ASTRO 2025: Varian-Led Research Seeks to Broaden the Boundaries of Radiotherapy | Varian

In today’s dynamic healthcare ecosystem, strategic coordination across departments and disease states has the potential to improve efficiency, care quality, and outcomes. This year’s ASTRO meeting offered a clear demonstration of that alignment in practice. While radiation therapy has long been synonymous with cancer care — 50-70% of all cancer patients need radiation therapy from curative to palliative care¹ — the research presented at ASTRO 2025 showed a wider view of what’s emerging as possible.

Aligned with this year’s theme, Rediscovering Radiation Medicine and Exploring New Indications, researchers showcased how radiotherapy may treat non‑oncological conditions like essential tremor, Alzheimer’s disease, and osteoarthritis. These findings highlight its potential to expand its role in modern medicine, offering non‑invasive alternatives, and renewed hope for patients and caregivers.

Varian’s scientific leadership was evident across the conference, with company-sponsored and investigator-led studies featured in multiple sessions. A strong Varian-advisory board presence was invited to speak at the ASTRO Presidential Symposium on research to explore potential applications ranging from Dupuytren’s disease to functional radiosurgery for movement disorders, and cardiac radiotherapy for ventricular tachycardia. Funded by Siemens Healthineers, Implantable Cardioverter‑Defibrillator (ICD) Artifacts Reduction for Radiotherapy of Ventricular Tachycardia² received a Physics Travel Award and was presented with an oral presentation designation. Both significant ASTRO recognitions, Huiming Dong (UCLA) was honored for developing MR Imaging methods to enhance precision in cardiac radiosurgery.

Expanding radiation therapy’s scope

For patients, expanding applications of radiation therapy may offer new options when other treatments have been unsuccessful or may carry significant risk. Examples include: medically refractory essential tremor, as well as low-dose radiation for adult patients with osteoarthritis who are not yet candidates for joint replacement but are clinically beyond simple medication management. Radiation is non-invasive, providing a precisely targeted alternative that may improve quality of life. And because linac-based radiosurgery can fit naturally into existing workflows for providers, it may open up new ways to optimize resources.

Non-oncologic radiotherapy took center stage at ASTRO 2025, with dozens of presentations and invited sessions exploring new clinical indications. Much of the attention focused on two complementary approaches: high-dose functional radiosurgery (FnSRS) and low-dose functional radiotherapy (FRT).

FnSRS uses highly targeted, high-dose radiation to ease symptoms in a range of brain disorders. The approach is already showing change outcomes for people with medically refractory essential tremor. At the Varian Users Meeting, patient Rachel Harris demonstrated this first-hand saying, "I have been able to reclaim a piece of myself since my treatment”. Her story set the stage for the multiple ASTRO podium sessions exploring how linac systems like TrueBeam and Edge may help physicians treat non-cancerous conditions.

Learn more about Rachel’s experiences.

At the other end of the dose spectrum, FRT uses very small amounts of radiation to help regulate inflammation and immune responses. Preliminary studies presented in San Francisco showed positive outcomes for inflammatory and degenerative diseases like osteoarthritis, plantar fasciitis, and tennis elbow. Together, these techniques could promise to redefine what radiation medicine can achieve.

Expanding disease frontiers

One of the headline studies at ASTRO 2025 showed that very small, precisely targeted doses of radiation can safely ease joint pain and reduce inflammation caused by osteoarthritis. A sham-controlled trial³ from Seoul National University College of Medicine found that patients who received this treatment improved far more than those who got a placebo, and none had serious side effects. Based on substantial prior evidence, re-confirmed by Dr. Kim's landmark trial, Varian secured FDA 510(k) clearance in early October on TrueBeam Linac series for "low dose radiation therapy for adults with medically refractory osteoarthritis.”

For patients, this offers an option to ease pain and regain movement without relying on medication. For clinicians, it demonstrates how the same radiation systems used in cancer care may also improve quality of life in non-cancer conditions. And for healthcare systems, it provides a scalable option for one of the world’s leading causes of disability and is already a common practice in many parts of the world. For example, one-third of patients treated with radiation therapy in Germany are for non-cancerous diseases, of which 40% are treated for osteoarthritis.^4,5

Other potential expanded applications include:
Connective-tissue disorders: Low-dose radiation therapy for non-oncologic joint and tendon pain, including conditions such as tendonitis and bursitis, demonstrates an excellent safety profile, with the incidence of serious adverse effects being exceedingly rare⁶ and presents as a potential non-invasive alternative to steroids or surgery.

Hyperproliferative disease: Dupuytren’s disease, is a genetic fibromatosis disease affecting the hands, which causes contractures and functional impairment in later stage disease. FRT is used to reduce the risk of later contracture when the disease is in its early stages. The DEPART trial led by Dr. Jarad Martin, from GenesisCare Australia, showed that FRT is a well-tolerated intervention with minimal toxicities at 3 years.⁷
Neurodegenerative disorders: Interim data from a multi-center sham controlled study⁸ led by Kyunghee University Hospital suggest small, targeted doses may slow memory decline in Alzheimer’s Disease by reducing brain inflammation, with encouraging cognitive gains and no side effects.

Cardiac disease: Shannon Jiang and colleagues at Washington University were recognized for a retrospective analysis, Stereotactic Arrhythmia Radiotherapy (STAR),⁹ showing that patients who received radiotherapy had similar heart arrhythmia control and safety outcomes to those who received standard of care. Additionally, new imaging and motion-tracking techniques enable precise targeting of ventricular tachycardia, positioning radiation as a viable option for moving organs once considered untreatable.

Opening the door to access

Clinical breakthroughs must also be practical and financially viable. During the Varian Users Meeting, Dr. Sushil Beriwal, Varian Vice President, Medical Affairs, shared survey data from 100 U.S. oncology leaders showing that 66% ranked workflow and operational efficiency among their top challenges, 72% cited hiring and staffing concerns, and more than half pointed to the difficulty of keeping pace with technological change.¹⁰

Faster planning, shortened treatment cycles, and enhanced automation provide promise in freeing time on radiation machines. That additional capacity could be used to treat non-cancerous conditions, thereby expanding access to more patients without new equipment.

A broader mission

The growing application of radiation medicine beyond oncology exemplifies Siemens Healthineers’ commitment to advancing global health through enhanced access, efficiency, and clinical excellence. As part of this mission, Varian is at the forefront of research and innovation, working to transform emerging therapies into dependable, routine care solutions that expand treatment possibilities for patients and healthcare providers worldwide.

The energy at ASTRO 2025 was unmistakable. Clinicians, researchers and healthcare administration representatives expressed genuine enthusiasm about radiation therapy’s growing role in transforming care for millions of new patients. The diverse research presented demonstrated how individual breakthroughs are now converging into a cohesive new discipline of radiation medicine.

Science is advancing on multiple fronts. New directions in research hint at how far the rediscovery of radiation medicine could reach — and Varian is helping guide this frontier responsibly, advancing innovation while ensuring rigor, access, evidence, safety, and patient benefit remain at the core. These new approaches are steadily transitioning from concept to clinical reality, redefining how precision radiation therapy can change lives for patients everywhere.

*The statement by the patient described here is based on results achieved in the unique clinical circumstances the patient experienced.  Because there is no “typical” clinical setting and many variables exist, there is no guarantee that other patients will achieve the same results.