ICRP Publication 120
Radiological Protection in Cardiology
Recommended citation
ICRP, 2013. Radiological protection in cardiology. ICRP Publication 120. Ann. ICRP 42(1).
Authors on behalf of ICRP
C. Cousins, D.L. Miller, G. Bernardi, M.M. Rehani, P. Schofield, E. Vaño , A.J. Einstein, B. Geiger, P. Heintz, R. Padovani, K-H. Sim
Abstract - Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff1 in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly.
The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113. This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission’s published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission.
This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention.
As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions, particular attention is devoted to clinical examples of radiation-related skin injuries from cardiac interventions, methods to reduce patient radiation dose, training recommendations, and quality assurance programmes for interventional fluoroscopy.
© 2012 ICRP. Published by Elsevier Ltd.
Keywords: Cardiology; Computed tomography; Nuclear medicine; Cardiac catheterisation; Radiological protection.
C. COUSINS, D.L. MILLER, G. BERNARDI, M.M. REHANI, P. SCHOFIELD, E. VAN˜ O´ , A.J. EINSTEIN, B. GEIGER, P. HEINTZ, R. PADOVANI, K-H. SIM
Key Points
Individuals who request, perform, or interpret cardiology imaging procedures should be aware of the radiation risks of the procedures.
Criteria and guidelines for appropriate use have been developed through the consensus efforts of professional societies, and should be used in clinical practice.
As with all other medical exposures, nuclear cardiology examinations, cardiac computed tomography examinations, interventional cardiology procedures, and electrophysiology procedures should be optimised, and dose reduction techniques should be used whenever applicable.
The informed consent process should include information on radiation risk if the risk of radiation injury is thought to be significant.
Radiation dose data should be recorded in the patient’s medical record after the procedure. Patient dose reports should be archived for quality assurance purposes.
When the patient’s radiation dose from an interventional procedure exceeds the institution’s trigger level, clinical follow-up should be performed for early detection and management of skin injuries.
Suggested values for the trigger level are a skin dose of 3 Gy, a kerma-area product of 500 Gycm2 , or an air kerma at the patient entrance reference point of 5 Gy.
Individuals who perform cardiology procedures where there is a risk of tissue reactions should be able to recognise these skin injuries.
Individuals who perform interventional cardiology or electrophysiology procedures should be familiar with methods to reduce radiation dose to patients and staff.
Nurses, radiographers/technologists, and other healthcare professionals who assist during imaging procedures (fluoroscopy, computed tomography, and scintigraphy) should be familiar with radiation risks and radiological protection principles in order to minimise their own exposure and that of others.
When there is a risk of occupational radiation exposure, staff should use appropriate personal protective shielding.
In addition to the training recommended for all physicians who use ionising radiation, interventional cardiologists and electrophysiologists should receive a second, higher level of radiological protection training.
Training programmes in radiological protection should include both initial training for all incoming staff, and regular updating and retraining.
A cardiologist should have management responsibility for the quality assurance programme aspects of radiological protection for cardiology procedures, and should be assisted by a medical physicist.
Quality assurance programmes in cardiology should include patient dose audits for fluoroscopy, computed tomography, and scintigraphy.
Quality assurance programmes should ensure the regular use of personal dosimeters, and should include a review of all abnormal dose values.
Executive Summary
(a) In cardiology, patient radiation exposure is due primarily to nuclear medicine, computed tomography (CT), interventional cardiology procedures and electrophysiology procedures. Cardiac nuclear medicine, cardiac CT, percutaneous coronary interventions, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff in cardiac catheterisation and electrophysiology laboratories may receive high radiation doses if radiological protection tools are not used properly.
1. The biological effects of radiation
(b) Stochastic effects (malignant disease and heritable effects) are effects for which the probability of an effect occurring, but not its severity, is regarded as a function of dose with no threshold. The likelihood of inducing a stochastic effect increases with dose, but the exact relationship between dose and effect is not known. Children are approximately two to three times more sensitive to the stochastic effects of radiation than adults. They also have a longer potential life span than adults, so they have more time to develop possible radiation-related sequelae.
(c) Tissue reactions (e.g. skin injury) are due to injury in populations of cells, and are characterised by a threshold dose and an increase in the incidence and severity of the reaction as the dose is increased. Tissue reactions are also termed ‘deterministic effects’. Radiation-induced skin injuries may not become fully manifest until months after the radiation dose was administered. The diagnosis of a radiation-induced skin injury is often delayed. Skin injuries may extend into deeper tissues and can cause symptoms that persist for years. Tissue reactions may be accompanied by an increase in the risk of stochastic effects.
(d) The mechanisms of cardiac radiation damage include inflammatory processes. After higher doses, there is also a progressive reduction in the number of patent capillaries, eventually leading to ischaemia, myocardial cell death and fibrosis, accelerated atherosclerosis in major blood vessels, decreased cardiac function, and fatal congestive heart failure. Cardiovascular radiation effects have been reported to occur at doses >0.5 Gy. Organ doses may reach this level in some complex fluoroscopically guided cardiac procedures. At low doses, there is a latency period of 10–20 years.
(e) The lens of the eye is a radiosensitive tissue. Ionising radiation typically causes posterior subcapsular cataract formation in the lens of the eye. Surveys of cardiologists and support staff working in catheterisation laboratories have found a high percentage of lens opacities attributable to occupational radiation exposure when radiological protection garments and devices have not been used properly, and radiation protection principles have been ignored. 2. Application of the principles of radiological protection in medicine
(f) The Commission recommends three principles of radiological protection: justification, optimisation of protection, and application of dose limits (ICRP, 2007b). The first two are source related and apply to all radiation exposure situations. The third applies to staff, but does not apply to medical exposures of patients, carers, or comforters.
(g) Justification in medicine means that a medical procedure should only be performed when it is appropriate for a particular patient; the anticipated clinical benefits should exceed all anticipated procedural risks, including radiation risk. Justification is a responsibility shared by the referring clinician and the cardiac imager or interventionalist.
(h) Optimisation in medicine means that the radiation dose to the patient is suitable for the medical purpose, and radiation that is clinically unnecessary or unproductive is avoided. Patient radiation protection is optimised when imaging is performed with the least amount of radiation required to provide adequate image quality, diagnostic information and, for fluoroscopy, imaging guidance.
3. Managing patient dose in fluoroscopically guided interventions
(i) The informed consent process should include information on radiation risk if the risk of radiation injury is thought to be significant (ICRP, 2000b). Important aspects of the patient’s medical history that should be considered when estimating radiation risk are genetic factors, co-existing diseases, medication use, radiation history, and pregnancy.
(j) Some of the factors that affect a patient’s radiation dose depend on the x-ray system, but many others depend on how the operator uses the x-ray system. During the procedure, the cardiologist should be kept aware of the fluoroscopy time, the number of cine series and cine frames, and the total patient dose. As patient radiation dose increases, the operator should consider the radiation dose already delivered to the patient and the additional radiation necessary to complete the procedure.
(k) Patient radiation dose reports should be produced at the end of the procedure and archived. Radiation dose data should be recorded in the patient’s medical record after the procedure. When the patient’s radiation dose from the procedure exceeds the institution’s trigger level, clinical follow-up should be performed for early detection and management of skin injuries. Suggested values for the trigger level are a skin dose of 3 Gy, a kerma-area product of 500 Gycm2, or an air kerma at the patient entrance reference point of 5 Gy. Patients who have received a substantial radiation dose should have follow-up 2–4 weeks after the procedure for detection of potential radiation injuries.
4. Protection of staff during interventional fluoroscopy
(l) The basic tools of occupational radiological protection are time, distance, and shielding. The use of personal protective shielding is necessary in interventional cardiology and electrophysiology laboratories. Occupational doses can be reduced to very low levels with proper use of ceiling-suspended lead shields and protective lead curtains suspended from the side of the procedure table. In general, reducing patient dose will also reduce operator dose. With proper use of radiological protection devices and techniques, the effective dose for an interventionalist is typically 2– 4 mSv/y, and is well below the dose limit of 20 mSv/y, averaged over a 5-year period, recommended by the Commission.
(m) Radiation exposure to the operator is neither uniform nor symmetrical. Radiological protection for the eyes is necessary for interventionalists. Proper use of personal monitoring badges is necessary in interventional cardiology laboratories in order to monitor and audit occupational radiation dose. 5. Radiological protection for nuclear cardiology
(n) Criteria and guidelines for appropriate use have been developed through the consensus efforts of professional societies. These criteria and guidelines help to set standards for justification of nuclear cardiology procedures. Justification needs to be performed on an individualised, patient-by-patient basis, and should weigh the benefits and risks of each imaging test under consideration as well as the benefits and risks of not performing a test. Assessment of radiation risk is one part of this process.
(o) Optimisation of protection in nuclear cardiology procedures involves the judicious selection of radiopharmaceuticals and administered activities to ensure diagnostic image quality while minimising patient dose. Administered activities should be within prespecified ranges, as provided in international and national guidelines, and should reflect patient habitus. If stress imaging is normal, rest imaging can be omitted to minimise total dose. For single-photon emission CT protocols, 99mTc-based agents yield lower effective doses than 201Tl, and are preferred on dosimetric grounds. Practitioners need good-quality dosimetric data to perform proper benefit–risk analyses for their patients.
6. Radiological protection for cardiac computed tomography
(p) As with nuclear cardiology, criteria and guidelines for appropriate use of cardiac CT have been developed, and justification needs to be performed in the same fashion. Dose from cardiac CT is strongly dependent on scanner mode, tube current, and tube potential. For patients with a heart rate <65–70 beats/min and a regular rhythm, diagnostic image quality can generally be maintained while using dose reduction methods such as axial imaging or electrocardiogram (ECG)-controlled tube current modulation. For non-obese patients, diagnostic image quality can generally be maintained using low-voltage (e.g. 100 kVp) scanning. The maximum tube current should be appropriate for the patient’s habitus. Further research is needed to develop and validate methods to reduce patient radiation dose.
7. Radiological protection training for cardiologists
(q) Legislation in most countries requires that individuals who take responsibility for medical exposures must be properly trained in radiological protection. Cardiologists worldwide typically have little or no training in radiological protection. The Commission recommends that, in addition to the training recommended for other physicians who use ionising radiation, interventional cardiologists and electrophysiologists should receive a second, higher level of radiological protection training (ICRP, 2009).
(r) Training programmes should include both initial training for all incoming staff, and regular updating and retraining. Scientific congresses should include refresher courses on radiological protection, attendance at which could be a requirement for continuing professional development.
(s) Training activities in radiological protection should be followed by an evaluation of the knowledge acquired from the training programme (a formal examination system). Physicians who have completed training should be able to demonstrate that they possess the knowledge specified by the curriculum by passing an appropriate certifying examination.
(t) The Commission recommends that nurses and other healthcare professionals who assist during fluoroscopic procedures should be familiar with radiation risks and radiological protection principles, in order to minimise their own exposure and that of others. The training should be commensurate with the individual’s role (ICRP, 2009).
8. Quality assurance programmes
(u) Two basic purposes of a radiological protection quality assurance programme (QAP) are to evaluate patient radiation dose periodically and to monitor occupational radiation dose for workers in cardiology facilities where radiation is used. A cardiologist should have management responsibility for the QAP aspects of radiological protection for cardiology procedures, and should be assisted by a medical physicist. The radiation protection advisor/radiation safety officer should also be involved in monitoring occupational radiation dose.
(v) The planning process for a new interventional fluoroscopy laboratory, CT scanner or nuclear medicine system in a cardiology facility, or the upgrade of existing equipment should include the participation of a medical physicist, a senior radiographer, and a senior cardiologist. These individuals should have experience with the procedures that will be performed using the new equipment.
(w) Periodical evaluation of image quality and procedure protocols should be included in the QAP. The QAP should establish trigger levels for individual clinical follow-up when there is a risk of radiation-induced skin injuries. The QAP should ensure the regular use of personal dosimeters and include a review of all abnormal dose values.
(x) Patient dose reports should be produced at the end of procedures, archived and recorded in the patient’s medical record. If dose reports are not available, dose values should be recorded in the patient’s medical record together with the procedure and patient identification. Patient dose audits (including comparison with diagnostic reference levels) and reporting are important components of the QAP.
ICRP, 2013. Radiological protection in cardiology. ICRP Publication 120. Ann. ICRP 42(1).
Authors on behalf of ICRP
C. Cousins, D.L. Miller, G. Bernardi, M.M. Rehani, P. Schofield, E. Vaño , A.J. Einstein, B. Geiger, P. Heintz, R. Padovani, K-H. Sim
Abstract - Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff1 in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly.
The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113. This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission’s published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission.
This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention.
As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions, particular attention is devoted to clinical examples of radiation-related skin injuries from cardiac interventions, methods to reduce patient radiation dose, training recommendations, and quality assurance programmes for interventional fluoroscopy.
© 2012 ICRP. Published by Elsevier Ltd.
Keywords: Cardiology; Computed tomography; Nuclear medicine; Cardiac catheterisation; Radiological protection.
C. COUSINS, D.L. MILLER, G. BERNARDI, M.M. REHANI, P. SCHOFIELD, E. VAN˜ O´ , A.J. EINSTEIN, B. GEIGER, P. HEINTZ, R. PADOVANI, K-H. SIM
Key Points
Individuals who request, perform, or interpret cardiology imaging procedures should be aware of the radiation risks of the procedures.
Criteria and guidelines for appropriate use have been developed through the consensus efforts of professional societies, and should be used in clinical practice.
As with all other medical exposures, nuclear cardiology examinations, cardiac computed tomography examinations, interventional cardiology procedures, and electrophysiology procedures should be optimised, and dose reduction techniques should be used whenever applicable.
The informed consent process should include information on radiation risk if the risk of radiation injury is thought to be significant.
Radiation dose data should be recorded in the patient’s medical record after the procedure. Patient dose reports should be archived for quality assurance purposes.
When the patient’s radiation dose from an interventional procedure exceeds the institution’s trigger level, clinical follow-up should be performed for early detection and management of skin injuries.
Suggested values for the trigger level are a skin dose of 3 Gy, a kerma-area product of 500 Gycm2 , or an air kerma at the patient entrance reference point of 5 Gy.
Individuals who perform cardiology procedures where there is a risk of tissue reactions should be able to recognise these skin injuries.
Individuals who perform interventional cardiology or electrophysiology procedures should be familiar with methods to reduce radiation dose to patients and staff.
Nurses, radiographers/technologists, and other healthcare professionals who assist during imaging procedures (fluoroscopy, computed tomography, and scintigraphy) should be familiar with radiation risks and radiological protection principles in order to minimise their own exposure and that of others.
When there is a risk of occupational radiation exposure, staff should use appropriate personal protective shielding.
In addition to the training recommended for all physicians who use ionising radiation, interventional cardiologists and electrophysiologists should receive a second, higher level of radiological protection training.
Training programmes in radiological protection should include both initial training for all incoming staff, and regular updating and retraining.
A cardiologist should have management responsibility for the quality assurance programme aspects of radiological protection for cardiology procedures, and should be assisted by a medical physicist.
Quality assurance programmes in cardiology should include patient dose audits for fluoroscopy, computed tomography, and scintigraphy.
Quality assurance programmes should ensure the regular use of personal dosimeters, and should include a review of all abnormal dose values.
Executive Summary
(a) In cardiology, patient radiation exposure is due primarily to nuclear medicine, computed tomography (CT), interventional cardiology procedures and electrophysiology procedures. Cardiac nuclear medicine, cardiac CT, percutaneous coronary interventions, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff in cardiac catheterisation and electrophysiology laboratories may receive high radiation doses if radiological protection tools are not used properly.
1. The biological effects of radiation
(b) Stochastic effects (malignant disease and heritable effects) are effects for which the probability of an effect occurring, but not its severity, is regarded as a function of dose with no threshold. The likelihood of inducing a stochastic effect increases with dose, but the exact relationship between dose and effect is not known. Children are approximately two to three times more sensitive to the stochastic effects of radiation than adults. They also have a longer potential life span than adults, so they have more time to develop possible radiation-related sequelae.
(c) Tissue reactions (e.g. skin injury) are due to injury in populations of cells, and are characterised by a threshold dose and an increase in the incidence and severity of the reaction as the dose is increased. Tissue reactions are also termed ‘deterministic effects’. Radiation-induced skin injuries may not become fully manifest until months after the radiation dose was administered. The diagnosis of a radiation-induced skin injury is often delayed. Skin injuries may extend into deeper tissues and can cause symptoms that persist for years. Tissue reactions may be accompanied by an increase in the risk of stochastic effects.
(d) The mechanisms of cardiac radiation damage include inflammatory processes. After higher doses, there is also a progressive reduction in the number of patent capillaries, eventually leading to ischaemia, myocardial cell death and fibrosis, accelerated atherosclerosis in major blood vessels, decreased cardiac function, and fatal congestive heart failure. Cardiovascular radiation effects have been reported to occur at doses >0.5 Gy. Organ doses may reach this level in some complex fluoroscopically guided cardiac procedures. At low doses, there is a latency period of 10–20 years.
(e) The lens of the eye is a radiosensitive tissue. Ionising radiation typically causes posterior subcapsular cataract formation in the lens of the eye. Surveys of cardiologists and support staff working in catheterisation laboratories have found a high percentage of lens opacities attributable to occupational radiation exposure when radiological protection garments and devices have not been used properly, and radiation protection principles have been ignored. 2. Application of the principles of radiological protection in medicine
(f) The Commission recommends three principles of radiological protection: justification, optimisation of protection, and application of dose limits (ICRP, 2007b). The first two are source related and apply to all radiation exposure situations. The third applies to staff, but does not apply to medical exposures of patients, carers, or comforters.
(g) Justification in medicine means that a medical procedure should only be performed when it is appropriate for a particular patient; the anticipated clinical benefits should exceed all anticipated procedural risks, including radiation risk. Justification is a responsibility shared by the referring clinician and the cardiac imager or interventionalist.
(h) Optimisation in medicine means that the radiation dose to the patient is suitable for the medical purpose, and radiation that is clinically unnecessary or unproductive is avoided. Patient radiation protection is optimised when imaging is performed with the least amount of radiation required to provide adequate image quality, diagnostic information and, for fluoroscopy, imaging guidance.
3. Managing patient dose in fluoroscopically guided interventions
(i) The informed consent process should include information on radiation risk if the risk of radiation injury is thought to be significant (ICRP, 2000b). Important aspects of the patient’s medical history that should be considered when estimating radiation risk are genetic factors, co-existing diseases, medication use, radiation history, and pregnancy.
(j) Some of the factors that affect a patient’s radiation dose depend on the x-ray system, but many others depend on how the operator uses the x-ray system. During the procedure, the cardiologist should be kept aware of the fluoroscopy time, the number of cine series and cine frames, and the total patient dose. As patient radiation dose increases, the operator should consider the radiation dose already delivered to the patient and the additional radiation necessary to complete the procedure.
(k) Patient radiation dose reports should be produced at the end of the procedure and archived. Radiation dose data should be recorded in the patient’s medical record after the procedure. When the patient’s radiation dose from the procedure exceeds the institution’s trigger level, clinical follow-up should be performed for early detection and management of skin injuries. Suggested values for the trigger level are a skin dose of 3 Gy, a kerma-area product of 500 Gycm2, or an air kerma at the patient entrance reference point of 5 Gy. Patients who have received a substantial radiation dose should have follow-up 2–4 weeks after the procedure for detection of potential radiation injuries.
4. Protection of staff during interventional fluoroscopy
(l) The basic tools of occupational radiological protection are time, distance, and shielding. The use of personal protective shielding is necessary in interventional cardiology and electrophysiology laboratories. Occupational doses can be reduced to very low levels with proper use of ceiling-suspended lead shields and protective lead curtains suspended from the side of the procedure table. In general, reducing patient dose will also reduce operator dose. With proper use of radiological protection devices and techniques, the effective dose for an interventionalist is typically 2– 4 mSv/y, and is well below the dose limit of 20 mSv/y, averaged over a 5-year period, recommended by the Commission.
(m) Radiation exposure to the operator is neither uniform nor symmetrical. Radiological protection for the eyes is necessary for interventionalists. Proper use of personal monitoring badges is necessary in interventional cardiology laboratories in order to monitor and audit occupational radiation dose. 5. Radiological protection for nuclear cardiology
(n) Criteria and guidelines for appropriate use have been developed through the consensus efforts of professional societies. These criteria and guidelines help to set standards for justification of nuclear cardiology procedures. Justification needs to be performed on an individualised, patient-by-patient basis, and should weigh the benefits and risks of each imaging test under consideration as well as the benefits and risks of not performing a test. Assessment of radiation risk is one part of this process.
(o) Optimisation of protection in nuclear cardiology procedures involves the judicious selection of radiopharmaceuticals and administered activities to ensure diagnostic image quality while minimising patient dose. Administered activities should be within prespecified ranges, as provided in international and national guidelines, and should reflect patient habitus. If stress imaging is normal, rest imaging can be omitted to minimise total dose. For single-photon emission CT protocols, 99mTc-based agents yield lower effective doses than 201Tl, and are preferred on dosimetric grounds. Practitioners need good-quality dosimetric data to perform proper benefit–risk analyses for their patients.
6. Radiological protection for cardiac computed tomography
(p) As with nuclear cardiology, criteria and guidelines for appropriate use of cardiac CT have been developed, and justification needs to be performed in the same fashion. Dose from cardiac CT is strongly dependent on scanner mode, tube current, and tube potential. For patients with a heart rate <65–70 beats/min and a regular rhythm, diagnostic image quality can generally be maintained while using dose reduction methods such as axial imaging or electrocardiogram (ECG)-controlled tube current modulation. For non-obese patients, diagnostic image quality can generally be maintained using low-voltage (e.g. 100 kVp) scanning. The maximum tube current should be appropriate for the patient’s habitus. Further research is needed to develop and validate methods to reduce patient radiation dose.
7. Radiological protection training for cardiologists
(q) Legislation in most countries requires that individuals who take responsibility for medical exposures must be properly trained in radiological protection. Cardiologists worldwide typically have little or no training in radiological protection. The Commission recommends that, in addition to the training recommended for other physicians who use ionising radiation, interventional cardiologists and electrophysiologists should receive a second, higher level of radiological protection training (ICRP, 2009).
(r) Training programmes should include both initial training for all incoming staff, and regular updating and retraining. Scientific congresses should include refresher courses on radiological protection, attendance at which could be a requirement for continuing professional development.
(s) Training activities in radiological protection should be followed by an evaluation of the knowledge acquired from the training programme (a formal examination system). Physicians who have completed training should be able to demonstrate that they possess the knowledge specified by the curriculum by passing an appropriate certifying examination.
(t) The Commission recommends that nurses and other healthcare professionals who assist during fluoroscopic procedures should be familiar with radiation risks and radiological protection principles, in order to minimise their own exposure and that of others. The training should be commensurate with the individual’s role (ICRP, 2009).
8. Quality assurance programmes
(u) Two basic purposes of a radiological protection quality assurance programme (QAP) are to evaluate patient radiation dose periodically and to monitor occupational radiation dose for workers in cardiology facilities where radiation is used. A cardiologist should have management responsibility for the QAP aspects of radiological protection for cardiology procedures, and should be assisted by a medical physicist. The radiation protection advisor/radiation safety officer should also be involved in monitoring occupational radiation dose.
(v) The planning process for a new interventional fluoroscopy laboratory, CT scanner or nuclear medicine system in a cardiology facility, or the upgrade of existing equipment should include the participation of a medical physicist, a senior radiographer, and a senior cardiologist. These individuals should have experience with the procedures that will be performed using the new equipment.
(w) Periodical evaluation of image quality and procedure protocols should be included in the QAP. The QAP should establish trigger levels for individual clinical follow-up when there is a risk of radiation-induced skin injuries. The QAP should ensure the regular use of personal dosimeters and include a review of all abnormal dose values.
(x) Patient dose reports should be produced at the end of procedures, archived and recorded in the patient’s medical record. If dose reports are not available, dose values should be recorded in the patient’s medical record together with the procedure and patient identification. Patient dose audits (including comparison with diagnostic reference levels) and reporting are important components of the QAP.
