Information Notice No. 84-85: Molybdenum Breakthrough from Technetium-99m Generators
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
November 30, 1984
INFORMATION NOTICE NO. 84-85: MOLYBDENUM BREAKTHROUGH FROM TECHNETIUM-99m
All NRC medical licensees, and radiopharmaceutical suppliers.
This information notice advises licensees of recent problems with
molybdenum-99 (Mo-99) breakthroughs during elution of technetium-99m
(Tc-99m) because of faulty generators. If the test of eluates is not done to
determine if a breakthrough problem has occurred, patients undergoing
medical diagnostic procedures might receive improper medical diagnoses and a
significant radiation dose to the liver, bladder, or kidney from the
unwanted Mo-99. It is expected that recipients will review the information
in this notice for applicability to their facilities and consider actions,
if appropriate, to preclude a similar problem. However, suggestions
contained in this information notice do not constitute NRC requirements;
therefore, no specific action or written response is required.
Description of Circumstances:
Tc-99m is used for medical diagnostic imaging procedures. Tc-99m is eluted
from Mo-99 in a device called a generator. When Tc-99m is eluted from a
faulty generator, some Mo-99 may "break through." Mo-99 is a contaminant
which has no medical application. Nuclear Regulatory Commission regulations
require that each elution from a generator be tested for Mo-99 breakthrough.
See 10 CFR 30.34(g). This rule applies to those who elute generators, not to
those who purchase prepared radiopharmaceuticals.
Recently, two radiopharmaceutical suppliers received faulty generators and
failed to perform the Mo-99 breakthrough test. Prepared doses were sent to
several hospitals. Some of the hospitals noted higher than anticipated
radiation levels from the packages (as a result of the higher energy Mo-99)
and contacted the supplier for an explanation. Some hospitals did not survey
the packages, or did not realize the significance of higher than "normal"
survey readings, and patients were injected with contaminated Tc-99m. This
resulted in unnecessary exposure of patients and workers due to the Mo-99
breakthrough and the readministration of the intended radiopharmaceutical in
order to perform the prescribed nuclear medicine procedure. The highest
confirmed amount of Mo-99 in a single dose was 234 microcuries; however,
unit doses may have been contaminated with up to 100 microcuries Flo-99 per
millicurie of Tc-99m.
November 30, 1984
Page 2 of 2
The NRC limit for Mo-99 contamination is 1 microcurie of Mo-99 per
millicurie of Tc-99m, not to exceed 5 microcuries Mo-99 per dose (10 CFR
No specific action or written response is required by this information
notice. If you have any questions about this matter, please contact the
Regional Administrator of the appropriate regional office or this office.
J. Nelson Grace, Director
Division of Quality Assurance, Safeguards,
and Inspection Programs
Office of Inspection and Enforcement
Technical Contact: Jack R. Metzger
Attachment: List of Recently Issued IE Information Notices
Page Last Reviewed/Updated Wednesday, March 24, 2021