MIDOS: a novel stochastic model towards a treatment planning system for microsphere dosimetry in liver tumors

Carlos Huesa-Berral; Julia D Withrow; Robert J Dawson; Chris Beekman; Wesley E Bolch; Harald Paganetti; Eric Wehrenberg-Klee; Alejandro Bertolet

doi:10.1007/s00259-023-06567-9

MIDOS: a novel stochastic model towards a treatment planning system for microsphere dosimetry in liver tumors

Eur J Nucl Med Mol Imaging. 2024 May;51(6):1506-1515. doi: 10.1007/s00259-023-06567-9. Epub 2023 Dec 29.

Authors

Carlos Huesa-Berral¹, Julia D Withrow², Robert J Dawson², Chris Beekman³, Wesley E Bolch², Harald Paganetti³, Eric Wehrenberg-Klee⁴, Alejandro Bertolet⁵

Affiliations

¹ Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. chuesaberral@mgh.harvard.edu.
² J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
³ Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
⁴ Division of Interventional Radiology, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
⁵ Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. abertoletreina@mgh.harvard.edu.

PMID: 38155237
PMCID: PMC11043005 (available on 2025-05-01)
DOI: 10.1007/s00259-023-06567-9

Abstract

Purpose: Transarterial radioembolization (TARE) procedures treat liver tumors by injecting radioactive microspheres into the hepatic artery. Currently, there is a critical need to optimize TARE towards a personalized dosimetry approach. To this aim, we present a novel microsphere dosimetry (MIDOS) stochastic model to estimate the activity delivered to the tumor(s), normal liver, and lung.

Methods: MIDOS incorporates adult male/female liver computational phantoms with the hepatic arterial, hepatic portal venous, and hepatic venous vascular trees. Tumors can be placed in both models at user discretion. The perfusion of microspheres follows cluster patterns, and a Markov chain approach was applied to microsphere navigation, with the terminal location of microspheres determined to be in either normal hepatic parenchyma, hepatic tumor, or lung. A tumor uptake model was implemented to determine if microspheres get lodged in the tumor, and a probability was included in determining the shunt of microspheres to the lung. A sensitivity analysis of the model parameters was performed, and radiation segmentectomy/lobectomy procedures were simulated over a wide range of activity perfused. Then, the impact of using different microspheres, i.e., SIR-Sphere®, TheraSphere®, and QuiremSphere®, on the tumor-to-normal ratio (TNR), lung shunt fraction (LSF), and mean absorbed dose was analyzed.

Results: Highly vascularized tumors translated into increased TNR. Treatment results (TNR and LSF) were significantly more variable for microspheres with high particle load. In our scenarios with 1.5 GBq perfusion, TNR was maximum for TheraSphere® at calibration time in segmentectomy/lobar technique, for SIR-Sphere® at 1-3 days post-calibration, and regarding QuiremSphere® at 3 days post-calibration.

Conclusion: This novel approach is a decisive step towards developing a personalized dosimetry framework for TARE. MIDOS assists in making clinical decisions in TARE treatment planning by assessing various delivery parameters and simulating different tumor uptakes. MIDOS offers evaluation of treatment outcomes, such as TNR and LSF, and quantitative scenario-specific decisions.

Keywords: Microspheres; Radioembolization; Segmentectomy; Tumor uptake; Yttrium-90.

MeSH terms

Embolization, Therapeutic / methods
Female
Humans
Liver Neoplasms* / diagnostic imaging
Liver Neoplasms* / radiotherapy
Male
Microspheres*
Models, Biological
Radiometry*
Radiotherapy Planning, Computer-Assisted* / methods
Stochastic Processes*

Abstract

MeSH terms

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