[226539]
This memo is to document an incident that occurred with the mobetron in o. R. 2 on 2001 at approx 11:15 am. After rotating the gantry to approx 340 degrees and a tilt of 15 degrees, the pt with attached cone was transported into position by moving the operating room table from the surgical position to the treatment position (the area of treatment under the collimator opening). The docking procedure was then initiated by the rptr using a hand control and the laser guidance system to make minor adjustments to the gantry angles (tilt and rotation) and gantry position (left, right, in, out, forward, backward) to align the axis of the beam with the axis of the cone. During this docking process, the gantry suddenly rotated approx 10 degrees to a gantry angle of approx 330 degrees. This movement was halted due to a collision of the gantry system with the electronic modulator stand, which prevented the gantry from colliding with the floor. Fortunately, nobody was injured by this incident. After the pt was removed from under the machine, the decision was made by the surgeon and the radiation oncologist to abort the intraoperative procedure and instead, to give the pt external beam radiation treatment after surgery. The surgical procedure was then completed without further incident. After the incident, the rptr immediately notified the chief engineer from intraop, inc and described the incident to him. At approx 2:15 pm, the engineer arrived in the o. R. , examined the gantry mechanism and determined that the cause of the problem was with a torque ring that connected the drive gear to the motor shaft. It was felt that this ring was not adequately tightened during mfg and assembly of the machine. The damage was subsequently repaired and the mobetron was tested by moving the gantry to mechanical limits of the system and was found to be in working order. Intraop, inc. Is preparing a report of the incident to the fda and this description will be appended to that report.
Patient Sequence No: 1, Text Type: D, B5