ENS 43746
ENS Event | |
|---|---|
18:00 Oct 24, 2007 | |
| Title | Gamma Knife Treatment to Wrong Side of Brain |
| Event Description | On October 24, 2007, a medical event occurred at Leksel Gamma Knife facility which resulted in the total dose delivered differing from the prescribed dose by more than20%.
1. Licensee's name: Karmanos Cancer Center. 2. Name of prescribing physician: [DELETED] 3. Brief description of the event: Due to a left - right reversal of the treatment planning MRI images, the patient's left side was targeted and treated rather than the right side. The error resulted in an 18 mm shift of isocenter across midline of the brain. The collimator diameter selected for the treatment was 18 mm, thus resulting in some overlap of the delivered 50% isodose volume with the correct intended target lesion volume. The event resulted in approximately 7% of the lesion volume receiving the prescribed dose of 18 Gy to the 50% isodose, rather than the preferred 95% of the lesion volume. 4. Why the event occurred: During the pre-treatment setup and simulation MRI imaging, a 'feet first' scan technique was used with the patient positioned in the MRI scanner head first. This had the effect of reversing the axial images left to right. The standard of practice in gamma knife radiosurgery is to position the patient in the MRI scanner head first, and to use the 'head first' scan technique. The gamma knife authorized medical physicist (AMP) failed to recognize the scanning error when importing the MRI images into the Gamma Knife treatment planning computer, and subsequently registered them as head first. This resulted in the wrong side of the patient being targeted and treated, i.e. the left cerebellum was targeted and treated rather than the right cerebellar lesion. 5. The effect on the individual who received the administration: To be determined. 6. What actions have been taken or are planned to prevent recurrence: For all future gamma knife cases, left/right alignment of the MRI images will be inspected by the AMP by using the Leksel anterior face plate with fiducial markers visible in the MRI images. A Gamma Knife MRI protocol will be written and posted in the MRI department and in the Gamma Knife suite. The protocol will clearly indicate the patient and scan orientation required for Gamma Knife planning and delivery, which are patient on table head first, with head first scanning protocol. 7. Certification that the licensee notified the individual, and if not, why not: The referring neurosurgeon will be notified this evening after he finishes with surgery. 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.
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| Where | |
|---|---|
| Karmanos Cancer Center Detroit, Michigan (NRC Region 3) | |
| License number: | 21-04127-06 |
| Organization: | Karmanos Cancer Center |
| Reporting | |
| 10 CFR 35.3045(a)(1) | |
| Time - Person (Reporting Time:+17.67 h0.736 days <br />0.105 weeks <br />0.0242 months <br />) | |
| Opened: | Joe Rakowski 11:40 Oct 25, 2007 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Oct 26, 2007 |
| 43746 - NRC Website | |
Karmanos Cancer Center with 10 CFR 35.3045(a)(1) | |
WEEKMONTHYEARENS 453082009-08-27T22:00:00027 August 2009 22:00:00
[Table view]10 CFR 35.3045(a)(1) Medical Event - Patient Received 60% Less Dose than Prescribed ENS 437462007-10-24T18:00:00024 October 2007 18:00:00 10 CFR 35.3045(a)(1) Gamma Knife Treatment to Wrong Side of Brain 2009-08-27T22:00:00 | |