The following information was provided by the State of
Colorado via email:
The [licensee] RSO reported that a patient received 40 percent less than the prescribed dose during a TheraSphere (Y-90) treatment on 10/14/2015. The exact cause is still under investigation.
Initial written direction was for 120 Gy. However, due to unavailability of this dose the written directive was amended to 140 Gy and the dose was ordered.
The AU [Authorized User] reported that stasis was not reached and it was believed the patient received the entire dose. The associated survey meter was reading 0 and the AU flushed the system 3 times - the meter continued to read 0. The procedure ended around 1430 MDT.
After the procedure the AMP [Authorized Medical Physicist] reviewed the paperwork, took waste measurements and performed calculations. At this point 40 Gy was found in the waste. The RSO was notified at 1545 MDT.
At this time, it is not known if the patient has been notified.
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.