The following information was obtained from the State of
New Jersey via email:
At 11:30 a.m. [EDT] on July 16, 2013, a patient was being treated for three lesions with an Elekta Leksell Gamma Knife Perfexion unit, serial number 6016, at Cooper Health System in Camden, New Jersey. The prescribed total dose for all three lesions was 58 Gray.
The first two lesions were treated as planned without incident.
During treatment of the third lesion, treatment was interrupted because of mechanical failure. A 'Sensor Failure' error occurred, which caused the patient couch to retract and the shielding doors to close. An Elekta service engineer was called and no other treatments were attempted after the 'Sensor Failure'. Treatment of the third lesion was to be re-scheduled.
It is estimated that only 44.8 Gray out of the prescribed dose of 58 Gray was actually delivered, which is an underdose of greater than 20%.
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.