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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 56235 | 24 October 2022 05:00:00 | Agreement State | Lost I-125 Brachytherapy Seed | The following information was provided by the Nebraska Department of Health and Human Services via email: A Radioactive Seed Localization (RSL) contained 247 microcuries of I-125 on 10/24/2022. After the tissue sample containing the seed was surgically removed from the patient, it was placed on a flat plastic pathology grid. It was then placed in a cabinet x-ray unit. The x-ray showed the seed was in the tissue sample and was in fact removed from the patient. The sample was transferred from the plastic grid to a specimen container and then secured with a lid. The container was placed in a bag for transport to the lab. The lab removed the cup from the bag and placed it on the processing bench. The cup was surveyed with a gamma probe to locate the seed. The pathologist was unable to locate the seed using the gamma probe. The pathologist began to slice the sample to locate the seed. All tissue, except the tissue being sent for analysis, was returned to the specimen cup. Pathology then notified the nuclear medicine technologists (NMTs). The NMTs told pathology to control access to the room and not remove any trash or equipment. The NMTs also notified the operating room about the missing seed and had them control access to the room, to include not removing any linens, equipment, or trash. The NMTs then notified the Radiation Safety Officer (RSO) of the missing seed. A NMT surveyed the operating room, the patient, and the operating room staff. Additionally, the x-ray unit, floor, linens, equipment carts, pathology grid, and trash in the operating room were surveyed multiple times. All operating room staff were surveyed, including their shoes, before being allowed out of the room. All surveys were performed with both a GM survey meter and a gamma probe. During this time, another NMT went to the pathology room where the sample was taken and surveyed the room and the staff. The processing bench and hood, floor, and trash of the pathology room were surveyed multiple times. All pathology staff in the room were surveyed multiple times, including their shoes, before being allowed to leave the room. Surveys in the pathology room were also completed with both a GM survey meter and a gamma probe. The RSO viewed the tissue sample x-ray, confirmed that the seed had been removed from the patient and determined the patient was able to go. The RSO performed a survey with the gamma probe of the specimen container, tissue sample, room, processing bench, and trash of the pathology room. The RSO also performed a survey of the operating room, x-ray unit, equipment carts, pathology grid, and trash. The seed was lost sometime after imaging the tissue sample and before the sample was processed by the pathologist in the pathology room. The RSO thinks either the source came loose when being transferred either from the plastic grid into the specimen cup or from the specimen cup onto the processing bench. The RSO thinks it is possible that the seed fell into a seam or opening inside the x-ray cabinet or processing bench and is being shielded by the metal structures. With no shielding the dose rate of the seed is about 0.04 mR/hr at one meter. The RSO stated that since even the most sensitive survey could not find any radiation above background, it is unlikely that any staff or member of the public would, or will, receive any unintended radiation exposure from the missing source. The licensee has revised their procedure to eliminate one of the tissue transfer steps. The tissue sample is now being place directly into the specimen container after removal from the patient. The sample will be x-rayed in the container instead of transferring it to the flat plastic grid. Source/Radioactive Material: Sealed Source Ionizing Radionuclide: I-125, 0.000247 Ci Nebraska Item Number: NE220005 THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf |