Hepatopulmonary Shunt Ratio Verification Model for Transarterial Radioembolization

Nami Yeyin; Fahrettin Fatih Kesmezacar; Duygu Tunçman; Özge Demir; Lebriz Uslu-Beşli; Osman Günay; Mustafa Demir

doi:10.2174/0118744710284130240108053733

Hepatopulmonary Shunt Ratio Verification Model for Transarterial Radioembolization

Curr Radiopharm. 2024 Jan 27. doi: 10.2174/0118744710284130240108053733. Online ahead of print.

Authors

Nami Yeyin¹, Fahrettin Fatih Kesmezacar², Duygu Tunçman², Özge Demir³, Lebriz Uslu-Beşli¹, Osman Günay⁴, Mustafa Demir¹

Affiliations

¹ Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty, Department of Nuclear Medicine, Fatih/Istanbul, Turkey.
² Istanbul University-Cerrahpasa, Vocational School of Health Service, Istanbul, Turkey.
³ Chemical Engineering Department, Engineering Faculty, Istanbul University-Cerrahpasa, Avcılar, 34320 Istanbul, Turkey.
⁴ Yıldız Technical University, Faculty of Electrical and Electronics Engineering, Department of Biomedical Engineering, Istanbul, Turkey.

PMID: 38288829
DOI: 10.2174/0118744710284130240108053733

Abstract

Introduction: The most important toxicity of transarterial radioembolization therapy applied in liver malignancies is radiation pneumonitis and fibrosis due to hepatopulmonary shunt of Yttrium-90 (90Y) microspheres. Currently, Technetium-99m macroaggregated albumin (99mTc-MAA) scintigraphic images are used to estimate lung shunt fraction (LSF) before treatment. The aim of this study was to create a phantom to calculate exact LFS rates according to 99mTc activities in the phantom and to compare these rates with LSF values calculated from scintigraphic images.

Materials and methods: A 3D-printed lung and liver phantom containing two liver tumors was developed from Polylactic Acid (PLA) material, which is similar to the normal-sized human body in terms of texture and density. Actual %LSFs were calculated by filling phantoms and tumors with 99mTc radionuclide. After the phantoms were placed in the water tank made of plexiglass material, planar, SPECT, and SPECT/CT images were obtained. The actual LSF ratio calculated from the activity amounts filled into the phantom was used for the verification of the quantification of scintigraphic images and the results obtained by the Simplicit 90YTM method.

Results: In our experimental model, LSFs calculated from 99mTc activities filled into the lungs, normal liver, small tumor, and large tumor were found to be 0%, 6.2%, 10.8%, and 16.9%. According to these actual LSF values, LSF values were calculated from planar, SPECT/CT (without attenuation correction), and SPECT/CT (with both attenuation and scatter correction) scintigraphic images of the phantom. In each scintigraphy, doses were calculated for lung, small tumor, large tumor, normal liver, and Simplicit 90YTM. The doses calculated from planar and SPECT/CT (NoAC+NoSC) images were found to be higher than the actual doses. The doses calculated from SPECT/CT (with AC+with SC) images and Simplicit 90YTM were found to be closer to the real dose values.

Conclusion: LSF is critical in dosimetry calculations of 90Y microsphere therapy. The newly introduced hepatopulmonary shunt phantom in this study is suitable for LSF verification for all models/brands of SPECT and SPECT/CT devices.

Keywords: 90Y microsphere therapy; Lung shunt fraction; hepatopulmonary phantom; radionuclide dosimetry; transarterial radioembolizati.