Targeted radiation therapy for breast cancer that's partially progressing

Plain-English translation of NCT06260033 on ClinicalTrials.gov ↗ · Source last updated October 2025 · Translation generated ·

What is this trial?

This trial is testing a combination approach for people with advanced breast cancer that has started to grow despite hormone therapy. The study uses stereotactic body radiation therapy (a precise, high-dose radiation treatment) paired with special imaging called FES PET/CT scans to target cancer spots that are growing while allowing patients to continue their current medications. Researchers want to see if this treatment can help slow overall cancer growth.

When advanced breast cancer starts growing in just a few spots while the rest remains controlled, doctors face a difficult choice: switch to a completely new medication or try to target just those growing areas. This trial explores whether using focused radiation on those specific spots might let patients stay on their current, working treatment longer and avoid switching medications.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been diagnosed with advanced estrogen receptor-positive breast cancer that has spread to other parts of your body
your cancer is growing in 4 or fewer specific spots, even though other areas are stable
you are able to read and understand English or Spanish
your doctor determines that radiation therapy can safely be delivered to all of your growing cancer spots

You likely don't qualify if…

you are pregnant or planning to become pregnant during the study
your cancer is growing in more than 4 different places in your body
you have active cancer in your brain or previously had leptomeningeal disease (cancer in the fluid around the brain and spine)
your growing cancer spots are too close to critical structures like your spinal cord or major organs that would make radiation unsafe
you have spreading cancer in your abdomen, pleural effusion (fluid around the lungs), or lymphatic involvement that is actively getting worse

What participation looks like

If you join this trial, you'll first have special imaging scans (FES PET/CT) to identify all your cancer spots. Then you'll receive 3 to 5 sessions of targeted radiation therapy over about 3 weeks, while continuing your current breast cancer medications. You'll return for follow-up imaging scans at 12 and 24 weeks to see how you're responding, complete questionnaires about your quality of life and any side effects, and have blood tests drawn to track your cancer markers over time.

Targeted radiation therapy for breast cancer that's partially progressing

What is this trial?

Do you qualify?

What participation looks like

Trial locations(2 sites)