Quantification of Nanoscale Dose Enhancement in Gold Nanoparticle-Aided External Photon Beam Radiotherapy
by
, ,
Elena Vlastou
1, 
Evaggelos Pantelis
2,
Efstathios P. Efstathopoulos
1
,
Pantelis Karaiskos
2,
Vasileios Kouloulias
1 and 
Kalliopi Platoni
1,* 
1
Medical Physics Unit, 2nd Department of Radiology, University General Hospital “Attikon”, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece
2
Medical Physics Laboratory, School of Medicine, National and Kapodistrian University of Athens, 11527 Athens, Greece
*
Author to whom correspondence should be addressed.
Cancers 2022, 14(9), 2167; https://doi.org/10.3390/cancers14092167
Submission received: 30 March 2022
/
Revised: 22 April 2022
/
Accepted: 23 April 2022
/
Published: 26 April 2022
(This article belongs to the Special Issue Recent Advances in Nanotechnologies for Cancer Detection and Treatment)
Simple Summary
Gold nanoparticles (AuNPs) have become common in radiation oncology research through the past decades. Their radiosensitization effect could offer a novel approach to cancer diagnosis and radiotherapy as well. The aim of this study is the assessment of dose enhancement attributed to the incubation of AuNPs in an irradiated target. The present work is focused on investigating the impact of AuNPs properties in dose increase under different irradiation conditions using 6 MV photon beams with and without a flattening filter via Monte Carlo simulations. Results from the simulated scenarios depict a sufficient dose raise especially at close distances to AuNPs, depending on the presence of a flattening filter in the path of the photon beam, AuNPs size, the type of modeled distribution and their concentration. Therefore, the obtained enhanced dose deposition due to AuNPs presence in an irradiated region could lead to more sufficient tumor cell destruction than irradiation alone.
Abstract
The recent progress in Nanotechnology has introduced Gold Nanoparticles (AuNPs) as promising radiosensitizing agents in radiation oncology. This work aims to estimate dose enhancement due to the presence of AuNPs inside an irradiated water region through Monte Carlo calculations. The GATE platform was used to simulate 6 MV photon histories generated from a TrueBeam® linear accelerator with and without a Flattening Filter (FF) and model AuNPs clusters. The AuNPs size, concentration and distribution pattern were examined. To investigate different clinical irradiation conditions, the effect of field size, presence of FF and placement of AuNPs in water were evaluated. The range of Dose Enhancement Factors (DEF = DoseAu/DoseWater) calculated in this study is 0.99 ± 0.01–1.26 ± 0.02 depending on photon beam quality, distance from AuNPs surface, AuNPs size and concentration and pattern of distribution. The highest DEF is reported for irradiation using un-flattened photon beams and at close distances from AuNPs. The obtained findings suggest that dose deposition could be increased in regions that represent whole cells or subcellular targets (mitochondria, cell nucleus, etc.). Nevertheless, further and consistent research is needed in order to make a step toward AuNP-aided radiotherapy in clinical practice.
