UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

OFFICE OF FEDERAL AND STATE MATERIALS 

AND ENVIRONMENTAL MANAGEMENT PROGRAMS 

WASHINGTON, D.C. 20555 

May 12, 2008 

NRC REGULATORY ISSUE SUMMARY 2008-11

PRECAUTIONS TO PROTECT CHILDREN WHO MAY COME IN 

CONTACT WITH PATIENTS RELEASED AFTER THERAPEUTIC 

ADMINISTRATION OF IODINE-131 

ADDRESSEES

All U.S. Nuclear Regulatory Commission (NRC) medical-use licensees, master material 

licensees, Agreement State Radiation Control Program Directors, and State Liaison Officers. 

INTENT

NRC is issuing this regulatory issue summary (RIS) to inform licensees of supplemental 

guidance to NUREG 1556, Volume 9, Rev. 2 “Program-Specific Guidance About Medical Use 

Licenses” on the precautions that should be taken to protect infants and young children who 

may come in contact with patients released after administration of therapeutic amounts of 

iodine-131 (I-131), such as oral sodium iodide I-131. No specific action or written response is 

required. NRC is providing this RIS to Agreement States for their information and for 

distribution to their medical licensees, as appropriate. 

BACKGROUND

On January 29, 1997, NRC published a final rule in the Federal Register on the “Criteria for the 

Release of Individuals Administered Radioactive Material” (62 FR 4120). This rule amended 

the patient release criteria in Title 10 of the Code of Federal Regulations (10 CFR), Section 

35.75, “Release of Individuals Containing Unsealed Byproduct Material or Implants Containing 

Byproduct Material,” replacing the activity-based or dose-rate-based release limit with a limit 

based on projected radiation doses to other individuals exposed to a patient released after 

therapeutic administration of radionuclide, such as oral sodium iodide I-131. These dose-based 

release limits used assumptions that the internal doses for individuals who may come in contact 

with released patients were very small compared with doses from external exposures. Also, 

these criteria were consistent with the recommendations of the National Council on Radiation 

Protection and Measurements (NCRP) and the International Commission on Radiological 

Protection (ICRP) at the time. 

ML080380666 
RIS 2008-11 

Page 2 of 3

However, in ICRP Publication 94 “Release of Patients after Therapy with Unsealed 

Radionuclides,” published in 2004, ICRP cautioned that the internal dose to the thyroid for 

infants and young children who may come in contact with a patient who was administered 

therapeutic quantities of I-131, such as oral sodium iodide I-131, has the potential to be far 

greater than the dose from external exposure. ICRP Publication 94 states that “contamination 

of infants and young children with saliva from a treated patient during the first few days after 

radioiodine therapy could result in significant doses to the child’s thyroid, and potentially raise 

the risk of subsequent radiation-induced thyroid cancer.” ICRP also repeats this statement in 

its new comprehensive radiation safety recommendations in ICRP Publication 103, “The 2007 

Recommendations of the International Commission on Radiological Protection,” which states 

that particular care should be taken to avoid the contamination of infants and children from 

patients treated with radioiodine. 

SUMMARY OF ISSUE 

The regulations in 10 CFR 35.75 permit a licensee to “authorize the release from its control any 

individual who has been administered unsealed byproduct material or implants containing 

byproduct material if the total effective dose equivalent to any other individual from exposure to 

the released individual is not likely to exceed 5 mSv (0.5 rem).” However, as described in the 

Background section of this RIS, for some I-131 therapies, such as oral administration of sodium 

iodide I-131, the ICRP cautions that the internal dose to infants and young children who may 

come in contact with a released patient could be significant. 

NRC has developed guidance on recommended instructions that licensees should give I-131 

therapy patients who are about to be released from licensee control and who will or may have 

contact with infants and young children. The guidance recommends that licensees consider not

releasing patients, administered I-131, whose living conditions may result in unnecessary 

exposure of infants and young children. 

The guidance mentioned above may be found in Enclosure 1 of this RIS and at the NRC’s Web 

page entitled “Medical Uses Licensee Toolkit” at http://www.nrc.gov/materials/miau/med-usetoolkit.html. Please note that this guidance is a supplement to the guidance found in Appendix 

U of NUREG-1556, Vol. 9, Rev. 2 “Program-Specific Guidance About Medical Use Licenses.” 

FEDERAL REGISTER NOTIFICATION

A notice of opportunity for public comment on this RIS was not published in the Federal 

Register because this RIS is informational and does not represent a departure from current 

regulatory requirements. 
RIS 2008-11 

Page 3 of 3

CONGRESSIONAL REVIEW ACT 

In accordance with the Congressional Review Act, the NRC has determined that this RIS is not 

a major rule and has verified this determination with the Office of Information and Regulatory 

Affairs of OMB. 

PAPERWORK REDUCTION ACT STATEMENT

This RIS does not contain information collections and, therefore, is not subject to the 

requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.). 

CONTACT 

This RIS requires no specific action or written response. If you have any questions about this 

summary, please contact the individual listed below or the appropriate regional office. 

 /RA/ 

 Robert J. Lewis, Director 

Division of Materials Safety 

 and State Agreements 

 Office of Federal and State Materials 

 and Environmental Management Programs 

Technical Contact: Duane White, FSME 

 (301)415-6272 

 E-mail: dew2@nrc.gov 

 

Enclosures: 

1. Guidance to Protect Children Who May Come in Contact with Patients Released after 

Therapeutic Administration of Iodine-131

2. List of Recently Issued FSME Generic Communications
RIS 2008-11 

Page 3 of 3

CONGRESSIONAL REVIEW ACT 

In accordance with the Congressional Review Act, the NRC has determined that this RIS is not 

a major rule and has verified this determination with the Office of Information and Regulatory 

Affairs of OMB. 

PAPERWORK REDUCTION ACT STATEMENT

This RIS does not contain information collections and, therefore, is not subject to the 

requirements of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501, et seq.). 

CONTACT 

This RIS requires no specific action or written response. If you have any questions about this 

summary, please contact the individual listed below or the appropriate regional office. 

 /RA/ 

 Robert J. Lewis, Director 

Division of Materials Safety 

 and State Agreements 

 Office of Federal and State Materials 

 and Environmental Management Programs 

Technical Contact: Duane White, FSME 

 (301)415-6272 

 E-mail: dew2@nrc.gov 

 

Enclosures: 

1. Guidance to Protect Children Who May Come in Contact with Patients Released after 

Therapeutic Administration of Iodine-131

2. List of Recently Issued FSME Generic Communications 

ML080380666

OFFICE FSME/DMSSA Tech.Editor DILR/RBB FSME/DMSSA FSME/DMSSA FSME/DMSSA 

NAME DWhite QTE via email NBhalla AMcIntosh CFlannery SWastler 

DATE 01/ 25 /08 01/ 25 /08 2/ 04 /07 02/ 01 /08 02/ 05 /08 02/ 04 /08 

OFFICE OIS OGC - NLO OGC - CRA DMSSA 

NAME TDonnell BJones TRothschild RLewis 

DATE 02/ 22 /08 02/ 21 /08 02/ 21 /08 03/ 04 /08 

OFFICIAL RECORD COPY 
Enclosure 1 

RIS 2008-11 

Page 1 of 2

Guidance to Protect Children Who May Come in Contact with Patients Released after 

Therapeutic Administration of Iodine-131 

The Nuclear Regulatory Commission (NRC) regulations in Title 10 of the Code of Federal 

Regulations (10 CFR), Section 35.75, “Release of Individuals Containing Unsealed Byproduct 

Material or Implants Containing Byproduct Material,” permits a licensee to “authorize the 

release from its control any individual who has been administered unsealed byproduct material 

or implants containing byproduct material if the total effective dose equivalent to any other 

individual from exposure to the released individual is not likely to exceed 5 mSv (0.5 rem).” For 

this guidance document, the individual or human research subject to whom the radioactive 

material has been administered is called the “patient.” Please note that this guidance is a 

supplement to the guidance found in Appendix U of NUREG-1556, Vol. 9, Rev. 2 “ProgramSpecific Guidance About Medical Use Licenses.” 

NRC’s current patient release criteria were based, in part, on the assumption that internal doses 

to an individual from a patient released after therapeutic administration of a radionuclide, such 

as oral sodium iodide I-131, was small compared with doses from external exposures. 

However, in 2004, the International Commission on Radiation Protection (ICRP), in ICRP 

Publication 94, “Release of Patients after Therapy with Unsealed Radionuclides,” cautioned that 

the internal dose to the thyroid for infants and young children who may come in contact with a 

patient who was administered therapeutic quantities of I-131, such as oral sodium iodide I-131, 

has the potential to be far greater than the dose from external exposure. ICRP Publication 94 

states that “contamination of infants and young children with saliva from a treated patient during 

the first few days after radioiodine therapy could result in significant doses to the child’s thyroid, 

and potentially raise the risk of subsequent radiation-induced thyroid cancer.” ICRP also 

repeats this statement in its new comprehensive radiation safety recommendations in ICRP 

Publication 103, “The 2007 Recommendations of the International Commission on Radiological 

Protection,” which states that particular care should be taken to avoid the contamination of 

infants and children from patients treated with radioiodine. 

 

Section 35.75(b) of 10 CFR Part 35 requires the licensee to provide the released individual, or 

the individual’s parent or guardian, with instructions, including written instructions, on actions 

recommended to maintain doses to other individuals as low as is reasonably achievable 

(ALARA) if the total effective dose equivalent to any other individual is likely to exceed 1 mSv 

(0.1 rem). In consideration of the more recent ICRP recommendations described above, the 

licensee, in implementing the requirements on written instructions in 10 CFR 35.75(b), should 

take into account whether the released patient may come in contact with infants or young 

children. In such a situation, in order to protect infants and young children from possible I-131 

contamination, the licensee should provide the patient with additional instructions. These 

additional instructions should include: 
Enclosure 1 

RIS 2008-11 

Page 2 of 2

• A recommendation to have patients avoid direct or indirect contact (e.g., indirect contact 

includes contamination from shared living space) with infants and young children for a 

specific period of time (e.g., consider having children stay outside the home with other 

family members). 

• A recommendation for patients to have adequate living space at home (e.g., bedroom, 

bathroom) that can be used exclusively by the patient for a specific period of time. 

• Information on the potential consequences, if any, from failure to follow these 

recommendations. 

Licensees should also consider not releasing patients, administered I-131, whose living 

conditions may result in the contamination of infants and young children.

 
Enclosure 2 

RIS 2008-11 

Page 1 of 1

List of Recently Issued FSME Generic Communications 

Date GC No. Subject Addressees 

10/04/07 RIS-07-22 Status Update For 

Implementation Of NRC 

Regulatory Authority for Certain 

Naturally-Occurring and 

Accelerator-Produced 

Radioactive Material 

All U.S. Nuclear Regulatory 

Commission materials licensees, 

radiation control program directors, 

State liaison officers, and the NRC’s 

Advisory Committee on the Medical 

Uses of Isotopes. 

10/04/07 RIS-07-23 Date For Operation Of National 

Source Tracking System 

All licensees authorized to possess 

Category 1 or Category 2 quantities of 

radioactive materials. All Radiation 

Control Program Directors and State 

Liaison Officers. 

12/05/07 RIS-07-27 Improving Public Understanding 

of the Risks Associated with 

Medical Events 

All U.S. Nuclear Regulatory 

Commission medical use licensees. All 

Radiation Control Program Directors, 

and State Liaison Officers 

12/07/07 RIS-07-28 Security Requirements for 

Portable Gauges 

U.S. Nuclear Regulatory Commission 

portable gauge licensees and 

Agreement State Radiation Control 

Program Directors and Liaison Officers

12/14/07 RIS-07-38 Ensuring Complete and Accurate 

Information in the 

Documentation of Training and 

Experience for Individuals 

Seeking Approval as Medical 

Authorized Users 

All U.S. Nuclear Regulatory 

Commission medical use licensees 

and NRC master materials licensees. 

All Agreement State Radiation Control 

Program Directors and State Liaison 

Officers 

02/01/08 RIS-08-02 Actions to Increase the Security 

of High Activity Radioactive 

Sources 

All U.S. Nuclear Regulatory 

Commission Materials and Master 

Materials Licensees. All Agreement 

State Radiation Control Program 

Directors and State Liaison Officers. 

Note: This list contains the six most recently issued generic communications, issued by the Office of 

Federal and State Materials and Environmental Management Programs (FSME). A full listing of all 

generic communications may be viewed at the NRC public website at the following address: 

http://www.nrc.gov/reading-rm/doc-collections/gen-comm/index.html