The Radiation Safety Officer for the Saint Louis University Hospital called in and emailed the following notification:
At approximately 1220 CDT on April 23, 2021, Y-90 SIR-Sphere was being administered to a patient. The prescribed dose [for the liver] was 43.2 mCi, the measured dose to be administered was 46.7 mCi, but due to a clog in the catheter, only a calculated 4.53 mCi dose was administered to the patient. Because this exceeds +/- 20 percent of the intended dose, we determined a medical event had occurred. There was no harm to the patient, and a follow-up dose is planned for Monday, April 26, 2021.
Preliminary Determination of Cause: The cause of the medical event was believed to be clogging of the catheter, but the exact reason for the resistance was undetermined. When the resistance was encountered, the procedure was stopped by the administering physician, with the intention of terminating the procedure, resulting in an administered dose variance greater than +/- 20 percent of the prescribed dose, and thus determined to be a medical event.
Additional Details:
� The Nuclear Medicine Technologist drew the dose per standard operating procedure. The procedure checklist was read and the dose administration set up was normal. All steps to prevent clumping of microspheres were followed.
� During the administration, the dose was agitated and attempted to be delivered. There was resistance on the plunger during the administration. The physician stated that the catheter was clogged. The procedure was stopped, with the intention to terminate the procedure, and to administer a second dose at a later time.
� The physician disconnected the A-line from the patient catheter. This caused the backpressure to expel the beads onto the administration table and the floor covering. The disposable covering of these surfaces were collected and disposed of in radioactive waste. The Interventional Radiology Suite was surveyed and released, with all wipe tests and G-M survey meter readings at background.
Licensee notified R3 NRC Inspector (O'DOWD)
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.