363 - Hepatic Vein Occlusion During 90Y Radioembolization in Patients with High Lung Shunt Fraction: Quantitative Analysis of 99mTc-MAA SPECT/CT and 90Y PET/CT

Wednesday, April 15, 2026

12:36 PM - 12:45 PM ET

Presenting Author(s)

Aakash N. Gupta, MD

Resident Physician
Stanford University, United States

Author/Co-author(s)

KG

Kip E. Guja, MD, PhD

Clinical Assistant Professor of Radiology (Nuclear Medicine)
Stanford University, United States
JS

Jagruti Shah, MD

Clinical Associate Professor of Radiology (Nuclear Medicine)
Stanford University, United States
EG

Erin E. Grady, MD

Clinical Professor of Radiology (Nuclear Medicine)
Stanford University, United States
AI

Andrei Iagaru, MD

Professor of Radiology (Nuclear Medicine)
Stanford University, United States
Lynne Martin, MD

Resident
Stanford, United States
Andrew Kesselman, MD, RPVI

Clinical Associate Professor
Stanford Medicine, United States
JL

John D. Louie, MD

Professor of Radiology
Stanford University, United States
Daniel Y. Sze, MD, PhD

Professor of Radiology
Stanford University, United States
MH

Matthew L. Hung, MD

Assistant Professor of Radiology
Stanford University School of Medicine, United States
David S. Wang, MD, FSIR

Clinical Associate Professor
Interventional Radiology, Stanford University, United States

Purpose: To quantify lung shunt fraction (LSF) reduction with hepatic vein occlusion (HVO) during yttrium-90 (⁹⁰Y) transarterial radioembolization (TARE) by analyzing LSF on pre-treatment technetium-99 (^99mTc) macroaggregated albumin (MAA) SPECT/CT and post-treatment ⁹⁰Y PET/CT.

Materials and Methods: A retrospective, single-center study of 17 patients treated with TARE with and without HVO from 2024-2025 was performed. Inclusion criterion was full lung coverage on post-treatment ⁹⁰Y PET/CT. Eight patients (median age 74 years; primary liver malignancy 75%) underwent TARE with HVO (glass N=5, resin N=3; lobar N=4, segmental N=4) for high LSF or estimated lung dose >30 Gy. If high LSF was suspected due to intra-tumoral shunting into hepatic veins, temporary or permanent HVO was performed in dominant draining hepatic veins corresponding to the TARE treatment territory during infusion of ⁹⁰Y microspheres. Nine consecutive control patients without high LSF (median age 72 years; primary liver malignancy 67%) underwent TARE without HVO (glass N=4, resin N=5; bilobar N=1, lobar N=3, segmental N=5). LSF was measured on 1) pre-treatment ^99mTc-MAA planar imaging (LSF_Planar), 2) pre-treatment ^99mTc-MAA SPECT/CT (LSF_SPECT), and 3) post-treatment ⁹⁰Y PET/CT (LSF_PET). Absolute and relative change from LSF_SPECT to LSF_PET were recorded. Paired statistical analysis was performed with Wilcoxon signed-rank test.

Results: In control patients, median LSF_Planar was 3.0% (range 1.1-10.4%) and median LSF_SPECT was 1.7% (range 0.8-5.9%). Median LSF_PET was 1.9% (range 0.4-4.6%), which was lower than LSF_Planar (p=0.004) but comparable to LSF_SPECT (p=0.80). HVO was technically feasible in 7 patients (88%) with 1 patient not feasible due to central hepatic vein tumor thrombus. In feasible patients, HVO was performed with temporary balloon occlusion (N=6, 86%) and permanent vascular plugs (N=1). Median balloon occlusion time was 30 minutes (range 5-60 minutes). In HVO patients, median LSF_Planar was 20.1% (range 10.0-32.0%) and median LSF_SPECT was 11.1% (range 3.6-18.4%), respectively. Median LSF_PET was 3.4% (range 0.4-15.6%), significantly lower than both LSF_Planar (p=0.016) and LSF_SPECT (p=0.016). From LSF_SPECT to LSF_PET, HVO had a median absolute LSF change of -6.9% (range -9.6% to -3.2%) and a median relative LSF change of -66.7% (range -88.9% to -52.2%). No HVO patients developed radiation pneumonitis.

Conclusion: Quantitative analysis of LSF on pre-treatment ^99mTc-MAA SPECT/CT and post-treatment ⁹⁰Y PET/CT supports HVO as a promising technique for LSF reduction in select patients with high LSF.