Astatement was approved in October 2004 by a group representing the American College of Cardiology Foundation (ACCF), the American Heart Association (AHA), the Heart Rhythm Society (HRS), and the Society for Cardiac Angiography and Interventions (SCAI), proposing a plan for insuring clinical competence and training for physicians who perform fluoroscopically guided invasive procedures.¹ This group was charged with the development of a document that would outline a curriculum for a physician knowledge base which ideally would optimize both patient safety and image quality.

       The ACCF/AHA/HRS/SCAI Fluoroscopy Clinical Competence Statement has appeared in JACC and is available online at the respective site of each of these organizations. The purpose of this article is to review the rationale for the document, look at the knowledge base proposed, and reflect on the implications for electrophysiology practices.

Why Has This Document Been Developed?
       Clinical electrophysiology in the cardiac catheterization lab has evolved from performance of just diagnostic EP studies to some rather lengthy ablation and device implant procedures. Because of the complexity involved, greater fluoroscopic exposure has become part of the package for both patients and staff.
       A very definite benefit from these procedures is experienced by millions of patients. However, an unintended consequence for some is radiation-induced injuries. The types of injuries which patients experience include entrance port skin ulceration and necrosis, cataracts and neoplasms. Attribution of cataracts and neoplasms, which may occur years later, to radiation exposure, is often difficult. Skin injuries too may be hard to attribute to radiation exposure, as it is often 2–3 weeks before any signs develop. The injuries present as areas of skin necrosis that do not heal. The area affected is the site of X-ray beam entrance, usually found on the back, and may be in the shape of an X-ray beam. Some cases require skin grafting. The injuries reported in the literature are thought to be only the tip of the iceberg.
       The use of ionizing radiation is governed by a principle call ALARA, which stands for ‘As Low As Reasonably Achievable’. Since no radiation exposure is considered safe, health care providers are responsible for minimizing patient exposure whenever possible.
       The group that developed the clinical competency statement determined that there are two general knowledge areas required by the physician. The first is knowing how to operate the equipment to produce optimal image quality, but with minimal radiation exposure to the patient and staff. The second is that the physician needs to recognize those patients and situations in which there is an increased risk of radiation injury.

What is the Recommended Physician Knowledge Base?
       The knowledge base proposed for physicians performing fluoroscopically guided procedures includes the contents of the Clinical Competence Statement along with a prior document, the ACC expert consensus document: Radiation Safety in the Practice of Cardiology, by Limacher et al.² Two different levels of certification have been recommended. The first level is that which is recommended for all cardiovascular medicine specialists who perform procedures in critical care units. The advanced curriculum is for those who perform fluoroscopically guided angiographic interventional and electrophysiologic cardiovascular procedures. The first level certification material/program is estimated to take four hours to complete, while the more advanced material/program takes about 12 hours to complete.

Table 1. Curriculum for Critical Care Unit Procedures.1

- Imaging Physics and Technology • X-ray dosimetry concepts • X-ray production and feedback control • Image formation • Fluoroscopic systems • Image handling Patient and Staff Radiation Management • Radiation risks including pregnancy and heritable concerns • Patient selection, consents, history, physical examinations, follow-up procedure • Review of radiation injury cases • Distance-time-shielding • Situational awareness • Pregnant staff Operational Certification for Each Fluoroscope Used in the Laboratory, Approximately 15 Minutes Per System Using the Target System • Location and function of key controls • Available clinical modes and their associated dose rates • Available radiation-shielding devices Certification Examination • Written certification examination with constructive review of responses.

       The basic certification has four components (Table 1). The first is knowledge about imaging physics and technology. Areas covered in this part include information related to X-ray dosimetry concepts: X-ray production and feedback control, image formation, fluoroscopic systems and image handling. The second portion involves patient and staff radiation management. Risks during pregnancy, patient selection and follow-up, review of radiation case injuries, distance-time-shielding concepts, situational awareness and issues related to pregnant staff are included in this portion. This portion would be followed by an operational certification for each fluoroscope used in the laboratory. Finally, a certification exam would be administered.

Table 2. Advanced Curriculum: X-Ray Production and Imaging.1

- Each of the following topics is recommended for 1 hour of presentation or study. X-Ray Generation and Control 1. Bremmstrahlung and X-ray properties X-ray generators, filters, collimators, brightness, and exposure rate controls X-Ray Dosimetry 2. Radiation dosimetry, units, and measurement Image formation 3. Effects of dose, kVp, geometry, and focal spot size on image contrast, spatial resolution, and noise Image Acquisition 4. Image intensifier and flat panel receptors Pulsed fluoroscopy (pulse duration, intensity, frame rate) Serial imaging Image Processing and Management 5. Basic aspects of the digital image (matrix size, bit depth) Digital image processing (subtraction, recursion) DICOM and PACS Image Laboratory — Demonstrations in the Cardiovascular Laboratory 6. Radiation-measuring instruments Effects of changing physical parameters on image quality Basic quality assurance testing

       The advanced certification (Tables 2 and 3) requires a greater depth of knowledge within each of the content areas plus detailed information about patient doses, an imaging laboratory with demonstrations, a safety laboratory demonstration component, information about FDA, state and JCAHO requirements/standards, and finally a written examination.

Table 3. Advanced Curriculum: Radiation Biology, Safety, and Protection.1

- Radiation Effects • Stochastic risk (including sensitivity factors) • Deterministic injury: skin, hair, eye, etc. • Pregnancy and Heritable concerns Patient Dose-Management Fundamentals • Clinical dose monitoring (dose @ IRP, DAP, IEC cumulative dose) • Consents, history, physical examinations, follow-up procedures • Effects of different operating modes on patient dose and image quality • Geometry factors and patient factors • Intraprocedural radiation benefit-risk evaluation • Review of radiation injury cases Staff Radiation Safety • Distance-time shielding • Situational awareness • Badges • Beam orientation effects • Pregnant staff Safety Laboratory — Demonstrations in the Cath Lab • Effects of patient size and imaging geometry on patient dose • Scatter radiation fields — intensity and orientation • Properties and use of radiation protection accessories Professional Standards and Regulatory Requirements (1/2 lecture) • Professional standards of practice (e.g., ACC, AHA, HRS, SCAI) • FDA • State • JCAHO Miscellaneous and Review (1/2 lecture) • Other topics of current or local interest Final Examination • Written certification examination

       Awareness of factors which affect dose can contribute greatly toward the goal of decreasing radiation exposure (Table 4). Equipment design and settings play a role here. Features such as the ability to move the C-arm, field-of-view size, fluoroscopy pulse rate and acquisition frame rates, preventative maintenance and calibration all factor in for patient dosing. Patient factors include issues such as prior radiation exposure and body size. Radiation dosage is cumulative, and those who have had extensive fluoroscopic procedures in the past may be at higher risk for injury. Patients who are larger require more dosage of radiation for adequate organ visualization.

Table 4. Factors Which Affect Dose.1,3

- Equipment Design and Settings • Movement capabilities of C-arm, X-ray source, image intensifier • Field-of-view size • Collimator position • Beam filtration • Fluoroscopy pulse rate and acquisition frame rate • Fluoroscopy and acquisition input dose rates • Automatic dose-rate control including beam energy management options • X-ray photon energy spectra • Software image filters • Preventative maintenance and calibration • Quality control Patient Factors • Patient body weight and habitus Physician Procedure Conduct • Positioning of image intensifier and X-ray source relative to the patient • Beam orientation and movement • Detector field-of-view size • Collimation • Acquisition and fluoroscopic technique factors on some units • Fluoroscopy pulse rate • Acquisition frame rate • Use of variable beam filtration • Total fluoroscopy time • Total acquisition time

       The physician can also conduct procedures in such a way that the dose of radiation is lessened. The position of the image intensifier, beam orientation and movement, fluoroscopy pulse rate and acquisition frame rate are all features which are under at least partial control of the physician.

What Will Need to be Done?
       As with any new recommendation or guideline, a mechanism for insuring incorporation into the academic and practice arena will be begun. The physician in training will see this content become part of his specialty training. Cardiac cath labs will seek ways to ensure this training occurs within their setting. This will take the form of didactic courses, self study or online programs. The JCAHO standards⁴ may also be consulted for guidance.

What are the implications for practice?
       Dr. Gregory Mishkel, Catheterization Laboratory Director at Prairie Heart Institute, St John’s Hospital, Springfield, Illinois sees multiple implications related to these guidelines. He believes that monitoring of procedure fluoroscopy time should become a quality indicator within the lab. Physicians who consistently perform cases with excessive exposure times may have to face queries from their peers. In addition, he pointed out that some of our new diagnostic tools such as EBCT actually have increased the amount of cumulative exposure; therefore, we need to have heightened awareness of the dose these tools contribute.
       The implications for electrophysiology are greatest in the realms of atrial fibrillation ablation and in placement of coronary sinus leads. These are cases which tend to be more prolonged and are often performed on patients who are older and at greater risk for complications. Operator awareness will prove to be a key element in reducing exposure times.
       Physicians may need to make it a practice to inform primary care physicians about fluoro times which have been prolonged in their patients, so that there is an increase in monitoring for skin sequelae. In addition, more detailed histories may be needed to identify patients who are at higher risk for injury.
       Industry is continually attempting to develop improved features in fluoro equipment, with dosage reduction an ongoing quest. Development of a magnetic catheter navigation system such as Stereotaxis, for example, has also resulted in reduced procedural radiation. The newer technology available for mapping assists in fluoro reduction, and as these systems are continually improved, their contribution will increase.
       The goal of further reducing radiation doses in patients undergoing fluoroscopic procedures is one which physicians are taking the clinical lead with through their new guidelines. Refinement of diagnostic tools furthers this achievement. The increased awareness which this brings to everyone in the clinical setting will surely improve outcomes and make the lab a safer place for our patients.