holmium microspheres (holmium (166Ho) microspheres)

Holmium-166 microspheres, marketed under the brand name QuiremSpheres, are a radioembolization therapy used for Selective Internal Radiation Therapy (SIRT) in patients with primary and secondary liver malignancies, including hepatocellular carcinoma (HCC) and liver metastases. The therapy consists of poly-L-lactic acid (PLLA) microspheres embedded with the radioactive isotope Holmium-166. Holmium-166 is a unique lanthanide that emits high-energy beta particles for therapeutic effect and gamma radiation for SPECT imaging. Crucially, it is also paramagnetic, which allows for real-time visualization and quantification of the microsphere distribution using MRI. This theranostic capability enables precise post-treatment dosimetry and treatment planning. The microspheres are delivered via a catheter into the hepatic artery, where they lodge in the microvasculature of tumors and deliver localized radiation while sparing healthy liver tissue.

Brand names

QuiremSpheres

Other names

holmium-166 microspheresholmium166 microspheresholmium 166 microspheresholmium microspheres166Ho-PLLA microspheres