Page 99 - ARNM-2-3

Advances in Radiotherapy &

Nuclear Medicine

SHORT COMMUNICATION
Determining beta radiation doses from Y-90

microsphere for the treatment of hepatic tumors
by using Monte Carlo and analytical methods

Leonardo Pessoa da Silva 1 , Henrique Trombini 2 , and Eduardo De Paiva *
1
1 Division of Medical Physics, Institute of Radiation Protection and Dosimetry, Rio de Janeiro, Brazil
2 Department of Exact and Applied Social Sciences, Federal University of Health Sciences of Porto
Alegre, Porto Alegre, Rio Grande do Sul, Brazil

Abstract

The very short range of beta radiation is a potential radiation treatment for tumor, which
can preserve sensitive structures. However, due to the limited range of beta radiation,
practical dosimetry of beta sources may be a point of concern, and theoretical dosimetry
methods play an important role. A resin microsphere loaded with the Yttrium-90 (Y-90)
radionuclide can be applied in the radioembolization of hepatic tumors. In this work,
we present initial calculations of dose rates around a microsphere loaded with the Y-90
radionuclide uniformly distributed on its exterior surface. Two approaches were used
to carry out the estimations: the first one by means of Monte Carlo simulations using
the PENELOPE code and the second one by means of the beta-point dose function
formalism. A Fortran code was developed to handle with the various quantities necessary
*Corresponding author: to perform the numerical integration of the beta-point dose function. A comparison
Eduardo De Paiva between results obtained by means of both methods indicated a maximum difference
(eduardo.paiva@ird.gov.br)
of ~5% up to the 0.3 cm distance from the center of the sphere.
Citation: da Silva LP, Trombini H,
De Paiva E. Determining beta
radiation doses from Y-90 Keywords: Radioembolization; Beta particles; Yttrium-90; Monte Carlo method; Beta-
microsphere for the treatment of point dose function
hepatic tumors by using Monte
Carlo and analytical methods.
Adv Radiother Nucl Med.
2024;2(3):3639.
doi: 10.36922/arnm.3639 1. Introduction
Received: May 12, 2024
Beta radiation plays an important role in the treatment of several kinds of diseases.
1
Accepted: June 26, 2024 The short range of beta particles and their high dose gradient make them an attractive
Published Online: August 13, 2024 clinical option for brachytherapy treatments. In particular, there is an increasingly use
of radioembolization with Yttrium-90 or Holmium-166 to treat primary and metastatic
Copyright: © 2024 Author(s).
This is an Open-Access article liver tumors. 2-12 Radioembolization consists of the administration of radioactive
13
distributed under the terms of the microspheres to the target region through a catheter in a hemodynamic procedure.
Creative Commons Attribution By lodging in the dysfunctional tissue through the local vasculature, in addition
License, permitting distribution,
and reproduction in any medium, to producing sufficient doses of radiation to promote the death of tumor cells, the
provided the original work is embolization generated prevents the arrival of oxygen and nutrients to this region,
properly cited. enhancing the desired effect. There are two commercial types of microspheres loaded
14
®
Publisher’s Note: AccScience with Y-90: those of resin (Sir-Spheres , Sirtex Medical Ltd., Sydney, Australia) and
Publishing remains neutral with those of glass (Therasphere , Boston Scientific, Boston, MA, USA); and there are also
®
regard to jurisdictional claims in ®
published maps and institutional the microspheres of PLLA (poly-L-lactic acid) loaded with Ho-166 (QuiremSpheres ,
affiliations Quirem Medical B.V., Deventer, The Netherlands). 2
Volume 2 Issue 3 (2024) 1 doi: 10.36922/arnm.3639