EN Revision Imported Date : 8/12/2020
EN Revision Text: AGREEMENT STATE REPORT - UNDERDOSE OF YTTRIUM-90 DURING TREATMENT
"A medical event was reported to the Massachusetts Radiation Control Program on Friday, February 14, 2020. A patient receiving a therapeutic radiation dose to the right lobe of the liver using Y-90 Theraspheres in 2 fractionated doses was intended to receive 135 Grays for each fraction. The patient was administered 45.5 Grays for the first fraction and 129.4 Grays for the second. The first fraction underdosed the right lobe of the liver by greater than 50 percent and differed from the prescribed dose by greater than 0.5 Sv (50 rem) effective dose equivalent. The actual underdose for the first fraction was 8,950 rads. This exceeds the reporting limits of 10 CFR 35.3045(a)(1)(i)(c), 'Report and Notification of a Medical Event,' and 105 CMR 120.594(A)(1)(a)(3).
"The licensee is investigating the cause of the event and will be reporting the results to the Massachusetts Radiation Control Program. "
* * * UPDATE ON 8/11/2020 AT 1715 EDT FROM SZYMON MUDREWICZ TO BETHANY CECERE * * *
"Medical event no. 14-4085 was reported to the Massachusetts Radiation Control Program (hereafter, 'Agency') by Massachusetts General Hospital (hereafter, 'licensee') on 02/14/2020 involving administration of TheraSphere Y-90 microspheres to a patient for liver cancer treatment. The patient was scheduled to receive two doses on 02/13/2020 to the right lobe and segment 4 of the liver; 1.59 GBq and 0.29 GBq, respectively. Administration of both doses went accordingly and no unusual signs were observed by the authorized used conducting the administration. There were no problems with the flow of liquid through the microcatheter, no excessive pressure was needed to push the spheres, no leaks were observed, and there were no visual indicators that spheres were collecting at junctions in the tubing. The RADOS dosimeter, supplied with the delivery system, was reading 0.0 mR/hr at conclusion of each dose delivery indicating minimal residual activity inside the delivery system. After each dose the microcatheter and delivery system tubing are placed in a waste container - for storage to decay - where the dose is measured to calculate the activity of any residual microspheres that were not delivered. The calculations were performed the morning of 02/14/2020 and it was determined that only 0.512 GBq (33.7%) of the first dose was delivered to the target site, whereas as 0.273 GBq (95.9%) of the second was delivered to the target site. These calculations identified a possible occlusion in either the microcatheter or delivery set tubing and also identified a malfunctioning dosimeter. No physiological risk to patient health was identified.
"The Agency considers this event closed."
Notified R1DO (Gray) and NMSS Events Notification (email)
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.