Radiation Safety in Perioperative Practice

RADIATION SAFETY IN PERIOPERATIVE PRACTICE

1970 1970 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

STUDY GUIDE

Disclaimer AORN and its logo are registered trademarks of AORN, Inc. AORN does not endorse any commercial company’s products or services. Although all commercial products in this course are expected to conform to professional medical/nursing standards, inclusion in this course does not constitute a guarantee or endorsement by AORN of the quality or value of such products or of the claims made by the manufacturers. No responsibility is assumed by AORN, Inc, for any injury and/or damage to persons or property as a matter of product liability, negligence or otherwise, or from any use or operation of any standards, recommended practices, methods, products, instructions, or ideas contained in the material herein. Because of rapid advances in the health care sciences in particular, independent verification of diagnoses, medication dosages, and individualized care and treatment should be made. The material contained herein is not intended to be a substitute for the exercise of professional medical or nursing judgment. The content in this publication is provided on an “as is” basis. TO THE FULLEST EXTENT PERMITTED BY LAW, AORN, INC, DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT OF THIRD PARTIES’ RIGHTS, AND FITNESS FOR A PARTICULAR PURPOSE. This publication may be photocopied for noncommercial purposes of scientific use or educational advancement. The following credit line must appear on the front page of the photocopied document:

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2 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

Radiation Safety in Perioperative Practice

TABLE OF CONTENTS

PURPOSE/GOAL ...... 4 OBJECTIVES...... 4 INTRODUCTION...... 5 IONIZING RADIATION ...... 5 ADVERSE EFFECTS OF IONIZING RADIATION...... 5 FUNDAMENTAL CONCEPTS AND PRACTICES...... 7 RADIATION SOURCES IN PERIOPERATIVE PRACTICE ...... 9 DOSE LIMITS AND REGULATIONS ...... 13 DOSIMETRY...... 13 CONCLUSIONS AND RESOURCES...... 17 GLOSSARY ...... 18 POST-TEST...... 23 POST-TEST ANSWERS...... 26

3 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

PURPOSE/GOAL The purpose of this study guide and accompanying video is to educate perioperative personnel on the clinical applications, risks, and safety practices for the use of ionizing radiation in perioperative practice.

OBJECTIVES After viewing the video and completing the study guide, the participant will be able to • define ionizing radiation; • summarize the acute and long-term adverse effects of ionizing radiation exposure; • list the types, sources, and applications of ionizing radiation in perioperative practice; • explain the linear-no-threshold model and the concept of ALARA; • describe how to use the principles of time, distance, and shielding to minimize radiation exposure for personnel and patients; • define federal dose limits and describe state regulations on occupational and public radiation exposure; and • understand the proper use of dosimetry to measure radiation exposure.

4 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

INTRODUCTION producing devices, Radiographic modalities that use ionizing radiation play an such as x-ray and essential diagnostic and therapeutic role in numerous areas of fluoroscopy machines, perioperative practice.1 For both patients and health care and radionuclides, personnel, however, ionizing radiation exposure can increase which are atoms with the risks of acute and long-term health effects, such as skin unstable nuclei that injury and cancer. By implementing proper radiation safety emit radioactive practices, perioperative nurses and other team members can particles as they substantially decrease the risks of ionizing radiation exposure decay.1 The most for patients and health care workers. common forms of ionizing radiation used for medical purposes are gamma radiation, x-rays, and positrons. Gamma radiation is electromagnetic radiation emitted from the nuclei of radioactive atoms.1 Gamma radiation can deeply penetrate living tissue and is used in nuclear The expanding use of ionizing radiation during invasive medicine. However, procedures underscores the need for radiation safety education gamma radiation exposure can also occur during the use of and training for perioperative nurses. This study guide and the Iodine-131 (I-131), an isotope that emits both gamma and beta accompanying video review the definitions, clinical uses and radiation. I-131 causes cell death when it undergoes beta risks of ionizing radiation, federal and state regulations and decay and is used during inpatient and outpatient thyroid radiation dose limits, and essential concepts and practices to procedures, such as in the treatment of hyperthyroidism and minimize radiation exposure for patients and personnel. thyroid cancer.1,3 X-rays share many characteristics with gamma radiation, but IONIZING RADIATION are emitted from the electronic shell instead of the nucleus of Radiation is energy emitted by matter in the form of high- atoms.4 X-ray photons used in medicine are created when 2 speed particles or rays. When radiation is of high enough electrons are accelerated to a high speed inside a metal tube frequency, it has sufficient energy to remove tightly bound before colliding with a metal target.1 X-rays are primarily used electrons from atoms. This process is called ionization in diagnostic radiology, computed tomography (CT), because it creates ions, and these high-energy forms of fluoroscopy, and during x-ray therapy for cancer. radiation are called ionizing radiation. Ionizing radiation (ie, radioactivity) includes gamma rays, x-rays, alpha particles, Positrons are positively charged particles emitted from the 1 beta particles, neutrons, and positrons. Non-ionizing radiation, nuclei of some radionuclides. When positrons and electrons which does not have sufficient energy to displace electrons interact, both are converted to photons. Positrons are used in from atoms, includes radio waves, microwaves, visible light, positron emission tomography (PET) scans to evaluate heat, and radar. This study guide and the accompanying video metabolic activity. Because malignancies have higher focus on ionizing radiation. metabolic activity than normal human tissue, PET scans are a sensitive and noninvasive method for detecting conditions Ionizing radiation penetrates and ionizes atoms and molecules such as malignant pulmonary nodules, breast tumors, and liver in living tissue, which is the basis of its applications in metastases.5,6 diagnostic and interventional radiology, nuclear medicine, and radiotherapy. Two sources of ionizing radiation used in ADVERSE EFFECTS OF IONIZING RADIATION perioperative and other clinical practice settings are radiation- Ionizing radiation has numerous potential diagnostic and

5 RADIATION SAFETY IN PERIOPERATIVE PRACTICE therapeutic benefits. However, exposure to ionizing radiation ionizing radiation, such as radiologic technologists, can be hazardous for patients as well as radiologists, radiologists, and perioperative team members, are at risk for radiologic technologists, surgeons, perioperative nurses, and radiation-induced cataracts unless proper eye protection is other personnel who work with radiologic modalities.1,7 It is consistently used. In one study of health care workers in essential to understand that ionizing radiation poses risks for Serbia, the occupational incidence of cataract was 64% for everyone, not just people who are pregnant or of reproductive radiologic technologists, 16% for radiologists, and 4% for age.7 At sufficient doses, all types of ionizing radiation can nurses.13 cause acute damage to tissue. In addition, ionizing radiation exposure directly increases the risk of serious long-term health outcomes, most notably cancer. While ionizing radiation can adversely affect all living cells, some types of cells are more sensitive to radiation exposure than others. When cells are dividing, DNA damage can cause the death or mutation of daughter cells.8 Cells that are highly mitotic (divide rapidly) or undifferentiated are most sensitive to the deleterious effects of ionizing radiation exposure. Thus, the most radiosensitive cells include those of the hematopoiesis system, gonads, and developing embryo, while the least radiosensitive include muscle and nerve cells.8-10 Ionizing radiation causes both stochastic and deterministic The primary perioperative nursing diagnosis relevant to this effects on human tissue.1,11 Deterministic effects occur acutely study guide is impaired skin integrity caused by gamma after a threshold radiation dose is reached, and increase in both radiation exposure.7 Acute cutaneous radiation injuries incidence and severity as dose increases past threshold. typically affect the epidermis during early stages and the Examples of deterministic effects include acute cutaneous dermis at later stages.14 Signs and symptoms include skin radiation injury, sterility, cataracts, acute radiation syndrome, erythema, edema, blistering, dry and moist desquamation, and teratogenesis or fetal death. These adverse outcomes result ulceration, hair loss or loss of the nails at the irradiated site, from cellular death, which is most likely to occur after itching, and localized changes in sensation. Complications can relatively high radiation doses delivered over a short time be serious and include pain, bleeding, fluid loss, and infection. period.1 Acute cutaneous radiation injuries can occur in patients who have undergone fluoroscopically guided interventional procedures, such as cerebral aneurysm embolization. Minimal threshold radiation doses associated with acute cutaneous radiation injury have been estimated at 3.5 to 5 gray (Gy).14 However, in a prospective study of 702 fluoroscopically guided endovascular neurosurgery cases, almost 40% of patients who received skin doses exceeding 2 Gy reported subsequent subacute skin changes or hair loss, and 30% of these patients reported permanent hair loss.15 Acute cutaneous radiation effects also can occur in patients who undergo radiation therapy for cancer. The concurrent use of chemotherapy further increases the risk of radiation-induced Because patients undergo direct irradiation during radiologic skin injury in cancer patients.16 procedures, they are at higher risk for deterministic health effects than health care workers. However, relatively low In contrast to deterministic effects, stochastic health effects threshold doses of ionizing radiation can cause progressive occur by chance.1 An example of a stochastic health effect is cataracts.12,13 One study reported that cataracts can occur if cancer, which is the most serious long-term adverse outcome the lens of the eye is exposed to ionizing radiation doses of from radiation exposure. Almost 41% of people born in the 100 centigray or less.13 Therefore, personnel who work with United States will be diagnosed with some type of cancer in

6 RADIATION SAFETY IN PERIOPERATIVE PRACTICE their lifetimes, according to population estimates by the dividing.1 The effects of ionizing radiation on an embryo or National Cancer Institute.17 Exposure to ionizing radiation fetus vary based on the stage of gestation and the radiation further increases this risk, as indicated by long-term follow- dose.1 During approximately the first 10 days after conception up studies of survivors of atomic bomb blasts.18,19 Although and before implantation, ionizing radiation exposure is radiation doses used in clinical practice are of course much thought to have an all-or-nothing effect on the embryo, lower, repeated exposure to medical doses of ionizing meaning that either development is unaffected or spontaneous radiation increases the risk of cancer.20-24 For example, abortion occurs.29 Ionizing radiation exposure later during ependymomas have been reported in patients who underwent gestation has been associated with increased rates of gamma knife surgery, a minimally invasive procedure in teratogenic effects in humans (eg, mental retardation, which gamma radiation is used to treat neurological disorders intrauterine growth retardation, childhood leukemia).1,28 such as spinal meningiomas.23 Furthermore, repeated Ionizing radiation can cause adverse health effects through exposure to ionizing radiation from CT scans has been both direct beam and scatter exposure.5 Direct beam associated with an increased risk of solid organ tumors.24 In exposure occurs when anatomical structures are directly in the one study of endovascular repair patients, patients who radiation beam. This risk is most relevant for patients, but can underwent eight CT scans for postoperative surveillance over affect health care workers who must manually position four years had a significantly increased risk of new solid organ patients during radiographic procedures.7 Scatter occurs when tumors compared to patients who underwent CT once in either radiation strikes and then deflects away from the body or from three or five years.24 surrounding surfaces, such as walls or procedure tables. It is important to keep in mind that scatter can occur in any direction and is the primary occupational source of ionizing radiation exposure in health care facilities.7 Practices for minimizing the risks of adverse effects of direct beam and scatter radiation exposure will be discussed in detail later in this study guide.

FUNDAMENTAL CONCEPTS AND PRACTICES This section of the study guide reviews concepts and general practices that are fundamental to radiation safety. First, studies of the stochastic effects of ionizing radiation exposure in humans and animals underlie an important hypothesis call the The long-term health effects of ionizing radiation exposure in linear-no-threshold model.30 This model proposes that health care personnel have been challenging to study because stochastic effects can result from any dose of ionizing individual dose data often are lacking.25 radiation and that the probability of occurrence increases Some researchers have proposed that exposure to ionizing linearly with radiation dose. The linear-no-threshold model is radiation can increase the risk of hereditary defects such as based on the assumption that a radiation dose of any size has trisomy 21 (Down syndrome).26 For example, a cluster of the potential to cause DNA double strand breaks (that is, sever both strands of DNA), which can result in cell death or trisomy 21 cases was reported in Berlin nine months after the 29 Chernobyl reactor accident.27 Reports of such clusters have genomic rearrangements. Thus, the linear-no-threshold contributed to the misconception that if a woman is exposed model asserts that the risk of stochastic health effects is very to ionizing radiation, her germ cells will be affected and her low when ionizing radiation doses are low, but that risk offspring will be more likely to have birth defects or cancer.1 increases with dose, and that there is no minimum safe dose To date, epidemiologic studies of humans exposed to ionizing of exposure. radiation have not confirmed this hypothesis, although this The linear-no-threshold model guides radiation safety effect has been observed in studies of animals.1,28 practices for both patients and health care workers. For In contrast, human prenatal exposure to ionizing radiation has patients, the model is used to weigh the decision to use definitely been linked to adverse effects in the fetus or ionizing radiation for clinical benefit against the patient’s developing embryo.1,28,29 Ionizing radiation poses greater risks long-term risk of cancer or other radiation-induced health during gestation because embryonic and fetal cells are rapidly problems. Based on this model, AORN specifies that patient exposure to ionizing radiation should be limited to situations

7 RADIATION SAFETY IN PERIOPERATIVE PRACTICE where medically indicated and to the anatomical structures who underwent percutaneous transluminal coronary that are being treated.7 angioplasty.33 Results indicated that when the distance between the radiation source and the phantom was decreased, estimated dose to the skin increased by 120-180%. The researchers concluded that these parameters could increase the risk for skin injuries following this procedure. Based on these data, AORN recommends that personnel limit the amount of time they spend near a radiation source when radiation exposure is possible, and that the radiation equipment operator give a verbal warning before activating the equipment.7 Shielding is used to attenuate direct beam and scatter radiation. Lead remains the most commonly used and widely studied material for shielding workers from occupational For health care workers, the linear-no-threshold model radiation doses. Lead of 0.5 mm thickness will attenuate at underlies the principle of keeping occupational radiation doses least 95% of scattered radiation.34 Numerous lead-based as low as reasonably achievable (ALARA).31 The ALARA options for shielding are available on the market, including concept is of paramount importance for perioperative nurses lead-lined aprons, skirts, and vests, thyroid shields, gloves, and all other personnel who work with ionizing radiation. This and mobile rigid shields. Lead-lined garments and devices are is because if appropriate protective measures are not taken, also used to shield patients from scatter or unnecessary direct personnel can accrue substantial occupational doses of beam radiation. ionizing radiation over time, leading to a significantly increased risk of adverse health effects. Flexible “lead alternative” apparel is also sold for radiation The concepts of time, distance, and shielding are essential protection. These flexible to keeping occupational doses of ionizing radiation as low as garments are advertised as reasonably achievable and to achieving dose optimization for lighter and more flexible than patients.7 Robust data indicate that ionizing radiation dose lead-lined garments. However, increases with increased exposure time, decreases with non-lead alternatives provide increased distance from the radiation source, and can be no protection from direct beam attenuated by means of proper shielding. It is therefore useful exposure and less protection to review data on time, distance, shielding, and general from scatter radiation. Some practices for implementing these concepts. Procedure-specific facilities do not use non-lead approaches related to time, distance, and shielding are alternatives in part because of discussed in the next section. concerns that they might be used to attempt to shield patients Studies indicate that when radiation exposure occurs at a from direct beam radiation. As of 2013, the federal constant rate, the total dose equivalent received depends on government did not regulate lead equivalent products used in the duration of exposure. Decreasing exposure time therefore aprons and other protective apparel. results in decreased dose. For example, in patients undergoing AORN specifies that shielding be used whenever possible treatment for breast cancer, cone-beam CT is used for to attenuate radiation of potentially exposed personnel.7 external-beam radiation therapy setup and to localize the target Health care workers who assist with radiographic procedures of radiotherapy.32 In a study of two cone-beam CT protocols, should wear a wrap-around apron shield if they must stand reducing exposure time by half resulted in a 50% decrease in with their back to an activated radiation device. If they must doses to patients’ organs.32 stand near the radiation beam, personnel should shield the Physical distance from the source of ionizing radiation is upper legs to protect the long bones and bone marrow from another important factor in radiation safety. When the distance radiation doses. If they need to stand near the tube, radiation from the point source of radiation is doubled, the exposure is can be reduced by shielding the upper chest and neck, such as approximately quartered.7 One study used polystyrene models with a thyroid collar. to estimate x-ray dose to the skin from fluoroscopy in patients

8 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

Shielding devices also should be handled carefully and perioperative sources of ionizing radiation and recommends visually inspected before use.7 Although the Joint measures for minimizing occupational exposure during Commission states that protective garments must be checked perioperative procedures. annually for defects, at present it does not specify how to do so. Both tactile and imaging methods can be used to evaluate Fluoroscopy protective apparel and other devices, but imaging is generally Fluoroscopy is an more accurate. One strategy for imaging protective lead advanced medical apparel is to line aprons and other items up on a CT table and imaging technique used scan them. This method can identify small pinhole defects that during many types of could easily be missed by tactile examination, and use of CT surgical and other also allows garments to be compared over time to assess invasive procedures.5 changes and better identify tears. In addition, personnel are Fluoroscopy functions not in the room when CT is performed so there is no much like an x-ray video. associated occupational exposure. To date, there is no A low-intensity x-ray regulation of how companies measure the amount or thickness beam passes continuously of lead in their products and no requirement for companies to through the patient’s body disclose how they perform these measurements. Therefore, it and strikes a detector under the patient. This detector converts is advisable to check new lead aprons and other new protective low-intensity x-rays to visible light, creating an image apparel for defects before they are worn. Finally, technology displayed on a computer monitor. such as radio-frequency identification (RFID) locator tags can Fluoroscopy is clinically valuable because it produces detailed be installed in lead-lined aprons and other protective garments. images of the body or of instruments or contrast agents as they These devices help prevent garments from being mislaid or move inside the body. However, fluoroscopy also can expose overlooked during annual screenings. patients to some of the highest radiation levels of any In addition, areas where ionizing radiation is used may be radiographic modality.7 This is because unlike conventional protected with lead-filled walls, windows, doors, and control radiography, fluoroscopy produces ionizing radiation booths. Clear leaded doors are acceptable for shielding rooms continuously over a duration of minutes. if they are properly constructed. It is advisable to require that Improvements in the complexity and capacity of fluoroscopic a radiation safety specialist evaluate new construction to be equipment have led to the expanded use of fluoroscopy during sure that lead was properly installed. A shielding integrity a range of procedures.35 Modern fluoroscopy includes both check can be performed by obtaining a radioactive source simple and interventional techniques.1 Simple fluoroscopic from the nuclear medicine department, placing it inside the procedures include angiography, catheter insertion and shielded room, and then using a survey meter to measure manipulation, orthopedic joint replacements and fracture radiation levels from outside the room to determine if ionizing repairs, and gastrointestinal imaging by means of barium radiation is penetrating the walls. swallow or barium enema. Interventional applications of fluoroscopy include endografts for treating aortic aneurisms, RADIATION SOURCES IN PERIOPERATIVE vertebroplasty and kyphoplasty for spinal fractures, uterine PRACTICE artery embolization, and endoscopic biliary and upper urinary Ionizing radiation plays a key and expanding role in the tract procedures.36 perioperative practice setting.1 It is used widely in traditional Several types of fluoroscopic devices are used in the ORs, hybrid operating suites, health provider offices, perioperative practice setting.1 These include portable C-arms diagnostic and interventional radiology departments, and and fixed fluoroscopy machines used in hybrid operating cardiac catheterization suites, among other locales. suites and cystoscopy rooms. Portable C-arms resemble Perioperative teams work with ionizing radiation during portable x-ray units.37 The “C” portion of the unit contains the procedures such as orthopedic surgery, coronary angiography, x-ray tube, and the chassis houses the generator and video- genitourinary procedures, sentinel lymph node biopsy, stent storage equipment. Portable C-arms are available in larger and insertion, shunt and pacemaker placements, peripheral miniature sizes. A clinician might use a larger portable C-arm vascular angioplasty, and low-dose and high-dose unit to visualize joint alignment and seating during a total hip brachytherapy. Such procedures can be lifesaving and can replacement or to visualize catheter and drain placement significantly improve quality of life. This section reviews

9 RADIATION SAFETY IN PERIOPERATIVE PRACTICE during surgery. Portable miniature C-arms are used during requirements.35 Because of this, fluoroscopy has been widely surgeries that require narrower visual fields, such as re-setting used by both physician specialists and non-physicians who bones in the extremities. are not trained or are inadequately trained in relevant principles of radiation safety. In response to this concern, AAPM published detailed guidelines in 2012 to help health care facilities establish fluoroscopy credentialing and privileging programs.35 During fluoroscopy, AORN recommends that staff members stand on the image detector side of the unit when possible to decrease radiation intensity.7 Personnel should also keep the patient as close as possible to the image detector and away from the tube. This practice decreases the dose required to produce an image, decreases scatter, and decreases the amount of radiation emitted to personnel. Leaded eyeglasses are also available and may be advisable if the Miniature C-arms produce less radiation than larger sized C- health care worker must stand within 24 inches of the x-ray arm units.38,39 For example, one study assessed doses of beam during fluoroscopic procedures. ionizing radiation created by conventional C-arms during several types of procedures, and compared these levels to Hybrid Suites doses from miniature C-arms used during the same types of Hybrid operating suites incorporate advanced imaging procedures.38 The results indicated significantly less radiation equipment into the sterile OR setting.41 This approach scatter to the surgeon when miniature C-arms were used, but facilitates minimally invasive surgery and allows the no significant difference in radiation exposure of patients. interdisciplinary integration of surgery with endovascular Based on these findings, the researchers recommended the use approaches and other interventional techniques.41,42 Examples of the miniature C-arm when possible. In another study, of procedures performed in hybrid suites include hybrid researcher used dosimeters to test exposure levels during 155 coronary revascularization, transcatheter valve replacement simulated procedures in which a miniature C-arm was used and repair, and placement of stents or grafts in the thoracic to image a replica upper extremity.39 The results indicated that aorta.41 scatter was relatively low and that the dosimeter only incurred a substantial amount of radiation when it was placed in the direct line of the beam. However, based on the linear non- threshold model, there is no minimum safe radiation level and appropriate precautions should be taken during the use of miniature C-arms and all other radiologic devices. In some cases, the use of fluoroscopy has caused serious cutaneous radiation injuries in patients, such as burns that progressed to large areas of necrotizing erosion.35 Fluoroscopy is also a significant source of ionizing radiation exposure for health care workers. In one study, researchers evaluated High-powered fixed angiography systems are a centerpiece occupational exposure to fluoroscopic radiation during spinal of many hybrid suites. These systems use a high frame rate surgery.40 The results indicated that surgeons received an and power output, and have superior imaging capacity average of 1,225 millirems (mrems) of ionizing radiation compared to mobile C-arms.43 For example, fixed during 37 minutes of fluoroscopic time. The next highest angiography systems are used to image the moving heart exposure measured was for first assistants, who received 369 during cardiac surgery. Some hybrid ORs are equipped with mrems. other advanced imaging modalities, such as CT and magnetic resonance imaging (MRI). The American Association of Physicists in Medicine (AAPM) has recently emphasized that technical and clinical advances Hybrid ORs offer numerous potential advantages, but also in the use of fluoroscopy have outpaced safety-related present special challenges with regard to radiation safety. To education and training initiatives, and credentialing minimize ionizing radiation exposure for staff and optimize

10 RADIATION SAFETY IN PERIOPERATIVE PRACTICE doses for patients, hybrid OR managers and designated of direct beam exposure.7 Instead, personnel should use radiation safety officers need to ensure that personnel who traction devices, slings, or sandbags to keep the patient in work in hybrid suites are fully trained regarding appropriate position during the study. In rare exceptions when a health use of fluoroscopic and other imaging and surgical care worker must use his or her hands to position the patient, equipment.42 Radiation protection and dose optimization must the use of protective shielding such as lead-lined gloves be part of procedure planning. Hybrid suites are covered in should be considered. more detail in a separate AORN learner video and study guide. Radiation safety during intraoperative MRI Cystoscopy Rooms Intraoperative MRI (iMRI) has numerous potential uses Cystoscopy rooms are usually located within surgery suites. during surgery and other invasive procedures. For example, Cystoscopy rooms are designed for genitourinary procedures iMRI is used during brain tumor biopsies and resections and such as those of the kidneys, bladder, prostate, and urethra.37 to guide placement of deep brain stimulation systems.45,46 Examples of fluoroscopically guided cystoscopic procedures Intraoperative MRI helps surgeons visualize, in real time, the include transurethral resection of the prostate and contrast locations of lesions and critical structures of the brain that studies of the kidneys and lower urinary tract. During many must not be damaged.45 This is particularly useful if the brain cystoscopic techniques, fluoroscopy is used intermittently or a tumor moves during resection or if cyst decompression rather than continuously; as a result, cumulative exposure occurs after cerebrospinal fluid is removed. levels are typically lower than for interventional fluoroscopy. However, MRI technology is potentially hazardous because 47 Conventional radiography it uses large magnets that create powerful magnetic fields. Conventional radiography is also used in conjunction with These magnetic fields interact with ferromagnetic materials operative and other invasive procedures to assess the skeleton such as iron, nickel, and certain types of stainless steel. If and soft tissue.5 Conventional radiography uses higher levels instruments, tools, or other items made from ferromagnetic of ionizing radiation compared to fluoroscopy, but shorter material are brought into a MRI room, they can be pulled suddenly and violently toward the magnet, resulting in a exposure times, which typically results in much lower levels 47,48 of exposure for the patient and less total scatter radiation. missile effect. Examples of ferromagnetic equipment include oxygen tanks, crash carts, tables, chairs, cleaning equipment, scissors, laryngoscopes, gurneys, and IV poles. Serious injuries and death have resulted from bringing ferromagnetic equipment into the MRI room.48 In one case, a pediatric patient was killed during routine postoperative MRI when a non-MR safe oxygen tank was accidentally brought into the MRI suite.48 The tank became a missile that was pulled through the air by the magnetic force created by the 10- ton magnet. The tank then struck the skull of the immobilized patient, causing fatal cerebral hemorrhage. Although the imaging capacity of mobile x-ray units has Because of these severe hazards, health care organizations improved, image quality tends to be lower than for fixed need to establish comprehensive policies and training units.44 This is because radiographic cassettes in mobile units activities to ensure the safety of patients and the perioperative cannot be aligned as accurately, and because the distance team and the most accurate possible interpretation of images.49 between the cassette and the x-ray tube varies.44 In addition, In 2013, the American College of Radiology (ACR) published the output of mobile units is lower, so the range of obtainable updated guidelines on the safe use of MRI.47 These expanded exposures is limited, which may necessitate the use of longer guidelines highlight the importance of establishing, exposure times.44 For these reasons, mobile radiography implementing, and maintaining current safety policies and generally should be used only when it is infeasible to examine procedures for the use of MRI in all settings. The guidelines a patient on a fixed x-ray machine. also emphasize that there should be zero tolerance for errors 47 Finally, radiologic technologists, perioperative nurses and in settings where MRI is used. other personnel should not restrain or position patients The ACR guidelines recommend that all sites that use MR for manually during radiographic studies because of the risk clinical or research purposes establish and maintain MR safety

11 RADIATION SAFETY IN PERIOPERATIVE PRACTICE policies.47 In addition, these sites should name an MRI checklists. Finally, an on-duty safety nurse can be assigned to medical director to ensure that these policies remain current screen patients and staff and to ensure that policies and with changing technologies and MRI practices. Adverse procedures are appropriately followed at all times when iMRI events, safety accidents, or near accidents related to the use is used. of MRI should be reported to the MRI medical director. The ACR guidelines further address MRI safety issues for specific PATIENTS AS SOURCES OF RADIATION groups such as pregnant women, pediatric patients, people EXPOSURE with claustrophobia, and patients with intracranial aneurysm In some situations, patients themselves must be regarded as clips, cardiac pacemakers, or implantable cardioverter potential sources of ionizing radiation exposure. Patients who defibrillators. have received therapeutic radionuclides, for example, are The ACR guidelines also specify how a facility should restrict potential sources of occupational radiation exposure until the access to its MRI site.47 In total, the ACR recommends four radionuclide has decayed or been eliminated from the body. access zones that restrict the movement of patients and Patients who have undergone iodine-131 thyroid therapy for personnel based on increasing levels of risk: hyperthyroidism or thyroid cancer or temporary or permanent brachytherapy for cancer can expose perioperative nurses and • Zone I is where MRI poses no risk and patients are other health care workers to ionizing radiation if appropriate permitted to move freely. An example of a Zone I area precautions are not taken.1 AORN recommends that safety is an outpatient entrance, reception, and waiting area protocols related to these patients be overseen by a for an MRI suite. Zone I channels patients and staff to radiation safety officer.7 In addition, several specific the prescreening area and helps restrict further access radiation safety practices should be followed. to the MRI suite.47 When body fluid or tissue is removed from a patient who has • Zone II serves as an interface or buffer zone between had a diagnostic nuclear medicine study or sentinel lymph Zone I and the highly controlled inner zones III and node biopsy, the samples should be labeled as radioactive and IV. In Zone II, patients can interact with health care handled in compliance with standard precautions and radiation personnel and move around under supervision. An safety procedures.7 These procedures should be based on example of a Zone II area is an MRI screening area in government regulations and recommendations. which health care personnel verbally assess patients and obtain medical and radiation histories.47 Before transferring patients who received therapeutic • Zone III has severely restricted access for both radionuclides in the OR, perioperative personnel should first patients and non-MRI staff. This is because the notify the staff receiving the patients about the radiation 1 presence of objects or equipment made from source and its anatomical location. Radiation precautions ferromagnetic substances can result in serious injury should then be followed during transfer. or death as a result of electromagnetic interactions with the scanner’s magnets. The ACR guidelines stipulate that MRI staff must strictly control access to Zone III and that this zone should be physically restricted from public access by means of key locks or passkey locking systems.47 • Zone IV is the MRI scanner magnet room itself. By definition, it is always located within Zone III. Zone IV is under severely restricted access.47 The MRI-integrated OR should be considered a high-risk zone in which there is no room for error.50 Several measures can promote the safest possible use of iMRI. For example, a health care organization can create a specific safety manual and implement a series of checklists and protocols for use of iMRI and actions to take in case of emergency.50 All personnel who Precautions are also necessary when working with patients work with iMRI can be required to undergo appropriate MRI who have received permanent or temporary radioactive 1 safety training and to use the surgical MRI safety manual and implants. An example of a permanent radioactive implant is

12 RADIATION SAFETY IN PERIOPERATIVE PRACTICE the placement of radioactive seeds (radioactive material in the performed in accordance with federal, state, and local form of micropolymer beads, also known as microspheres) regulations. into organs.1 These procedures are used to treat diseases such At the federal level, the United States Nuclear Regulatory as liver or prostate cancer. The microbeads are infused through Commission (NRC) requires radiation protection programs to a catheter, travel through the arterial system, and lodge in the use procedures and engineering controls that keep radiation hepatic capillary bed. An interventional radiologist usually doses as low as reasonably achievable.31 The NRC also sets performs this procedure. The infusion syringe must be radiation dose limits for occupational exposure and exposure shielded to decrease external exposure. In addition, of members of the public. precautions are needed to prevent spillage of the microspheres, and universal precautions should be practiced to protect staff Occupational dose limits for adults are:31 from internal exposure. • Total body: 5 rems per year • Lens of the eye: 15 rems per year • Skin: 50 rems per year • Extremities: 50 rems year In the event that minors are employed, their annual occupational dose limits are 10% of the dose limits for adults.31 The NRC also sets dose limits for members of the public, defined as people who do not work directly with ionizing radiation and have not received radiation safety training.31 Dose limits for these people are 0.1 rem per year and less than 0.002 rem in any hour. These are the maximum doses that an individual should receive from any operation or facility that An example of a temporary radioactive implant is eye plaques, is licensed to use ionizing radiation. which are used in the treatment of choroidal melanoma.1 For eye plaque implantation, radionuclide seeds are placed in a States, and in some cases local governments, also regulate the silastic insert, which is secured to a disc (or plaque) and use of radiation in health care settings. However, state sutured next to the tumor. Plaques are made of gold to reduce regulations vary considerably in terms of licensure scatter radiation to the optic nerve, choroid, and retina, and requirements for health care facilities that use radiation and typically are removed after several days. requirements for registering radiation devices and training both physicians and non-physicians who work with radiation. AORN specifies that manufacturers’ written instructions 7 In cases where state regulations are stricter than federal be followed when preparing eye plaques. In addition, if regulations, state requirements must be followed. The implants are sterilized in-house, the manufacturer’s written American Association of Physicists in Medicine and the recommendations should be followed and the process should Conference of Radiation Control Program Directors have be overseen by a radiation safety officer or designee. Plaques published an online interactive map of radiation control also should be kept secure and tracked at all times. programs in the United States.

DOSE LIMITS AND REGULATIONS DOSIMETRY Because of the health risks of radiation exposure, governments Dosimeters, commonly known as badges, are used to monitor regulate the use of radiation devices and the activities of radiation doses to health care workers and other personnel radiation safety programs and personnel. Many health care who work in settings where ionizing radiation is used. Federal organizations designate radiation safety officers who supervise regulations require that radiation doses be monitored if an radiation safety programs and ensure that staff and patients occupational dose is likely to exceed 10% of the limit of 5 are appropriately protected. Radiation safety officers also rems per year, regardless of the practice setting.31 However, determine which personnel are in frequent proximity to states and localities also regulate dosimeter use and may have ionizing radiation, how occupational exposure should be more stringent requirements. These stricter regulations must monitored and recorded, and who should wear monitoring be followed if they are in place. devices to assess radiation exposure. These activities must be

13 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

durable and OSL dosimeters have the widest useful dose range (0.001 rem to 1000 rem). In addition, ring dosimeters are used to assess radiation to the extremities. Ring dosimeters are required for people who are likely to meet or surpass the annual dose limit to the extremities of 50 rem.31

In addition to following federal, state, and local regulations on who must wear a dosimeter, some radiation safety officers elect to provide dosimeters to everyone who requests them. This approach allows health care workers to determine their cumulative radiation dose in the future if they want, even if they are not expected to exceed 10% of the annual dose limits. If a dosimeter’s readings are higher than expected, it can be Badges are the most accurate source of data on a cumulative helpful to consider some basic troubleshooting questions. For occupational radiation exposure levels, and as such they example, if a badge was accidentally left on an apron, it might should be worn in careful accordance with radiation safety have been irradiated when someone else used the apron, or if protocols.1,7 Several practices should be followed to increase the apron was placed on a table when service engineers were the accuracy of dosimetry data. Badges should be used only testing or repairing ionizing radiation equipment. In other at work, not taken home where they could be lost, forgotten cases, badges have even accidentally been included in checked when returning to work, or accrue exposure to environmental luggage that is directly exposed to ionizing radiation at the sources of ionizing radiation. Badges also should be treated airport. High dosimeter readings also might be recorded if a as an individual record of radiation exposure and not left on dosimeter is worn for much longer than the designated wear aprons or other protective garments when not in use. period or if a dosimeter that was lost is found, turned in, and read. Regulations related to radiation monitoring are enforced by state programs or the NRC. When two dosimeters are used, the most common practice is for one to be worn inside the leaded apron to measure whole-body exposure, and the other to be worn on the collar outside the apron to measure exposure to the head, neck, and lens of the eye. When only one dosimeter is used, AORN recommends that all personnel wear it on the same area of the body.7 Staff members might use a single collar dosimeter or a chest dosimeter, for example. In addition, ring dosimeters might be required for personnel who handle radioactive material or who are otherwise at risk of exposing their hands to ionizing radiation in the workplace.1 An example is an interventional cardiologist who performs catheterization procedures. The use of dosimetry during pregnancy is an important topic. If a health care worker becomes pregnant, she has the option Personnel who are involved with fluoroscopic procedures to notify the radiation safety officer at her place of should wear at least one dosimeter that is made by a vendor employment.1 This is called declaring the pregnancy. The certified by the National Voluntary Laboratory rights of workers with declared pregnancies with regard to Accreditation Program.7 Dosimeters that meet this radiation exposure are federally defined. The NRC dose limit requirement include film badges, thermoluminescent for an embryo or fetus is 0.5 rem for the entire gestation dosimeters, and optically stimulated luminescent (OSL) period, and work restrictions are required if an embryo or fetus dosimeters.1 Thermoluminescent and OSL badges are more is expected to receive more than this dose.31

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To assess fetal dose, a dosimeter should be worn on the a recent study in Italy reported that between 1970 and 2009, abdomen at waist level beneath the shielding apron.1 In ionizing radiation exposure increased approximately 155% addition, some health care facilities use aprons designed for for patients hospitalized with ischemic heart disease.52 The pregnant workers that include 1 mm of lead in the abdominal study’s authors attributed this rise to the increased use of CT region and 0.5 mm throughout the rest of the apron.1 For and invasive fluoroscopy in this patient population. personnel who are pregnant, dosimeters should be read Increasing exposure to medical doses of ionizing radiation can monthly, not quarterly.7 have measurable adverse consequences. In the United States, If the dose equivalent to the embryo or fetus exceeds 0.5 rem it has been estimated that 0.02-0.4% of CT scans have been (500 mrem) or is within 0.05 rem of the dose limit by the time associated with the subsequent development of cancer in a woman declares her pregnancy to the radiation safety officer, patients.53 One risk modeling analysis estimated that 29,000 the NRC licensee is considered in compliance with NRC future cancers could be related to CT scans performed in the regulations if any additional dose to the embryo or fetus is less United States in 2007.54 The primary procedures implicated than or equal to 0.05 rem for the rest of the pregnancy. in the risk model were scans of the chest, abdomen and pelvis, and head, as well as chest CT angiography. The gestation period is assumed to be 10 months, meaning that the monthly dose limit is 50 mrem. Monthly fetal In 2011, in response to concerns about increases in ionizing dosimeter measurements should be closely monitored. If a radiation exposure, the Joint Commission published a Sentinel spike in exposure is observed, it should be proactively Alert on the use of radiation for clinical purposes.55 This alert investigated and addressed even if the monthly exposure limit emphasized that diagnostic imaging occurs in a wide variety has not been reached. This is an example of how ALARA is of health care settings and that current practice guidelines and applied in the workplace. US regulations allow any physician to order tests using radiation at any dose, without first evaluating radiation history.55 The Joint Commission made several recommendations in response to these concerns. These included ordering the right radiologic tests; optimizing patient doses; expanding the role of the radiation safety officer to include patient safety; ensuring that physicians and staff are educated regarding doses and equipment use; and developing policies and procedures on use of lead shielding for staff and patients.55 In addition, the Joint Commission underscored the role of medical physicists in testing diagnostic imaging equipment according to pre-determined schedules and the importance of RADIATION SAFETY FOR PATIENTS developing an organizational culture of safety regarding Radiation safety practices have undergone increased scrutiny radiation use. 51,52 during the past several years. This stems from awareness In 2010, the US Food and Drug Administration also of marked increases in the public’s exposure to ionizing established the Initiative to Reduce Unnecessary Radiation radiation in the United States and elsewhere. In 2006, for Exposure from Medical Imaging.56 This initiative is based on example, reported levels of cumulative radiation exposure for two major principles— justification and dose optimization. US residents was more than seven times greater than during Justification means that an imaging procedure should be the early 1980s, according to a report by the National Council judged to do more good than harm. Dose optimization means 51 on Radiation Protection and Measurement. The Council that patients should receive the lowest radiation dose that noted that the majority of this increase was attributable to the delivers an image of adequate quality for diagnosis or increased use of CT and nuclear medicine. These modalities intervention. are invaluable clinical tools that also expose patients to relatively high levels of ionizing radiation, particularly with Other researchers have emphasized that increasing levels of repeated use. radiation exposure highlight the need for policies guiding the justification of decisions to order and perform radiographic Analyses of cumulative ionizing radiation exposure elsewhere procedures, and supporting the careful optimization of correlate with findings from the United States. For example, radiation doses.52 The goal of dose optimization for patients

15 RADIATION SAFETY IN PERIOPERATIVE PRACTICE reflects the fundamental assumptions of the linear-no- the record that could help reduce patients’ risk of radiation threshold model: that any level of radiation exposure increases injury, such as fluoroscopic time or the area that was the risk of stochastic effects such as cancer, and that risk irradiated, this information should be reported to the treating increases in direct proportion with increased dose.30 To physician. Second, measures to protect patients from optimize radiation doses, health care providers must assess a radiation exposure should be documented in the patient’s radiation history, screen for pregnancy and acute or perioperative nursing record.7 Third, during procedures chronic conditions that could contraindicate the use of such as invasive fluoroscopy, ionizing radiation doses ionizing radiation, and then minimize radiation doses to the should be continually monitored and recorded.57 This extent possible while maintaining image quality or the desired practice allows clinicians to assess the total dose received and therapeutic benefit.57,58 In the case of CT, for example, this to assess the risk of deterministic effects such as cutaneous could mean incrementally reducing the dose while altering radiation injury. one parameter at a time.58 Patients also should be screened before undergoing procedures that use ionizing radiation to ensure they do not have substantial amounts of residual radioactive material in their bodies, such as from recent procedures involving nuclear medicine or radiation oncology.7 If significant amounts of material remain, it may be necessary to delay additional procedures in which ionizing radiation is used.

Perioperative nurses and other team members play an essential role in protecting patients from unnecessary or excessive doses of ionizing radiation. AORN recommends that perioperative team members develop evidence-based policies and procedures to minimize radiation exposure for patients and to protect patients from unnecessary radiation exposure.7 This should be done in collaboration with the In addition, all reasonable efforts should be made to reconcile radiation safety staff and members of the radiology incorrect needle, sponge, or instrument counts before imaging department at the health care facility. is used to try to locate missing items.7 If imaging must be used AORN further recommends that safety policies and for this purpose, total exposure time should be kept to a procedures specify who in the health care facility has authority minimum. and is responsible for radiation safety, how the facility will Radiation exposure also should be minimized for patients by protect patients and staff from unnecessary exposure to keeping all extraneous body parts out of the primary radiation radiation, and what procedures to use when handling and beam and by placing lead shielding between the radiation disposing of tissue and body fluids that may be radioactive.7 source and the patient to help prevent radiation injury.7 Lead These protocols should also specify requirements for wearing shielding should not be placed under the patient so that the radiation monitoring devices and schedules for testing leaded patient is between the lead shield and the radiation source, as protective devices. this practice can actually increase radiation exposure by The nursing record serves as an important means of protecting increasing scatter.1 Lead shielding also should be used to patients from unnecessary or excessive ionizing radiation protect the patient’s ovaries or testes and to protect the exposure. First, perioperative nurses should study their thyroid.7 In addition, female patients of reproductive age patients’ medical records and note whether they have should be asked about the possibility of pregnancy. undergone fluoroscopy or other diagnostic or therapeutic To screen patients for acute cutaneous radiation injury, radiographic modalities. If relevant information is found in perioperative nurses should examine patients after

16 RADIATION SAFETY IN PERIOPERATIVE PRACTICE procedures to ensure that the skin is intact, smooth, and free of redness, tenderness, or blistering.7 Cutaneous radiation injuries also are associated with an increased long- term risk of squamous and basal cell carcinomas. Therefore, patients with a history of cutaneous radiation injuries should have the site examined at least annually.59

CONCLUSIONS AND RESOURCES Ionizing radiation has numerous potential diagnostic and therapeutic benefits, and its role in the perioperative practice setting continues to expand. However, the improper use of ionizing radiation for medical purposes carries substantial risks for patients and health care workers, the most serious of which is cancer. Perioperative nurses play an essential role in protecting patients and staff from unnecessary or excessive exposure to ionizing radiation. Because of this, perioperative nurses need to fully understand the clinical effects of ionizing radiation and the risks and benefits of various radiologic modalities. Radiation safety programs establish practices to minimize occupational exposure to ionizing radiation, optimize radiation doses for patients, monitor radiation exposure levels, and promote patient and staff safety at all times when ionizing radiation is used. AORN has published several online tools designed to help health care organizations develop and implement radiation safety programs. These include a customizable manual of policies and procedures for reducing radiation exposure in the perioperative practice setting and an evaluation tool that provides performance criteria for perioperative nurses and designated radiation representative or radiation safety officers. These tools are available at the AORN website. • A Policy and Procedure Manual • Radiation Safety Evaluation Tool

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GLOSSARY ALARA - an acronym for As Low As Reasonably Achievable. This is a radiation safety principle for minimizing radiation doses and releases of radioactive materials by employing all reasonable methods. ALARA is not only a sound safety principle, but is a regulatory requirement for all radiation safety programs. Centigray - the international system (SI) unit of radiation dose expressed in terms of absorbed energy per unit mass of tissue. A centigray is 1 hundredth of a Gray, which is the unit of absorbed dose and has replaced the rad. 1 gray = 1 Joule/kilogram and also equals 100 rad. Deterministic effects - health effects, the severity of which varies with the dose and for which a threshold is believed to exist. Deterministic effects generally result from the receipt of a relatively high dose over a short time period. Skin erythema (reddening) and radiation-induced cataract formation is an example of a deterministic effect (formerly called a nonstochastic effect). Declared pregnant woman - a woman who is also a radiation worker and has voluntarily informed her employer, in writing, of her pregnancy and the estimated date of conception. Ependymomas - the most common primary tumor of the spinal cord (especially in adults) and the third most common pediatric CNS tumor. Gray - the international system (SI) unit of radiation dose expressed in terms of absorbed energy per unit mass of tissue. A Gray is the unit of absorbed dose and has replaced the rad. 1 gray = 1 Joule/kilogram and also equals 100 rad. Ionization - the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes. Ionizing radiation - radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from the orbit of an atom, causing the atom to become charged or ionized Isotope - one of two or more atoms with the same number of protons, but different numbers of neutrons in their nuclei. Thus, carbon-12, carbon-13, and carbon-14 are isotopes of the element, carbon, the numbers denoting the mass number of each isotope. Isotopes have very nearly the same chemical properties, but often have different physical properties. For example, carbon-12 and carbon-13 are stable; carbon-14 is unstable, that is, it is radioactive. A radioisotope is an unstable isotope of an element that decays or disintegrates spontaneously, emitting radiation. Approximately 5,000 natural and artificial radioisotopes have been identified. Linear-no-threshold model - conventionally, the cancer risk from long-lived radicals has been estimated by use of the linear no-threshold theory (LNT). For example, it is assumed that the cancer risk from 0.001 Sv (100 mrem) of dose is 0.001 times the risk from 1 Sv (100 rem). mrems – also called millirem. One thousandth of a rem. Optically stimulated luminescent (OSL) dosimeter - a personal radiation monitoring device similar to the thermoluminescence dosimeter but using aluminum oxide to absorb the energy of x-rays and a laser rather than heat to release the stored energy and measure the dose of ionizing radiation received. Rad - the original unit developed for expressing absorbed dose, which is the amount of energy from any type of ionizing radiation (e.g., alpha, beta, gamma, neutrons, etc.) deposited in any medium (e.g., water, tissue, air). A dose of one rad is equivalent to the absorption of 100 ergs (a small but measurable amount of energy) per gram of absorbing tissue. The rad has been replaced by the gray in the SI system of units (1 gray = 100 rad). Radiation safety officer - a person who has the knowledge and responsibility to apply appropriate regulations for protection against radiation and who assures that radioactive materials possessed under the license conform to the materials authorized by the license. Radio-frequency identification (RFId. - the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to objects.

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Radionuclide - a radioisotope. Rem (Roentgen Equivalent Man) - a unit in the traditional system of units that measures the effects of ionizing radiation on humans. Scatter exposure - exposure from radiation that, during its passage through a substance, has been changed in direction. It may also have been modified by a decrease in energy. It is one form of secondary radiation. Stochastic effects - effects that occur by chance and which may occur without a threshold level of dose, whose probability is proportional to the dose and whose severity is independent of the dose. In the context of radiation protection, the main stochastic effect is cancer.

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23. Wang K, Pan L, Che X, Lou M. Gamma knife surgery-induced ependymoma after the treatment of meningioma - a case report. Neurol Neurochir Pol. 2012;46(3):294-296. 24. Motaganahalli R, Martin A, Feliciano B, Murphy MP, Slaven J, Dalsing MC. Estimating the risk of solid organ malignancy in patients undergoing routine computed tomography scans after endovascular aneurysm repair. J Vasc Surg. 2012;56(4):929-937. 25. Yoshinaga S, Mabuchi K, Sigurdson AJ, Doody MM, Ron E. Cancer risks among radiologists and radiologic technologists: review of epidemiologic studies. Radiology. 2004;233(2):313-321. 26. Sperling K, Neitzel H, Scherb H. Evidence for an increase in trisomy 21 (Down syndrome) in Europe after the Chernobyl reactor accident. Genet Epidemiol. 2012;36(1):48-55. 27. Sperling K, Pelz J, Wegner RD, Dörries A, Grüters A, Mikkelsen M. Significant increase in trisomy 21 in Berlin nine months after the Chernobyl reactor accident: temporal correlation or causal relation? BMJ. 1994;309(6948):158-162. 28. Jacquet P. Sensitivity of germ cells and embryos to ionizing radiation. J Biol Regul Homeost Agents. 2004;18(2):106-114. 29. Wieseler KM, Bhargava P, Kanal KM, Vaidya S, Stewart BK, Dighe MK. Imaging in pregnant patients: examination appropriateness. Radiographics. 2010;30(5):1215-1229. 30. Shah DJ, Sachs RK, Wilson DJ. Radiation-induced cancer: a modern view. Br J Radiol. 2012;85(1020):e1166- e1173. 31. Part 20: standards for protection against radiation. nited Stateshttp://www.nrc.gov/reading-rm/doc- collections/cfr/part020/full-text.html. Updated May 23, 2014. Accessed June 16, 2014. 32. Alvarado R, Booth JT, Bromley RM, Gustafsson HB. An investigation of image guidance dose for breast radiotherapy. J Appl Clin Med Phys. 2013;14(3):4085. 33. Miralbell R, Doriot PA, Nouet P, Rouzaud M. X-ray dose to the skin in patients undergoing percutaneous transluminal coronary angioplasty. Catheter Cardiovasc Interv. 2000;50(3):300-306. 34. Occupational Safety & Health Administration. Physical Hazards. https://www.osha.gov/dte/library/industrial_hygiene/industrial_hygiene.html. Accessed July 29, 2014. 35. AAPM report no. 124: a guide for establishing a credentialing and privileging program for users of fluoroscopic equipment in healthcare organizations. College Park, MD: American Association of Physicists in Medicine. 2012. http://www.aapm.org/pubs/reports/RPT_124.pdf. Accessed July 8, 2013. 36. National Cancer Institute. Interventional fluoroscopy: reducing radiation risks for patients and staff. http://www.cancer.gov/cancertopics/causes/radiation/interventionalfluoroscopy/page1 Accessed July 10, 2013. 37. Harrington D. Imaging devices. In: Dyro J, ed. Clinical engineering handbook. Burlington: Elsevier Academic Press; 2004:392-400. 38. Shoaib A, Rethnam U, Bansal R, De A, Makwana N. A comparison of radiation exposure with the conventional versus mini C arm in orthopedic extremity surgery. Foot Ankle Int. 2008;29(1):58-61. 39. Giordano BD, Ryder S, Baumhauer JF, DiGiovanni BF. Exposure to direct and scatter radiation with use of mini-c- arm fluoroscopy. J Bone Joint Surg Am. 2007;89(5):948-952. 40. Mulconrey DS. Fluoroscopic radiation exposure in spinal surgery: in vivo evaluation for operating room personnel. J Spinal Disord Tech. 2013 Nov 7. [Epub ahead of print] 41. Nollert G, Wich S. Planning a cardiovascular hybrid operating room: the technical point of view. Heart Surg Forum. 2009;12(3):E125-130. 42. Bartal G, Vano E, Paulo G, Miller DL. Management of patient and staff radiation dose in interventional radiology: current concepts. Cardiovasc Intervent Radiol. 2014;37(2):289-298. 43. Resch TA, Acosta S, Sonesson B. Endovascular techniques in acute arterial mesenteric ischemia. Semin Vasc Surg. 2010;23(1):29-35.

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44. Martin CJ. Optimisation in general radiography. Biomed Imaging Interv J. 2007;3(2):e18. 45. Orringer DA, Golby A, Jolesz F. Neuronavigation in the surgical management of brain tumors: current and future trends. Expert Rev Med Devices. 2012;9(5):491-500. 46. Lee MW, De Salles AA, Frighetto L, Torres R, Behnke E, Bronstein JM. Deep brain stimulation in intraoperative MRI environment - comparison of imaging techniques and electrode fixation methods. Minim Invasive Neurosurg. 2005;48(1):1-6. 47. Expert Panel on MR Safety, Kanal E, Barkovich AJ, et al. ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging. 2013;37(3):501-530. 48. Stokowski LA. Ensuring safety for infants undergoing magnetic resonance imaging. Adv Neonatal Care. 2005;5(1):14-27. 49. Johnston T, Moser R, Moeller K, Moriarty TM. Intraoperative MRI: safety. Neurosurg Clin N Am. 2009;20(2):147- 153. 50. Rahmathulla G, Recinos PF, Traul DE, et al. Surgical briefings, checklists, and the creation of an environment of safety in the neurosurgical intraoperative magnetic resonance imaging suite. Neurosurg Focus. 2012;33(5):E12. 51. NCRP report no. 160, ionizing radiation exposure of the population of the United States. http://www.ncrponline.org/Publications/Press_Releases/160press.html Accessed July 12, 2013. 52. Carpeggiani C, Landi P, Michelassi C, Marraccini P, Picano E. Trends of increasing medical radiation exposure in a population hospitalized for cardiovascular disease (1970-2009). PLoS One. 2012;7(11):e50168. 53. Meer AB, Basu PA, Baker LC, Atlas SW. Exposure to ionizing radiation and estimate of secondary cancers in the era of high-speed CT scanning: projections from the Medicare population. J Am Coll Radiol. 2012;9(4):245-50. 54. Berrington de Gonzáles A, Mahesh M, Kim KP, et al: Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009;169(22):2071-2077. 55. Radiation risks of diagnostic imaging. Sentinel Event Alert. 2011 August 24, 2011;(47):1-4. http://www.jointcommission.org/assets/1/18/sea_471.pdf. Accessed June 16, 2014. 56. Initiative to reduce unnecessary radiation exposure from medical imaging. http://www.fda.gov/Radiation- EmittingProducts/RadiationSafety/RadiationDoseReduction/default.htm Accessed June 16, 2014. 57. Miller DL, Balter S, Schueler BA, Wagner LK, Strauss KJ, Vañó E. Clinical radiation management for fluoroscopically guided interventional procedures. Radiology. 2010;257(2):321-332. 58. Goldman AR, Maldjian PD. Reducing radiation dose in body CT: a practical approach to optimizing CT protocols. AJR Am J Roentgenol. 2013;200(4):748-754. 59. Ward KA, Jaimes JP, Coots NV. Cutaneous manifestations of acute radiation exposure: a review. Int J Dermatol. 2012;51(11):1282-1291.

22 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

POST-TEST RADIATION SAFETY IN PERIOPERATIVE PRACTICE Multiple choice. Please choose the word or phrase that best completes the following statements.

1. Ionizing radiation is useful for diagnostic radiology 6. In health care settings, the primary occupational because source of radiation exposure is a. it can harm cells. a. lasers. b. it is of low frequency. b. direct beam radiation. c. it can penetrate tissue. c. MRI scanners. d. it is absorbed by lead. d. scatter. 2. Choose the TRUE statement 7. Lead shielding should be used a. Only pregnant women are at risk from ionizing a. only at the discretion of a surgeon or radiation exposure. radiologist. b. The risks of adverse effects from ionizing b. whenever possible to attenuate radiation. radiation exposure decrease with increasing c. if a patient or staff person requests it. dose. d. if an ionizing radiation dose to a patient is c. Anyone exposed to ionizing radiation can have expected to exceed 20 rem. adverse effects. 8. A 0.25 mm lead apron will reduce scattered x-rays d. There is a minimum (safe) threshold for by approximately exposure to ionizing radiation. a. 15%. 3. The primary occupational source of ionizing b. 25%. radiation exposure in health care facilities is c. 50%. a. carelessness d. 95%. b. incorrect positioning of equipment 9. Average cumulative radiation exposure has c. scatter ______in the past several decades as a result d. lack of following radiation protocols of changes in medical applications of ionizing 4. The three fundamental principles of radiation safety radiation. are a. decreased a. regulations, protocols, and consistency. b. increased b. measure, protect, and report. c. remained about the same c. aprons, dosimeters, and leaded walls. d. time, distance, and shielding. 10. A person who works with radiation is required to be 5. Ionizing radiation doses should be monitored if a. monitored only if the radiation worker is a a. he or she asks to be. minor or is older than 50 years. b. his or her annual dose is likely to exceed 15 b. administered at the highest level necessary, mrem. regardless of a patients’ exposure history. c. he or she is likely to exceed 10% of the dose c. kept as low as reasonably achievable. limit. d. monitored only if the radiation worker is d. he or she is likely to exceed 50% of the dose pregnant. limit.

23 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

11. For adults who work with radiation, the annual 18. Badges worn by pregnant personnel should be worn occupational whole body dose limit is at waist level and read every a. 5 rems. a. week. b. 15 rems. b. month. c. 50 rems. c. three months. d. 500 rems. d. six months. 12. For adults who work with radiation, the annual dose 19. If a health care worker who works with radiation limit for the skin/extremities is becomes pregnant, she should a. 5 rems. a. stop working with any form of radiation. b. 15 rems. b. promptly inform the radiation safety officer. c. 50 rems. c. wear a badge at waist level outside her apron. d. 500 rems. d. switch from a lead apron to a lead-free alternative for comfort. 13. For adults who work with radiation, the annual dose limit for the lens of the eye is 20. The most serious long-term effect of ionizing a. 5 rems. radiation exposure is b. 15 rems. a. blindness. c. 50 rems. b. osteoporosis. d. 500 rems. c. cancer. d. skin injuries. 14. For minors who work with radiation, the annual dose limit is 21. To minimize patients’ risk of adverse effects from a. 10% of adult dose limits. radiation exposure, perioperative nurses should do b. 50% of adult dose limits. all of the following except c. 75% of adult dose limits. a. keep extraneous body parts out of the primary d. 150% of adult dose limits. radiation beam. b. place lead shielding between the radiation 15. The dose limit for a fetus is source and the patient. a. 0.5 rem during the entire pregnancy. c. place lead shielding on the opposite side of the b. 0.5 rem per month. patient from the radiation source. c. 5 rem during the entire pregnancy. d. check medical records before radiographic d. 5 rem per month. procedures to ensure patients do not have 16. The linear-no-threshold model assumes that the substantial amounts of residual radioactive stochastic effects of radiation material in their bodies. a. are inversely proportional to the dose. 22. Radiation dose limits for members of the public are b. are directly proportional to the dose. ______rem per year and less than c. occur only after a certain level of cumulative ______rem in any hour. exposure. a. 0.1, 0.002 d. increase exponentially as exposure increases. b. 1, 0.02 17. All of the statements about the proper use of c. 5, 1 dosimeters (badges) in the workplace are TRUE d. 10, 20 except for. a. When one dosimeter is used, all personnel should wear it at the same place on the body. b. Badges should be exchanged for assessment and replaced at pre-determined intervals. c. Badges should not be taken home at the end of the workday. d. The best place to leave a badge when not in use is on an apron.

24 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

23. Select the TRUE statement about appropriate 27. Which cell type or tissue is least sensitive to the handling of shielding garments. effects of ionizing radiation? a. Protective garments should be discarded a. Neurons. annually b. Bone marrow. b. Leaded eyewear is not indicated unless c. Gonads. personnel are within 6 inches of the primary d. Embryonic cells. beam. 28. According to American College of Radiology c. Protective garments can be evaluated for guidelines on magnetic resonance (MR) safety, damage by lining them up and scanning them a. patients and non-MR staff should be allowed to on a CT table. travel freely through Zone II. d. RFIDs contribute to radioactivity and should b. patients and non-MR staff should have not be used in equipment protecting against unrestricted access to Zone III. radioactivity. c. non-MR staff should have access to Zone II as 24. According to the 2013 American College of long as they are wearing a dosimeter. Radiology guidelines on MR safety, d. access to Zones III and IV should be severely a. all clinical and research MR sites should restricted because of the risk of injury or death maintain MR safety policies. from magnetic interactions with ferromagnetic b. an MR medical director should be designated to materials. ensure that safety guidelines are established and 29. A woman undergoes standard thoracic radiographs updated. (x-rays) for a chronic cough and enlarged left c. the MRI suite should be a zero tolerance zone cervical lymph node. Her prior exposure to ionizing where adverse events, MR safety incidents, or radiation is minimal. The woman later determines near accidents are promptly reported to the MR that she was approximately 10 days pregnant when medical director. the radiographs were taken. This woman most likely d. All of the above. has a 25. Select the behavior or practice that does not conform a. substantially increased risk of later developing with the radiation safety principles of time, distance, cancer. and shielding. b. very small increased risk of later developing a. Wear a lead-free (lead alternative) garment to cancer. protect against direct beam exposure. c. substantially increased risk of spontaneous b. Stand on the image detector side of the abortion. fluoroscopy system, away from the tube. d. substantially increased risk of having a child c. Shield the upper legs when standing near the with a hereditary defect, such as trisomy 21 radiation beam. (Down’s syndrome). d. Stand facing the radiation source or wear a 30. When distance from the point source of radiation wrap-around apron. doubles, ionizing radiation exposure is 26. Which is not an appropriate way to decrease approximately exposure to ionizing radiation from patients? a. one quarter of the previous level. a. Shield syringes containing radioactive b. one third of the previous level. microspheres (eg, seeds, microbeads). c. the same as before. b. Follow universal precautions when patients are d. twice the previous level. treated with I-131 for thyroid cancer. c. When patients have undergone diagnostic nuclear medicine studies, handle their body fluids and tissues the same way as for any invasive procedure. d. Label sentinel lymph node biopsy specimens as radioactive in accordance with facility policies.

25 RADIATION SAFETY IN PERIOPERATIVE PRACTICE

POST-TEST ANSWERS

RADIATION SAFETY IN PERIOPERATIVE PRACTICE

0 a 30.

9 b 29.

8 d 28.

7 a 27.

6 c 26.

5 a 25.

4 d 24.

3 c 23.

2 a 22.

1 c 21.

0 c 20.

9 b 19.

8 b 18.

7 d 17.

6 b 16.

5 a 15.

4 a 14.

3 b 13.

2 c 12.

1 a 11.

0 c 10.

.b 9.

.d 8.

.b 7.

.d 6.

.c 5.

.d 4.

.c 3.

.c 2. .c 1.