358 - High-Specific-Activity Resin Yttrium-90 Radiation Segmentectomy of Hepatocellular Carcinoma: A Study of Effectiveness, Safety, and Dosimetry Considerations

Wednesday, April 15, 2026

11:51 AM - 12:00 PM ET

Presenting Author(s)

Ali Afrasiabi, MD

Postdoctoral Researcher
University of North Carolina - Chapel Hill - Department of Interventional Radiology, United States

Author/Co-author(s)

Alex Villalobos, MD

Assistant Professor
University of North Carolina - Chapel Hill, United States
PV

Paolo Nicolas Varela Alvarez, MD

Research fellow
University of North Carolina, United States
RV

Roshan Valentine, MD, MBBS

Fellow in Interventional Oncology
Division of Vascular & Interventional Radiology, Department of Radiology, University of North Carolina at Chapel Hill, United States
BG

Bahareh Gholami, MD

Post doctoral research scholar
University of North Carolina, United States
DM

David Mauro, MD

Associate Professor
University of North Carolina, United States
Hyeon Yu, MD, FSIR (he/him/his)

Professor
UNC School of Medicine, United States
Jd

Johannes du Pisanie, Jr., MD (he/him/his)

Integrated Interventional Radiology Resident
UNC School of Medicine, United States
HS

Haneyeh Shahbazian, MD

Diagnostic Radiology Resident
UNC Chapel Hill, United States
NS

Neil Shah, MD

Associate Professor
UNC Chapel Hill, United States
Nima Kokabi, MD

Associate Professor of Radiology
University of North Carolina - Chapel Hill, United States

Purpose: To evaluate efficacy, safety, voxel-based dosimetry, and particle density of high-specific-activity (HSA) resin-based (RB) Yttrium-90 radiation-segmentectomy (Y90-RS) of hepatocellular-carcinoma (HCC).

Materials and Methods: All 4- and 5-day pre-calibration (DPC) Y90-RS performed on patients with HCC were identified between July 2023 and May 2025. mRECIST and CTCAE v5 were utilized to assess both tumor-response and treatment adverse-events (AE) at 3, 6, and 12 months. Voxel-based dosimetry analysis on post-Y90 SPECT/CT was performed to create tumor-dose (TD) volume-histograms and particle density (PD) assessment. Receiver-operator-characteristics curves were used to evaluate the dose-thresholds able to predict a tumor complete-response (CR) in relation to TD and PD. Variable differences were assessed with a student’s t and the Chi-Square tests.

Results: 60 HCC patients (63 tumors) underwent HSA RB Y90-RS (62% 4-DPC). Overall, the cohort was 62% male, median age 66 years, and with 95% solitary HCC. At 3 months, overall tumor control was 100% and CR was 79%. HSA RB Y90-RS was well-tolerated with no ≥3-grade AEs. Total mean TD was 423 Gy, with the CR cohort showing higher mean TD than the incomplete response cohort (546 Gy vs 299 Gy; p=0.0003). Mean-PD and Mean-TD thresholds able to predict CR were 73,131 microspheres/ml (AUC=0.80) and 416 Gy (AUC=0.82), respectively. D95 TD of >245 Gy was associated with CR (AUC=0.76).

Conclusion: Curative intent ablative Y90-RS of HCC with HAS RB microspheres is safe and efficacious. A mean TD threshold of 416 Gy and a tumor PD of 73,131 microspheres/mL are associated with a tumor CR.