Recall – Radiotherapy system failure to function with software upgrade

Company: Varian Medical Systems, Inc.
Date of Enforcement Report: 5/13/2020
Class II


Varian Multileaf Collimator [MLC]; Millenium Multileaf Collimator [52, 80, 120 leaf]; High Definition 120 Multileaf Collimator Model Number(s): product code: H54 and H56; MLC software version 8.5 – Product Usage: is intended to assist the clinician in the delivery of external beam radiation to defined target volumes during radiosurgery and radiotherapy while sparing surrounding normal tissue and critical organs from excess radiation.

Recall Number: Z-1899-2020


After a recent upgrade to the collimator software version 8.5, the firm became aware that the multi-leaf collimator leaves did not move during an arc treatment. The issue is related to a transient carriage primary- secondary interlock due to carriage fault on the MLC that immediately preceded the initiation of the arc treatment. The issue will occur only with MLC software version 8.5 and only affects conformal arc treatments, including VMAT and RapidArc. There have been no reports of adverse health consequences due to this issue.


Varian Medical Systems, Inc. on 8/12/2019. Voluntary:  Firm Initiated recall is ongoing.


151 units


US Nationwide and International

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