ASTRO 2026: Bringing an Evolving Science into Practice

Scientific Committee Chair Kenneth Rosenzweig, MD, reflects on the research shaping shorter treatment courses, more focused radiation therapy, and an expanding role for radiation oncology.

For Kenneth Rosenzweig, MD, one of the clearest messages emerging from the 2026 ASTRO Annual Meeting is not that radiation oncology is undergoing a sudden transformation, but that years of clinical investigation and technological progress are increasingly producing changes that practicing radiation oncologists can bring directly into the clinic.

Rosenzweig, Chair of Radiation Oncology at the Icahn School of Medicine at Mount Sinai and Chair of the ASTRO Annual Meeting Scientific Committee, had a broad view of the science presented at this year’s meeting. In a conversation with Applied Radiation Oncology, he repeatedly returned to a central theme: advances in evidence, imaging, and treatment precision are allowing radiation oncologists to accomplish clinical objectives with fewer treatments and, in some cases, less radiation.

Shorter Treatment Courses Continue to Move Forward

The trend toward hypofractionation is hardly new, but the evidence supporting shorter treatment courses continues to expand across disease sites.

Rosenzweig pointed to breast and prostate cancer as examples of areas in which fewer treatments can reduce the burden of care without compromising appropriate clinical outcomes. The implications extend beyond convenience. Fewer visits can reduce the financial, logistical, and emotional burden of radiation therapy for patients, families, and caregivers.

That may be particularly important for patients who do not live near a radiation oncology facility. Rosenzweig noted that access remains a challenge in rural areas, where patients may have to travel significant distances for treatment. A course delivered in several fractions rather than over several weeks can make radiation therapy considerably more feasible for these patients.

Shorter courses also have implications for multidisciplinary cancer care. For patients receiving effective systemic therapy, a brief course of radiation may allow clinicians to address a specific lesion while minimizing interruption of systemic treatment.

“We can, as a radiation oncologist, give a short course of radiotherapy and then kind of get out of the way so the patient can get back to the systemic therapy,” Rosenzweig said in discussing treatment for patients with multiple myeloma.

A Changing Approach to Brain Radiation

Among the research Rosenzweig considered potentially most relevant to current practice was evidence supporting a more selective approach to brain radiation, particularly in patients with small cell lung cancer.

He pointed to research evaluating the use of stereotactic radiosurgery (SRS) rather than whole-brain radiation therapy for patients who develop brain metastases, reflecting a broader movement toward more focal treatment when clinically appropriate. He also highlighted evidence challenging the routine use of prophylactic cranial irradiation (PCI) in small cell lung cancer. With greater access to MRI surveillance, clinicians may increasingly be able to monitor patients for intracranial disease and treat it if it develops, potentially reducing the toxicity and quality-of-life impact associated with prophylactic treatment.

For Rosenzweig, these developments illustrate how advances in imaging and more precise radiation techniques are changing longstanding approaches to brain treatment. Importantly, he viewed this as research with near-term relevance to clinical practice.

“Again, I think we can take that home on Wednesday and adapt that in our clinic,” he said.

Greater Precision Also Raises the Stakes

As radiation therapy moves from courses of 30 or more fractions toward SBRT, SRS, and other highly focused approaches delivered in only a few treatments, the practice of radiation oncology itself is changing.

Rosenzweig noted that shorter treatment courses can alter the traditional interaction between radiation oncologists and their patients. At the same time, the clinical and technical intensity of each treatment increases.

With radiosurgery and other highly precise treatments, he explained, there is less opportunity to compensate across subsequent fractions. Each treatment therefore demands careful decision-making, planning, and execution. In Rosenzweig’s words, radiation oncology has become “a much more intense specialty,” requiring physicians to be highly present for each treatment.

For community practices, this evolution also reinforces the importance of multidisciplinary integration. Radiation oncologists increasingly work alongside medical oncologists, surgeons, radiologists, physicists, and other members of the cancer team as focal radiation is incorporated into longer-term treatment strategies.

Rosenzweig noted that this integration has matured considerably, particularly as radiation is used to manage individual sites of disease while patients continue systemic therapy. Shorter courses can make that coordination easier, allowing radiation oncology to address a specific clinical need without unnecessarily disrupting the patient’s broader treatment plan.

Radiation Oncology Looks Beyond Cancer

ASTRO 2026 also offered a glimpse at another potential expansion of the specialty: radiation therapy for nonmalignant disease.

Rosenzweig discussed renewed interest in low-dose radiation therapy for knee osteoarthritis, an approach with a longer history outside the United States but limited contemporary utilization domestically. Rather than viewing the treatment as broadly applicable, he emphasized the need to determine which patients are most likely to benefit and where radiation belongs within a treatment continuum that ranges from conservative therapies and injections to joint replacement.

“There’s going to be a subset of people who can benefit from it,” he said.

Rosenzweig also pointed to other functional applications of radiation that remain more experimental. For him, the opportunity is intriguing, but the challenge will be defining the specific indications and patient populations for which radiation provides meaningful benefit.

As with other technologies that are either discovered or rediscovered, he suggested, the initial possibilities can appear broad before evidence ultimately establishes the appropriate clinical niche.

Distilling the Science for the Practicing Radiation Oncologist

Perhaps most relevant to ARO readers was Rosenzweig’s description of how the Scientific Committee approached the meeting itself.

With approximately 2,700 research submissions and a scientific program spanning numerous disease sites and disciplines, no attendee can absorb everything presented. Rosenzweig said one of the committee’s objectives was therefore to help distill the science into information a practicing radiation oncologist could absorb in a limited amount of time and bring back to practice.

“What I really wanted is for the practicing radiation oncologist, maybe someone who’s not involved on the national committees to go and just in a couple of hours of time, really hear what’s going on and what they could take back,” he said.

That focus was particularly important for physicians practicing outside large subspecialized academic departments. Rosenzweig acknowledged that even smaller community practices often develop areas of expertise among individual physicians, making it important for the meeting to provide opportunities to understand both what may be ready for implementation and what remains too early for routine practice.

For Rosenzweig, that distinction is an important part of translating a meeting as large as ASTRO into meaningful clinical education: identifying not only what is new, but what practicing physicians need to know now and what they should continue watching.

An Evolution Practitioners Can Bring Home

Asked what radiation oncologists unable to attend ASTRO 2026 should take away from the meeting, Rosenzweig returned to three themes: evidence supporting shorter courses of radiation continues to grow; the role of whole-brain radiation continues to decrease as more focused approaches become possible; and the potential role of functional radiation continues to expand as investigators better define where it may provide benefit.

Taken together, these developments point toward a specialty becoming increasingly precise not simply in how radiation is delivered, but in determining when, where, and how much treatment is necessary.

Rosenzweig stopped short of characterizing any single development presented at ASTRO 2026 as transformative. Instead, he offered a description that may better capture the significance of this year’s meeting for everyday practice.

“I don’t think anything was a revolution this year, which rarely is, but a pretty significant evolution,” he said.