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Yttrium-90 Radioembolization and Tumor Hypoxia: Gas-challenge BOLD Imaging in the VX2 Rabbit Model of Hepatocellular Carcinoma. Acad Radiol 2021 06;28(6):849-858

Date

06/12/2020

Pubmed ID

32522403

Pubmed Central ID

PMC7719607

DOI

10.1016/j.acra.2020.04.012

Scopus ID

2-s2.0-85086017926   1 Citation

Abstract

RATIONALE AND OBJECTIVES: To use a rapid gas-challenge blood oxygen-level dependent magnetic resonance imaging exam to evaluate changes in tumor hypoxia after 90Y radioembolization (Y90) in the VX2 rabbit model.

MATERIALS AND METHODS: White New Zealand rabbits (n = 11) provided a Y90 group (n = 6 rabbits) and untreated control group (n = 5 rabbits). R2* maps were generated with gas-challenges (O2/room air) at baseline, 1 week, and 2 weeks post-Y90. Laboratory toxicity was evaluated at baseline, 24 hours, 72 hours, 1 hours, and 2 weeks. Histology was used to evaluate tumor necrosis on hematoxylin and eosin and immunofluorescence imaging was used to assess microvessel density (CD31) and proliferative index (Ki67).

RESULTS: At baseline, median tumor volumes and time to imaging were similar between groups (p = 1.000 and p = 0.4512, respectively). The median administered dose was 50.4 Gy (95% confidence interval:44.8-55.9). At week 2, mean tumor volumes were 5769.8 versus 643.7 mm3 for control versus Y90 rabbits, respectively (p = 0.0246). At two weeks, ΔR2* increased for control tumors to 12.37 ± 12.36sec-1 and decreased to 4.48 ± 9.00sec-1 after Y90. The Pearson correlation coefficient for ΔR2* at baseline and percent increase in tumor size by two weeks was 0.798 for the Y90 group (p = 0.002). There was no difference in mean microvessel density for control versus Y90 treated tumors (p = 0.6682). The mean proliferative index was reduced in Y90 treated tumors at 30.5% versus 47.5% for controls (p = 0.0071).

CONCLUSION: The baseline ΔR2* of tumors prior to Y90 may be a predictive imaging biomarker of tumor response and treatment of these tumors with Y90 may influence tumor oxygenation over time.

Author List

Gordon AC, White SB, Gates VL, Procissi D, Harris KR, Yang Y, Zhang Z, Li W, Lyu T, Huang X, Omary RA, Salem R, Lewandowski RJ, Larson AC

Author

Sarah B. White MD, MS, FSIR, FCIRSE Vice Chair, Professor in the Radiology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Carcinoma, Hepatocellular
Embolization, Therapeutic
Liver Neoplasms
Rabbits
Tumor Hypoxia
Yttrium Radioisotopes