Focused very high-energy electron beams as a novel radiotherapy modality for producing high-dose volumetric elements

K Kokurewicz,A J Chalmers,M Boyd,A Sorensen,C Desrosiers,G H Welsh,G Schettino,D A Jaroszynski,A Subiel,E Brunetti,S M Wiggins

doi:10.1038/s41598-019-46630-w

Abstract

The increased inertia of very high-energy electrons (VHEEs) due to relativistic effects reduces scattering and enables irradiation of deep-seated tumours. However, entrance and exit doses are high for collimated or diverging beams. Here, we perform a study based on Monte Carlo simulations of focused VHEE beams in a water phantom, showing that dose can be concentrated into a small, well-defined volumetric element, which can be shaped or scanned to treat deep-seated tumours. The dose to surrounding tissue is distributed over a larger volume, which reduces peak surface and exit doses for a single beam by more than one order of magnitude compared with a collimated beam.

Highlights

Targeting of deep-seated tumours requires accurate delivery of high radiation doses through thick layers of tissue
Focusing at depths of 5, 10 and 15 cm was investigated by varying the source to surface distance to displace the position of the high-dose volumetric element, as shown in Fig. 3c,d for 200 MeV and 2 GeV electron beams and f/1.2
We have considered the level of activation produced when focused very high-energy electrons (VHEEs) interact with dense materials

Summary

Introduction

Targeting of deep-seated tumours requires accurate delivery of high radiation doses through thick layers of tissue. To do this we have used a general purpose Monte Carlo numerical code (FLUKA21) to model the propagation of VHEE beams in a water phantom for different focusing strengths. The dose is normalised to the maximum dose of a collimated beam

Objectives

Methods

Results

Discussion

Conclusion