Researchers presented an approach using circulating tumor DNA (ctDNA) detected in blood plasma to tailor radiotherapy and treatment decisions for patients with oligometastatic cancers. The strategy was highlighted at the ESTRO 2026 meeting, where investigators reported a blood-based biomarker concept aimed at guiding therapeutic planning. The concept focuses on extracting actionable signals from ctDNA in advance of and alongside treatment, potentially enabling more individualized management without relying solely on imaging features. If validated in larger studies, this could accelerate broader adoption of liquid-biopsy workflows in radiation oncology and inform how clinicians select and sequence local therapies.