Yttrium-90-labeled microsphere-targeted tumor tissue

The phrase "Tumor tissue via local beta radiation emission from yttrium‑90‑labeled microspheres" does not refer to a specific molecular or cellular therapeutic target such as a receptor, enzyme, or transporter. Instead, it describes the **anatomical and pathological site**—tumor tissue—being treated by a physical process involving radioactive medical devices. In this therapy (commonly called selective internal radiation therapy [SIRT] or radioembolization), microscopic beads loaded with the radioactive isotope yttrium‑90 are delivered via catheter into arteries supplying the tumor. The beads become lodged in small blood vessels within the tumor; there they emit beta radiation over about two weeks. This localized irradiation destroys nearby cancer cells while minimizing exposure to healthy surrounding tissues due to limited penetration of beta particles. The approach is primarily used for unresectable primary and metastatic liver cancers. This entry is **not a canonical druggable molecular target** but rather an anatomical treatment strategy using device-based delivery of local radiotherapy. Once trapped in the tumour’s microvasculature, the microspheres emit beta radiation that travels a limited distance—generally a few millimetres—destroying nearby tumour cells while sparing healthy liver tissue further away. The glass microspheres penetrate the tumor arteriolar capillaries where they emit lethal beta radiation that is localised to the surrounding tumor tissue. Because this "target" refers only to **tumor location** rather than any specific molecule or protein expressed by those tumors, it should be flagged as incorrect for structured molecular targeting purposes.

Other names

Yttrium-90 radioembolization targetSIRT targetY-90 microsphere tumor siteRadioembolization target tissue

Local emission of beta radiation from yttrium‑90 within the tumor vasculature causes lethal DNA damage and cell death in nearby tumor cells while sparing most normal tissue due to limited penetration distance