Elekta is pushing back its time frame expectation of CE approval for its MR-linac to add additional functional imaging capabilities and spend more time validating its linac control system.

The Swedish-based manufacturer plans to add diffusion-weighted imaging (DWI) to the first commercial release of its MR-linac, Unity, for enabling dose painting, and is taking more time to validate the linac control system for optimal preparation in the potential release of dynamic, online adaptive treatments. As a result, expectation for CE approval has now been pushed back from the end of 2017 to the first half of 2018.

“This is a prerequisite for dose painting, where higher doses of radiation are deposited into the more active areas of tumors,” Kevin Brown, vice president, research and innovation at Elekta, told HCB News. “Functional imaging will provide the ability to capture MR information that is directly related to tissue biology and that could potentially be regarded as biomarkers that inform the treatment.”
DWI is one of the most common, studied and recognized biomarkers of MR in radiation therapy, with many scientific publications reporting on its potential for predicting responses of tumors to determine if patients are responding well or poorly to radiation treatment. Such information could enable earlier changes in course treatment, as opposed to waiting weeks to observe if changes will happen or not at anatomical levels.

Unity is equipped with a diagnostic high-field 1.5 Tesla MR component and can initiate anatomical imaging at the same time as scanning. It also can acquire 4-D MR datasets to analyze and characterize respiration-induced motion, provides information on the shape and position of anatomical objects in motion, and identifies the dynamic range of motion to help improve RT planning.

The linac control system is designed to power the most advanced solution for high-precision RT, with the extra time for validation ensuring it will be capable of handling the more rigorous requirements that may come with the release of dynamic, online adaptive treatments.

“This unprecedented technology is a key differentiator of the MR-linac system. Given the significance of the control system, Elekta is taking additional steps as part of its validation to guarantee it will meet rigorous performance requirements and provide the transformative benefits that MR-linac has the potential to bring to cancer therapy.”

Unity was installed this past year at the Christie NHS Foundation Trust in the U.K., the Sunnybrook Health Sciences Centre in Toronto, and at the Netherlands Cancer Institute.

The delay in CE marking will not impact the aim of Elekta to generate orders for 75 systems before the end of 2019, nor will it impact the installation of the pilot and research systems or have a financial effect on the performance of the 2017-2018 fiscal year.

Unity is not yet available for sale.

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