The following information was received from the State of
Illinois via email:
On April 2, 2012 the licensee contacted the [Illinois Emergency Management] Agency [IEMA] to provide a preliminary notification that they believed a medical event had occurred as a result of a Therasphere treatment the previous workday. On March 30, 2012 a patient had been administered Y-90 for the treatment of liver cancer according to their standard protocol. No unusual anomalies took place during the treatment and no shunting of the dose was observed. The treatment was completed as expected including initial agitation of the vial, 'tapping' of the system during administration and repeated flushing of the delivery system upon completion of the five minute process.
However, when post-treatment measurements were conducted of the delivery system and vial, a measurable amount of activity was determined to still be present. Analysis of the associated microcatheter, tubing, vial and the rest of the delivery system resulted in an assessment that only 92 of the prescribed 130 Gy [71%] of dose had been delivered. Additional measurements and imaging identified that an aggregate of microspheres remained in the vial and at the hub of the microcatheter where it connects to the delivery system. No other activity or contamination was noted in associated equipment.
The patient was advised the next day of the substantial lowering of the dose delivered. No immediate effect on the patient is expected at this time and no determination has been made as to any corrective action or additional dose to supplement the partial treatment. A follow up with the patient is pending. Similarly, the licensee is unaware of any corrective action necessary for future treatments pending additional evaluations and assessments. Consideration is being given to having the delivery system returned to the manufacturer for an engineering analysis once the radioactivity present has decayed. An investigation by IEMA is pending.
IL Item Number: IL12007
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.