71 - Where We Are and Where We Need to Be: Exploring Tumor Recurrence Post-Y90 Treatment – Correlating Underdosed Regions from Voxel-Based Dosimetry with CBCT Perfusion and SPECT Imaging

Monday, March 31, 2025

12:10 PM – 1:10 PM CT

Location: Music City Center, Expo Poster Area

Author/Co-author(s)

NN

Neel Nirgudkar, MD

Resident
Interventional Radiology, United States

Poster Presenter(s)

Jackie Brenner, BS (she/her/hers)

Medical Student
University of Miami, United States

Author/Co-author(s)

Marisela Neff (she/her/hers)

Medical Student
University of Miami, United States
NB

Nikita Bansal, BS

Medical Student
University of Miami, United States
JC

John Cacciatore, BS

Medical Student
University of Miami, United States
KR

Kenneth Richardson, MD

Resident
Department of Radiology, University of South Florida, Tampa, United States
Bradford J. Wood, MD, FSIR

United States
JZ

Joseph Zikria, MD

Assistant Professor of Clinical Radiology
University of Miami, United States
JK

Jessica Kumar, MD

Attending
University of Miami, United States
US

Usman Shahid, MD

Attending
University of Miami, United States
SV

Shree Venkat, MD

Attending
University of Miami, United States
FA

Francisco Alessandrino, MD

Attending
University of Miami, United States
LP

Lorraine Portelance, MD

Attending
University of Miami, United States
BS

Benjamin Spieler, MD

Attending
University of Miami, United States
LT

Lindsay Thornton, MD

APD
University of Miami Miller School of Medicine, United States

Learning Objectives:

Explore the role of virtual perfusion to refine pre-procedural predictive measures in Y90.

Explore spatial variability and its role in underdosed regions.

Clinical correlation between imaging and treatment response.

Background: Y90-TARE is a key locoregional therapy for HCC and liver metastases, but tumor recurrence remains a challenge, often due to undertreated "cold" regions (1). Traditional dosimetric models, like MIRD and partition, estimate overall dose but lack the spatial resolution to address dose heterogeneity within tumors (2,3). Voxel-based dosimetry overcomes this by assessing dose distribution on a voxel level, with metrics like D95 and D70 correlating with tumor response and pathologic necrosis, underscoring the importance of achieving adequate dose coverage throughout the tumor (4-6). However, its clinical adoption is limited by computational demands and integration challenges in routine practice.

Clinical Findings/Procedure Details:

Combining voxel-based dosimetry with advanced imaging modalities like cone-beam CT, VPP, and SPECT may offer a more comprehensive solution. CBCT VPP enables real-time mapping of hepatic perfusion, identifying underdosed regions and optimizing catheter positioning during Y90 delivery. Post-treatment SPECT verifies microsphere distribution, correlating delivered dose with clinical outcomes (5,7,8).

Specifically, comparison metrics will be assessed with Dice & Hausdorf coefficients comparing paired volumes of any two different modalities (pre-CT, SPECT, procedure CBCT, post CT), and correlating these metrics with survival and local failure. This study aims to integrate voxel-based dosimetry, CBCT VPP, and SPECT to assess dose distribution and its link to tumor recurrence after Y90 TARE, guiding adaptive strategies for improved tumor control.

Conclusion and/or Teaching Points: The combination of these technologies may represent a significant advancement in personalized dosimetry, potentially improving precision, standardization, and predictive models in patients undergoing Y90 therapy. Predicting tissue at risk for underdosing could enable closed-loop procedures, allowing for real-time adjustments and more effective, tailored combination therapies. This would optimize precise, personalized, and dose-specific TARE, ensuring the appropriate dose is delivered to the target tissue and patient at the optimal time.