ENS 47393
ENS Event | |
|---|---|
04:00 Jun 29, 2011 | |
| Title | Overdose To Patient Of 48% During Gammamed High Dose Rate Treatment |
| Event Description | Patient was treated intraoperatively following surgical removal of a metastatic lesion in the sacral region. Treatment involved Ir-192 in a Gammamed HDR (High Dose Rate).
In standard cases implant geometry calls for a single-plane treatment, and entry of treatment plan into a commercial planning treatment system to control stopping positions of dwell times of source catheter. Size of treatment volume was such in this case that two treatment planes were required. Decision was made to select a single plane midway between the two treatment planes so that both treated regions would receive required dose. Prescribed dose was 15 Gray at a position 1cm away from the source plane on either side, thus simulating a volume source implant. Treatment plan in this case required manual input of treatment parameters. Physicist incorrectly entered distance between treatment planes as 3 cm, instead of 3 mm. A treatment plan was generated using the larger distance, and corresponding source stopping positions and dwell times for this separation. The result was incorrectly large dwell times and an overdose to the two treatment planes separated in fact by 3 mm. It was calculated that the dose delivered was 22.2 Gray rather than the prescribed 15 Gy, an overdose of 48%. Discovery of Event: Event was discovered during chart rounds when a supervising physicist noticed the difference between prescribed dose and the iCheck results. After discovery of the event, it became evident upon reconstructing the timeline of events that treatment planning sheets in the patient's record had been altered. Effect on Patient: In the opinion of the attending radiation oncologist, it is unlikely that there will be any medical consequences. Root Cause of Event: An analysis concluded that the root cause of the event included:
Actions Taken to Prevent Recurrence of Event:
Inspection Results: An inspector from the Office of Radiological Health conducted an inspection on 9/21/11. The inspector found the circumstances of the event to be as described above. In addition, the inspector found that:
The inspector found licensee to be highly cooperative and believes that actions taken in the wake of this event were satisfactory. No formal violation was issued. 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 | |
|---|---|
| Memorial Sloan-Kettering Cancer Center New York, New York (NRC Region 1) | |
| License number: | 75-2968-01 |
| Organization: | New York City Bureau Of Rad Health |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+2987.77 h124.49 days <br />17.784 weeks <br />4.093 months <br />) | |
| Opened: | Tobias Lickeman 15:46 Oct 31, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | Oct 31, 2011 |
| 47393 - NRC Website | |
Memorial Sloan-Kettering Cancer Center with Agreement State | |
WEEKMONTHYEARENS 496492013-11-21T05:00:00021 November 2013 05:00:00
[Table view]Agreement State Agreement State Report - Hdr Brachytherapy Source Placed Incorrectly ENS 473932011-06-29T04:00:00029 June 2011 04:00:00 Agreement State Overdose to Patient of 48% During Gammamed High Dose Rate Treatment ENS 469632009-10-06T04:00:0006 October 2009 04:00:00 Agreement State Medical Underdose During Bone Radiation Therapy 2013-11-21T05:00:00 | |