MEVION S250i, MEVION S250; Proton Radiation Treatment System - Product Usage: intended to deliver proton radiation treatment to patients with localized tumors or any other conditions susceptible to treatment by radiation

Treatment beam information disappears on Treatment Console screen while beam delivery continues potential for harm to a patient could occur

Mevion issued User Notice by mail or FedEx, with return receipt confirmation on October 22, 2020. The letter states reason for recall, health risk and action to take: The User should actively monitor the TC screen during beam delivery. In the event the TC screen beam information appears blank during Beam On, the user should: Immediately suspend treatment by selecting Beam Off on the Beam Control Box. Record the MU counts displayed on the HMUC before any other action is taken. Consult physics to make manual adjustments of the plan. Notify Field Service to retrieve machine records of the partial beam delivery. Resumption of treatment requires Setup workflow to be repeated. Corrective Action All users should be notified of this scenario and the proper response. Please contact Mevion Customer service with any questions or concerns. Please distribute this notice to all users of the Mevion Medical Systems device at your organization who may be affected by this issue User confirmation of receipt shall also be received from each affected customer site. Customer Service Engineers are also permanently in working residence at customer sites and will ensure awareness of the issue.