records Sets action levels for staff doses Dose audits and DRLs DRLs for cardiovascular procedures (Peterzol et al 2005, Neofotistou et al 2003, Balter et al 2008, D'Helft et al 2009). Proper use of protection tools and techniques Interventionist effective dose (2 4 msv/year); well below 20 msv/year limit recommended by ICRP

20 Personal Monitoring

21 The 10 Pearls by IAEA- for users

22 The updates :

23 In December 2012 International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) sponsored an International Conference on Radiation Protection in Medicine: Setting the Scene for the Next Decade, in Bonn Germany A list of priorities for radiation protection in medicine for the next decade, called the Bonn Call for Action Supported by FDA, governments, and scientific societies and organizations

24 1: Enhance implementation of the principle of justification 2: Enhance implementation of optimization of protection and safety 3: Strengthen manufacturers role in contributing to the overall safety regime 4: Strengthen radiation protection education and training of health professionals 5: Shape and promote strategic research agenda for RP in medicine 6: Increase availability of global information (medical/occupational exposures) 7: Improve prevention of medical radiation incidents and accidents 8: Strengthen radiation safety culture in health care 9: Foster an improved radiation benefit-risk-dialogue 10: Strengthen the implementation of safety requirements globally

25 Worldwide Campaigns EuroSafe in 2014 CanadaSafe in 2015 AfroSafe in 2015 LatinSafe in 2015

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27 Supported by scientific societies and professionals in radiation medicine.

28 ArabSafe Aims 1. Involve radiation health professionals in Arab countries 2. Promote beneficial use of radiation through the following actions: Educate health care professionals about the benefit and risk of radiological procedures. Start regular radiation dose monitoring, recording and reporting of all diagnostic imaging procedures performed in government and private sectors. Advise the establishment of diagnostic reference levels for all types of diagnostic imaging procedures. Promote the use of guidelines and appropriateness criteria for referrals. Promote and assist in regular professional development and training in radiation safety. Create public awareness on radiation safety. Promote and help develop a radiation safe culture in health care facilities.

29 Thanks a lot