The meeting also brings personal recognition for UCLA leadership in the field. Dr. Daniel Low, professor and vice chair of medical physics research and innovation in the department of radiation oncology, is receiving the 2026 ASTRO Gold Medal, the organization’s highest honor, in recognition of his outstanding contributions to radiation oncology through research and professional service. He will be recognized during the Awards Ceremony on September 29. Dr. Luca Valle, associate professor of radiation oncology at the David Geffen School of Medicine at UCLA, has been selected for the 2026 ASTRO-PCF Young Investigator Award from ASTRO and the Prostate Cancer Foundation, and Dr. Jie Deng, assistant professor-in-residence of radiation oncology, has received an American Cancer Society Clinician Scientist Development Grant co-sponsored by ASTRO and designated in honor of Felix Feng, MD, an expert in translational genomics and preclinical therapeutics for prostate cancer.

Dr. Michael Steinberg, professor and chair of radiation oncology at the David Geffen School of Medicine at UCLA and director of Clinical Affairs at the Jonsson Comprehensive Cancer Center, framed the presentations as evidence of rapid evolution across the discipline. Radiation oncology, he noted, continues to evolve quickly, and the research being presented reflects the breadth of innovation in the department, from more personalized approaches to treatment to new ways of combining radiation with other therapies. In his view, the studies demonstrate how advances in technology, biology, and clinical research are shaping the way cancer treatment and care are approached. That combination of physics, genomics, and clinical trial design is a recurring theme throughout the UCLA program at this year’s meeting.

Among the most consequential findings is a study validating a genetic test that identifies men with prostate cancer who are at higher risk of long-term urinary side effects after stereotactic body radiation therapy, a technique that delivers very high doses of radiation in a small number of treatments. The test, called PROSTOX, examines inherited genetic differences that may influence how a patient responds to radiation. Led by Dr. Amar Kishan, executive vice chair of radiation oncology, and Dr. Joanne Weidhaas, professor of radiation oncology and vice chair of molecular and cellular oncology, the work addresses one of the central dilemmas in modern prostate cancer care: SBRT is convenient and increasingly popular, but a subset of patients experience lasting genitourinary toxicity that can substantially affect quality of life.

The clinical implications of the PROSTOX validation are striking. In a prospective clinical trial, using the test to guide treatment reduced the risk of moderate to severe urinary side effects, in part by steering patients flagged as high risk toward a longer course of conventional radiation instead of SBRT. To quantify how strongly the genetic signal predicts toxicity, the researchers analyzed pooled data from four clinical trials involving 457 men. Patients classified as high risk by PROSTOX were approximately 36 times more likely to develop late urinary side effects than those classified as low risk, an effect size that is unusual in the field of radiation toxicity prediction and suggests the test captures a genuinely informative biological mechanism rather than a marginal statistical association. Kishan will present the research, Abstract 311, on Tuesday, September 29, and the findings point toward a routine role for germline genetic testing in counseling men before they choose a radiation regimen.

Weidhaas will also present separate findings, Abstract 1238, showing that inherited genetic differences may help identify patients with head and neck cancer who are more likely to experience serious side effects from radiation and chemotherapy, or to have shorter overall survival. The study analyzed genetic and clinical data from 171 patients treated with radiation and cisplatin in a large clinical trial. Models that combined genetic markers with clinical factors outperformed clinical information alone in predicting both short-term and long-term treatment side effects. The models also stratified survival: patients identified as higher risk of dying within four years had a median survival of 2.25 years, compared with 4.46 years among those predicted to be at lower risk. If validated more broadly, such testing could allow oncologists to intensify monitoring or modify treatment for vulnerable patients before severe toxicity or disease progression occurs, rather than reacting after the fact.

A third UCLA presentation extends precision radiation into a challenging transplant setting. Dr. Trudy Wu, assistant professor of radiation oncology, conducted a retrospective analysis spanning 14 years of clinical data suggesting that MRI-guided stereotactic body radiation therapy can provide strong and lasting local control for patients with unresectable cholangiocarcinoma, a cancer of the bile ducts, while they await liver transplantation. Because transplant waiting periods can be lengthy, controlling the tumor during that interval is a critical clinical problem, and radiation may offer an important bridge while patients receive systemic therapy and await a donor organ. The study reviewed 38 patients who received MRI-guided SBRT followed by chemotherapy or chemoimmunotherapy at UCLA while being evaluated for transplantation. The use of MRI guidance is technically significant, because it allows clinicians to visualize the tumor and adjacent organs in real time during treatment delivery, enabling ablative doses to be concentrated on the tumor while sparing the remaining functional liver tissue.

The outcomes in the bile duct cancer cohort were notable for both survival and tolerability. Eleven patients ultimately underwent liver transplantation and had significantly longer overall survival than those who did not, with a median survival of about 150 weeks compared with 94 weeks. Among the patients who underwent transplantation, more than one-third had no remaining cancer detected in the liver at the time of surgery, a finding that suggests the radiation may have eradicated viable tumor in a substantial fraction of cases. The treatment was also generally well tolerated, with most patients reporting no radiation-related side effects. Wu will present the research, Abstract 1159, on Tuesday, September 29, and the results highlight the potential of precise, MRI-guided radiation as a well-tolerated strategy to control an otherwise unresectable tumor and help patients maintain control of their disease while pursuing transplantation.

The prostate cancer program at UCLA also includes a study, Abstract 1217, comparing treatment approaches for men whose prostate cancer has returned in a small number of locations, with the goal of delaying progression while avoiding or limiting hormone therapy, which can cause significant quality-of-life burdens. Dr. Esther Yu, a radiation oncology resident at UCLA Health, will present findings comparing patients who received metastasis-directed SBRT alone with those who received SBRT combined with either a targeted radioligand therapy called 177Lu-PSMA or a combination of hormone-blocking drugs. Radioligand therapy represents a distinct therapeutic paradigm: a radioactive molecule is linked to a compound that binds a specific target on cancer cells, in this case the prostate-specific membrane antigen, delivering radiation directly to tumor deposits while limiting exposure to healthy tissue.

The results of the comparison favor combination treatment, with important nuances. Both combination approaches significantly delayed cancer progression compared with SBRT alone, with a median time to progression of 19.4 months for SBRT plus radioligand therapy and 21.7 months for SBRT plus hormone therapy, compared with 6 months for SBRT alone. The two combination strategies produced similar efficacy, but the toxicity profiles differed: grade 3 or higher side effects occurred in 10 percent of patients receiving SBRT plus radioligand therapy, compared with 21 percent of those receiving the hormone therapy combination, although the difference was not statistically significant. The research, led by Kishan and Dr. Nicholas Nickols, assistant professor of radiation oncology, will be presented by Yu on Tuesday, September 30. Taken together with the PROSTOX findings and the head and neck genetic signatures study, the UCLA presentations at ASTRO 2026 argue that the next phase of radiation oncology will be defined not only by better machines and sharper imaging, but by genomic tests that match each patient to the regimen most likely to control the cancer while sparing them the side effects they are least able to tolerate.

Subject of Research: Personalized radiation therapy and radioligand approaches for prostate, bile duct, and head and neck cancers presented at ASTRO 2026

Article Title: ASTRO: Targeted radioactive therapy for prostate cancer, new SBRT approaches, personalized radiation and more

Article References: ASTRO: Targeted radioactive therapy for prostate cancer, new SBRT approaches, personalized radiation and more. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: radiation oncology, ASTRO 2026, prostate cancer, SBRT, PROSTOX genetic test, radioligand therapy, 177Lu-PSMA, cholangiocarcinoma, liver transplantation, head and neck cancer, genetic biomarkers, UCLA Health