Radiation Protection and Regulations for the Nuclear Medicine Physician Man Yu Chen, MPH, DABSNM, CHP As authorized users of radioactive material, nuclear medicine (NM) physicians play a leading role in the use and management of these agents. Regarding patient management, NM physicians are responsible for ensuring both the appropriateness of exams and the associated patient doses. Along with radiologists, NM physicians are the ones developing and implementing processes that provide guidance to and dialog with referring physicians to ensure that patients receive the most appropriate type of imaging exams. Regarding regulatory compliance, in collaboration with radiation safety officers, NM physicians are the ones educating their staff about principles of radiation protection and radiation safety with adherence to regulations from agencies such as the Nuclear Regulatory Commission, the Department of Transportation, the Environmental Protection Agency, and the Food and Drug Administration. On occasion, these regulations and standards can be difficult to comprehend. This article is intended to serve as a condensed guide for NM physicians who are in the process of applying for a radioactive materials license, establishing a new radiation protection program, or want to ensure continued compliance and maintenance of safety and security of licensed materials in the clinical or research settings. Semin Nucl Med 44:215-228 C 2014 Elsevier Inc. All rights reserved.

Introduction

D

iagnostic imaging including radionuclide imaging has made remarkable advances in the past 3 or 4 decades. Instead of performing invasive procedures to diagnose a patient’s problem, many different imaging modalities are being used. With the increased use of radiation and radioactive materials as part of these imaging modalities, radiation hazard has progressively become a concern. To minimize radiation hazards, organizations such as the International Committee for Radiation Protection and the National Council on Radiation Protection and Measurements (NCRP) publish guidelines for the safe use of radiation and radioactive materials. The Nuclear Regulatory Commission (NRC) and state radiation control programs adapt many of these guidelines into regulations for implementation of a radiation protection program. This article describes the development, implementation, and documentation of an appropriate radiation protection program that will

Montefiore Medical Center, Bronx, NY. Address reprint requests to Man Yu Chen, MPH, DABSNM, CHP, Radiation Safety Office, 3335 Steuben Ave, 3rd floor, Bronx, NY 10467. E-mail: mchen@montefiore.org

http://dx.doi.org/10.1053/j.semnuclmed.2014.03.005 0001-2998/& 2014 Elsevier Inc. All rights reserved.

ensure the safe use of radioactive materials as well as regulatory compliance in the clinical and research settings.

Sources of Radiation Exposure As we all know, members of the public are exposed to sources of ionizing radiation. These sources of ionizing radiation could be from natural background radiation such as radon and thoron, cosmic and terrestrial radiation, or man-made radiation such as those from x-ray or nuclear medicine (NM) procedures. The NCRP first published Report 93 in 1987 addressing radiation exposure of the U.S. population from various sources. Indicated in Report 93, radiation exposure to the U.S. population consisted of a contribution of 300 mrem (3 mSv) from natural background radiation, 53 mrem (0.53 mSv) from medical exposure, and 7 mrem (0.07 mSv) from other sources (consumer products, occupational, and other sources). At that time, NM and x-ray procedures were only small components of the average annual radiation exposure of the U.S. population (approximately 15%) while most background radiation was composed of radon gas (approximately 55%). The average annual radiation exposure for the U.S. population was only 360 mrem (3.6 mSv).1 The 215

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216 percentage contribution of various radiation sources to the average total effective dose equivalent (TEDE) in the U.S. population in the 1980s is shown in Figure 1. (Note: definition of the TEDE and other terms that are referred to in this article can be found in Table 1.) With the advancement in technology, there was tremendous increase in the use of radiation and radioactive materials to diagnose and treat patients. The NCRP re-evaluated radiation exposure to the U.S. population based on data from 2006 and released Report 160 in 2009.2 Report 160 indicated a contribution of 310 mrem (3.1 mSv) from natural background radiation, 300 mrem (3.0 mSv) from medical exposure, and 10 mrem (0.1 mSv) from all other sources (consumer products, occupational, and other sources). Medical radiation exposure to the U.S. population had increased by nearly 6 times (300 mrem in Report 160 compared with 53 mrem in Report 93). The percentage contribution of various radiation sources to the average total effective dose in the U.S. population in 2006 is shown in Figure 2. The largest contribution of the U.S. population’s collective dose in 2006 was from CT and NM procedures. Together they contributed 36% of the total radiation exposure (CT approximately 24% and NM approximately 12%). This was owing to the significant increased use of CT and NM procedures in the past few decades. In fact, the number of CT and NM procedures performed annually in the 1980s was approximately 3 and 7 million, respectively. In 2006, the number of CT and NM procedures increased to approximately 67 and 18 million, respectively.1,2 Although these diagnostic imaging procedures proved to be enormously effective in assisting patient diagnosis, it also raised the question of how much radiation is considered excessive. People started to compare the benefit of imaging studies vs the risk of radiation exposure. In an effort to educate health care professionals and to help them to optimize efforts to ensure the right exam with the least dose to patients, in recent years,

Figure 1 Sources of radiation exposure in the U.S. population. The percentage contribution of various radiation sources to the average total effective dose equivalent in the U.S. population in the 1980s. (Adapted with permission from NCRP Report 93: Radiation Exposure to the Population of the United States. Bethesda, MD, NCRP, 19871: Figure 8.1, http://NCRPpublications.org.)

various radiologic organizations worked together to launch the Image Gently Campaign for pediatric patients and the Image Wisely Campaign for adult patients. The Image Gently Campaign was launched in 2008 as the Alliance for Radiation Safety in Pediatric Imaging’s initiative to educate radiology professionals that “one size does not fit all” and institutions need to reduce or “child size” the amount of radiation used when obtaining a CT scan in children.3 Following the Image Gently Campaign, the Image Wisely Campaign was launched in 2010 to encourage radiology professionals to take the responsibility to ensure the appropriateness of exams and radiation dose to patients.4 As the emphasis on the right test and right dose becomes more and more prevalent, NM physicians, along with radiologists, must assume the key role in reducing radiation exposures to both patients and staff through implementation of an effective radiation protection program.

Regulatory Bodies The use of radiation and radioactive materials is highly regulated. Among the various federal agencies that regulate the use of radiation or radioactive materials, the NRC is the one that regulates the use of radioactive (byproduct) material as well as source and special nuclear material. On the local level, many states wanted to establish their own regulations for the use of radioactive materials. As a result, many states have entered into an agreement with the NRC, which authorizes them to regulate the byproduct materials as well as naturally occurring and accelerator-produced radionuclides. The rules and regulations of these states must be at least as restrictive as those of the NRC. As of January 2014, 37 “Agreement States” exist which gives them the authority to license and inspect radioactive materials used or possessed within their borders. The NRC still regulates radioactive materials within federal agencies or federally recognized Indian tribes, the 13 nonagreement states, and the District of Columbia.5 Besides the NRC, there are other regulatory agencies that deal with other aspects of radiation and radioactive materials. The Food and Drug Administration regulates approval of radiopharmaceuticals and manufacture of x-ray equipment. The Department of Transportation (DOT) regulates transportation of radioactive materials. The Environmental Protection Agency (EPA) regulates radioactive discharges into the atmosphere and into water and recovery and disposal of radioactive wastes not regulated under the Atomic Energy Acts of 1946 and 1954. The relevant regulations from these federal agencies can be found in the code of federal regulations (CFR). NRC regulations can be found in 10 CFR, the Food and Drug Administration regulations in 21 CFR, DOT regulations in 49 CFR, and EPA regulations in 40 CFR. In addition, there are other organizations that do not publish regulations but are still, in some ways, involved in ensuring regulatory compliance. The Joint Commission, an accreditation body of medical institutions, publishes standards on the safe use of radiation and radioactive materials and expects medical institutions to be in full compliance with its established standards as well as

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Figure 2 The percentage contribution of various radiation sources to the average total effective dose in the U.S. population in 2006. (Adapted with permission from NRCP Report 160: Radiation Exposure to the Population of the United States. Bethesda, MD, NCRP, 20092: Figure 8.2, http://NCRPpublications.org.)

other applicable federal and state regulations. The American College of Radiology and the Intersocietal Accreditation Commission also maintain accreditation programs that are relevant to NM. For medical institutions to be authorized for the use of radioactive materials, they need to apply for a radioactive materials license or permit, issued from the NRC or an Agreement State. Institutions that are issued radioactive materials licenses or permits are called “licensee” by the NRC or the Agreement State. The use of radioactive materials in medical institutions is governed by the NRC mainly under title 10 of the CFR (10 CFR) parts 19 (Notices, Instructions and Reports to Workers: Inspection and Investigations), 20 (Standards for Protection Against Radiation), and 35 (Medical Use of Byproduct Material). Agreement States may have similar or different regulations regarding the medical use of radioactive materials. This article specifically discusses NRC regulations regarding their effect on NM. Licensees that are regulated by an Agreement State need to check their own state regulations to ensure regulatory compliance.

The 10 CFR 19—Notices, Instructions and Reports to Workers: Inspection and Investigations The 10 CFR 19 addresses requirements for posting of “Notice to Employees,” instructions to employees and reports of radiation exposure to workers. The licensee is required to post NRC Form 3 “Notice to Employees,” emergency procedures, any Notice of Violations, the license, license conditions, documents incorporated into

a license by reference, amendments, and operating procedures applicable to licensed activities and NRC regulations. If posting is not practicable, the licensee may post a notice to inform workers where these documents can be found. The NRC requires that all individuals who can potentially receive an occupational dose of more than 100 mrem (1 mSv) in a year need to be kept informed and instructed by the licensee on radiation or radioactive material with which they are working, any potential health concerns associated with exposure to radiation or radioactive material, institutional policies and procedures to minimize exposure, protective devices that are available to workers and how to operate these devices, the applicable provisions of NRC regulations and licenses, and appropriate response to emergencies involving radiation or radioactive materials. Workers also need to be instructed of their responsibilities to report promptly to the licensee any condition that may lead to or cause a violation of NRC regulations and license conditions or unnecessary exposure to radiation or radioactive material. The licensee is required to provide an annual exposure report to individuals monitored under 10 CFR 20.1502 if the individual’s annual occupational dose exceeds 100 mrem (1 mSv) TEDE or 100 mrem (1 mSv) to any individual organ or tissue, or if the individual requests his or her annual dose report.6

The 10 CFR 20—Standards for Protection Against Radiation The 10 CFR 20 addresses the standard for protection against radiation, which includes dose limits to the general public and

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218 Table 1 Definitions of Terms Absorbed dose Quality factor (Q)

The energy imparted by ionizing radiation per unit mass of irradiated material. The modifying factor (listed in tables 1004(b).1 and 1004(b).2 of §20.1004) that is used to derive dose equivalent from absorbed dose. Is the product of the absorbed dose in tissue, quality factor, and all other necessary modifying Dose equivalent (HT) factors at the location of interest. Deep-dose equivalent (Hd) The dose equivalent at a tissue depth of 1 cm (1000 mg/cm2). Shallow-dose equivlent (Hs) It applies to the external exposure of the skin of the whole body or the skin of an extremity and is the dose equivalent at a tissue depth of 0.007 cm (7 mg/cm2). Lens dose equivalent (LDE) Applies to the external exposure of the lens of the eye and is the dose equivalent at a tissue depth of 0.3 cm (300 mg/cm2). Committed dose equivalent The dose equivalent to organs or tissues of reference (T) that will be received from an intake of (HT,50) radioactive material by an individual during the 50-y period following the intake. Weighting factor (WT) The proportion of the risk of stochastic effects resulting from irradiation of that organ or tissue to the total risk of stochastic effects when the whole body is irradiated uniformly. Committed effective dose The sum of the products of the weighting factors applicable to each of the body organs or tissues equivalent (HE,50) that are irradiated and the committed dose equivalent to these organs or tissues (HE,50 ¼ ΣWTHT.50). Total effective dose equivalent The sum of the effective dose equivalent (for external exposures) and the committed effective dose (TEDE) equivalent (for internal exposures). Collective dose The sum of the individual doses received in a given period by a specified population from exposure to a specified source of radiation. Annual limit on intake (ALI) The derived limit for the amount of radioactive material allowed to be taken into the body of an adult worker by inhalation or ingestion in a year. Derived air concentration (DAC) Is the concentration of a given radionuclide in air that results in an intake of one ALI for a reference man working under light-work condition for a working year of 2000 h. Written directive A written order by the authorized user for administration of any therapeutic dose or dosage of a radionuclide or any dosage of quantities 430 mCi (1.11 MBq) of sodium iodide I-131 to a patient or human research subject. Occupational dose The dose received by an individual in the course of employment in which the individual’s assigned duties involve exposure to radiation or to radioactive material from licensed and unlicensed sources of radiation, whether in the possession of the licensee or other person. Occupational dose does not include doses received from background radiation, from any medical administration the individual has received, from exposure to individuals administered radioactive material and released under §35.75, from voluntary participation in medical research programs, or as a member of the public. Declared pregnant woman A woman who has voluntarily declared her pregnancy and estimated date of conception to the licensee in writing. Controlled area Is an area, outside of a restricted area but inside the site boundary, access to which can be limited by the licensee for any reason. Nationally tracked source A sealed source containing a quantity equal to or greater than category 1 or category 2 levels of any radioactive material listed in Appendix E of 10 CFR 20. Adapted with permission from 10 CFR 20.1003 Definitions.

radiation workers, As Low As Reasonably Achievable (ALARA) concept, security of radioactive materials, signage and posting requirements, radioactive materials labeling and handling of package, record keeping, and reporting requirements.7

The 10 CFR 35—Medical Use of Byproduct Material The 10 CFR 35 addresses requirements on medical use of radioactive (byproduct) material, which include training and experience requirements on authorized users (AUs), radiation safety officers (RSOs), authorized nuclear pharmacists (ANPs), and authorized medical physicists (AMPs). AU is an individual identified by the NRC or the Agreement State license who is authorized to use radioactive material. Part 35 also addresses specific requirements on administration of radioactive

materials to patients and human research subjects and any radiation safety concerns because of such administration.8

Licensing Requirements Authorization for medical use of radioactive material is granted by issuance of a license by the NRC or an Agreement State. The rules applicable to domestic licensing of radioactive material can be found in 10 CFR 33. NUREG-1556, Volume 9, Revision 2, Consolidated Guidance About Material Licenses, Program-Specific Guidance About Medical Use Licenses provides further guidance on how to prepare a medical-use license application. To apply for a radioactive materials license, an original and a copy of NRC Form 313, “Application for Material License,” which includes the facility diagram, equipment, and training and experience qualifications of the RSO,

Radiation protection and regulations for the nuclear medicine physician AU(s), AMP(s), and ANP(s) as well as procedures required by §35.610, 35.642, 35.643, and 35.645, as applicable, need to be submitted by the institution to the NRC.5,9

Types of Licenses There are 2 types of specific licenses issued by the NRC for medical use of radioactive material in medical practices and facilities: specific license of limited scope and the specific license of broad scope. Limited scope license can be issued to private or group medical practices and to medical institutions for specific use of limited quantities of radioactive materials in humans. For specific licenses of limited scope, AU(s) are specifically listed on the license. Specific licenses of limited scope require a RSO to manage the radiation protection program but do not require a Radiation Safety Committee to be established (often times, a properly trained NM physician takes on the role of the RSO on a limited scope license). For a specific license of limited scope, the licensee must apply for and receive a license amendment: (1) before anyone is permitted to work as an AU, ANP, or AMP under the license, except those individuals who meet the board certification and recent training requirement outlined in part 35, or individuals who are recognized as AUs on a NRC or Agreement State license or other equivalent permit or license recognized by the NRC; (2) before it changes RSO(s), except as temporary RSO; (3) before it receives radioactive material in excess of the amount or in a different form or receives a different radionuclide than is authorized on the license; and (4) before it adds to or changes the physical areas of use identified in the application or on the license. If the AU applicant is board certified or previously authorized by a license from the NRC or an Agreement State, the individual is permitted to work as an AU as long as the licensee provides the NRC the necessary documentation no later than 30 days after the individual starts to work as an AU. The necessary document includes a copy of the board certification and the written attestation(s) signed by a preceptor, or the NRC, or the Agreement State license or permit indicating the individual as previous AU. A licensee is required to notify NRC no later than 30 days after the following situations: (1) discontinuation of duty of an AU, an ANP, a RSO, or an AMP; (2) an AU or an individual qualified to be a RSO is permitted to function as a temporary RSO and to perform the functions of a RSO; (3) the licensee’s mailing address changes; (4) the licensee’s name changes, if the name change does not constitute a transfer of control of the license; or (5) adding or changing the physical areas of use identified in the application or on the license. Specific license of broad scope is exempted from these limited scope provisions. Therefore, the aforementioned

219 license amendment or notification to the NRC is not required. For a broad scope license, a Radiation Safety Committee and a RSO are required to implement and monitor all aspects of radiation safety in the use and disposal of radioactive material. Under the broad scope license, the RSO is responsible for establishment, implementation, and maintenance of the radiation protection program. The institution may choose to have the RSO and Radiation Safety Committee be responsible for all uses of ionizing radiation, including both radioactive materials and x-ray-producing equipment. Responsibilities of the RSO include the following: investigation of overexposure, accidents, spills, losses, thefts, medical events (a new term for misadministration), and unauthorized receipts, uses, and transfers. If deficiencies or violations are identified, corrective action needs to be implemented. In addition, the RSO must establish and enforce policies and procedures for order, receipt, storage, transfer, and disposal of radioactive material and conduct periodic checks of radiation-related activities. The Radiation Safety Committee oversees the use of licensed materials and acts on behalf of the NRC or the Agreement State to approve individual users to conduct specific protocols using radioactive materials or add to or change areas of use of radioactive material as identified on the license. The Radiation Safety Committee uses the same criteria as the NRC or the Agreement State for approving or disapproving these changes. The Radiation Safety Committee needs to consist of at least one user for each type of use permitted by the license, the RSO, a representative from nursing, and a representative from management. Additional members may be included as per the institution’s discretion. The committee is required to meet at least quarterly to evaluate all proposals for research, diagnostic, and therapeutic uses of radiation and review and recommend radiation safety procedures according to the ALARA concept. At least annually, the RSO needs to report to the Radiation Safety Committee and senior management on the performance of the radiation protection program.

Regulations Pertaining to NM in 10 CFR 35 There are 7 categories of medical uses of radioactive (byproduct) material as defined in 10 CFR 35. Of the 7 categories, 4 pertain to NM: §35.100 use of unsealed byproduct material for uptake, dilution, and excretion studies for which a written directive is not required, §35.200 use of unsealed byproduct material for imaging and localization studies for which a written directive is not required, §35.300 use of unsealed byproduct material for which a written directive is required, and §35.1000 use of other medical uses of byproduct material or radiation from byproduct material. Examples of use authorized under §35.100 and 35.200 include general NM and nuclear cardiology studies such as brain scan, liver scan, kidney scan, lung ventilation-perfusion scan, rest-stress test, thyroid uptake and scan, parathyroid scan, and PET/CT scan. Examples of use authorized under §35.300 include administration of a radioactive material to treat or palliate a particular disease, such as I-131 sodium iodide for treatment of hyperthyroidism or ablation of thyroid cancer metastasis, Sr-89 and Sm-153 for palliation of bone pain in patients with cancer, and Ra-223 for treatment of prostate

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220 cancer. Example of use authorized under §35.1000 includes SIR-Sphere therapy treatment for hepatic tumors.

Training Requirements for AU There are different training requirements for proposed AU (s) applying for the uses authorized under §35.100, 200, 300, and 1000. AU applicants must have successfully completed the applicable training and experience criteria within 7 years preceding the date of the application. General training requirements for AU applying for the uses authorized under §35.100, 35.200, and 35.1000 are as follows: except as provided in §35.57, an AU of unsealed radioactive material needs to be a physician who is certified by a medical specialty board whose certification process has been recognized by the NRC or an Agreement State and who meets the requirements or has completed the specified hours of didactic training and work experience under an AU and obtained written attestation, signed by a preceptor AU. AU applicants applying for the uses authorized under §35.100 and 35.200 need to fill out NRC form 313A(AUD). AU applicants applying for the uses authorized under §35.1000 need to meet the criteria in §35.490 and 35.290 including supervised work experience under the supervision of a §35.490 AU and preceptor. Training requirements for applying for the uses authorized under §35.390 use of unsealed byproduct material for which a written directive is required, §35.392 oral administration of sodium iodide I-131 requiring a written directive in quantities less than or equal to 33 mCi (1.22 GBq), §35.394 oral administration of sodium iodide I-131 requiring a written directive in quantities greater than 33 mCi (1.22 GBq), and §35.396 parenteral administration of unsealed byproduct material requiring a written directive are as follows: an AU of unsealed byproduct material for the uses authorized under §35.300 needs to be a physician who is certified by a medical specialty board whose certification process has been recognized by the NRC or an Agreement State and who meets the requirements or has completed the specified hours of didactic training and work experience under an AU and obtained written attestation, signed by a preceptor AU. Types of classroom and laboratory training, supervised work experience, and supervised clinical case experience vary depending on what the AU applicant is applying for. In order to request authorized user status in the categories of §35.390, 392, 394, and 396, the proposed user needs to document a minimum of 3 cases of administration of radioactive drugs to patients or human research subjects in each of the categories that he or she is applying to. AU applicants applying for the uses authorized under §35.390, 392, 394, and 396 need to fill out NRC form 313A(AUT). One interesting note regarding AU is that the NRC does not require that diagnostic images or results of therapeutic procedures must be interpreted by an AU.

Radiation Protection Program To ensure regulatory compliance with relevant NRC regulations, the licensee needs to develop and implement an

institutional radiation protection program. Elements of a radiation protection program include signage and posting; dose limits for the general public; occupational dose program (ALARA); area surveys; sealed source inventory and leak testing; ordering, receiving, and opening of packages; patient dosage determination and preparation; minimization of contamination and spills; waste decay in storage and disposal; reporting; record keeping; and audits of the radiation protection program.7

§20.1902 Posting Requirements Licensee is required to post signage, if applicable, to warn people of possible hazards from the presence of radiation or radioactive material. The appropriate postings for areas that require signage are shown in Table 2. (1) Unrestricted area means an area that the licensee does not limit or control access to. The dose from external sources in an unrestricted area does not exceed 0.002 rem (0.02 mSv) in any given hour. Note that it is acceptable for an unrestricted area to have a potential for a dose rate of 40.002 rem/h (0.02 mSv/h) as long as the total dose does not exceed 0.002 rem (0.02 mSv) in any given hour. Restricted area means an area that the licensee limits or controls access to for the purpose of protecting individuals against undue risks from exposure to radiation and radioactive materials. Restricted area is defined as one where the dose from external

Table 2 Signage and Posting Areas That Require Posting

Restricted area

Radiation area

High-radiation area

Very high-radiation area

Area where 410 times the quantity of licensed material specified in Appendix C to 10 CFR part 20 is used or stored

Examples of Appropriate Posting

Radiation protection and regulations for the nuclear medicine physician

(2)

(3)

(4)

(5)

sources could be greater than 0.002 rem (0.02 mSv) in any given hour. Radiation area means an area in which an individual can potentially receive a dose equivalent in excess of 0.005 rem (0.05 mSv) but less than 0.1 rem (1 mSv) in 1 hour at 30 cm from either the radiation source or any surface that the radiation penetrates. Such posting may not be necessary in most clinical NM settings except perhaps when a phantom is being imaged or a research project is in progress. High-radiation area means an area in which an individual can potentially receive a dose equivalent in excess of 0.1 rem (1 mSv) in 1 hour at 30 cm from either the radiation source or any surface that the radiation penetrates. Such posting is very uncommon in a clinical NM setting. Very high-radiation area means an area in which an individual can potentially receive an absorbed dose in excess of 500 rads (5 grays) in an hour at 1 m from either a radiation source or any surface that the radiation penetrates. Such posting is very uncommon in a clinical NM setting. “CAUTION, RADIOACTIVE MATERIAL(S)” sign is for an area or a room in which more than 10 times the quantity of licensed material specified in Appendix C to part 20 is used or stored. For example, “CAUTION, RADIOACTIVE MATERIAL(S)” sign is needed if more than 10 mCi (370 MBq) of Tc-99 m or 10 mCi (370 kBq) of I-131 is used or stored in an area. The radiopharmacy (“hot lab”), injection room, imaging room, and stress lab for nuclear cardiology may require such posting.

§20.1301 Dose Limits for Individual Members of the Public Member of the public is referred to any individual except when that individual is receiving an occupational dose. The annual dose limit for the members of the public is 0.1 rem (1 mSv) TEDE. This annual dose limit does not include background radiation, medical administration, exposure from released patients, voluntary participation in medical research programs, and licensee’s disposal of radioactive materials into the sewer. When designing facilities that use radiation or radioactive materials, the licensee needs to ensure compliance with dose limits for individual members of the public in the unrestricted and controlled areas. Compliance is confirmed by performing calculations or measurements and surveys of radiation levels in unrestricted and controlled areas and radioactive materials in effluents released to these areas as appropriate.

Occupational Dose Program Occupational dose limit is covered under §20.1201 occupational dose limits for adults, §20.1207 occupational dose limits for

221 minors, and §20.1208 dose equivalent to an embryo or fetus. The annual occupational dose limit for adults is as follows: (1) The more limiting of the following: (A) TEDE equals to 5 rem (50 mSv) or (B) the sum of the deep-dose equivalent and the committed dose equivalent to any individual organ or tissue other than the lens of the eye equals to 50 rems (500 mSv). (2) The lens dose equivalent equals to 15 rem (150 mSv). (3) A shallow-dose equivalent of 50 rem (500 mSv) to the skin of the whole body or to the skin of any extremity. For minors (o18 years of age), the annual occupational dose limit is 10% of the adult occupational dose limit. For a declared pregnant woman, the occupational dose limit is 0.5 rem (5 mSv) for the entire pregnancy, with the recommendation that the woman not receiving more than 0.05 rem (0.5 mSv) in a month during her pregnancy. If by the time the woman declares her pregnancy to the licensee, the dose equivalent to the embryo or fetus has exceeded 0.5 rem (5 mSv) or is within 0.05 rem (0.5 mSv), as long as the additional dose equivalent to the embryo or fetus does not exceed 0.05 rem (0.5 mSv) during the remainder of the pregnancy, the licensee is deemed to be in compliance.

§20.1502 Conditions Requiring Individual Monitoring of External and Internal Occupational Dose The licensee is required to supply dosimeters or devices to monitor occupational exposure to radiation from radiation sources external to the body for the following: (1) adults likely to receive more than 10% of the annual occupational dose limit; (2) minor likely to receive in 1 year, a deep-dose equivalent of more than 0.1 rem (1 mSv), a lens dose equivalent of more than 0.15 rem (1.5 mSv), or a shallow-dose equivalent to the skin or to the extremities of more than 0.5 rem (5 mSv); (3) declared pregnant women likely to receive a deep-dose equivalent of more than 0.1 rem (1 mSv) during the entire pregnancy; and (4) individuals entering a high- or very high-radiation area. The annual occupational dose limit is expressed in TEDE, which represents a total risk from external and internal exposures. If workers are assigned in areas where inhalation and ingestion of radioactive material are possible, it may be necessary to assess the worker’s intake of radioactivity. The NRC requires the licensee to monitor the occupational intake of radioactive material and assess committed effective dose equivalent (CEDE) for adults likely to receive an annual intake 410% of the applicable annual limit on intake, minors likely to receive an annual CEDE 4 0.1 rem (1 mSv), and declared pregnant women likely to receive a CEDE 4 0.1 rem (1 mSv) during the entire pregnancy. If a licensee uses radioactive gas or

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222 aerosols, room ventilation needs to be evaluated based on the size of the room and the number of studies performed on a weekly basis. Concentration of the gas or aerosol in the room needs to be less than the derived air concentration (Table 1 for definition). Personnel dosimeters issued to workers need to be worn at areas of highest exposure. For individuals that might potentially receive a substantially higher dose on a specific part of the body than the whole-body dose, the licensee must evaluate the need for an additional dosimeter (e.g., ring dosimeters issued to workers who are handling and administering radiopharmaceuticals). Commonly used dosimeters for monitoring external exposures are film, optically stimulated luminescence, and thermoluminescence dosimeters. The monitoring period can be monthly or quarterly depending on the types of dosimeters and previous exposure history. These dosimeters are sent to a National Voluntary Laboratory Accreditation Program–accredited vendor for reading. As an alternative, licensees can also use pocket ion chamber or electronic dosimeters to monitor radiation exposures. The advantage of these devices is that they provide real-time readings and would be beneficial to use in incidents such as responding to an emergency. These may also be useful when implementing a new program and evaluating which component of the endeavor delivers most of the occupational dose. The disadvantage is the absence of permanent record for determining yearly compliance of exposure limits.

ALARA Program Licensee must not only aim for maintenance of regulatory compliance by keeping worker’s exposure below the annual occupational dose limit but also should strive to keep radiation exposure ALARA. ALARA is a concept from the NRC that urges licensees to make a reasonable effort to maintain individual and collective radiation exposure as low as possible. This means that the institutional operational dose limit for any radiological activity needs to be more restrictive, if possible, than the occupational dose limit. ALARA can be achieved by designing processes, implementing procedures, and using engineering controls to minimize radiation exposure. Institutions use ALARA-recommended threshold levels to initiate an investigation process to determine whether exposure levels are in line with the ALARA concept, and if any additional engineering or administrative controls should be implemented to reduce worker exposure. A model ALARA program is as follows: for workers who receive doses 410% of the annual occupational limit (investigational level I), the RSO needs to investigate the exposure and review the actions that might be taken to reduce the probability of recurrence. For workers who receive doses 430% of the annual occupational limit (investigational level II), the RSO needs to investigate the exposure and review actions to be taken to reduce the probability of recurrence. These findings and reports regarding levels exceeding ALARA threshold are presented to the Radiation Safety Committee on a quarterly basis for review. Methods to reduce or minimize radiation exposure include time, distance, and shielding. Regarding time, it is directly

proportional to exposure. Minimizing the time in the proximity of a radioactive source will minimize exposure. Regarding distance, exposure is inversely related to the square of the distance from a small source of radiation (i.e., moving from 1-2 m will reduce exposure by approximately a factor of 4). Therefore, it is always recommended that workers should keep the greatest possible distance from the radiation source. Regarding shielding, high atomic number materials such as lead or tungsten are effective in absorbing gamma radiations whereas low atomic number materials such as plastic or glass are effective in absorbing certain beta radiations, hence use of the appropriate absorbing materials in handling radionuclides can help to reduce exposure to staff.10 Some practical ways that NM staff can use to reduce radiation exposures are as follows: explain the procedure to patient and address questions or concerns before injecting the patient to minimize time spent around a radioactive patient, use tongs or other devices to handle radioactive materials to maximize distance, use syringe shield during dose preparation and administration, store doses in lead containers, and shield the areas in the hot lab where radioactive materials are stored and doses are prepared.

Area Surveys and Leak Tests Surveys are effective tools for evaluating radiological conditions and potential hazards. The licensees are required to develop, document, and implement provisions for radiation surveys. The different types of surveys that occur in NM include personnel surveys for contamination before leaving the facility, area surveys at the end of work day or after a spill, surveys of incoming packages, surveys of newly established areas where radioactive material will be used or stored, and surveys of waste before disposal. These evaluations may be measurements (e.g., radiation levels detected by survey instruments or wipe tests for detection of contamination), calculations, or a combination of measurements and calculations. The survey instruments used for measurement of radiation levels, radioactive contamination, and radioactivity need to be appropriate for the type and energy of radiation used. Survey instruments used in NM must be calibrated before first use, annually and after repair. For quantitative radiation measurements, instruments used must be calibrated for the radiation measured. Survey meter calibrations must be performed by individuals who are qualified to perform such calibrations. Typically, institutions send their survey meters to a qualified vendor for calibration. However, institutions may choose to perform their own calibrations as long as the person who is performing the calibration is deemed qualified. Surveys are required to be performed daily in all radiopharmaceutical elution, preparation, assay, and administration areas when using radiopharmaceuticals requiring a written directive and weekly in all radionuclide use, storage, and waste storage areas. Removable contamination surveys are required to be performed weekly for radiopharmaceutical elution, preparation, assay, and administration areas; radionuclide storage areas; and radionuclide waste storage areas. Surveys and wipe tests must be performed either at the end of the day or the week depending on the frequency required. If trigger

Radiation protection and regulations for the nuclear medicine physician levels are exceeded, the cause must be investigated. If needed, decontaminate area and survey again until it drops below the trigger level. Recommended survey trigger level is 5.0 mrem/h (50 mSv/h) in restricted areas and 0.2 mrem/h (2 mSv/h) in unrestricted areas. Recommended contamination trigger levels are 20,000 dpm/100 cm2 for radionuclides such as Tc-99m, Ga-67, and Tl-201 and 2000 dpm/100 cm2 for radionuclides such as I-131, I-123, I-125, In-111, Y-90, and Sm-153 in restricted area.5

§ 35.67 Requirement for Possession of Sealed Sources Sealed sources are required to be inventoried and leak tested every 6 months. Leak test records must include the type of radionuclide, estimated activity, model number and serial number if applicable, result of the test, date of the test, and the individual performing the test. If the wipe test indicates Z0.005 μCi (185 Bq) of removable contamination, the sealed source needs to be immediately withdrawn from use and stored, disposed, or repaired in accordance with the relevant NRC regulations. A report needs to be filed with the NRC within 5 days of the leak test.

Packaging and Transportation of Radioactive Materials Packaging and transportation of radioactive materials is regulated by the NRC under 10 CFR 71 and the DOT under 49 CFR 100, 107, 171, 173, and 178. Packages containing radioactive materials are shipped either as excepted, type A, or type B packages. Excepted package is defined as exposure rate o0.5 mrem/h (5 mSv/h) at contact from the package and radioactivity not exceeding limited quantity derived value found in 49 CFR 173.435. Excepted package only requires a “radioactive” mark; a radioactive label is not required. Once radioactivity exceeds the limited quantity derived value, it needs to be shipped as either a type A or type B package. Type A packages are further classified into white I–, yellow II–, or yellow III– labeled packages. Determination of the type of labels to be used is dependent on the exposure rates at surface and 1 m from the package. Exposure rate at 1 m in mrem/h is called the transport index (TI). DOT type A package labels and labeling categories

223 are showed in Table 3. In general, type A package labels need to include the sign “RADIOACTIVE,” name of the radionuclide, quantity (in Bq), and TI if applicable on both sides of the package. (Note: only yellow II and III labels need to have a TI. White I label does not have a TI as the exposure rate at 1 m needs to be background for white I–labeled package.) Almost all NM radiopharmaceuticals or sealed source packages are shipped as either excepted or type A packages. Radioactive material needs to be shipped as a type B package when exposure rate at contact or 1 m from the package exceeds limit specified for a type A package or if it is in a very large quantity. Packaging for a type B is required to be more accident resistant compared with type A. In addition, a type B package requires NRC approval or certification of package.12,13 Before preparing a radioactivelabeled package for shipment, personnel need to receive appropriate training. Depending on the shipping method, DOT or International Air Transport Association training on shipping radioactive materials may be required. Licensees should note that when returning radioactive materials to the commercial radiopharmacy or radioactive calibration sources to the manufacturer, the licensees are the shippers and thus their personnel require appropriate and routine DOT training.

Ordering, Receiving, and Opening of Packages Containing Radioactive Materials Ordering of radioactive materials needs to be authorized by an AU. The requesting AU is responsible for verifying that the requested materials and quantities are authorized by the license for use and that possession limits are not exceeded. The licensees need to maintain records on ordering and receiving of licensed material. The record needs to include the ordering AU or department, radionuclide, physical form or chemical form or both, activity, and supplier. In recent years, because of concern of terrorist activities involving radioactive materials, security of radioactive material, especially material classified as a “Nationally Track Source,” has become a major focus of the NRC as well as the Agreement State. Medical institutions are considered an area of vulnerability as they are high-traffic areas, and security in medical institutions is generally not as tight as industry or academic institutions. The NRC requires the licensees to implement requirements on increased controls for a “Nationally Track

Table 3 DOT Label Requirements for Type A Package White I

Yellow II

Yellow III

Cannot exceed 0.5 mrem/h No detectable radiation (background)

Cannot exceed 50 mrem/h Cannot exceed 1 mrem/h

Cannot exceed 200 mrem/h Cannot exceed 10 mrem/h

Label

Exposure rate at surface Exposure rate at 1 m (TI)

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224 Source.” For licensed materials with activity less than those of the “Nationally Track Source,” the licensees still need to implement policies and procedures to ensure security of their licensed materials. In addition, the licensees need to ensure that the actual practice reflects the policy. It is recommended for institutions to require radiopharmaceuticals be delivered directly to the department during regular working hours. During off-hours, only designated individuals can accept and secure these packages. Before opening packages containing radioactive materials, monitoring needs to be performed as soon as practical after receipt of the package, but not later than 3 hours after the package is received at the facility if it is received during the licensee’s normal working hours or not later than 3 hours from the beginning of the next working day if it is received after working hours. The first step is to visually inspect the package for any sign of damage (e.g., wet or crushed), followed by monitoring the external surfaces of a labeled package for radioactive contamination (wipe test) and radiation levels. If there is any reason to suspect contamination, wipe the external surface of the final source container to see if there is any removable radioactivity. The RSO or designee needs to be notified if there are any broken seals or vials, loss of liquid, condensation, or discoloration of the packing material. Before discarding the packing material and the empty packages, monitor for contamination with a radiation-detection survey meter. If no contamination is found, the radiation labels need to be removed or defaced before discarding packaging materials as in-house trash. When removable radioactive surface contamination exceeds the limits of 22 dpm/cm2 for beta- and gammaemitting radionuclides or if the external radiation level for a type A package exceeds 200 mrem/h (2 mSv/h) at contact or 10 mrem/h (0.1 mSv/h) at 1 m from the package, the licensee is required to immediately notify the final delivery carrier and the NRC Operations Center by telephone.11,12

Dosage Determination and Preparation In 10 CFR 35.60 and 35.63, the NRC describes requirements for the use, possession, calibration, and check of instruments (e.g., dose calibrators) used to measure patient dosages. For diagnostic procedures, the AU can prescribe a dosage or dosage range. If a dosage is prescribed, the NRC allows a deviation of ⫾20% of the prescribed dose. If the licensee uses only unit dosages made by a manufacturer (and does not split, combine, or otherwise modify unit dosages), an instrument to measure the dosage is not required. Furthermore, the NRC allows licensees to rely on the provider’s dose label for the measurement of the dosage and decay correct the dosage to the time of administration. For other than unit dosages, the NRC requires that the activity be determined by direct measurement, a combination of radioactivity measurement and mathematical calculation, or a combination of volumetric measurement and mathematical calculation. These dosages are typically assayed in a dose calibrator. Equipment used to measure dosages must be calibrated in accordance with nationally recognized standards (e.g., The American National Standards Institute) or the manufacturer’s instructions. The equipment needs to be

appropriate for the type and energy of radiation emitted. It needs to be calibrated and demonstrated to be both accurate and reliable over its entire range of operation (typically for 20 μCi to hundreds of mCi). For licensees who elute a 99Mo generator for 99mTc, 10 CFR 35.204 describes that the requirements for testing for permissible 99Mo concentration. The licensees must determine the activity of 99Mo present in the first eluate, and it must be r0.15 mCi 99Mo/mCi 99mTc (0.15 kBq 99Mo/MBq 99mTc). For licensees who prepare their own radiopharmaceuticals for emergency studies, the United States Pharmacopeia o7974 Pharmaceutical Compounding—Sterile Preparations immediateuse provision allows certain sterile products to be prepared without the need for special facilities and practices. The immediate-use provision is as follows: the number of kit reconstitutions is limited to 2, and the administration of each prepared radiopharmaceutical from these preparations is not more than 1 hour following the start of the reconstitution of the first kit preparation. Even though the immediate-use provision allows not more than 2 entries into any 1 container of sterile solution in a nonsterile environment, it should be noted that standard aseptic technique must be employed and special care must be taken to avoid touch contamination.13

Minimization of Contamination and Spills The 10 CFR 20.1406 requires new license applicants to include a description in the application outlining how facility design and procedures for operation will minimize contamination and generation of radioactive waste. Good laboratory practice and following proper protocols are the keys to minimize contamination and spills. Emergency procedures on how to respond to contamination and spills need to be established and implemented by the institution, and NM staff need to be trained on such procedures. Only trained staff should handle spill cleanup. It is recommended that the spill cleanup procedures be posted in the department and a spill cleanup kit to be readily available. Spills are classified as minor or major spills. Generally speaking, a minor spill is when the spill can be contained, very few people are involved, and the activity is below the activity specified in Table 4. A major spill is when the spill activity is Table 4 Radionuclide Activity Limit for Classification of Major Spill Radionuclide

mCi

Radionuclide

mCi

P-32 Cr-51 Co-57 Co-58 Fe-59 Co-60 Ga-67 Se-75 Sr-85 Sr-89

1 100 10 10 1 1 10 1 10 1

Tc-99m In-111 I-123 I-125 I-131 Sm-153 Yb-169 Hg-197 Au-198 Tl-201

100 10 10 1 1 10 10 10 10 100

Adapted with permission from U.S. NRC NUREG-1556, Volume 9, Revision 2 Table N.1.5

Radiation protection and regulations for the nuclear medicine physician difficult to contain, relatively large number of people are involved, or the activity is equal to or above the activity specified in Table 4. Proper steps to respond to a minor spill are as follows: notify persons in the area that a spill has occurred; prevent the spread of the spill; clean the spill; survey area, clothes, shoes, and person; and notify the RSO. Proper steps to respond to a major spill are as follows: clear the area of all individuals not involved with the spill, prevent the spread of the spill, shield the source if possible, close and secure the room, and notify the RSO. The RSO will supervise the cleanup of a major spill as opposed to a minor spill where trained staff can clean up the spill and then notify the RSO.5

Waste Disposal and Decay in Storage There are several methods to manage radioactive waste: decay in storage, release into the sewerage system, return to the manufacturer, or disposal through an authorized waste vendor. Regarding decay in storage, disposal of radionuclides with halflife less than 120 days is achieved by allowing the radionuclide to decay in storage until the radiation level is indistinguishable from background. This can be verified by measuring with an appropriate survey meter. Before disposing waste as either regular waste or infectious waste or other waste types, the radioactive labels need to be removed or defaced. Licensees that choose decay in storage need to document the disposal date, instrument used to survey, radiation level measured at the surface of the waste, background radiation level, and the person who performed the survey. Regarding release into the sewerage system, the licensee may discharge licensed materials into the sewer if each of the following conditions is met: (1) the material is soluble or readily dispersible in water, (2) the quantity of licensed or other radioactive material released into the sewer by the licensee on a monthly basis does not exceed the concentration listed in Table 3 of Appendix B to 10 CFR part 20, and (3) the total quantity of licensed or other radioactive material released into the sewer by the licensee on an annual basis does not exceed 5 Ci (185 GBq) of H-3, 1 Ci (37 GBq) of C-14, and 1 Ci (37 GBq) of all other radioactive materials combined. Discharge of licensed materials to the sanitary sewer needs to be documented. Regarding sealed sources and generators, the licensee may return them to the manufacturer. Lastly, for radionuclides with a half-life greater than 120 days that cannot be returned to the manufacturer, the licensee needs to use an authorized radioactive waste removal company to dispose the waste. In this case, radioactive waste is generally disposed via either landfill or incineration. Both methods of disposal are under strict regulations. According to the EPA, the institution that generates the waste is the “generator.” The generator is responsible for proper management of the waste from the point of generation to the point of disposal and beyond. Therefore, it is essential that these wastes are handled and disposed of properly. Radioactive waste disposal regulations can be found in 40 CFR part 266 and 10 CFR part 61.14,15

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§35.315 Safety Precautions A licensee who is authorized to administer therapeutic dosages to patients needs to make a determination whether patients should be treated as inpatients or outpatients. According to §35.315, patient release is based on any of the following criteria: a given dose of iodine is o33 mCi (1.22 GBq), a patient external measurement is o7 mR/h at 1 m, or patientspecific dose calculations can be made to demonstrate that the total annual projected dose to an individual member of the public from a patient is not exceeding 500 mrem (5 mSv). Verbal and written instructions must be given to the patient if the total annual projected dose to an individual of the public from the released patient is likely to exceed 100 mrem (1 mSv). This is to ensure that the annual projected dose will stay less than the 500-mrem (5 mSv) limit. If the aforementioned criteria cannot be met, then the patient or human research subject cannot be released and needs to be treated as an inpatient. For inpatient treatment, the licensee needs to place the patient or the human research subject in either a private room with a private sanitary facility or in a room, with a private sanitary facility, with another individual who also has received therapy with unsealed radioactive material and who also cannot be released under §35.75. The patient’s or the human research subject’s room needs to visibly post a “Radioactive Materials” sign and a note on the door or in the patient’s or human research subject’s medical record to indicate the distance and time limits for visitor and staff to stay in the patient’s or the human research subject’s room. Materials and items removed from the patient’s or the human research subject’s room need to be monitored with a radiation-detection survey meter, set on its most sensitive scale, to determine their radioactivity. If they cannot be distinguished from the natural background radiation level, they can be disposed as in-house waste or other types of waste. If they are more than the background level, they need to be handled as radioactive waste (either decay in storage until background level or dispose as radioactive waste). If the patient or human research subject has a medical emergency or dies, the RSO, or his or her designee, and an AU need to be notified as soon as possible. If a nursing patient is to be studied, she needs to be advised about nursing restrictions to ensure an effective radiation dose to her infant is less than 0.1 rem (1 mSv). These instructions include guidance on interruption or discontinuation of breastfeeding. If the patient chooses not to follow the guidance, she needs to be informed of any potential consequences because of failure to comply with the guidance. Table 5 outlines the level of activity of radiopharmaceuticals that require instructions and records when administered to patients who are breastfeeding an infant or child.

§35.310 Safety Instructions Radiation safety instruction needs to be provided initially and annually thereafter by the licensees to personnel caring for patients or human research subjects who cannot be released under §35.75. Instructions need to commensurate with the duties of the personnel and include the following: patient or human research subject control, visitor control, contamination

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Table 5 Activity of Radiopharmaceuticals That Required Instruction and Records When Administered to Patients Who are Breast-Feeding an Infant or Child Radiopharmaceutical

I-131 NaI I-123 NaI I-123 OIH I-123 mIBG

Activity Above Activity Above Examples of Recommended Duration Which Instructions Which a Record is of Interruption of Breast-Feeding are Required Required (MBq)

(mCi)

(MBq)

0.01 20 100 70

0.004 0.5 4 2

0.07 100 700 400

(mCi) 0.002 3 20 10

I-125 OIH I-131 OIH Tc-99m DTPA Tc-99m MAA Tc-99m pertechnetate

3 10 1000 50 100

0.08 0.30 30 1.3 3

10 60 6000 200 600

0.4 1.5 150 6.5 15

Tc-99m DISIDA Tc-99m glucoheptonate Tc-99m HAM Tc-99m MIBI Tc-99m MDP Tc-99m PYP Tc-99m red blood cell in vivo labeling Tc-99m red blood cell in vitro labeling Tc-99m sulfur colloid Tc-99m DTPA aerosol Tc-99m MAG3 Tc-99m white blood cells

1000 1000 400 1000 1000 900 400 1000 300 1000 1000 100

30 30 10 30 30 25 10 30 7 30 30 4

6000 6000 2000 6000 6000 4000 2000 6000 1000 6000 6000 600

150 170 50 150 150 120 50 150 35 150 150 15

Ga-67 citrate

Cr-51 EDTA In-111 white blood cells Tl-201 chloride

1

0.04

7

0.2

60 10 40

1.6 0.2 1

8 1 5

8 1 5

Complete cessation (for this infant or child)

24 h for 10 mCi (370 MBq) 12 h for 4 mCi (150 MBq)

12.6 h for 4 mCi (150 MBq) 24 h for 30 mCi (1100 MBq) 12 h for 12 mCi (440 MBq)

6 h for 20 mCi (740 MBq) 6 h for 12 mCi (440 MBq)

24 h for 5 mCi (1100 MBq) 12 h for 2 mCi (440 MBq) 1 mo for 4 mCi (150 MBq) 2 wk for 1.3 mCi (50 MBq) 1 wk for 0.2 mCi (7 MBq) 1 wk for 0.5 mCi (20 MBq) 2 wk for 3 mCi (110 MBq)

Adapted with permission from U.S. NRC NUREG-1556, Volume 9, Revision 2 Table U.3.5

control, waste control, and notification of the RSO, or his or her designee, and an AU if the patient or the human research subject has a medical emergency or dies.

Reports The licensees are required to report to the NRC via telephone or written report, or both, in the event that the safety or security of radioactive material may be compromised. There are several potentially reportable categories: theft or loss of licensed material, exposures, radiation levels, and concentrations of radioactive material exceeding the constraints or limits, medical events, dose to an embryo or fetus or a nursing child, and a leaking source. § 20.2201 Reports of Theft or Loss of Licensed Material If there is any lost, stolen, or missing licensed material in an aggregate quantity equal to or greater than 1000 times the quantity specified in Appendix C to 10 CFR part 20 and it appears to the licensee that persons in an unrestricted area could be exposed, the licensee needs to report to the NRC by telephone immediately after its occurrence becomes known.

For example, if Z1 Ci (37 GBq) of Tc-99m or 1 mCi (37 MBq) of I-131 is lost, stolen, or missing, and persons in an unrestricted area could be exposed, this needs to be reported immediately to the NRC. In addition, if there is any lost, stolen, or missing licensed material in a quantity greater than 10 times the quantity specified in Appendix C to part 20, the licensee has 30 days to search for the source. If the source is not found, the licensee needs to report this to the NRC within the 30 days after such occurrence. For example, if more than 1 mCi (37 MBq) of Co-57 or 0.1 mCi (3.7 MBq) of Cs-137 is lost, stolen, or missing, the license needs to report to the NRC within 30 days. The written report needs to include a description of kind, quantity, and chemical and physical forms of the licensed material involved; a description of the event; a statement of disposition, or probable disposition, of the licensed material involved; exposures of individuals to radiation; circumstances under which the exposures occurred; the possible TEDE to persons in unrestricted areas; any attempts that have been taken, or will be taken, to recover the material; and actions or procedures that have been, or will be, adopted to prevent against future recurrence.

Radiation protection and regulations for the nuclear medicine physician §20.2203 Reports of Exposures, Radiation Levels, and Concentrations of Radioactive Material Exceeding the Constraints or Limits The licensee needs to report to the NRC in writing within 30 days after learning any of the following: (1) the occupational dose limits for adults, the occupational dose limits for a minor, the limits for an embryo or fetus of a declared pregnant woman, the limits for an individual member of the public, any applicable limit in the license, the ALARA constraints for air emissions have been exceeded; or (2) levels of radiation or concentrations of radioactive material exceeded any applicable limit in a restricted area or 10 times any applicable limit in an unrestricted area. The written report must describe the extent of exposure of individuals to radiation and radioactive material, including, as appropriate, estimated dose to each individual, levels of radiation and concentrations of radioactive material involved, the cause of the elevated exposures, dose rates, or concentrations, and corrective actions taken or planned to prevent future recurrence. The NRC also requires that the report must include the name, Social Security number, and date of birth of each occupationally overexposed individual in a separate and detachable part of the report and must be clearly labeled “Privacy Act Information: Not for Public Disclosure.” §35.3045 Report and Notification of a Medical Event The NRC requires the licensee to report a medical event that involves any of the following: administration of the wrong radioactive drug, administration of a radioactive drug by the wrong route of administration, administration of a dose to the wrong individual or human research subject, a leaking sealed source, a total dosage delivered differs from the prescribed dosage by Z20% or falls outside the prescribed dosage range, a single fraction of the fractionated dose delivered differs from the prescribed dose by Z50% and resulted in a dose exceeding 5 rem (0.05 Sv) effective dose equivalent, 50 rem (0.5 Sv) to an organ or tissue, or 50 rem (0.5 Sv) shallow-dose equivalent to the skin. If patient intervention of an administration of radioactive material results or will result in unintended permanent functional damage to an organ or a physiological system, as determined by a physician, the licensee needs to notify the NRC of such event (patient intervention means administration interrupted or discontinued by patient, whether intentionally or unintentionally). The notification requirements for medical event are as follows: the licensee needs to notify the NRC Operations Center by telephone no later than the next calendar day after discovery of the medical event. In addition, the licensee needs to notify the patient’s referring physician and the patient no later than 24 hours after its discovery, unless the referring physician personally informs the licensee that he or she will inform the patient or it is not medically advisable to give such information to the patient. In that case, the information will be made available to the patient’s responsible relative or guardian. If the referring physician, the patient, or the patient’s responsible relative or guardian cannot

227 be reached within 24 hours, they should be notified as soon as practicable. The licensee may not delay any appropriate medical care for the patient. If a verbal notification is made to the patient or appropriate responsible relative or guardian, he or she needs to be informed that a written description of the event can be obtained from the licensee on request. Within 15 days after discovery of the medical event, the licensee needs to submit a written report to the appropriate NRC Regional Office. The written report needs to include names of all individuals involved in the event (including the name of the licensee, individuals involved in the event, the patient, and the patient’s referring physician), a description of the event, why the event occurred, the effect on the patient, actions taken to prevent recurrence, and certification that the licensee notified the patient (or the patient’s responsible relative or guardian), and if not, why not. §35.3047 Report and Notification of a Dose to an Embryo or Fetus or a Nursing Child Unless the dose to the embryo or fetus was specifically approved by an AU in advance, if an administration of radioactive material to a pregnant individual resulted in a dose to an embryo or fetus that is greater than 5 rem (0.05 Sv) dose equivalent, the NRC needs to be notified. In addition, any dose to a nursing child that is greater than 5 rem (0.05 Sv) TEDE, or has resulted in unintended permanent functional damage to an organ or a physiological system of the child, as determined by a physician because of an administration of radioactive material to a breast-feeding individual needs to be reported to the NRC. The reporting requirement is no later than the next calendar day after discovery of such event. In addition, the licensee needs to submit a written report to the appropriate NRC Regional Office within 15 days after discovery of such event.

Record Keeping The licensees are required to keep records of radiation protection programs, authority and responsibilities for radiation protection programs, radiation protection program changes, survey, individual monitoring results, dose to individual member of the public, calibration of instruments used to measure activity of unsealed radioactive material, radiation survey instrument calibration, dosage of unsealed radioactive material for medical use, leak tests and inventory of sealed sources, decay in storage, and 99Mo concentrations if applicable. The general rule of thumb for record keeping is 3 years with the following exceptions: records of authority and responsibilities for radiation safety programs and changes of radiation safety program are required to be kept for 5 years and records of individual monitoring results and provisions of the radiation protection programs must be maintained until the termination of the license.

Audits Under 10 CFR 20.1101, the NRC requires the licensees to review the content and implementation of the radiation protection program on an annual basis. The purpose of the review is to

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228 ensure compliance with NRC regulations, applicable regulations from other regulatory bodies, the terms and conditions of the license, and that occupational doses and doses to members of the public are ALARA. The annual review needs to be performance based. It is recommended that the licensees consider performing unannounced audits by observing work in progress, interviewing staff about the radiation protection program, and spot-checking required records. Violations or deficiencies identified during the audit need to be corrected comprehensively and in a timely manner, and evidence of resolution needs to be documented.

Joint Commission As many medical institutions are accredited by the Joint Commission, being familiar with the Joint Commission standards becomes important in ensuring compliance and obtaining continued accreditation. In December 2013, the Joint Commission issued the new and revised diagnostic imaging standard. This new and revised standard will become effective on July 1, 2014 with additional requirements to be phased in by 2015. Effective on July 1, 2014, before installation of new imaging equipment, replacement of existing imaging equipment, or modification to rooms where ionizing radiation will be emitted or radioactive materials will be stored, the new and revised standard requires that a medical physicist conducts a structural shielding design to specify required radiation shielding. After installation of imaging equipment or construction in rooms where ionizing radiation will be emitted or radioactive materials will be stored, a radiation protection survey needs to be conducted by a medical physicist to verify that the installed shielding is adequate. This survey needs to be conducted before clinical use of the room. For organizations that provide NM or PET services or both, the standard requires that a diagnostic medical physicist conducts a performance evaluation of all NM and PET imaging equipments at least annually. The evaluations are conducted for all of the image types produced clinically by each NM and PET scanner (e.g., planar or tomographic or both) and include the use of phantoms to assess the following imaging metrics: image uniformity and system uniformity, high-contrast resolution and system spatial resolution, lowcontrast resolution or detectability (not applicable for planar acquisitions), and artifact evaluation. Sensitivity, energy resolution, and count-rate performance tests are required for NM cameras but only recommended for PET scanners. The annual testing conducted by the medical physicist for NM or PET services also needs to include testing of image-acquisition display monitors for maximum and minimum luminance, luminance uniformity, resolution, and spatial accuracy. If deficiencies are identified during the evaluation process, recommendations for corrective actions as well as the evaluation results need to be documented. Under medication management, the new and revised standard requires that staff verifies the dose to be administered is within 20% of the prescribed dose or within the prescribed dose range before administering radiopharmaceuticals for diagnostic purposes. In addition, staff also verifies that it is the correct patient, correct imaging site,

and correct patient positioning. Lastly, patient’s age and recent imaging examinations need to be considered when deciding on the most appropriate type of imaging exam for the patient.16

Conclusion Policies and procedures on the security and safe use of radioactive materials are not detailed in the NRC regulations. Institutions generally develop and implement their own radiation protection program based on the model policies and procedures outlined in NUREG-1556 Volume 9, Revision 2. Working in collaboration with the RSO, AMP, and NM technologists, NM physicians play an essential role in the development and implementation of operating policies and procedures as part of an overall radiation protection program. NM physicians also play an important role in ensuring the appropriateness of each exam and dose to patients. To achieve that, NM physicians need to maintain an ongoing dialog with referring physicians, educating them about the appropriateness of exams for patients. In addition, NM physicians need to review clinical protocols to ensure that reference doses are based on anatomy, purpose of study, patient size, and adhere to the latest available information and recommendations. Only by working together with referring physicians, patients, and staff, can the ALARA concept be accomplished and maintained.

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