Safety Alert for RayStation 4.5, 4.7, 4.9, 5, 6, 7, 8A

Safety alert

2018-07-03

2018-07-03

Hong Kong

DH

https://www.mdco.gov.hk/english/safety/recalls/recalls_20180703.html

Medical device safety alert: raysearch laboratories ab, raystation 4.5, 4.7, 4.9, 5, 6, 7, 8a medical device manufacturer, raysearch laboratories ab, has issued a medical device safety alert concerning its raystation 4.5, raystation 4.7, raystation 4.9 (rayplan 1), raystation 5, raystation 6 (rayplan 2), raystation 7 (rayplan 7) and raystation 8a (rayplan 8a) [build number: 4.5.0.19, 4.5.1.14, 4.5.2.7, 4.7.0.15, 4.7.1.10, 4.7.2.5, 4.7.3.13, 4.7.4.4, 4.7.5.4, 4.9.0.42, 5.0.0.37, 5.0.1.11, 5.0.2.3, 6.0.0.24, 6.1.0.26, 6.1.1.2, 6.2.0.7, 7.0.0.19, 8.0.0.61]. it has come to the manufacturer‘s attention that an issue found with the dmlc “sliding window” photon dose calculation in the affected products for machines with jaw movement per beam, x-jaws and where the mlc is not above both jaws (i.E., varian style linacs). if the beam model has a highly asymmetric primary source, it is not correctly taken into account in the calculation of dmlc fields when the collimator is rotated. according to the manufacturer, the issue has not caused any patient mistreatment; however, the user must be aware of the stated information to avoid incorrect dose calculations during treatment planning. if a plan affected by the error is approved for treatment without plan qa measurements, this could result in over-dosage in the entire irradiated volume. the issue relates to an error that is triggered only for certain conditions in a well-defined use case. there is an acceptable workaround that can be easily understood by users and adhered to in order to avoid harm. the issue will therefore be corrected by means of updated labeling. a field safety notice will be distributed to all affected customers. for future installations of the affected versions, the description of the error and the workaround shall be included in the product installation as an additional release note. with the correction in the form of updated labeling, the residual risk is acceptable. the instructions for use requires users to study the release notes carefully, as the notes provide final instructions on how to use the system. when following the instructions in the updated labeling, the affected work flow will be safely avoided and there is no risk of harm. the long term solution is to release a new version of the raystation system eliminating the problem. the affected users are advised to take the following actions: inspect the beam model for all linacs with jaw movement per beam, x-jaws and where the mlc is not above both jaws (i.E., varian style linacs) that allow dmlc planning. if either the x- or y width of the primary source is below 0.01 cm or if they differ with more than a factor 2, do not use this beam model for dmlc. contact the manufacturer for further assistance in adjusting the beam model and identifying potentially affected patients. the issue will be resolved in the next version of raystation/ rayplan. if customers wish to continue using versions of raystation/rayplan affected by the notice, all users must maintain awareness of the notice. alternatively, the customers can choose to upgrade to the new version once it becomes available for clinical use. according to the local supplier, the affected product is distributed in hong kong. if you are in possession of the affected products, please contact your supplier for necessary actions. posted on 3 july 2018.