Page 61 - ARNM-2-4

Advances in Radiotherapy &

Nuclear Medicine

ORIGINAL RESEARCH ARTICLE
Comparison of different approaches for the

computation of biologically effective dose in
a non-uniformly irradiated treatment target in

stereotactic body radiation therapy

Vadim Y. Kuperman* , Yücel Altundal , and Rebecca Weinberg
Florida Cancer Specialists and Research Institute, Hudson, Florida, United States of America

Abstract
The biologically effective dose (BED) for a non-uniformly irradiated treatment target
can be determined using two approaches: averaging BEDs for different voxels in
the target and averaging the probability of tumor cell survival in the target. This
study compared these approaches for the computation of BED by examining their
general properties and comparing BEDs for different treatment plans. The mean
BED (BED mean ) determined by averaging BEDs in different parts of the target and
BED (BED ) determined by averaging the probability of survival were computed for
nud
51 cases of stereotactic body radiation therapy. For each case, two treatment plans
were created using dynamic conformal arcs (DCAs) and volumetric modulated arc
*Corresponding author: therapy (VMAT). For the plans with DCAs, the sample mean of BED was 18% > that
Vadim Y. Kuperman mean
−1
(vadimkuperman@yahoo.com) of BED nud (for α = 0.35 Gy and α/β =10 Gy). Conversely, for the VMAT plans and the
same values of radiobiological parameters, the sample mean of BED was only
Citation: Kuperman VY, Altundal mean
Y, Weinberg R. Comparison 5%> that of BED . Theoretically, BED mean is always ≥BED . When the mean dose in
nud
nud
2
of different approaches for the the target is fixed, BED mean increases with increasing variance of the target dose (σ ).
computation of biologically effective In contrast, BED decreased with increasing σ . Although BED depends on both
2
dose in a non-uniformly irradiated nud nud
treatment target in stereotactic body alpha and beta parameters for the irradiated malignant cells, BED mean depends only
radiation therapy. Adv Radiother on the alpha/beta ratio. Thus, the use of BED mean instead of BED can cause incorrect
nud
Nucl Med. 2024;2(4):4826. ranking of treatment plans.
doi: 10.36922/arnm.4826
Received: September 12, 2024
Keywords: Biologically effective dose; Stereotactic body radiation therapy; Dynamic
Accepted: November 7, 2024 conformal arc; Volumetric modulated arc therapy; Dose variance
Published Online: December 23,
2024
Copyright: © 2024 Author(s).
This is an Open-Access article 1. Introduction
distributed under the terms of the
Creative Commons Attribution 1.1. Background
License, permitting distribution,
and reproduction in any medium, The goal of radiotherapy is to deliver a tumoricidal dose to targeted malignant cells while
provided the original work is minimizing the risk of normal tissue complications. Conventionally, the assessment
properly cited. of treatment plans and their ranking in three-dimensional conformal radiotherapy
Publisher’s Note: AccScience or intensity-modulated radiotherapy have been performed by considering the dose
Publishing remains neutral with distributions in the planning target volume (PTV) and critical normal structures. The
regard to jurisdictional claims in
published maps and institutional employed criteria for plan evaluation are based on several established dose-volume
affiliations parameters (DVPs). For example, in lung tumors treated with a standard regimen of

Volume 2 Issue 4 (2024) 1 doi: 10.36922/arnm.4826