MRIdian Linac Radiation Therapy System Model 10000 and 20000

Issue with transferring treatment regiment from one system to another. Adequate instructions for transferring treatment plan(s) are not provided within the operator's manual or within the software operating system.

On 03/03/2019, the firm emailed an "URGENT DEVICE RECALL" to customers to inform them of a safety issue with the Treatment Planning and Delivery System (TPDS) in the MRIdian System. The notice explained that when a partially-completed patient treatment regiment is moved to their system from another system, the use needs to rescale the plan. The TPDS does not automatically rescale the treatment plan. The customers are instructed: If they want to move a treatment plan from one system to another and still show the total original prescribed dose on the MRIdian TPDS the customer will have multiple ways to do this. 1. Once the user/operator has evaluated the plan at the full dose, ensure the prescription matches the dose and number of fractions to be delivered on the MRIdian, and scale the dose to the target by either renormalizing or changing the target objective in the optimizer. 2. Keep the original total number of fractions (including those delivered elsewhere) in the prescription but when the plan is assigned to the fractions in the delivery calendar, Discontinue the number of fractions that have already been delivered on another system. 3. Import the previously delivered dose files as a RTDose and fuse with the plan images. Optimize to the remaining target dose that is to be deliver on MRIdian. Include the imported dose as Previously Delivered Dose and Calculate in the Finish screen to display the full dose which has and will be delivered. Ensure the prescription matches the dose and number of fractions to be delivered on the MRIdian. 4. Import the previously delivered dose files as RTDose and fuse with the plan images. Optimize to the original total dose, including the Previously Delivered Dose as part of the optimization. Ensure the prescription matches the total dose and number of fractions including those treated elsewhere and those to be delivered on the MRIdian. The customer is also informed that the Recalling Firm will address this is