Elekta Impac Software Sequencer Verify & Record System, for MOSAIQ, manufactured by Elekta Impac Software, Sunnyvale, CA. The intended use of Sequencer (generically referred to as a verification system) is to assist in the process of process of patient treatment on a radiotherapy treatment machine.

Mistreatment-- The database conversion utility used during the upgrade errantly changes the start gantry angle to zero. Any affected treatment fields, if not already treated, would start delivering from zero instead of the original prescribed value.

ELEKTA IMPAC SOFTWARE sent a USER NOTICE dated February 19, 2010, to all customers. The notice identified the product, the problem, and the action to be taken by the customers. Customers were urged to verify the start angle of the gantry against the treatment field definition prior to delivery. Review all treatment plans and charts with conformal arcs. If a treatment plan with an errant gantry start angle was identified, customers were to cease using that plan immediately. A workaround was to be re-imported into their current version of MOSAIQ. IMPAC Support was to follow-up with each site and execute a script to detect and correct all affected treatment plans. For questions, concerns, and requests for upgrade, customers were to email [email protected] or call their support center.