scholarly journals Stopping-power ratio of mouthpiece materials for charged-particle therapy in head and neck cancer

2021 ◽  
Author(s):  
Hiroaki Ikawa ◽  
Taku Inaniwa ◽  
Masashi Koto ◽  
Tapesh Bhattacharyya ◽  
Takashi Kaneko ◽  
...  
Keyword(s):  
Ion Beam ◽  
Acrylic Resin ◽  
Ethylene Vinyl Acetate ◽  
Peak Shift ◽  
Particle Therapy ◽  
Stopping Power ◽  
Conversion Table ◽  
Charged Particle Therapy ◽  
Carbon Ion Beam ◽  
The Difference

AbstractIn this study, the stopping-power ratios (SPRs) of mouthpiece materials were measured and the errors in the predicted SPRs based on conversion table values were further investigated. The SPRs of the five mouthpiece materials were predicted from their computed tomography (CT) numbers using a calibrated conversion table. Independently, the SPRs of the materials were measured from the Bragg peak shift of a carbon-ion beam passing through the materials. The errors in the SPRs of the materials were determined as the difference between the predicted and measured values. The measured SPRs (errors) of the Nipoflex 710™ and Bioplast™ ethylene–vinyl acetate copolymers (EVAs) were 0.997 (0.023) and 0.982 (0.007), respectively. The SPRs of the vinyl silicon impression material, light-curable resin, and bis-acrylic resin were 1.517 (0.134), 1.161 (0.068), and 1.26 (0.101), respectively. Among the five tested materials, the EVAs had the lowest SPR errors, indicating the highest human-tissue equivalency.

scholarly journals Stopping-power ratio of mouthpiece materials for charged-particle therapy in head and neck cancer

2020 ◽  
Author(s):  
Hiroaki Ikawa ◽  
Taku Inaniwa ◽  
Masashi Koto ◽  
Tapesh Bhattacharyya ◽  
Takashi Kaneko ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Charged Particle ◽  
Head And Neck ◽  
Treatment Planning ◽  
Neck Cancer ◽  
Particle Therapy ◽  
Stopping Power ◽  
Ct Number ◽  
Conversion Table ◽  
Charged Particle Therapy

Abstract Background: In charged-particle therapy treatment planning, CT numbers of a patient’s body are converted into stopping power ratios (SPRs) using a CT-number-to-SPR conversion table constructed for standard human tissues. Since artificial devices used in treatments of head and neck cancer, such as mouthpieces, do not fit into the CT-number-to-SPR conversion table, they may deteriorate treatment accuracy. In this study, the SPRs of five mouthpiece materials were measured, and the error in predicted SPRs based on the conversion table was investigated.Methods: SPRs of five mouthpiece materials were predicted from their CT numbers using a calibrated conversion table. Independently, the SPRs of the materials were measured by the Bragg-peak shift of a carbon-ion beam passing through the materials. The errors in SPR of the materials were determined as the difference between the predicted and measured SPRs.Results: The SPRs (error) of the ethylene-vinyl acetate copolymers (EVAs), Nipoflex 710TM and BioplastTM, were 0.997 (0.023) and 0.982 (0.007), respectively. The SPRs (error) of the vinyl silicon impression material (Exafine putty typeTM), the light curable resin (Clear Photoreactive Resin for Formlabs 3D printersTM), and the bis-acrylic resin (TempsmartTM) were 1.517 (0.134), 1.161 (0.068), and 1.26 (0.101), respectively. Conclusions: The EVA BioplastTM had the minimum SPR error among the five tested materials, indicating the highest human-tissue equivalency. If other artificial materials such as Exafine putty typeTM are used as mouthpieces, it is recommended that their SPRs be overwritten by the correct values in treatment planning processes.

TU-E-BRB-10: Investigation of the Water-to-Air Stopping Power Ratio for Carbon Ion Beam Dosimetry Based on Experimental Data and FLUKA Simulation

2011 ◽  
Vol 38 (6Part29) ◽  
pp. 3768-3769
Author(s):  
D Sanchez-Parcerisa ◽  
A Gemmel ◽  
K Parodi ◽  
O Jäkel ◽  
E Rietzel
Keyword(s):  
Experimental Data ◽  
Ion Beam ◽  
Stopping Power ◽  
Power Ratio ◽  
Carbon Ion ◽  
Carbon Ion Beam ◽  
Beam Dosimetry

scholarly journals FLUKA particle therapy tool for Monte Carlo independent calculation of scanned proton and carbon ion beam therapy

2019 ◽  
Vol 64 (7) ◽  
pp. 075012 ◽  
Author(s):  
Wioletta S Kozłowska ◽  
Till T Böhlen ◽  
Caterina Cuccagna ◽  
Alfredo Ferrari ◽  
Francesco Fracchiolla ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ion Beam ◽  
Particle Therapy ◽  
Carbon Ion ◽  
Ion Beam Therapy ◽  
Carbon Ion Beam ◽  
Independent Calculation

Experimental determination of modulation power of lung tissue for particle therapy

2021 ◽  
Author(s):  
Jan Michael Burg ◽  
Veronika Flatten ◽  
Matthias Witt ◽  
Larissa Derksen ◽  
Uli Weber ◽  
...  
Keyword(s):  
Lung Tissue ◽  
Ex Vivo ◽  
Ion Beam ◽  
Particle Beam ◽  
Particle Therapy ◽  
New Material ◽  
Carbon Ion Beam ◽  
Porcine Lungs ◽  
Micro Structures

Abstract In particle therapy of lung tumors, modulating effects on the particle beam may occur due to the microscopic structure of the lung tissue. These effects are caused by the heterogeneous nature of the lung tissue and cannot be completely taken into account during treatment planning, because these micro structures are too small to be fully resolved in the planning CT. In several publications, a new material parameter called modulation power (P mod ) was introduced to characterize the effect. For various artificial lung surrogates, this parameter was measured and published by other groups and ranges up to approximately 1000 µm. Studies investigating the influence of the modulation power on the dose distribution during irradiation are using this parameter in the rang of 100 to 800 µm. More precise measurements for P mod on real lung tissue have not yet been published. In this work, the modulation power of real lung tissue was measured using porcine lungs in order to produce more reliable data of P mod for real lung tissue. For this purpose, ex-vivo porcine lungs were frozen in a ventilated state and measurements in a carbon ion beam were performed. Due to the way the lungs were prepared and transferred to a solid state, the lung structures that modulate the beam could also be examined in detail using micro CT imaging. An optimization of the established methods of measuring the modulation power, which takes better account of the typical structures within lung tissue, was developed as well.

scholarly journals Stopping power accuracy and achievable spatial resolution of helium ion imaging using a prototype particle CT detector system

2017 ◽  
Vol 3 (2) ◽  
pp. 401-404 ◽  
Author(s):  
Lennart Volz ◽  
Charles-Antoine Collins-Fekete ◽  
Pierluigi Piersimoni ◽  
Robert P. Johnson ◽  
Vladimir Bashkirov ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Spatial Resolution ◽  
Ion Beam ◽  
Reconstruction Algorithm ◽  
Detector System ◽  
Particle Therapy ◽  
Stopping Power ◽  
Proton Radiography ◽  
Custom Made ◽  
Particle Imaging

AbstractA precise relative stopping power map of the patient is crucial for accurate particle therapy. Charged particle imaging determines the stopping power either tomographically – particle computed tomography (pCT) – or by combining prior knowledge from particle radiography (pRad) and x-ray CT. Generally, multiple Coulomb scattering limits the spatial resolution. Compared to protons, heavier particles scatter less due to their lower charge/mass ratio. A theoretical framework to predict the most likely trajectory of particles in matter was developed for light ions up to carbon and was found to be the most accurate for helium comparing for fixed initial velocity. To further investigate the potential of helium in particle imaging, helium computed tomography (HeCT) and radiography (HeRad) were studied at the Heidel-berg Ion-Beam Therapy Centre (HIT) using a prototype pCT detector system registering individual particles, originally developed by the U.S. pCT collaboration. Several phantoms were investigated: modules of the Catphan QA phantom for analysis of spatial resolution and achievable stopping power accuracy, a paediatric head phantom (CIRS) and a custom-made phantom comprised of animal meat enclosed in a 2 % agarose mixture representing human tissue. The pCT images were reconstructed applying the CARP iterative reconstruction algorithm. The MTF10% was investigated using a sharp edge gradient technique. HeRad provides a spatial resolution above that of protons (MTF1010%=6.07 lp/cm for HeRad versus MTF10%=3.35 lp/cm for proton radiography). For HeCT, the spatial resolution was limited by the number of projections acquired (90 projections for a full scan). The RSP accuracy for all inserts of the Catphan CTP404 module was found to be 2.5% or better and is subject to further optimisation. In conclusion, helium imaging appears to offer higher spatial resolution compared to proton imaging. In future studies, the advantage of helium imaging compared to other imaging modalities in clinical applications will be further explored.

scholarly journals Study of an Online Plan Verification Method and the Sensitivity of Plan Delivery Accuracy to Different Beam Parameter Errors in Proton and Carbon Ion Radiotherapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Jun Zhao ◽  
Zhi Chen ◽  
Xianwei Wu ◽  
Ying Xing ◽  
Yongqiang Li
Keyword(s):  
Particle Number ◽  
Ion Beam ◽  
Reconstruction Algorithm ◽  
Spot Size ◽  
Particle Therapy ◽  
Beam Parameter ◽  
Carbon Ion ◽  
Carbon Ion Beam ◽  
Beam Parameters ◽  
Delivery Accuracy

For scanning beam particle therapy, the plan delivery accuracy is affected by spot size deviation, position deviation and particle number deviation. Until now, all plan verification systems available for particle therapy have been designed for pretreatment verification. The purpose of this study is to introduce a method for online plan delivery accuracy checks and to evaluate the sensitivity of plan delivery accuracy to different beam parameter errors. A program was developed using MATLAB to reconstruct doses from beam parameters recorded in log files and to compare them with the doses calculated by treatment planning system (TPS). Both carbon ion plans and proton plans were evaluated in this study. The dose reconstruction algorithm is verified by comparing the dose from the TPS with the reconstructed dose under the same beam parameters. The sensitivity of plan delivery accuracy to different beam parameter errors was analyzed by comparing the dose reconstructed from the pseudo plans that manually added errors with the original plan dose. For the validation of dose reconstruction algorithm, mean dose difference between the reconstructed dose and the plan dose were 0.70% ± 0.24% and 0.51% ± 0.25% for carbon ion beam and proton beam, respectively. According to our simulation, the delivery accuracy of the carbon ion plan is more sensitive to spot position deviation and particle number deviation, and the delivery accuracy of the proton plan is more sensitive to spot size deviation. To achieve a 90% gamma pass rate with 3 mm/3% criteria, the average spot size deviation, position deviation, particle number deviation should be within 23%, 1.9 mm, and 1.5% and 20%, 2.1 mm, and 1.6% for carbon ion beam and proton beam, respectively. In conclusion, the method that we introduced for online plan delivery verification is feasible and reliable. The sensitivity of plan delivery accuracy to different errors was clarified for our system. The methods used in this study can be easily repeated in other particle therapy centers.

scholarly journals Charge identification of fragments with the emulsion spectrometer of the FOOT experiment

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 383-394
Author(s):  
Giuliana Galati ◽  
Andrey Alexandrov ◽  
Behcet Alpat ◽  
Giovanni Ambrosi ◽  
Stefano Argirò ◽  
...  
Keyword(s):  
Charged Particle ◽  
Dynamic Range ◽  
Ion Beam ◽  
Particle Therapy ◽  
Particle Beams ◽  
Cross Sectional ◽  
Charged Particle Beams ◽  
Oxygen Ion ◽  
Charged Particle Therapy ◽  
Target Experiment

Abstract The FOOT (FragmentatiOn Of Target) experiment is an international project designed to carry out the fragmentation cross-sectional measurements relevant for charged particle therapy (CPT), a technique based on the use of charged particle beams for the treatment of deep-seated tumors. The FOOT detector consists of an electronic setup for the identification of Z ≥ 3 Z\ge 3 fragments and an emulsion spectrometer for Z ≤ 3 Z\le 3 fragments. The first data taking was performed in 2019 at the GSI facility (Darmstadt, Germany). In this study, the charge identification of fragments induced by exposing an emulsion detector, embedding a C 2 H 4 {{\rm{C}}}_{2}{{\rm{H}}}_{4} target, to an oxygen ion beam of 200 MeV/n is discussed. The charge identification is based on the controlled fading of nuclear emulsions in order to extend their dynamic range in the ionization response.

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