Tumor-associated tissue

Tumor-associated tissue refers to the malignant cells and the specialized microvasculature that supports tumor growth, particularly in the liver. In the context of yttrium-90 (Y-90) microsphere localization, this tissue acts as the physiological target for Selective Internal Radiation Therapy (SIRT) (Salem et al., 2019, Lancet Oncology). The therapy exploits the fact that liver tumors receive the majority of their blood supply from the hepatic artery, while healthy liver tissue is primarily supplied by the portal vein (Kennedy et al., 2006, Int J Radiat Oncol Biol Phys). When Y-90 microspheres are injected into the hepatic artery, they become trapped in the small vessels of the tumor-associated tissue due to their size. This localization allows for the delivery of high-dose, localized beta radiation directly to the tumor, causing cell death through DNA damage while sparing the surrounding healthy liver (FDA, 2021, TheraSphere Package Insert). This method is primarily utilized for treating unresectable hepatocellular carcinoma and liver-dominant metastatic colorectal cancer.

Other names

Tumor tissueNeoplastic tissueTumor microvasculatureHypervascular liver tumor

Radioembolization involving the delivery of beta-emitting yttrium-90 isotopes via microspheres that lodge in the tumor-associated microvasculature, providing localized radiotherapy and embolic effects.