Varian Medical Systems Inc.

06/16/2025 | News release | Distributed by Public on 06/16/2025 09:35

ESTRO 2025 Research Roundup: Translating Innovations into Improved Patient Care

ESTRO 2025 Research Roundup: Translating Innovations into Improved Patient Care

Centerline

June 16, 2025

"Innovation through partnership," the theme of the 2025 European Society for Radiotherapy and Oncology (ESTRO) congress, has long been a cornerstone of Varian's mission to drive forward the standard of cancer care across the globe.

Varian, a Siemens Healthineers company, collaborates with premier research institutions worldwide to translate our technology innovations into improved outcomes for patients and increased efficiency for clinicians charged with their care.

At this year's ESTRO congress in Vienna, Austria, research teams presented nearly 100 abstracts sharing results of investigations into the clinical benefit of photon counting computed tomography (CT) and magnetic resonance imaging (MRI) technologies by Siemens Healthineers, as well as three key Varian innovations - HyperSight* imaging solution, RapidArc Dynamic,^ and Ethos adaptive therapy- a remarkable achievement in what are highly-competitive and sought after slots in the ESTRO scientific agenda.

"Our goal, as ever, is to give clinicians the tools to deliver the optimal care at the right time," said Sushil Beriwal, MD, Vice President, Medical Affairs for Varian. "These studies highlight how these patient-centric technologies seek to help care teams improve efficiency and patient experience with personalization of care."

Additionally, two Varian-funded papers were awarded prestigious honors and reflect the breadth of Varian's focus on addressing clinical and operational challenges to the cancer care pathway to better outcomes for patients.

The EMBRACE II trial1, which is funded in part by Varian, was recognized with the Hollywood Award, given to the best abstract selected for presentation at an ESTRO congress. This prospective, interventional, multicenter trial investigating advanced treatment strategies for Locally Advanced Cervical Cancer (LACC) may establish a new standard of care, especially in high-risk groups, with integration of VMAT/IMRT and MRI-based adaptive brachytherapy showing excellent local control and reduced morbidities.

Funded by a Varian research grant, the ESTRO Health Economics in Radiation Oncology (HERO) cost accounting tool2 was recognized with the Best Interdisciplinary Award. The tool was recognized for its strength to help inform national resource planning and relevant national reimbursement coding.

Research presented at ESTRO highlights the potential impact that technologies by Varian and Siemens Healthineers are driving throughout the cancer care pathway.

CT Simulation

4DCT imaging is essential for motion management, as breathing-induced artifacts can impede treatment planning and affect clinical outcomes, such as local control.

Irregular breathing during 4DCT data acquisition can lead to stack artifacts, which negatively impact image quality. A study3 conducted at the University Hospital Erlangen in Germany demonstrated that the new reconstruction algorithm ZeeFree RT by Siemens Healthineers can reduce stack artifacts, and thereby "demonstrated significant improvements in image quality and anatomical correctness," which may enable improved treatment planning.

A separate retrospective study4 including 103 in-house stereotactic treatments of thoracic metastasis from University Medical Center Hamburg-Eppendorf in Germany, showed how the 4DCT acquisition technique Direct i4D by Siemens Healthineers adapts to the patient breathing in real time and thereby reduces artifacts caused by irregular breathing. The authors show that Direct i4D, when compared to standard spiral 4DCT, mitigates interpolation artifacts and exhibits fewer double structures. If not accounted for, such artifacts "negatively influence clinical outcome in SBRT of lung and liver metastases," as the Hamburg team had shown in a previous study5.

A study6 conducted by the University of Zurich in Switzerland investigated different image reconstructions for photon-counting CT in radiation therapy, focusing on CT number accuracy. Phantom scans acquired on a NAEOTOM Alpha† photon-counting CT scanner by Siemens Healthineers showed an expected calibration curve for 120kVp-equivalent reconstructions and accurate quantitative results for the direct reconstruction of electron density using the spectral data. An evaluation of patient data showed that photon-counting CT may allow for identifying and overwriting unknown high-density materials and thereby enable a more precise dose calculation.

Magnetic Resonance Imaging

A study7 from Institute Jules Bordet in Anderlecht, Belgium, conducted dosimetric evaluation of different CT scans to assign bone bulk densities for online adaptive MR-guided RT planning: classical CT using SOMATOM go.Open Pro, direct density CT and an AI-based synthetic CT generated from an MRI scan using Siemens Healthineers MAGNETOM Aera† and syngo.via† platform. Researchers found only negligible dosimetric deviations in the treatment plan when deriving the bone bulk density from synthetic CT compared to classical or direct density CT and concluded that Siemens Healthineers AI-based synthetic CT solution can be used clinically for MR-guided online adaptive radiotherapy of prostate cancer.

A study8 by University Hospital Erlangen in Germany examined the need for a receive coil holder in pelvic MR-only treatment planning, which is typically required when acquiring pelvis MRIs for treatment planning to avoid body surface deformation but can be cumbersome to set up and reduce image quality as they increase the distance to the receiver coil. The study found when acquiring pelvis imaging for radiotherapy with the MAGNETOM Free.Max RT Edition† by Siemens Healthineers, the new lightweight contour coils don't require coil holders anymore.

HyperSight

Varian's HyperSight* imaging solution, which allows clinicians to acquire high-quality cone-beam CT (CBCT) images comparable to that of a CT simulation image and is available as an optional feature on the Halcyon, Ethos, TrueBeam, and Edge radiotherapy systems, was the subject of research on three continents.

"Several studies highlight the workflow advantages of HyperSight for both offline and online adaptive planning, potentially enabling direct dose calculation for plan modification, and thereby saving time by avoiding repeat CT scans on a simulator," Dr. Beriwal said.

A study9 by Nova Scotia Health in Canada points to the suitability of HyperSight CBCT images for direct dose calculation during adaptive treatment. Investigators assessed the image quality and accuracy of HyperSight imaging compared to simulation CT images in 19 head & neck patients and found that HyperSight images were less affected by the metal artifacts and provided greater Hounsfield Unit (HU) accuracy. According to the researchers, this accuracy could translate into CBCT-based dose calculation differences of less than 1% in the head and neck region and, and thus could be used interchangeably for online adaptive planning.

Researchers at Ajou University School of Medicine in South Korea determined10 that HyperSight CBCT has the potential to contribute more effective and efficient offline adaptive radiotherapy for breast cancer patients. The improved reconstruction algorithm enhanced HU accuracy, which increased the precision of treatment plan modifications and dose calculations. As a result, HyperSight can minimize delays for breast cancer patients with changing volumes, potentially improving treatment outcomes and workflow efficiency.

RapidArc Dynamic

Powered by next-generation algorithms, Varian's RapidArc Dynamic solution combines a dynamic collimator and modulated ports working seamlessly in a single arc treatment field, providing clinicians with supreme control for optimal dose delivery. Several studies presented at ESTRO this year focused on translating the innovative RapidArc Dynamic technology, which is available as an optional feature for the latest versions of Eclipse treatment planning system and the TrueBeam radiotherapy delivery platform, to improve clinical outcomes across a wide breadth of cancer sites.

"In clinical application, these research teams are adding to the evidence that RapidArc Dynamic shows significant gains in efficiency for planning and delivery. The data presented showed that, when planning for lung, esophagus, breast and brain tumors, target coverage was similar or better with significant reduction in dose to the critical organs, which has the potential to reduce morbidities and thus improve outcomes," Dr. Beriwal said.

A blinded evaluation of 60 breast cancer cases11 at Icon Cancer Centres across Australia found that planning with RapidArc Dynamic was not only 78% faster than traditional VMAT planning, it was also preferred for target coverage, OAR dose, and overall plan quality. In fact, RapidArc Dynamic plans were chosen over VMAT in 100% of reviews by radiation oncologists.

In a planning study12 at the University of California San Diego, RapidArc Dynamic outperformed traditional VMAT in hippocampal sparing whole brain RT. It showed improved sparing of the hippocampus, as well as better target coverage.

Ethos adaptive therapy

Varian Ethos therapy solution unites artificial intelligence and advanced imaging to deliver truly personalized adaptive radiotherapy. At the 2025 ESTRO congress, Varian research collaborators contributed 60 abstracts and oral presentations on their work involving Ethos adaptive therapy with evidence suggesting that Ethos may improve clinical outcomes and enhance workflows.

"These research studies highlight the efficiency and outcome benefits that are potentially achievable with Varian technology solutions for online adaptive treatment," Dr. Beriwal said.

For example, a trial of online adaptive therapy (oART) in breast cancer patients13 at Amsterdam University Medical Center (AUMC) demonstrated that quality online adaptive therapies, with improved target coverage and OAR sparing, can be accomplished in a treatment time of 25 minutes or less. At AUMC, where up to 15% of breast cancer patients may require replanning, oART on Ethos enabled daily plan optimizations in an efficient workflow that prevented the need for offline replanning.

As a first step to adaptive radiotherapy for liver SBRT, investigators at Erasmus Medical Center in Rotterdam, Netherlands, developed a workflow for online adaptive VMAT plans for liver SBRT on an Ethos system and compared them with non-coplanar plans in a different platform. In this study14 of 32 patients, the coplanar Ethos VMAT plans provided better planning target volume (PTV) coverage and reduced dose to organs at risk (OAR) showing benefit of online adaptation in achieving better therapeutic ratio.

Can functional MRI-based imaging biomarkers be used with CBCT to assess early response to online adaptive radiotherapy? A research team at the German Cancer Research Center in Heidelberg, Germany, thinks it is possible. Thirteen patients with non-small cell lung cancer received daily oART on the Ethos system and weekly high-resolution, functional diffusion-weighted MRI in the treatment position using Siemens Healthineers MAGNETOM Vida RT Pro Edition. Coregistered CBCT and MRI sequences showed shrinkage of the target volumes and an increase of ADC (apparent diffusion coefficient), which could indicate positive tumor response to treatment. The research showed15 that the Ethos platform can integrate CBCT and functional MRI which could provide a potential imaging biomarker for response assessment during radiation. This may help in the future for dose adjustment based on response during radiation treatment.

"Ultimately, the real value of technology is how it ultimately helps patient care, without compromising the efficiency of treatment planning and delivery," Dr. Beriwal said. "Through these collaborations and other research studies, we are seeing how this technology translates into patient benefits, making it easier for clinical teams to deliver high-quality, personalized care."

Learn more about Varian's Medical Affairs work and support of clinical research.

*HyperSight is an optional feature on Varian's TrueBeam, Edge, Halcyon, and Ethos systems.

^RapidArc Dynamic is available as an optional feature for the latest versions of Eclipse treatment planning software and the TrueBeam radiotherapy delivery platform.

† The products/features (mentioned herein) are not commercially available in all countries. Their future availability cannot be guaranteed.

The statements by Siemens Healthineers and Varian customers described here is based on results achieved in the customer's unique clinical setting. Because there is no "typical" clinical setting and many variables exist, there is no guarantee that other customers will achieve the same results.

  1. Pötter, R. et al, EMBRACE II - a multicenter prospective interventional cohort study on IGRT-IMRT+cisplatin+MR-IGABT in locally advanced cervix cancer: overall results, ESTRO 2025 Proffered Paper 2638
  2. Bouchez, Q. et al, Advancing the ESTRO-HERO cost tool for innovative treatment costing and flexible resource allocation, ESTRO 2025 Proffered Paper 1679
  3. Bert, C. et al, Quantitative and qualitative assesment of a novel algorithm for correcting stack-artifacts in 4DCT Reconstruction, ESTRO 2025 Digital Poster 3789
  4. Wimmert, L. et al, Clinical application of Intelligent 4DCT (i4D): Analysis of image artifact frequency and comparison to conventional 4DCT, ESTRO Digital Poster 1095
  5. Sentker, T. et al, 4D CT image artifacts affect local control in SBRT of lung and liver metastases. Radiotherapy and Oncology, Volume 148, 229 - 234
  6. Psoroulas, S. et al, First implementation of photon counting CT in radiotherapy dose calculation for material distinction and identification, ESTRO 2025 Digital Poster 2176
  7. Gulyban, A., et al, Bone bulk density based on classical, Direct Density and synthetic CT for prostate MR guided SBRT: Is there a relevant dosimetric impact?, ESTRO 2025 Digital Poster 3440
  8. Putz F., et al, Assessing the Necessity of a Receive Coil Holder in Pelvic MR-Only Treatment Planning: Interim Results from the MR.pelvis Study at a 0.55T system, ESTRO 2025 Digital Poster 218
  9. Yashayaeva, A. et al, HyperSight-ARCHER Head and Neck clinical trial: Image Quality Analysis, ESTRO 2025 Digital Poster 808
  10. Park, H. et al, Clinical Potential of Offline Adaptive Radiotherapy Using Halcyon-HyperSight CBCT for Breast Cancer Patients: Image quality and dosimetric evaluation, ESTRO 2025 Digital Poster 1742
  11. Archibald-Heeren, B. et al, Clinical Meaningful Improvements to Breast Radiotherapy: A Blinded Evaluation of a new Hybrid VMAT/IMRT Technique featuring Dynamic Collimation, ESTRO 2025 Poster Discussion 1488
  12. Kim, G. et al, Improved Hippocampal Sparing in Whole Brain Radiotherapy using VMAT with optimized Dynamic Collimator Rotation and Modulated Ports, ESTRO 2025 Digital Poster 2228
  13. Vlaenderen, A. et al, Online adaptive radiotherapy in breast cancer patients - a prospective trial, BREAST-ART NL2021.0624, ESTRO 2025 Digital Poster 3455
  14. Aninditha, K. et al, Clinical Application of CBCT-based Online Adaptive Radiotherapy (oART) for Bladder Cancer, ESTRO 2025 Digital Poster 2378
  15. Niklas, M. et al, Towards MRI-based biomarkers for prognostic response assessment of adaptive radiotherapy in non-small cell lung cancer (NSCLC), ESTRO 2025 Digital Poster 3870

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