Radiation Safety

Purpose

This document provides guidance for preventing patient and health care worker injury from exposure to medical ionizing radiation during therapeutic, diagnostic, or interventional procedures performed in the perioperative environment. Guidance is included on protective measures related to the administration of radionuclides and radiopharmaceuticals; this guidance applies to patients, perioperative team members, and caregivers of patients who are treated with radionuclides or have radiopharmaceuticals circulating in their bloodstream.

Medical radiation exposure occurs

• in most perioperative specialties (eg, trauma, cardiac, neurosurgery, orthopedics, urology, vascular, podiatry)^1-3 ;

• in various settings (eg, operating rooms [ORs], hybrid ORs, ambulatory surgery centers, inpatient and outpatient endoscopy suites, physician offices, interventional radiology suites, cardiac catheterization laboratories)³ ; and

• in the community (eg, when a patient has brachytherapy implants).⁴ 

Studies have demonstrated that medical ionizing radiation can have adverse effects on the human body.^5-7  The adverse effects of radiation are classified as tissue reactions (previously known as deterministic effects) or stochastic effects. Tissue reactions from radiation (eg, radiation burns, radiation dermatitis, skin erythema, hair loss, cataract formation, infertility, circulatory disease) appear at various times after the exposure.^4,7-10  The reactions ranged in severity from skin rashes and epilation to necrosis of the skin and its underlying structures. These reactions may appear at any time, even years after the exposure.⁴  Tissue reactions frequently appear at the radiation entrance site (eg, back, neck, buttocks, anterior of the chest).⁴  Stochastic effects (eg, cancer,¹¹  genetic effects,^12-14  congenital anomalies¹⁵ ) can appear at any time after the exposure, but usually appear after several years.^10,16  Stochastic effects occur when radiation causes a mutation within the cell or cell death. For both tissue reactions and stochastic effects, the severity and type of damage are related to the dose received (ie, the greater the dose, the greater the potential for damage).¹¹ 

Patients and personnel may receive different amounts of radiation based on the

• modality used (eg, portable or fixed x-ray machine, brachytherapy seed or balloon implants, radiopharmaceuticals, intraoperative radiation therapy, mobile [eg, C-arm (eg, standard, mini), O-arm] or fixed fluoroscopy unit)^{3, 4, 10, 17, 18} ;

• procedure^1,2 ;

• operator¹⁹ ; and

• patient-specific factors (eg, gender, body mass index [BMI], disease process).^20-26 

Farah et al²⁷  reviewed the radiation doses received by 319 patients undergoing a thrombectomy after a stroke. The researchers analyzed the dose area product (DAP), cumulative air kerma (AK), fluoroscopy time, and the number of images taken. They concluded that male sex, number of passages, and success of recanalization were key parameters affecting the patient dose.

The dosage is also affected by the patient’s BMI. Researchers who studied patients undergoing coronary angiography,²⁶  fracture repairs,^23-25  fluoroscopically guided injections,^21,22  and transcatheter aortic valve replacement²⁰  have noted a significant increase in dosage corresponding to an increase in the patient’s BMI.

Pravata et al²⁸  measured the dose received by the patient and the dose received by the operator during 26 computed tomography (CT)-guided spine procedures. The researchers found that the greater the dose to the patient the greater the dose to the operator.

Although radiation doses vary by procedure and other factors, Faroux et al²⁹  found that for patients undergoing percutaneous coronary interventions, the DAP decreased for the same procedures between 2006 and 2016. Casella et al¹⁹  also found a decrease in the DAP from 2010 to 2016 for 6,095 electrophysiological and 2,055 device implantation procedures. The decrease in the dosages was believed to be related to technological advances.^19,29 

Perioperative team members are exposed to radiation from three different sources independent of the modality used. These sources include

• primary radiation, which is emitted directly by the modality;

• leakage radiation, which emanates from the x-ray modality housing; and

• scatter radiation, which is reflected off of the patient, tabletop, and shielding material.³⁰ 

The main source of radiation exposure for team members in the perioperative setting is scatter radiation, with different team members receiving varying doses during the same procedure.^31,32  The amount of radiation perioperative team members receive is affected by the direction of the beam,³³  the beam quality, the field size, the position of the person in relation to the position of the beam originator,³⁴  and the dose being administered.²⁸ 

Limitations of the evidence include a small sample size in many of the studies, and some studies offered no recommendations for action related to minimizing exposure to radiation. Many of the studies focused on the operator, usually the physician, who stands at the sterile field close to the source of radiation; other perioperative team members in the room are frequently excluded from the study data.³⁵ 

The following subjects are outside the scope of this document:

• management of radioactive specimens (See the AORN Guideline for Specimen Management³⁶ );

• safety precautions during use of magnetic resonance imaging (See the AORN Guideline for Minimally Invasive Surgery³⁷ );

• non-ionizing radiation (laser) precautions (See the AORN Guideline for Laser Safety³⁸ );

• protocols for reduction of dosage;

• safety precautions during procedures outside of the perioperative setting using gamma knife, cyber knife, or stereotactic radiosurgery;

• the informed consent process for examinations or procedures that involve radiation;

• collimation (ie, determining the size of the area of the beam);

• the principles of justification (ie, a risk-benefit assessment completed by the person requesting the radiological examination);

• precautions to be taken during positron emission tomography (PET)/CT scanning;

• selection of the C-arm orientation;

• procedural equipment selection, including use of non-radiation-emitting equipment versus radiation-emitting equipment; and

• measures to calculate or regulate the patient’s radiation dose.

Evidence Review

A medical librarian with a perioperative background conducted a systematic search of the databases Ovid MEDLINE^®, Ovid Embase^®, EBSCO CINAHL^®, and the Cochrane Database of Systematic Reviews. The search was limited to literature published in English from January 2014 through February 2020. At the time of the initial search, weekly alerts were created on the topics included in that search. Results from these alerts were provided to the lead author until April 2020. The lead author requested additional articles that either did not fit the original search criteria or were discovered during the evidence appraisal process. The lead author and the medical librarian also identified relevant guidelines from government agencies, professional organizations, and standards-setting bodies.

Search terms included abdominal radiography, accidents (occupational), advanced imaging system, ambulatory care facility, ambulatory surgery, balloon dilatation, biplane fluoroscopy, brachytherapy, burns, catheterization, cat scan, catheterization (central venous), catheterization (peripheral), catheterization (peripheral central venous), catheterization (umbilical vessels), cleaning, conceptus, CT scan, disinfection, dose area products, dosimeter, dosimetry, equipment contamination, equipment failure, extremities, fertility, fetus, fixed advanced imaging system, fluoroscopy, glasses, goggles, gonads, hazardous waste (handling/storage/transport), heart catheterization, hybrid imaging equipment, intraoperative CT scan, intraoperative radiotherapy, interventional radiography, interventional radiology, invasive procedures, iodine radioisotopes, lead apron, lead garment, lead glasses, lead goggles, lead shield, leaded apron, leaded garment, leaded glasses, leaded goggles, leaded shield, monoplane fluoroscopy, occupational hazards, occupational accident, occupational diseases, occupational exposure, occupational health, occupational injuries, occupational radiation dose, ocular radiation injury, operating room, operating room personnel, operating suite, operating theater, operating theatre, outpatient surgery, patient injuries, patient safety, pregnancy, pregnancy outcomes, protective clothing, protective gloves, radiation, radiation burn, radiation exposure, radiation (ionizing), radiation injuries, radiation monitoring, radiation parameters, radiation protection, radiation safety officer, radiation safety precautions, radiation safety procedures, radioactive pollutants, radioactive tracers, radioactive waste (handling/storage/transport), radiography, radiography (abdominal), radiography (interventional), radioisotopes, radiometry, radiopharmaceuticals, radioprotection, radiosurgery, radiotherapy, radiotherapy (intraoperative), risk assessment, staff dose, and zygote.

Included were research and non-research literature in English, complete publications, and publications with dates within the time restriction when available. Excluded were non-peer-reviewed publications and older evidence within the time restriction when more recent evidence was available. Editorials, news items, and other brief items were excluded. Low-quality evidence was excluded when higher-quality evidence was available, and literature outside the time restriction was excluded when literature within the time restriction was available (Figure 1).

Figure 1

Flow Diagram of Literature Search Results

Adapted from Moher D, Liberati A, Tetzlaff J, Atman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA Statement. PLoS Med. 2009;6(6):e1000097.

Articles identified in the search were provided to the project team for evaluation. The team consisted of the lead author and an evidence appraiser. The lead author and the evidence appraiser reviewed and critically appraised each article using the AORN Research or Non-Research Evidence Appraisal Tools as appropriate. The literature was independently evaluated and appraised according to the strength and quality of the evidence. Each article was then assigned an appraisal score. The appraisal score is noted in brackets after each reference as applicable.

Each recommendation rating is based on a synthesis of the collective evidence, a benefit-harm assessment, and consideration of resource use. The strength of the recommendation was determined using the AORN Evidence Rating Model and the quality and consistency of the evidence supporting a recommendation. The recommendation strength rating is noted in brackets after each recommendation. I

In the literature, various metrics were used to report the dose of radiation received; the abbreviations are listed in Table 1. Additional dose-related definitions are provided in the glossary.

Note: The evidence summary table is available at http://www.aorn.org/evidencetables/.

Editor’s note: MEDLINE is a registered trademark of the US National Library of Medicine’s Medical Literature Analysis and Retrieval System, Bethesda, MD. Embase is a registered trademark of Elsevier B.V., Amsterdam, The Netherlands. CINAHL, Cumulative Index to Nursing and Allied Health Literature, is a registered trademark of EBSCO Industries, Birmingham, AL.

Note: The use of x-ray equipment is regulated by each state and the use of radioactive materials in a medical setting is regulated by the Nuclear Regulatory Commission (NRC) or by the state in which the facility resides. The states that do not follow the NRC regulations are referred to as Agreement States and many have differing regulations.³⁹  Before adopting the recommendations rated as regulatory requirements in this guideline, confirm with the radiation safety officer or local authority having jurisdiction whether they apply in your location.