UCLA Researchers Present Breakthrough 177Lutetium-PSMA Therapy Results for Recurrent Prostate Cancer at ASTRO 2025
Key Insights
UCLA's LUNAR clinical trial demonstrates promising results for 177Lutetium-PSMA (search) targeted radioactive therapy combined with ablative radiotherapy in men with recurrent prostate cancer.
The SCIMITAR trial shows 62% of patients remained cancer-free four years after stereotactic body radiation therapy following prostate surgery, with rare local recurrences.
New 5DCT imaging technology provides more accurate lung tumor visualization for patients with irregular breathing patterns, improving radiation treatment planning.
UCLA Health Jonsson Comprehensive Cancer Center (search) researchers are presenting groundbreaking findings at the 2025 American Society for Radiation Oncology (ASTRO) Annual Meeting, with the most significant development being results from the LUNAR clinical trial evaluating 177Lutetium-PSMA (search) targeted radioactive therapy for recurrent prostate cancer.
Dr. Amar Kishan, executive vice chair of radiation oncology at UCLA and co-director of the Cancer Molecular Imaging, Nanotechnology and Theranostics Program, will present findings from the LUNAR clinical trial examining the addition of 177Lutetium-PSMA (search) as a treatment given before ablative radiotherapy for men with recurrent prostate cancer. The results will be highlighted during an oral presentation on Sunday, September 28 at 1:10pm PDT and featured in the ASTRO news briefing.
Long-term SBRT Outcomes Show Promise
The SCIMITAR phase II clinical trial, led by Kishan and presented by Dr. Jesus Juarez Casillas, evaluated stereotactic body radiation therapy (SBRT) in men at risk of prostate cancer returning after surgery. After four years, 62% of patients had no signs of cancer returning, local recurrences were rare, and outcomes compared favorably with conventional radiation approaches.
Advanced Imaging Technology Improves Treatment Precision
Dr. Daniel Low will report findings from the first large study of 5DCT, a new CT imaging technique designed to improve scans for patients with lung tumors who breathe irregularly. In a study of 108 patients, 5DCT allowed clinicians to more accurately define tumor size and motion, supporting better radiation planning. Unlike conventional 4DCT, which can produce unreliable images, 5DCT accounts for breathing motion in three dimensions as well as the rate and depth of each breath, producing clearer, artifact-free images.
MRI-Guided Therapy Comparisons Reveal Treatment Insights
Research comparing standard high-dose MRI-guided stereotactic body radiotherapy (MRgSBRT) versus an adaptive "dose-painted" approach showed that patients receiving the adaptive dose-painted therapy experienced higher acute side effects as measured by physicians, particularly urinary and bowel symptoms. However, patient-reported quality-of-life outcomes were similar between the two groups.
The MIRAGE trial examining sexual function in men receiving SBRT for prostate cancer found that despite using MRI guidance to reduce radiation exposure to key nerves and blood vessels, nearly one-third of men in both CT-guided and MRI-guided SBRT groups experienced a significant decline in sexual function two years after treatment.
Genetic Drivers of Radiation Resistance Identified
Dr. Beth Neilsen will present findings from a study analyzing tumors from patients with prostate cancer that returned after radiation therapy. The research revealed that these recurrent tumors carry a higher frequency of mutations in genes linked to aggressive disease and faulty DNA repair, including BRCA1 (search), BRCA2 (search), RAD51B (search), and POLQ (search). Compared with treatment-naïve cancers, they also showed more aggressive molecular subtypes, higher genomic risk scores, and reduced androgen receptor activity.
Head and Neck Cancer Treatment Advances
A study evaluating postoperative SBRT for patients with newly diagnosed or recurrent head and neck cancer found that SBRT was well-tolerated, with no severe acute side effects and only two late serious toxicities, though about half of patients experienced cancer recurrence within two years. The study suggests that postoperative SBRT is a feasible, shorter treatment option.
"UCLA studies featured at this year's ASTRO meeting offer exciting new insights into emerging radiation therapies and imaging technologies, pointing to innovative approaches to make cancer treatment safer, more precise, and more effective," said Dr. Michael Steinberg, professor and chair of radiation oncology at the David Geffen School of Medicine at UCLA.