TomoH(R) System, Model Number 1018284 Product Usage: The TomoTherapy treatment system is intended to be used as an integrated system for t he planning and precise delivery of radiation therapy, stereotactic radiotherapy, or stereotactic radiosurgery to tumors or other targeted tissues while minimizing the delivery of radiation to vital healthy tissues. The megavoltage x-ray radiation is delivered in a rotational, non-rotational, modulated (IMRT), or non- modulated (non-IMRT/3 dimensional conformal) format in accordance with the physicians prescribed and approved plan.

Uncontrolled couch Z-axis movement (descent)

Accuray sent an Urgent Field Safety Notice letter dated November 8, 2017, to affected customers. The letter identified the affected product, problem and actions to be taken. The letter stated the following: "Accuray(R) will correct all affected High-Performance Patient Couches. An Accuray representative will contact you to arrange a time to update your system. The update includes the installation of TomoTherapy(R)' H(TM) Series software version 2.1.2 (Hi Art(R) vS.1.2) on your system, as well as the replacement of cables within the couch subsystem." For questions contact Accuray Customer Support by phoning the regional support lines.