ENS Event | |
|---|---|
07:00 Mar 26, 2025 | |
| Title | Medical Event |
| Event Description | The licensee initially reported an underdose event that involved a CyberKnife (linear accelerator), and the event was referred to our X-ray inspection unit. On 4/11/25, our X-ray unit informed us that the underdose event involved an Elekta Gamma Knife Perfexion (Co-60) that experienced an electrical sensor failure that caused the patient's treatment to be interrupted.
The original planned treatment using stereotactic radiosurgery to the right trigeminal nerve using a single 4 mm collimator open shot to deliver a maximum of 80 Gy (76 Gy at the 95 percent isodose line). The treatment time was to take 49.24 minutes. However, after 12.47 minutes of treatment, a system error on the GK unit triggered a stop in treatment. All radiation sources (Co-60) were retracted to home positions and the patient was automatically removed from the treatment bore by the robotic couch with the shielding doors automatically closing. The patient only received 25 percent of the dose on 3/26/25, or about 20 Gy. On 3/27/25, the machine was successfully repaired by an Elekta engineer and the patient came back to the facility to complete treatment. The authorized user physicians modified their written directive and treatment plan to give an additional maximum dose of 70 Gy (66.5 Gy at the 95 percent isodose line) to the same treatment area. The patient successfully completed the treatment. California 5010 Number: 032625 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 | |
|---|---|
| Hoag Memorial Hospital Presbyterian Newport Beach, California (NRC Region 4) | |
| License number: | 0272-30 |
| Organization: | California Radiation Control Prgm |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+398.42 h16.601 days <br />2.372 weeks <br />0.546 months <br />) | |
| Opened: | Robert Greger 21:25 Apr 11, 2025 |
| NRC Officer: | Ian Howard |
| Last Updated: | Apr 11, 2025 |
| 57662 - NRC Website | |
Hoag Memorial Hospital Presbyterian with Agreement State | |
WEEKMONTHYEARENS 576622025-03-26T07:00:00026 March 2025 07:00:00
[Table view]Agreement State Medical Event ENS 513882015-08-26T07:00:00026 August 2015 07:00:00 Agreement State Agreement State Report - Lost Radioactive Material 2025-03-26T07:00:00 | |