Radioembolization is a widely used treatment for non-resectable primary and secondary liver cancer. This handbook addresses the radiation biology, physics, nuclear medicine, and imaging for radioembolization using Yttrium-90 (90Y) microspheres, in addition to discussing aspects related to interventional radiology. The contents reflect on and off-label treatment indications, dose-response relationships, treatment-planning, therapy optimization, radiation safety, imaging follow-up and many other facets of this therapy necessary for both novice and advanced users alike.