The History and Evolution of 90Y Radioembolization and Dosimetry

Abstract

Transarterial radioembolization (TARE) has become an established and increasingly used locoregional therapy for hepatocellular carcinoma and selected hepatic metastases. Given that TARE's path to popularity has not been linear, it is important to understand the history of how TARE dosimetry has evolved from non-selective treatment with empiric dosimetry to personalized, selective treatment, often with curative intent. Studies from the mid-20th century established that non-specific regional infusion (initially into the aorta) was inefficient and possibly dangerous. Over the following decades, particularly as angiographic techniques improved, minimally invasive treatments became technically feasible. Concurrently, advances in dosimetry calculations improved the safety and efficacy of TARE. Particularly, the absorbed dose-based partition model—the current gold standard method—marked a major inflection point by making tumor and normal liver compartments usable in treatment planning, allowing personalization based on tumor biology and treatment objectives. However, due to practical and technical limitations, initial trials used the body surface area prescription with resin microspheres and single-compartment absorbed-dose planning for glass microspheres, possibly explaining limited treatment efficacy in early trials. Contemporary trials have moved beyond these initial techniques. This review traces the evolution of Yttrium-90 (90Y) TARE and the evolution in dosimetry to today's era of personalized treatment planning.