ENS 57037
ENS Event | |
|---|---|
05:00 Mar 18, 2024 | |
| Title | Dose to Unplanned Site |
| Event Description | The following was received from the Iowa Health and Human Services (HHS) via email:
On 3/19/2024, MercyOne Des Moines Medical Center reported an equipment failure involving a Best Vascular Inc. A1000 series intravascular brachytherapy device, and a 2.16 Gbq (58.4 mCi) strontium-90 source that occurred on 3/18/2024. The initial attempt to send the source train failed to reach the dwell position and stopped short of the treatment area by about 30 millimeters. After the authorized users (AU) attempts to try and increase pressure to send the sources further to the treatment area failed, the licensee decided to return the source to the device. There was a small delay in the source returning, because there was a slight bend in the catheter, and it seemed that was impeding the water pressure to push the source back. The licensee straightened the catheter a little bit, and when they did the source train returned to the device. At that point, the licensee disconnected and reconnected the catheter to try again and the source train again stopped in the same exact place. The licensee returned the source immediately. In total the source was in the incorrect position for approximately 30 seconds. The source was at the same position about 30 millimeters proximal to the treatment area. The AU picked up the radiopaque marker set to put back in and see if they could see how far it would go in on fluoroscopic imaging. When the AU picked up the radiopaque marker set, he noticed that there was a very strong kink (almost 90-degree bend) in the radiopaque marker set. Instead of putting the source radiopaque marker set back in, the licensee decided to pull the entire catheter and place a new beta-cath catheter in the patient. While testing the new radiopaque marker set (pulled them out, push them back in) the AU realized that when he did it on the other radiopaque marker set, he had felt a click at some point. The licensees hypothesis is that, when the AU felt the click, the radiopaque marker set bent and there is a potential that when it bent, there was damage to the catheter itself, and it would not allow the source train to go past that position where the kink happened. With the new catheter in place, the AU connected the device and sent the source train out to the treatment position without issue. The licensee continued to treat for the prescribed treatment time. Preliminary information: It is estimated that the source train sat for approximately 30 seconds in the wrong location. The dose delivered to that area about 30 millimeter proximal to the treatment site is 0.0632 Gy/s times 30 s equals 1.896 Gy, which is greater than the limits described in 10 CFR 35.3045(a)(1)(iii) reports and notification of a medical event. Iowa HHS will do a reactive inspection on 3/20/2024 and will update this event as more details are confirmed.
The following was received from the Iowa Health and Human Services (HHS) via email: Iowa HHS performed a reactive inspection on 3/20/2024 to confirm the facts and dose information. During this inspection, it was determined that the source train stopped in the aorta (30 mm vessel) in which the licensees initial dose calculations was to a 2 mm vessel. Due to the characteristics of the strontium-90 beta emitter, there is a significant drop off in dose to the tissue with increased distance (3.75 mm goes below the 50 rem threshold). The catheter was not resting against the aorta wall when it had stopped for 20-30 seconds and the actual dose to the tissue was determined to be 5.25 rads [0.0525 Gy], which is approximately 10 percent of the reportable medical event threshold as described in 10 CFR 35.3045. Additionally, the reporting requirements described in 10 CFR 30.50(b)(2) also were not met. Specifically, the day of the incident the licensee used a new catheter and successfully treated without incident so there was redundant equipment available and operable to perform the required safety function. The licensee has sent the partially failed catheter to the vendor for an evaluation." Notified R3DO (Edwards) and NMSS Events Notification via email. A Medical Event may indicate potential problems in a medical facilitys use of radioactive materials. It does not necessarily result in harm to the patient. |
| Where | |
|---|---|
| Mercyone Des Moines Medical Center Des Moines, Iowa (NRC Region 3) | |
| License number: | 0008-1-77-MET |
| Organization: | Iowa Department Of Public Health |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+36.88 h1.537 days <br />0.22 weeks <br />0.0505 months <br />) | |
| Opened: | Stuart Jordan 17:53 Mar 19, 2024 |
| NRC Officer: | Ossy Font |
| Last Updated: | Apr 4, 2024 |
| 57037 - NRC Website | |
Mercyone Des Moines Medical Center with Agreement State | |
WEEKMONTHYEARENS 570372024-03-18T05:00:00018 March 2024 05:00:00
[Table view]Agreement State Dose to Unplanned Site 2024-03-18T05:00:00 | |