DOSIMETRIC STUDY OF PROTON BORON CAPTURE THERAPY BASED ON MONTE CARLO SIMULATION AND MACHINE LEARNING ALGORITHMS

Sep 17, 2026

Proton boron capture therapy enhances conventional proton therapy by using the 11B(p,α)3α nuclear reaction to amplify dose in a localized region. The work investigates Bragg curve behavior of proton beams with Geant4 Monte Carlo simulations, quantifying the dosimetric effects of 11B. Introducing a pure 11B target produces a forward shift of the Bragg peak due to increased stopping power and nuclear reactions. Using 800 proton energies (0–80 MeV), machine learning models predict Bragg peak position in water; gaussian process regression achieves R² = 0.999997 and RMSE ≈ 0.0273 mm. A characterized correction links the initial water Bragg peak with 11B-induced shift for more accurate treatment depth.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages7

Reading Time18 min

AccessFree to download

Introduction

Materials and Methods

Simulation Setup (Geant4)

Physics List and Target Modeling

Results and Modeling Approach

Bragg Curve Characteristics and Forward Shift

Machine Learning Prediction of Bragg Peak Position

DOSIMETRIC STUDY OF PROTON BORON CAPTURE THERAPY BASED ON MONTE CARLO SIMULATION AND MACHINE LEARNING ALGORITHMS by YanBang TANG 1,2* 1 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China 2University of Chinese Academy of Sciences, Beijing, China Scientific paper [https://doi.org/10.2298/NTRP2502145T](https://doi.org/10.2298/NTRP2502145T) Proton boron capture therapy offers a promising enhancement to conventional proton therapyby leveraging the 11B(p,􀁄)3􀁄 nuclear reaction for localized dose amplification. This study systematically investigates the Bragg curve characteristics of proton beams using the Geant4 Monte Carlo toolkit, with a particular focus on the dosimetric impact of ¹¹B. The introduction ofa pure ¹¹B target induced a consistent forward shift in the Bragg peak position, attributed to increased stopping power and nuclear reactions. Furthermore, Proton boron capture therapy demonstrated enhanced local energy deposition along the central axis due to the generation of high linear energy transfer alpha particles, with minimal lateral broadening. To facilitate precise treatment planning, Bragg curve data for 800 distinct proton energies (0-80 MeV) in water were generated. Various machine learning algorithms were subsequently employed to develop predictive models for the Bragg peak position. Comparative analysis identified gaussian process regression as the optimal model, achieving an R² of 0.999997 anda root mean squared error of approximately 0.0273 mm for predicting Bragg peak positions in water. Crucially, this research pioneers a novel pathway for proton boron capture therapy treatment planning by combining high-accuracy machine learning-based prediction of the initial Bragg peak (in water) with a characterized correction for the ¹¹B-induced forward shift, enabling more precise determination of the actual treatment depth. This work provides critical dosimetric characterization, quantifies key ¹¹B-induced phenomena, and offers a validated predictive framework, thereby establishing a theoretical foundation and technical support for dose optimization in this emerging therapeutic modality. Key words: proton boron capture therapy, Monte Carlo simulation, Bragg curve, machine learning INTRODUCTION Proton therapy is a form of radiotherapy that utilizes the unique depth-dose distribution of charged particles to deliver a highly conformal radiation dose to tumor tissues while minimizing exposure to surrounding healthy structures. The rapid rise in energy deposition, culminating in a sharp maximum known as the Bragg peak, enables precise irradiation of deep-seated tumorsand offers significant dosimetric advantages over conventional photon-based modalities [1-4] . Proton boron capture therapy (PBCT) is an innovative approach that aims to enhance the biological effectiveness of proton therapy through the nuclear reaction between incident protons and 11B atoms selectively introduced into tumor tissues [5-7] . When protons interact with 11B at specific energies, the 11B(p,􀁄)3􀁄 reaction generates three high linear energy transfer alpha * Corresponding author, e-mail: [tangyanbang2022](tangyanbang2022@163.com)[@](tangyanbang2022@163.com)[163.com](tangyanbang2022@163.com) particles, leading to localized dose amplification within the boron-loaded region [8-10]. This approach is conceptually analogous to boron neutron capture therapy, employing protons instead of thermal neutrons while leverages the infrastructure of existing proton therapy centers. Recent experimental and modeling studies have investigated the dosimetric and biological implications of PBCT, with some reports of enhanced tumor cell killing and increased cytogenetic damage atthe distal edge of the Bragg peak, corresponding to the resonance peak of the 11B(p,􀁄) reaction cross section [11-13] . In this study, we systematically investigate the Bragg curve characteristics of proton beams at various energies using Geant4-

FAQs

What mechanism makes proton boron capture therapy dosimetrically distinct from conventional proton therapy?

PBCT leverages the 11B(p,α)3α nuclear reaction to create localized dose amplification through alpha particle production in the boron-loaded region.

How does the 11B target affect the proton Bragg peak in the study?

Adding a pure 11B target induces a consistent forward shift in the Bragg peak position, attributed to increased stopping power and nuclear reactions.

Which machine learning approach performed best for predicting Bragg peak position in water?

Gaussian process regression provided the strongest performance, with R² = 0.999997 and RMSE around 0.0273 mm.

Sep 17, 2026

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