The annual meeting of the American Society for Radiation Oncology is the place to be to discover the latest radiotherapy technology developments and new product launches. And this year was no exception. The ASTRO 2026 meeting, held this week in Boston, MA, saw Siemens Healthineers unveil its newest radiotherapy system – Accela – which combines precision delivery with speeds fast enough to enable stereotactic treatments in a single breath-hold.
Accela achieves this by implementing a new delivery technique known as NeoArc dynamic modulated arc therapy (DMAT). DMAT is a type of arc therapy, in which the treatment beam rotates continuously around the patient during treatment, with the beam shape and intensity controlled to deliver the prescribed treatment plan.
But while conventional arc-based approaches such as volumetric-modulated arc therapy (VMAT) primarily optimize treatment plans for the dose distribution, DMAT evaluates dosimetric objectives and delivery efficiency simultaneously. This enables clinicians to tailor treatments for both speed and precision, to optimize the balance between them and, ultimately, to reduce the patient time on the treatment table.
Sasa Mutic, head of radiation oncology solutions at Siemens Healthineers, tells Physics World that the product launch at ASTRO was a great success. “The response to Accela from customers and the medical community has been overwhelming and overwhelmingly positive,” he says. “It was extremely gratifying to see that the ASTRO audience instantly grasped the significance of what we’ve accomplished and the impact it will have on clinicians and patients.”
Done in 60 seconds
Accela integrates high-speed gantry rotation of up to 2.5 rpm, dose rates of up to 40 Gy/min and a dual-layer multileaf collimator (MLC) with leaf speeds of up to 6.25 cm/s. This combination means that, as well as single breath-hold stereotactic treatments, Accela can deliver multi-site stereotactic body radiotherapy (SBRT) in less than 60 s – including on-couch imaging with a large HyperSight cone-beam CT panel, couch shifts and the treatment delivery.
An additional benefit of ultrafast radiotherapy is the potential to actually alter the body’s biological response.
Computational model determines dose to blood during radiotherapy
“Because the treatment times are potentially as quick as a single breath hold, there is much less blood irradiated,” explains Dee Khuntia, chief medical officer at Varian, the Siemens Healthineers cancer-care business. “This allows for preservation of lymphocytes, which are necessary for helping the body heal, fight infection and fight cancer. It is also well documented that patients undergoing radiation or chemo-radiation who have lymphopenia [not enough lymphocytes in the blood] have lower survival rates.”
The first patient treatments with Accela are scheduled for December in Europe. By this time, the system will have the CE mark, with FDA clearance expected early next year. One of the first centres to use Accela will be Maastro in the Netherlands, which plans to initially treat small lung tumours, lung metastases, brain tumours and metastases in the vertebrae – sites that require a high radiation dose administered extremely precisely, while sparing healthy tissue and nearby vulnerable organs.
