Medical device manufacturer, Varian Medical Systems has issued a medical device safety alert concerning Eclipse Treatment Planning System, ARIA for Radiation Oncology, ARIA Radiation Therapy Management, and Acuity. The affected software versions are 11 and 13.
An anomaly has been identified with the Plan Parameters workspace within Eclipse Treatment Planning System, ARIA Radiation Oncology, ARIA Radiation Therapy Management, and Acuity. When a dose relevant parameter is changed and "Do not clear Monitor Units and Reference Point dose" is selected, the Monitor Units may change.
The Monitor Units of the plan may change without the user being aware when all of the following conditions are fulfilled:
When all these conditions are fulfilled, the dose is rescaled such that the 100% isodose is shifted to the primary reference point location. Consequently, the Monitor Units for each treatment field will change and will not meet the dose prescription intended.
For example, if the dose prescription percentage was 85% in the original plan, and a dose relevant parameter is changed, the dose prescription percentage will rescale to 100%. The Monitor Units will be correspondingly increased. Thus, the plan will no longer meet the intended dose prescription.
Also, the manufacturer recommends a thorough review of treated patient plans for plans with a primary reference point with geometric location and where modifications were made in the Plan Parameter workspace.
The manufacturer is developing a technical correction for the issue.
According to the local supplier, the affected products were distributed in Hong Kong.
If you are in possession of the affected product, please contact your supplier for necessary actions.
Posted on 9 December 2013