The following information was obtained from the
New York City Office of Radiological Health via email:
Type of event: Therapy, gammaknife
Description of event: Patient was being treated by gammaknife Model C-23004 for a meningioma. Halfway through, the treatment was automatically terminated. It was discovered that the latch that fastens the immobilizing frame of the head to the couch failed. Termination of treatment resulted in an underdose of more than 50% below the prescribed dose for that fraction. This was the third of three patients who were being treated at about that time. The first two patients were treated without incident.
Discovery of Event: Event was discovered when treatment was automatically terminated in the course of treatment.
Effect on Patient: In the opinion of the responsible physician, there are no expected sequelae for this patient as a result of this event.
Root Cause of Event: The root cause of this event was mechanical failure. There was not found to be any computer failure involved.
Actions Taken to Prevent Recurrence of Event: Replacement of latch mechanism.
Inspection Results: An inspector from the [NYC] Office of Radiological Health conducted an inspection on 11/17/11. The inspector found the circumstances of the event to be as described above.
Any Issuance of Violations: No formal violation was issued.
This case is considered closed.
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.