ENS 51418
ENS Event | |
|---|---|
14:00 Sep 23, 2015 | |
| Title | Medical Underdose During Sirsphere Administration |
| Event Description | SirSphere administration to [the patient] on Wednesday Sept 23, 2015.
[The patient] was prescribed, with appropriate written directives, 0.27 GBq and 0.29 GBq to segments in the posterior and anterior right lobe of the liver. Paperwork for determination of the activities and volumes are available. The SirSpheres were received on Sept 22, 2015, calibrated for 1800 [EDT] on Sept 23, 2015. The two doses were prepared between 0900 and 0930 AM on Wed Sept 23, 2015. The procedure used is attached as are the worksheets for verification of activity. No unusual behavior was observed (e.g. clumping or unusual settling of the spheres). The posterior right lobe treatment was given first. The system was set up with D5W for the agitating solution and contrast in a three way set up for the contrast flush. The interventional radiologist administered in the method that has been used for all prior, successful, administrations. [The radiologist] reports that he did not encounter any difference in resistance in the syringe, nor did [medical center staff] note any difference in the appearance of the solution flowing through the three way stopcock. The administration was completed and the residual immediately checked using the method of pre vs post assay of delivery vial then delivery vial and associated tubing. The post reading was initially higher than the pre. The vial and tubing was carefully put onto a plastic backed pad and it was determined that there were higher readings from the vicinity of the three way stopcock. This patient was scheduled for two infusions due to their vasculature, and after much discussion it was decided, based on our prior success with treatments, to proceed with the second but pay very close attention to whether there were some spheres that were backed up at the three way. In the past, [medical center staff] have been able to dislodge such an occurrence by gentle knocking of the three way prior to the clearing of the vial with air. A new administration set was installed and the administration proceeded. Frustratingly, it was immediately apparent that some of the spheres were clumping at the three way but that some had passed through and were then in the patient. With gentle knocking of the stopcock, it was possible to dislodge many of the spheres. However, the after reading again showed that there was a measurable amount of activity that had stuck somewhere in the delivery tubing. Because the pre and post readings are so dependent on the presence of the plastic for both stopping the electrons and production of Bremmstrahlung, it was not possible to get any type of accurate assessment of the activity remaining. However, it was possible to evaluate the last three Sirsphere post Brem SPECT scans, determine a counts/administered activity, and evaluate that number. For the three patients the values were acceptably comparable, that this calibration value was then used to determine the activity present for the after study Brem scan on today's patient. This gave an estimate of approximately 70% of the written directive. Please note that this report is a preliminary report and an updated will be forwarded as this is reviewed by all concerned and also further evaluations performed. The licensee will contact the manufacturer to troubleshoot the issue, and will notify the patient, prescribing physician, and NRC Region 1.
Based on re-analysis of the data, and with concurrence of USNRC Region I DNMS Inspector (Nguyen), it was determined that the patient received between 82% and 90% of the prescribed dose. Based on this information, this event no longer meets the reporting criteria and is being retracted by the licensee. Notified R1DO (Bower) and NMSS Events Resource (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. |
| Where | |
|---|---|
| Univ Of Vt Medical Center Burlington, Vermont (NRC Region 1) | |
| License number: | 44-10187-03 |
| Organization: | Univ Of Vt Medical Center |
| Reporting | |
| 10 CFR 35.3045(a)(1) | |
| Time - Person (Reporting Time:+-1.85 h-0.0771 days <br />-0.011 weeks <br />-0.00253 months <br />) | |
| Opened: | Marleen Moore 12:09 Sep 23, 2015 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Sep 29, 2015 |
| 51418 - NRC Website | |
Univ Of Vt Medical Center with 10 CFR 35.3045(a)(1) | |
WEEKMONTHYEARENS 514182015-09-23T14:00:00023 September 2015 14:00:00
[Table view]10 CFR 35.3045(a)(1) Medical Underdose During Sirsphere Administration 2015-09-23T14:00:00 | |