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Nuclear Regulatory Commission (NRC)

Advisory Committee on the Medical Use of Isotopes (ACMUI)

Subcommittee on

Radioactive Seed Localization for Non-Palpable Breast Lesions

Response to NRC Working Group Draft “Low Activity Radioactive Seeds Used for 

Localization of Non-palpable Lesions and Lymph Nodes Guidance”

Subcommittee Members:

Dr. Ronald Ennis (Chair)

Mr. Frank Costello

Dr. Darlene Metter

Dr. Pat Zanzonico

Introduction

This subcommittee has previously presented on this topic in a report dated September 21, 2015. 

The recommendations in that report were presented to the ACMUI at its meeting on October 12, 

2015. Since then, Dr. Philip Alderson has been appointed Chairman of the ACMUI. As a result, he 

can no longer serve on this subcommittee and has been replaced by Dr. Darlene Metter.

Written Directive

The most significant change from our subcommittee’s recommendations in the NRC Working 

Group (WG) Draft, “Low Activity Radioactive Seeds Used for Localization of Non-Palpable 

Lesions and Lymph Nodes Guidance,” hereafter referred to as NRC WG Draft Guidance, is the 

elimination of the requirement for a written directive (WD). The rationale for the WG’s 

recommendation is that a WD is required for therapeutic procedures. Since this is a diagnostic 

procedure, a WD is not necessarily required. Furthermore, elimination of a WD does not eliminate 

the possibility of a Medical Event (ME) and all of the standard ME criteria still apply. The 

subcommittee accepts this change on the basis of an implicit understanding that there will be 

documentation in the patient’s medical record of the Authorized User (AU)’s intention prior to the 

Radioactive Seed Localization (RSL) procedure and post-procedure documentation in the medical 

record documenting what was actually performed. It is the understanding of the subcommittee that 

this documentation will provide regulators with the required information to assess that an RSL 

procedure had been performed in accordance with the applicable regulations. 

Authorized User

Another significant change in the NRC WG Draft Guidance is the creation of an alternative

pathway to become an AU for RSL. In this pathway, radiologists whose training and experience 

did not qualify them for AU status under 35.290 or surgeons can become AUs for RSL with 80 

hours of training and experience including a minimum of 40 hours of classroom and laboratory 

training in basic handling techniques applicable to the medical use of sealed sources (details of 
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which are listed in the NRC WG Draft Guidance in (3) i-ii (page 4)). The subcommittee 

understands that a gap in training and experience exists for some radiologists who are active in the 

area of needle localizations and biopsies under image guidance (e.g. mammographers who routinely 

perform biopsies and place clips in the breast). Such physicians are the ones who most naturally 

would be called upon to place radioactive seeds for this diagnostic purpose. However, even if their

training and experience was not enough to achieve 35.290 AU status, their radiology training (i.e. a 

residency in radiology) provided substantial background in all aspects of the medical use of 

radiation including safety, protection, biology and physics. Accordingly, the subcommittee 

supports an alternative (i.e. non-35.290) pathway for these radiologists to achieve AU status for 

RSL. However, the subcommittee believes strongly that surgeons or others without a significant 

background in radiation (from a residency or some other similarly intense education and practical 

experience) would be entirely unqualified to function as an AU for RSL with only 80 hours of 

training .

Medical Event

The NRC WG Draft Guidance has eliminated the time component from the definition of ME. This 

component is replaced with the following criterion: an ME has occurred “...if the licensee fails to 

perform the explantation surgery,” with the caveat that such an outcome would not be an ME if “the 

physician makes the determination not to explant the seed for various patient conditions (e.g. doing 

so would jeopardize the patient’s well-being.)” The subcommittee accepts this change and support 

the exclusion from ME the situation in which the physician deems removal not to be in the best 

interest of the patient. Additionally, the subcommittee supports the position that an ME has not 

occurred in the event the patient failed to return for the surgical removal procedure, considering this 

to be an instance of “patient intervention”.

Safety Precautions

The subcommittee is disappointed the NRC WG Draft Guidance does not include an explicit 

requirement to advise patients who have undergone RSL of the breast not to breast feed with the

implanted breast until the seed has been explanted. The subcommittee is concerned about the 

exposure of a newborn child to even small doses of unnecessary radiation and the potential risk to 

that child later in life. It is well known to those trained in radiation safety and human health that the 

damaging effects of radiation are much more pronounced in children. However, the public and 

medical professionals who are not highly educated in issues of radiation safety and human health 

may be unaware of this distinction. Therefore, a mother may assume if it is safe for her to have this 

radioactive seed in her breast, it is also safe for her baby to be exposed to the radiation via breast 

feeding. The subcommittee, therefore, feels this is an important omission and recommends inclusion 

of the following in the Draft Guidance: “Patient should be advised not to breast feed from a breast 

into which one or more radioactive seeds been implanted and not yet removed. Breast feeding is, of 

course, permissible once the seed(s) has(ve) been removed. In the event of seed rupture within the 

breast, the subcommittee recommends the patient be advised to never breast feed from the effected 

breast for this child.”(Note: The end time of the restriction on breast feeding in the setting of a 

ruptured seed has been changed from “10 half-lives”, which had been recommended in our previous 

recommendation, to “this child” to make this recommendation consistent with the recommendations 

for I-131.)
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Other recommendations

The subcommittee agrees with the remainder of the NRC WG Draft Guidance, including those 

portions related to previous recommendations of the subcommittee (see Subcommittee’s previous 

report dated September 21, 2015). 

Respectfully submitted, June 10, 2016

Subcommittee on Radioactive Seed Localization for Non-Palpable Breast Lesions,

Advisory Committee on the Medical Use of Isotopes (ACMUI),

Nuclear Regulatory Commission (NRC)