SIR 2024
Interventional Oncology
Melinda Wang, MD
Resident
University of California San Francisco
Financial relationships: Full list of relationships is listed on the CME information page.
Parmede Vakil, MD, PhD
Resident
UCSF
Financial relationships: Full list of relationships is listed on the CME information page.
Evan Lehrman, MD, FSIR (he/him/his)
Associate Professor of Clinical Radiology in Interventional Radiology
UCSF
Financial relationships: Full list of relationships is listed on the CME information page.
Nicholas Fidelman, MD
Professor
University Of California San Francisco
Financial relationships: Full list of relationships is listed on the CME information page.
R. Peter Lokken, MD, MPH, FSIR (he/him/his)
Associate Professor of Clinical Radiology
UCSF Department of Radiology and Biomedical Imaging
Financial relationships: Full list of relationships is listed on the CME information page.
A retrospective, single center, analysis of patients with HCC who received Y90 RS prior to liver transplantation or resection from 2018 to 2023 and who had correlating treatment angiosome to gross pathology data was performed. In total 29 explanted tumors in 27 patients were included. 17 patients were male, and 10 were female. The mean age at treatment was 64.5 +/- 4.9 years. Exclusion criteria included secondary locoregional therapy to the explanted tumor (n=3) and non-HCC pathology at explant (n=1). Percentage pathologic necrosis was calculated using the volume of histologically viable tumor relative to the pre-treatment MRI tumor volume. Tumor necrosis was classified as complete (100%), extensive (50-99%), or partial (< 50%). Absorbed doses were estimated using the MIRD model.
Results:
Median target tumor size was 2.7 (IQR: 2.1-3.5) cm. 23 (79%) tumors had complete pathologic necrosis (CPN) at explant, and six (21%) tumors had extensive necrosis. No tumors had partial necrosis. Median radiation dose was 279 (IQR: 228-361) Gy. The median radiation dose to tumors with CPN was 301 (IQR: 250-414) Gy compared to 204 (IQR: 185-226) Gy for tumors without CPN (p = 0.02). 11/11 (100%) patients who received > 350 Gy had CPN.
Mean activity per particle (578 +/- 331 Bq/particle in tumors with CPN versus 295 +/- 173 Bq/particle in tumors with PN, p = 0.04) and mean activity per volume of tissue treated (7.60 +/- 3.33 MBq/cc in tumors with CPN versus 4.80 +/- 1.21 MBq/cc in tumors with PN, p = 0.03) were higher in tumors with CPN. No difference was observed in mean particles per volume of tissue treated (17,500 particles/cc in tumors with CPN versus 13,140 particles/cc in tumors with PN, p = 0.19). There was no statistically significant difference in 3-month toxicity rates between patients with CPN and without CPN (p = 0.28).
ROC analysis showed that dose > 406 Gy (AUC 0.76) and particle activity > 773 Bq (AUC 0.68) were predictive of CPN.
Conclusion:
In patients with HCC undergoing radiation segmentectomy with Y-90, dose > 406 Gy and particle activity > 773 Bq is predictive of CPN, supporting prescription of doses > 400 Gy (1,2) and radiation segmentectomy treatment intensification (3).