September 09, 2021

Advisory Committee Makes Recommendations to NRC on Extravasation Reporting

The U.S. Nuclear Regulatory Commission (NRC) Advisory Committee on the Medical Uses of Isotopes (ACMUI) this month recommended only the reporting of extremely rare outlier cases that result in confirmed radiation injuries be reportable to the agency as medical events (MEs) following qualitative assessments by physician-authorized users. The recommendation was one of several options identified by NRC staff in a preliminary evaluation report released in August. Prior to approval, the committee made two clarifications recommended by the American College of Radiology® (ACR®) in an Aug. 27, written statement.

Extravasations are broadly exempted from ME requirements alongside other occurrences outside the control of medical licensees, such as patient intervention-caused events, shunting and stasis with yttrium-90 microspheres and migration of implanted brachytherapy seeds. Whereas small volume extravasations of nuclear medicine agents are generally unpreventable and clinically insignificant, reportable MEs are meant to indicate errors or major problems with the licensee’s use of byproduct material. Moreover, ME reports are intended to provide actionable information to regulators and lessons learned to other medical licensees. Examples of currently reportable MEs include administrations of a different radiopharmaceutical than intended, high or low doses that significantly differ from written directives, or administering byproduct material to someone other than the intended patient.

The NRC’s ME exemption for extravasation was challenged in a 2020 petition for rulemaking (PRM-35-22) filed by the CEO of a vendor selling injection site monitoring products and corresponding cloud-based dosimetry services. The company requested that NRC eliminate the longstanding ME exemption policy for extravasation, and that an arbitrary dose-based threshold be set to estimate whether a given extravasation is reportable. There is no national standard methodology for nuclear medicine agent extravasation dosimetry, nor is it trivial to estimate local tissue dose from a small volume, mobile source such as traces of extravasated material. Were NRC to adopt the company’s preferred regulatory construct, proprietary devices would need to be positioned prior to administration and remain positioned for a series of measurements following the administration to provide input data for nonstandard dosimetry to estimate if the NRC’s reporting threshold has been reached.

The appropriateness of requiring novel tools and nonstandard, assumption-based dosimetry for regulatory compliance purposes has been called into question by experts unaffiliated with the company. Negative impacts include severe resource strains for providers and undue impositions on patient care without offsetting radiation safety improvements. The petition has been publicly opposed by virtually all national scientific and medical societies with relevant expertise, including the ACR, Society of Nuclear Medicine and Molecular Imaging, American Society for Radiation Oncology, Health Physics Society and the American Association of Physicists in Medicine.

The ACMUI recognized the medical and scientific communities’ concerns and unanimously recommended that only extremely rare radiation-caused harms from extravasation be made reportable to NRC. NRC is considering the recommendation of ACMUI and plans to make recommendations to agency leadership next spring.

For more information or if you have questions, please contact Gloria R. Romanelli, JD, ACR Senior Director of Legislative and Regulatory Relations, at, or Michael Peters, ACR Government Affairs Director, at or 1-202-223-1670.