Clustering effects in nanoparticle-enhanced β− emitting internal radionuclide therapy: a Monte Carlo study. (15th June 2020)

• Record Type: Journal Article
• Authors: Maschmeyer, R T; Gholami, Y H; Kuncic, Z
• Is Part Of: Physics in medicine & biology. Volume 65:Number 12(2020:Jun.)
• Publication Date: 2020-06-15
• Subjects: radiotherapy -- Geant4 -- nanoparticles -- SPIONS -- clustering -- copper-67 -- classical Monte Carlo simulations; Biophysics -- Periodicals; Medical physics -- Periodicals; 610.153
• DOI: 10.1088/1361-6560/ab8079
• Languages: English
• ISSNs: 0031-9155

Abstract

Abstract: We investigate the effects of an increase in the production of secondary electrons when a β − source commonly used in internal radionuclide therapy, 67 Cu, is radiolabelled to a super-paramagnetic iron oxide nanoparticle (SPION), with specific emphasis on the role of SPION cluster size and geometry. A positive relationship is found between the degree to which the nanoparticles are clustered and the associated radio-enhancement effects, with cluster population size playing a major role, as well as SPION separation within a cluster and the distance between clusters. Our simulation results indicate that SPIONs labelled with 67 Cu can induce a nonlinear amplification in the number of secondary electrons produced of up to 4% in bulk, with localised regions of nearer inter-SPION separation producing an increase of over 400% for a 20 nm average SPION separation. Such variation in enhancement due to local concentration effects may help identify clinical strategies that enhance efficacy for a given radiation dosage, or achieve equal efficacy with reduced radiation dosage.