Provision of Italian diagnostic reference levels for diagnostic and interventional radiology.

OBJECTIVES: The diagnostic reference level (DRL) is a useful tool for the optimisation of medical exposures. Thus, a Working Party coordinated by the Italian National Institute of Health and the National Workers Compensation Authority has been formed to provide Italian DRLs, for both diagnostic and interventional procedures, to be used as appropriate for the implementation of the 2013/59 European Directive into the national regulation. MATERIALS AND METHODS: The multidisciplinary Working Party was formed by professionals involved in diagnostic and interventional radiology medical exposures and started from a critical revision of both the literature and the results of previous Italian surveys. The procedures were divided into five sections for adult (projection radiography, mammography, diagnostic fluoroscopy, CT and interventional radiology) and two sections for paediatric patients (projection radiography and CT). The provided DRL values have been identified for "normal" adult patients and for age-classes of paediatric patients. RESULTS: Some of the DRL values provided by the Working Party are reported in this study as an example, divided by adult/paediatric patients, radiological technique and examination: specifically, DRLs for new radiological practices and new dose quantities as DRLs metric were introduced. The median value (rather than the mean) for each procedure, derived from a sample of patients, has to be compared with the corresponding DRL value, and dosimetric data related to a minimum number of patients should be collected for each examination. CONCLUSIONS: The approach to the definition and use of DRLs through guidelines of national Authorities in collaboration with scientific Associations should simplify the periodical updating and could be useful for keeping the optimisation of medical exposures faithful to the development of radiological practice.

Past and present work practices of European interventional cardiologists in the context of radiation protection of the eye lens-results of the EURALOC study.

This paper investigates over five decades of work practices in interventional cardiology, with an emphasis on radiation protection. The analysis is based on data from more than 400 cardiologists from various European countries recruited for a EURALOC study and collected in the period from 2014 to 2016. Information on the types of procedures performed and their annual mean number, fluoroscopy time, access site choice, x-ray units and radiation protection means used was collected using an occupational questionnaire. Based on the specific European data, changes in each parameter have been analysed over decades, while country-specific data analysis has allowed us to determine the differences in local practices. In particular, based on the collected data, the typical workload of a European cardiologist working in a haemodynamic room and an electrophysiology room was specified for various types of procedures. The results showed that when working in a haemodynamic room, a transparent ceiling-suspended lead shield or lead glasses are necessary in order to remain below the recommended eye lens dose limit of 20 mSv. Moreover, the analysis revealed that new, more complex cardiac procedures such as chronic total occlusion, valvuloplasty and pulmonary vein isolation for atrial fibrillation ablation might contribute substantially to annual doses, although they are relatively rarely performed. The results revealed that considerable progress has been made in the use of radiation protection tools. While their use in electrophysiology procedures is not generic, the situation in haemodynamic procedures is rather encouraging, as ceiling-suspended shields are used in 90% of cases, while the combination of ceiling shield and lead glasses is noted in more than 40% of the procedures. However, we find that still 7% of haemodynamic procedures are performed without any radiation protection tools.

Summary of the Italian inter-society recommendations for radiation protection optimization in interventional radiology.

OBJECTIVES: A Working Group coordinated by the Italian National Institute of Health (Istituto Superiore di Sanità) and the National Workers Compensation Authority (Istituto Nazionale per l'Assicurazione contro gli Infortuni sul Lavoro, INAIL) and consisting of 11 Italian scientific/professional societies involved in the fluoroscopically guided interventional practices has been established to define recommendations for the optimization of patients and staff radiation protection in interventional radiology. A summary of these recommendations is here reported. MATERIALS AND METHODS: A multidisciplinary approach was used to establish the Working Group by involving radiologists, interventional radiologists, neuroradiologists, interventional cardiologists, occupational health specialists, medical physicists, radiation protection experts, radiographers and nurses. The Group operated as a "Consensus Conference". Three main topics have been addressed: patient radiation protection (summarized in ten "golden rules"); staff radiation protection (summarized in ten "golden rules"); and education/training of interventional radiology professionals. RESULTS: In the "golden rules", practical and operational recommendations were provided to help the professionals in optimizing dose delivered to patients and reducing their own exposure. Operative indications dealt also with continuing education and training, and recommendations on professional accreditation and certification. CONCLUSIONS: The "Consensus Conference" was the methodology adopted for the development of these recommendations. Involvement of all professionals is a winning approach to improve practical implementation of the recommendations, thus getting a real impact on the optimization of the interventional radiology practices.

Application of off-line image processing for optimization in chest computed radiography using a low cost system.

 The objective of this study was to improve the visibility of anatomical details by applying off-line postimage processing in chest computed radiography (CR). Four spatial domain-based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann-Whitney U-test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005 ≤ p ≤ 0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60 ≤ kVp ≤ 70. However, there was no improvement for images acquired using 102 ≤ kVp ≤ 107 (0.127 ≤ p ≤ 0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists.

Subclinical carotid atherosclerosis and early vascular aging from long-term low-dose ionizing radiation exposure: a genetic, telomere, and vascular ultrasound study in cardiac catheterization laboratory staff.

OBJECTIVES: This study sought to assess the association between long-term radiation exposure in the catheterization laboratory (cath lab) and early signs of subclinical atherosclerosis. BACKGROUND: There is growing evidence of an excess risk of cardiovascular disease at low-dose levels of ionizing radiation exposure. METHODS: Left and right carotid intima-media thickness (CIMT) was measured in 223 cath lab personnel (141 male; age, 45 ± 8 years) and 222 unexposed subjects (113 male; age, 44±10 years). Leukocyte telomere length (LTL) was evaluated by quantitative reverse transcriptase polymerase chain reaction. The DNA repair gene XRCC3 Thr241Met polymorphism was also analyzed to explore the possible interaction with radiation exposure. The occupational radiological risk score (ORRS) was computed for each subject on the basis of the length of employment, individual caseload, and proximity to the radiation source. A complete lifetime effective dose (mSv) was recorded for 57 workers. RESULTS: Left, right, and averaged CIMTs were significantly increased in high-exposure workers compared with both control subjects and low-exposure workers (all p values<0.04). On the left side, but not on the right, there was a significant correlation between CIMT and ORRS (p=0.001) as well as lifetime dose (p=0.006). LTL was significantly reduced in exposed workers compared with control subjects (p=0.008). There was a significant correlation between LTL and both ORRS (p=0.002) and lifetime dose (p=0.03). The XRCC3 Met241 allele presented a significant interaction with high exposure for right side (pinteraction=0.002), left side (pinteraction<0.0001), and averaged (pinteraction<0.0001) CIMTs. CONCLUSIONS: Long-term radiation exposure in a cath lab may be associated with increased subclinical CIMT and telomere length shortening, suggesting evidence of accelerated vascular aging and early atherosclerosis.

Feasibility of concervative breast surgery and intraoperative radiation therapy for early breast cancer: a single-center, open, non-randomized, prospective pilot study.

Intraoperative radiotherapy (IORT) consists of an accelerated, single-dose, partial breast irradiation, performed immediately after breast conservative surgery. In the present study, we report the results of our feasibility protocol study using IORT between 2005 and 2009. We analyzed the data from a single-center, open, non-randomized, prospective pilot study including patients who underwent breast conservative surgery for invasive breast cancer between January 2005 and December 2009 at our Clinic of Surgery. Patients were divided based on IORT performance and stratified by age (≥48 or <48 years). Data were analyzed using R (version 2.15.2), considering a level of significance at p<0.05. Among the 247 eligible patients, 81 accepted the IORT protocol. Intraoperative IORT feasibility was 95.1% (77/81). In 71.4% (55/77) of the cases no postoperative complication was registered. Concerning local recurrence and overall survival, no significant difference was observed between women who underwent the IORT protocol or standard treatment. Among the patients aged <48 years, no local recurrence was noted after IORT protocol, and among women aged ≥48, local recurrences developed later in patients treated with IORT than with standard treatment. IORT represents a feasible and promising technique for the treatment of early breast cancer, with low morbidity, and beneficial aesthetic and oncologic results. Further studies are required in order to extend the inclusion criteria and offer IORT to a larger number of breast cancer patients.

Risks Related To Fluoroscopy Radiation Associated With Electrophysiology Procedures.

The benefits of cardiac imaging are immense, and modern cardiac electrophysiology (EP) requires the extensive and versatile use of a variety of cardiac imaging and radiology-based techniques. In the cardiac electrophysiology lab, doses can range around a reference effective dose (ED) of 15 milliSievert corresponding to 750 chest x-rays for a cardiac radiofrequency ablation, ranging from less than 2 to > 60 mSv. The reference dose for a regular pacemaker or ICD implant is 4 mSv (range 1.4-17) and for a CRT implant is 22 mSv (range 2.2-95). Doses on the order of magnitude of 10-100 milliSievert (mSv) correspond to a low (albeit definite, not negligible) additional lifetime risk of fatal and non-fatal cancer from between 1 in 1000 (10 mSv) to 1 in 100 (100 mSv). The increasing use and complexity of cardiac electrophysiology techniques have not been matched by increasing awareness and knowledge by prescribers and practitioners. The protection of doctors is just as important as protection of patients. Most experienced (and most exposed) interventional cardiologists and electrophysiologists have an exposure per annum of around 5 mSv, two to three times higher than diagnostic radiologists, with a typical cumulative lifetime attributable risk on the order of magnitude of 1 cancer (fatal and non-fatal) per 100 exposed subjects. Operator dose per procedure correlates somewhat with the patient dose, but may be typically 1000 times lower depending upon the shielding employed (one unit of incidence scatter dose for the operator when 1000 units of incident dose are given to the patient). However, adequate radiation protection training and diligent protection can reduce this radiation exposure by 90%. The priority given to radioprotection in every cardiology department is an effective strategy for primary prevention of cancer, a strong indicator of the quality of the cardiology division, and the most effective shielding for enhancing the safety of patients, doctors, and staff.

Recommendations for occupational radiation protection in interventional cardiology.

The radiation dose received by cardiologists during percutaneous coronary interventions, electrophysiology procedures and other interventional cardiology procedures can vary by more than an order of magnitude for the same type of procedure and for similar patient doses. There is particular concern regarding occupational dose to the lens of the eye. This document provides recommendations for occupational radiation protection for physicians and other staff in the interventional suite. Simple methods for reducing or minimizing occupational radiation dose include: minimizing fluoroscopy time and the number of acquired images; using available patient dose reduction technologies; using good imaging-chain geometry; collimating; avoiding high-scatter areas; using protective shielding; using imaging equipment whose performance is controlled through a quality assurance programme; and wearing personal dosimeters so that you know your dose. Effective use of these methods requires both appropriate education and training in radiation protection for all interventional cardiology personnel, and the availability of appropriate protective tools and equipment. Regular review and investigation of personnel monitoring results, accompanied as appropriate by changes in how procedures are performed and equipment used, will ensure continual improvement in the practice of radiation protection in the interventional suite. These recommendations for occupational radiation protection in interventional cardiology and electrophysiology have been endorsed by the Asian Pacific Society of Interventional Cardiology, the European Association of Percutaneous Cardiovascular Interventions, the Latin American Society of Interventional Cardiology, and the Society for Cardiovascular Angiography and Interventions.

A summary of recommendations for occupational radiation protection in interventional cardiology.

The radiation dose received by cardiologists during percutaneous coronary interventions, electrophysiology procedures, and other interventional cardiology procedures can vary by more than an order of magnitude for the same type of procedure and for similar patient doses. There is particular concern regarding occupational dose to the lens of the eye. This document provides recommendations for occupational radiation protection for physicians and other staff in the interventional suite. Simple methods for reducing or minimizing occupational radiation dose include minimizing fluoroscopy time and the number of acquired images; using available patient dose reduction technologies; using good imaging-chain geometry; collimating; avoiding high-scatter areas; using protective shielding; using imaging equipment whose performance is controlled through a quality assurance program; and wearing personal dosimeters so that you know your dose. Effective use of these methods requires both appropriate education and training in radiation protection for all interventional cardiology personnel, and the availability of appropriate protective tools and equipment. Regular review and investigation of personnel monitoring results, accompanied as appropriate by changes in how procedures are performed and equipment used, will ensure continual improvement in the practice of radiation protection in the interventional suite. These recommendations for occupational radiation protection in interventional cardiology and electrophysiology have been endorsed by the Asian Pacific Society of Interventional Cardiology, the European Association of Percutaneous Cardiovascular Interventions, the Latin American Society of Interventional Cardiology, and the Society for Cardiovascular Angiography and Interventions.

Core curriculum for medical physicists in radiology. Recommendations from an EFOMP/ESR working group.

Some years ago it was decided that a European curriculum should be developed for medical physicists professionally engaged in the support of clinical diagnostic imaging departments. With this in mind, EFOMP (European Federation of Organisations for Medical Physics) in association with ESR (European Society of Radiology) nominated an expert working group. This curriculum is now to hand. The curriculum is intended to promote best patient care in radiology departments through the harmonization of education and training of medical physicists to a high standard in diagnostic radiology. It is recommended that a medical physicist working in a radiology department should have an advanced level of professional expertise in X-ray imaging, and additionally, depending on local availability, should acquire knowledge and competencies in overseeing ultrasound imaging, nuclear medicine, and MRI technology. By demonstrating training to a standardized curriculum, medical physicists throughout Europe will enhance their mobility, while maintaining local high standards of medical physics expertise. This document also provides the basis for improved implementation of articles in the European medical exposure directives related to the medical physics expert. The curriculum is divided into three main sections: The first deals with general competencies in the principles of medical physics. The second section describes specific knowledge and skills required for a medical physicist (medical physics expert) to operate clinically in a department of diagnostic radiology. The final section outlines research skills that are also considered to be necessary and appropriate competencies in a career as medical physicist.

Performance evaluation of three computed radiography systems using methods recommended in American Association of Physicists in Medicine Report 93.

The performances of three clinical computed radiography (CR) systems, (Agfa CR 75 (with CRMD 4.0 image plates), Kodak CR 850 (with Kodak GP plates) and Kodak CR 850A (with Kodak GP plates)) were evaluated using six tests recommended in American Association of Physicists in Medicine Report 93. The results indicated variable performances with majority being within acceptable limits. The variations were mainly attributed to differences in detector formulations, plate readers' characteristics, and aging effects. The differences of the mean low contrast scores between the imaging systems for three observers were statistically significant for Agfa and Kodak CR 850A (P=0.009) and for Kodak CR systems (P=0.006) probably because of the differences in ages. However, the differences were not statistically significant between Agfa and Kodak CR 850 (P=0.284) suggesting similar perceived image quality. The study demonstrates the need to implement quality control program regularly.

Initial quality performance results using a phantom to simulate chest computed radiography.

The aim of this study was to develop a homemade phantom for quantitative quality control in chest computed radiography (CR). The phantom was constructed from copper, aluminium, and polymenthylmethacrylate (PMMA) plates as well as Styrofoam materials. Depending on combinations, the literature suggests that these materials can simulate the attenuation and scattering characteristics of lung, heart, and mediastinum. The lung, heart, and mediastinum regions were simulated by 10 mm x 10 mm x 0.5 mm, 10 mm x 10 mm x 0.5 mm and 10 mm x 10 mm x 1 mm copper plates, respectively. A test object of 100 mm x 100 mm and 0.2 mm thick copper was positioned to each region for CNR measurements. The phantom was exposed to x-rays generated by different tube potentials that covered settings in clinical use: 110-120 kVp (HVL=4.26-4.66 mm Al) at a source image distance (SID) of 180 cm. An approach similar to the recommended method in digital mammography was applied to determine the CNR values of phantom images produced by a Kodak CR 850A system with post-processing turned off. Subjective contrast-detail studies were also carried out by using images of Leeds TOR CDR test object acquired under similar exposure conditions as during CNR measurements. For clinical kVp conditions relevant to chest radiography, the CNR was highest over 90-100 kVp range. The CNR data correlated with the results of contrast detail observations. The values of clinical tube potentials at which CNR is the highest are regarded to be optimal kVp settings. The simplicity in phantom construction can offer easy implementation of related quality control program.

Implementation and validation of a commercial portal dosimetry software for intensity-modulated radiation therapy pre-treatment verification.

Electronic portal imaging devices (EPIDs) are extensively used for obtaining dosimetric information of pre-treatment field verification and in-vivo dosimetry for intensity-modulated radiotherapy (IMRT). In the present study, we have implemented the newly developed portal dosimetry software using independent dose prediction algorithm EPIDose(™) and evaluated this new tool for the pre-treatment IMRT plan quality assurance of Whole Pelvis with Simultaneous Integrated Boost (WP-SIB-IMRT) of prostate cases by comparing with routine two-dimensional (2D) array detector system (MapCHECK(™)). We have investigated 104 split fields using γ -distributions in terms of predefined γ frequency parameters. The mean γ values are found to be 0.42 (SD: 0.06) and 0.44 (SD: 0.06) for the EPIDose and MapCHECK(™), respectively. The average γ∆ for EPIDose and MapCHECK(™) are found as 0.51 (SD: 0.06) and 0.53 (SD: 0.07), respectively. Furthermore, the percentage of points with γ < 1, γ < 1.5, and γ > 2 are 97.4%, 99.3%, and 0.56%, respectively for EPIDose and 96.4%, 99.0% and 0.62% for MapCHECK(™). Based on our results obtained with EPIDose and strong agreement with MapCHECK(™), we may conclude that the EPIDose portal dosimetry system has been successfully implemented and validated with our routine 2D array detector.

Radiation protection of medical staff.

The continuing increase in the worldwide use of X-ray imaging has implications for radiation protection of medical staff. Much of the increased usage could be viewed as simply a workload issue with no particular new challenges. However, advances in technology and developments in techniques have seen an increase in the number of X-ray procedures in which medical personnel need to maintain close physical contact with the patient during radiation exposures. The complexity of many procedures means the potential for significant occupational exposure is high, and appropriate steps must be taken to ensure that actual occupational exposures are as low as reasonably achievable. Further attention to eye protection may be necessitated if a lowering of the dose limit for the lens of the eye is implemented in the near future. Education and training in radiation protection as it applies to specific situations, established working procedures, availability and use of appropriate protective tools, and an effective monitoring programme are all essential elements in ensuring that medical personnel in X-ray imaging are adequately and acceptably protected.

Patient doses and dosimetric evaluations in interventional cardiology.

Interventional cardiological examinations may be associated with excessive radiation exposures which may cause skin injuries and higher probabilities of stochastic effects. Dose-area product (DAP) and skin doses of 325 patients were measured using alternative dosimetric techniques for different cardiological examinations. Data were collected from five different systems with the involvement of 11 cardiologists. All these dosimetric information has been collected separately for each of 10 projections together with the exposure parameters of X-ray systems. Mean DAP values measured with a transparent ion chamber were 49.1 Gy cm(2), 66.8 Gy cm(2), 106.9 Gy cm(2) and 124.7 Gy cm(2), respectively, for coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) or stent (PT-SI), coronary angiography and/or PTCA and/or stent (CA-PT-SI), and ablation examinations. Radiochromic films, thermoluminescent dosimeters (TLD) and point measurement of air kerma (AK) were carried out for skin dose assessments. Skin doses of 23 patients measured with radiochromic films were found to be between 2 Gy and 6 Gy. Although the complexity of the procedures was the major reason for these excessive doses, considerable contributions of high X-ray output of some fluoroscopy units were also noticed. In addition to the direct measurement of DAP, alternative DAP values were also determined from the skin dose measurement techniques; exposed areas were summed on digitized radiochromic films in one technique, The product of AK reading with X-ray field size measured at the patient entrance using slow X-ray films was taken as another DAP. Good correlations were found among the DAP results and also between the entrance skin doses calculated from AK measurements and direct DAP readings (R(2)=0.91). A trigger DAP value of 130 Gy cm(2) for the 2 Gy of skin doses was derived from this relationship. Collection of dosimetric data for each projection was also investigated regarding a possible standardization of clinical techniques; in the case of coronary angiography examinations LAO 45 and RAO 30 were found as the dominant projections which may also simplify the dosimetric technique.

The effect of fellows' training in invasive cardiology on radiological exposure of patients.

The aim of this work was to evaluate and quantify the impact of an invasive training of cardiology fellows on some exposure parameters. From 1 January 2000 to 31 December 2002, three staff members performed 2.582 diagnostic procedures (Group 1) that were compared with 819 performed by, or with the participation of five cardiology fellows (Group 2). Exposure parameters were as follows (Group 1/Group 2): fluoroscopy time 3.8 +/- 4.5/5.5 +/- 5.9 min (+38%), mean number of frames 589 +/- 282/642 +/- 260 (+9%), Kerma-area product (KAP) during fluoroscopy 10.6 +/- 14/15.5 +/- 16 Gycm2 (+45%), KAP during cine-angiography 20.8 +/- 14/22.5 +/- 12 (+8%), total KAP 31.5 +/- 28/38.1 +/- 28 (+21%). Differences were all significant (P

Occupational dose constraints in interventional cardiology procedures: the DIMOND approach.

Radiation fields involved in angiographic suites are most uneven with intensity and gradient varying widely with projection geometry. The European Commission DIMOND III project addressed among others, the issues regarding optimization of staff doses with an attempt to propose preliminary occupational dose constraints. Two thermoluminescent dosemeters (TLD) were used to assess operators' extremity doses (left shoulder and left foot) during 20 coronary angiographies (CAs) and 20 percutaneous transluminal coronary angioplasties (PTCAs) in five European centres. X-ray equipment, radiation protection measures used and the dose delivered to the patient in terms of dose-area product (DAP) were recorded so as to subsequently associate them with operator's dose. The range of staff doses noted for the same TLD position, centre and procedure type emphasizes the importance of protective measures and technical characteristics of x-ray equipment. Correlation of patient's DAP with staff shoulder dose is moderate whereas correlation of patient's DAP with staff foot dose is poor in both CA and PTCA. Therefore, it is difficult to predict operator's dose from patient's DAP mainly due to the different use of protective measures. A preliminary occupational dose constraint value was defined by calculating cardiologists' annual effective dose and found to be 0.6 mSv.