Event Notification Report for December 29, 2025

AGREEMENT STATE REPORT - MEDICAL EVENT

The following information was provided by the Washington State Department of Health (the Department) via email:


"On 12/19/2025, at 1647 PST, the Department was notified of a misadministration of a 200 mCi Lu-177 prostate-specific membrane antigen dose for a patient on a research protocol.

"During the infusion, there was some pressure buildup in the system causing an alarm from the infusion pump. The infusion was halted as a blockage was suspected in the intravenous line. After troubleshooting attempts, it was decided to attempt the manual syringe injection method, but during the manipulations there was concern that the vial's sterility was compromised and the remaining infusion was aborted. Imaging was immediately performed, and it was estimated that only 50-75 mCi was infused.

"A detailed report will follow within 15 days."

Washington Incident Number: WA-25-019

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

MEDICAL EVENT

The following information was provided by the licensee via phone and email:

"A patient was treated for metastatic disease of the liver, involving bilobar treatments with Y-90 microspheres (TheraSpheres). The right lobe was treated on 11/18/25, without complication. The left lobe was treated on 12/19/25 (1239 EST) with 1.77 GBq (47.8 mCi) of Y-90 microspheres. Pre-treatment coil embolization of the accessory left hepatic artery coming from the left gastric artery was performed, to prevent gastric activity that was observed on the Tc-99m macroaggregated albumin (MAA) mapping study (11/4/25). Proper catheter placement in the hepatic artery was verified by digital subtraction angiography (DSA), and the Y-90 microspheres were administered. Following the standard of care for Y-90 microsphere administrations, single photon emission computed tomography (SPECT/CT) was performed after the administration to confirm proper distribution of the microspheres.

"Approximately 2 hours post-administration (after the patient had been discharged), nuclear medicine physicians evaluating the SPECT/CT results notified the prescribing physician of abnormal uptake into the stomach wall and to a lesser extent the upper left quadrant (not organ-specific). Retrospective review (with enhancement) of DSA showed a possible small accessory right gastric artery branch that potentially provided a path for extrahepatic distribution of the Y-90 microspheres, though it is diminutive in size relative to the left hepatic artery and its branches (and was not expected to contribute to extraheptic uptake). However, this was not observable on the initial DSA (without enhancement). Initial estimates of the extrahepatic uptake were approximately 70 percent of the administered dose.

"The authorized user physician, authorized medical physicist, and radiation safety officer were immediately notified, and the prescribing physician contacted the patient to evaluate clinical status; the patient noted fatigue, decreased appetite, and some left upper quadrant pain. The prescribing physician informed the patient of the extrahepatic uptake (predominantly in the stomach) and asked the patient to return to the emergency department (ED) for examination. In the ED, the prescribing physician discussed plans for monitoring, administering a proton-pump inhibitor and sucralfate (Pepto) to ameliorate any developing gastritis, recommended avoiding non-steroidal anti-inflammatory drugs (NSAID), and instructed to return to the ED if any food intolerance (because the patient hadn't eaten since before the procedure) or worsening abdominal pain. The prescribing physician made arrangements to repeat SPECT/CT imaging at day 3 post-administration to confirm distribution of the microspheres and help determine the percentages distributed intra-hepatically and extrahepatically.

"Potential causes were (1) catheter placement within the left hepatic artery such that preferential flow went into the diminutive branch, which may provide flow to the stomach, (2) possible dislodgement or advancement of the catheter into the diminutive branch between angiogram confirmation within the larger left hepatic artery and Y-90 administration, resulting in dominant flow into the small accessory branch, or (3) catheter dislodgement after spot film (fluoroscopy) but prior to administration due to respiratory variation or tension.

"Of note, Tc-99m MAA administration on 11/4 (during treatment planning) did detect extrahepatic uptake to the stomach. This was initially credited to an accessory left hepatic artery (observed on CT-angiography and confirmed with angiography) and close proximity of supraduodenal and gastroduodenal arteries observed on angiography and intra-arterial liver CT-angiography. While treatment of these putative extrahepatic sources was performed prior to the administration of Y-90, there was no information or data to definitively exclude other potential collaterals that may result in extrahepatic distribution.

"All involved parties agreed that this event may meet the definition of a medical event in 35.3045(a)(2)(iii)(C) - and possibly (2)(i) and (2)(ii) - assuming the microspheres went directly into the stomach wall and were not implanted in the liver.

"Discussions of corrective actions are ongoing. The licensee will follow up with the required 15-day report."

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

AGREEMENT STATE REPORT - STOLEN MOISTURE DENSITY GAUGE

The following information was provided by the California Department of Public Health, Radiologic Health Branch (RHB) via email:

"The licensee's radiation safety officer (RSO) reported the theft of a CPN moisture density gauge (serial number 70308642). The gauge contains a 10 mCi Cs-137 and a 50 mCi Am-241/Be sealed source. The transit case and the gauge both have the owner's name and contact information taped to them.

"Sometime over the weekend, thieves broke into the company's high security modular storage unit and then cut the lock and cable used to secure the gauge transport case to the mobile unit. The gauge operator confirms that the gauge's trigger lock was engaged after it was last used on Friday, 12/19/2025.

"The licensee reported the theft to the Beaumont Police Department and will contact their gauge service company. The RSO was asked to post an ad in local news for the safe return of the gauge. The RHB will be conducting an investigation."

CA Incident Number: 122225

THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

MANUAL REACTOR SCRAM DUE TO RCS LEAK

The following information was provided by the licensee via phone and email:

"At 1606 CST with Unit 1 in mode 1 at 93 percent power, the reactor was manually tripped due to degrading containment parameters associated with a leak from the 'B' reactor recirculation pump line, which has been isolated. The trip was not complex, however the 'A' reactor recirculation pump tripped to OFF instead of down-shifting to slow speed. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B).

"Operations responded using emergency operations procedures and stabilized the unit in plant mode 3 (hot shutdown). Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 2 is not affected.

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."