ENS 44537
ENS Event | |
|---|---|
04:00 Sep 8, 2008 | |
| Title | Lost I-125 Seed |
| Event Description | One I-125 sealed source ('seed') intended for permanent prostate implantation on 9/8/08 cannot be located definitively inside the patient or inside the hospital and is assumed lost. The calibrated activity was 0.481 mCi on 8/25/08.
On the morning of 9/8/08, a permanent prostate implant was performed in our high dose rate (HDR) treatment room in Radiation Oncology under sterile conditions. The implant was to consist of 62 seeds, in twenty needles each containing a varying number of seeds of 0.408 milliCurie of I-125. Seventy I-125 seeds were ordered and pre-loaded in a cartridge and were received sterilized from Isotron. Prior to treatment, one of the seeds was expelled from the cartridge and used for calibration. It was stored in a separate shielded container, and not used in the patient treatment. The written directive and treatment plan intended implantation of 62 I-125 seeds into a patient's prostate for the treatment of cancer. Using the Nucletron seedSelectron remote afterloading system, each needle was placed under ultrasonic guidance in the patient's prostate. The seedSelectron was connected to each needle and the seeds ejected from the cartridge into the needle. This procedure was performed for each of the twenty needles with only one needle being implanted at a time injecting a total of 62 seeds. The treatment progressed normally as planned and was successfully completed. At the conclusion of the treatment, X-rays were taken to verify the number of seeds implanted, and the count of 61 instead of 62 was confirmed radiographically. Prior to exiting the room, all staff (radiation oncologist, nurse, physicist, brachytherapy specialist) completed the routine required survey which included the soles of the shoes. The residual seeds in the cartridge were x-rayed and seven I-125 seeds were identified by at least 3 medical physicists. At least 3 medical physicists and the authorized user examined the patient's x-rays, and each could clearly identify only 61 seeds in the patient. The one I-125 seed used for calibration was accounted for in the inventory. The patient was scheduled to return for bi-plane views on 9/10/08, so that additional radiographs could potentially identify the missing seed. When the patient returned on 9/10/08, he had excreted four I-125 seeds which were properly handled and placed in the secure designated storage area. On the follow up x-rays, only 57 seeds were clearly identified. The anatomy surrounding the prostate was also imaged, but only 57 seeds were clearly identified. The entire pelvic region, abdomen and chest were also imaged with no results. It is possible that the seed may have migrated to an area inside the patient which was not included on the follow up x-rays. The pre-loaded cartridge of seeds was not x-rayed prior to the treatment, so the presence of all 70 seeds was not confirmed prior to the treatment. It is conceivable that only 69 seeds were shipped. We contacted Isotron and they provided us with their documentation showing that they shipped 70 seeds. The most probable disposition is that the seed is located inside the patient, but has migrated to an area which does not allow us to confirm its presence radiographically. The second most likely explanation is that we only received 69 seeds instead of 70 seeds. It is unlikely that the seed is lost inside our HDR suite, given the normal progression of the implantation procedure and the thoroughness of our search. It is very unlikely that the seed was disposed of in the landfill or sewer, since it was not detected when the team of medical physicists individually surveyed each item of linen and trash, and thoroughly surveyed the sink. No exposure of individuals to radiation from the one missing I-125 in restricted and unrestricted areas is expected. A thorough search was initiated immediately, using a pancake thin end window Geiger-Mueller detector in the micro-R/hr range (Ludlum Model 14C, calibrated on June 4, 2008). The surgical table, floor, each item of trash, each item of linen and all personnel were carefully surveyed. All cartridges and needles were rechecked several times. A thorough survey of the surgical table was conducted, urine collection bag and patient (even near the pelvis, although exposure from the implant made detection in this vicinity unlikely). The low survey readings in adjacent areas of the patient made it unlikely that the seeds were on the patient. The patient was released and removed from the HDR room and transferred to Phase I recovery. The survey also included the entire entrance hallway to the HDR room and the radiation oncologist's office. The Radiation Safety Officer designate for Radiation Oncology was notified and an additional survey of the room was conducted with the Johnson survey instrument (GSM-15) with a plastic scintillator (GLE-1), calibrated with an I-125 source on January 4, 2008. The surface of the floor including the small cracks in the floor covering and at the baseboards was surveyed. Each item of trash and linen was checked separately. The Corporate Radiation Safety Officer was notified and conducted an independent search with the Johnson survey instrument which included the entire floor, baseboards, sink, each item of equipment in the HDR room, the linen and trash. When nothing was found, the room was released so that patient treatments could be resumed in the room. A repeat survey of the patient using a Geiger-Mueller detector in the microR/hr range (Victoreen model 190 with pancake probe, calibrated April 24, 2008) as well as the areas surrounding the patient, trash and linens was performed in the Phase I area. All readings were low indicating the source was not in the vicinity. The patient was then discharged to Phase II. A survey including the patient, stretcher, linens, trash, urinary catheter, urinary bag and area was performed in Phase II. Low readings were again observed indicating the source was not in the area. The unused seeds were returned to the locked cabinet in the other HDR room for inventory and storage. Procedures or measures that have been, or will be, adopted to ensure against a recurrence of the loss of licensed material: (1) All personnel involved with prostate implants will receive refresher training regarding proper procedure. (2) An image of the loaded cassette will be taken to verify the receipt of the correct number of seeds. This image will be retained along with the patient records. In the event the seed count on the image does not agree with the count per the manufacturer, the situation will be reconciled prior to treatment. (3) Every effort will be made to obtain a seed count that accounts for all of the seeds received from the manufacturer prior to the discharge of the patient. The licensee has reported this event to NRC Region III. 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. Although IAEA categorization of this event is typically based on device type, the staff has been made aware of the actual activity of the source, and after calculation determines that it is a Less than Cat 3 event. Note: the value assigned by device type "Category 2" is different than the calculated value "Less than Cat 3 |
| Where | |
|---|---|
| William Beaumont Hospital Royal Oak, Michigan (NRC Region 3) | |
| License number: | 21-01333-01 |
| Organization: | William Beaumont Hospital |
| Reporting | |
| 10 CFR 20.2201(a)(1)(ii) | |
| LER: | 05000412/LER-2008-003 |
| Time - Person (Reporting Time:+610.75 h25.448 days <br />3.635 weeks <br />0.837 months <br />) | |
| Opened: | Cheryl Schultz 14:45 Oct 3, 2008 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Oct 3, 2008 |
| 44537 - NRC Website | |
William Beaumont Hospital with 10 CFR 20.2201(a)(1)(ii) | |
WEEKMONTHYEARENS 445372008-09-08T04:00:0008 September 2008 04:00:00
[Table view]10 CFR 20.2201(a)(1)(ii) Lost I-125 Seed 2008-09-08T04:00:00 | |