[57933559]
This notification reports a product malfunction associated with the. Decimal proton range compensator. No serious injury or death has occurred, but there is a potential for serious injury, if the event were to recur. A patient was placed in treatment position on a patient treatment couch to be treated by the mevion medical systems mevion s250. As the patient was lying on the treatment table, the range compensator, a product manufactured by decimal, separated from its mounting screws holding it to the clamp ring. This caused the range compensator to fall from it's mounting above the patient onto the patient's chest. This particular event did not result in a serious injury or death. However, if this event were to recur, under particular conditions, it could potentially result in a serious injury, as assessed below. The design team evaluated the potential harm that could result from recurrence of this issue. The results conclude: the range compensator is made of plastic or wax and can weigh as much as (b)(6) pounds in an extreme case. The greatest hazard posed would be a fully retracted compensator falling from above the patient onto their head. This would be a fall of 20 cm or less, with a resulting energy of 8 joules. If the impact is absorbed in 1 cm of stopping distance that would generate a force of (b)(6) newtons (b)(6) lbs of force). As some of the shock is transferred to the head support this is a reasonable worst case. This is enough force to cause lacerations and bruising, but not enough to cause a skull fracture in an adult patient. In pediatric patients the nose and clavicle are particularly fragile bones. These could conceivably suffer a fracture from such forces, but the trauma would be moderate and treatable. Other body parts would suffer less trauma as the impact would be dissipated over a greater distance. Such impact may require medical intervention, of a low to moderate nature.
Patient Sequence No: 1, Text Type: D, B5