Nuclear medicine imaging techniques in yttrium-90 microsphere radioembolization for liver tumors: Clinical perspectives and advances

Abstract

Yttrium-90 (⁹⁰Y) microsphere radioembolization (RE) has become an important locoregional therapy for unresectable primary and metastatic liver tumors, supported by advances in catheter-based delivery and quantitative nuclear medicine imaging. Successful treatment requires coordinated multidisciplinary collaboration, with nuclear medicine playing a central role from initial patient selection through post-treatment verification and follow-up assessment. Pre-treatment imaging—particularly 18F-FDG positron emission tomography/computed tomography (PET/CT) and pathology-specific non-FDG tracers—supports staging, characterization of tumor biology, and prognostic stratification. In parallel, 99mTc macroaggregated albumin or Single Photon Emission Computed Tomography (SPECT) mapping enables identification of extrahepatic shunting, lung dose estimation, and predictive intrahepatic dose modeling, thereby guiding treatment feasibility and personalized dosimetry. Following microsphere administration, post-therapy imaging with 90Y PET/CT, Bremsstrahlung SPECT/CT, or hybrid PET/magnetic resonance imaging provides essential confirmation of microsphere distribution and supports voxel-based dose-response evaluation. Emerging quantitative metrics, including metabolic tumor volume, total lesion glycolysis, and radiomics-derived features, offer additional prognostic insight and may refine individualized treatment planning. This review synthesizes current evidence on the clinical utility, technical considerations, and evolving applications of nuclear medicine imaging throughout the ⁹⁰Y-RE workflow. It highlights practical decision-making principles relevant to nuclear medicine physicians, interventional radiologists, oncologists, and medical physicists, with the objective of supporting optimized patient selection, improving dosimetric accuracy, and enhancing post-therapy response evaluation in liver-directed radionuclide therapy.

Keywords

Yttrium-90 microspheres / Radioembolization / Nuclear medicine imaging / Positron emission tomography / Single photon emission computed tomography

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