Page 63 - ARNM-3-3

Advances in Radiotherapy &

Nuclear Medicine

ORIGINAL RESEARCH ARTICLE
Post-therapeutic dosimetric evaluation of Ho
166
radioembolization for liver malignancies: Impact
of software on tumor and liver doses

Rita Albergueiro * , Rafael Silva 3 , and João Santos 1,3,4
1,2
1 Medical Physics, Radiobiology and Radiation Protection Group, IPO Porto Research Center,
Portuguese Oncology Institute of Porto/Porto Comprehensive Cancer Center, Porto, Portugal
2 Department of Nuclear Medicine, São João University Hospital Center, Porto, Portugal
3 Department of Nuclear Medicine, Santo António University Hospital Center, Porto, Portugal
4 Department of Pathology and Molecular Immunology, Abel Salazar Institute of Biomedical Sciences,
Porto, Portugal

Abstract

Transarterial radioembolization using holmium-166 microspheres is a promising
treatment for primary and secondary liver malignancies. Accurate post-therapeutic
dosimetry is critical for optimizing outcomes, particularly in voxel-based dose
assessment using quantitative single-photon emission computed tomography/
computed tomography (SPECT/CT). This study aimed to evaluate the impact
*Corresponding author: of software choice and calibration method on absorbed dose estimates to the
Rita Albergueiro
(rita.albergueiro@ulssjoao.min- liver and tumor, by comparing two advanced dosimetry platforms: Hermia Voxel
saude.pt) Dosimetry and Q-Suite . Despite the recent discontinuation of Ho-microsphere
™
166
™
Citation: Albergueiro R, Silva R, production, such studies remain highly relevant given the global emphasis on
Santos J. Post-therapeutic personalized dosimetry, quantitative imaging in nuclear medicine, and potential
dosimetric evaluation of Ho applicability to other therapeutic radiopharmaceuticals and future microsphere
166
radioembolization for liver
malignancies: Impact of software technologies. Fourteen patients underwent a scout procedure, followed by therapy
on tumor and liver doses. Adv and post-treatment SPECT/CT imaging. Initial analysis revealed substantially lower
Radiother Nucl Med. mean liver and tumor doses with Hermia (12 ± 4 Gy and 58 ± 23 Gy) compared
2025;3(3):55-64.
doi: 10.36922/ARNM025220023 to Q-Suite (44 ± 9 Gy and 209 ± 83 Gy), with statistically significant differences
(p=0.002 and p<0.001). Discrepancies were due to the gamma camera dead time
Received: May 31, 2025 and Hermia’s fixed calibration factor (CF). A patient-specific CF, derived from the
Revised: July 22, 2025 camera’s response curve and administered activity, was applied to correct Hermia
Accepted: August 4, 2025 dose maps. The corrected doses, 42 ± 6 Gy and 196 ± 17 Gy, closely matched those
from Q-Suite (p=0.69 and p=0.64). These findings underscore the critical role of
Published online: August 18, 2025 system-specific calibration and acquisition timing in achieving accurate voxel-
Copyright: © 2025 Author(s). based dosimetry. Underestimation of absorbed doses may lead to suboptimal
This is an Open-Access article clinical decisions, including undertreatment or unrecognized toxicity. Thus,
distributed under the terms of the
Creative Commons Attribution implementing patient-specific calibration protocols or equivalent corrections
License, permitting distribution, for dead time is essential to support safe, consistent, and effective radionuclide
and reproduction in any medium, therapy in clinical practice.
provided the original work is
properly cited.
Publisher’s Note: AccScience Keywords: Calibration factor; Gamma camera response; Holmium-166; Transarterial
Publishing remains neutral with radioembolization; Personalized radionuclide therapy; Single-photon emission
regard to jurisdictional claims in
published maps and institutional computed tomography/computed tomography quantification; Voxel-based dosimetry
affiliations.

Volume 3 Issue 3 (2025) 55 doi: 10.36922/ARNM025220023