scholarly journals Proton Therapy for Mandibula Plate Phantom

Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 167
Author(s):  
Güler Burcu Senirkentli ◽  
Fatih Ekinci ◽  
Erkan Bostanci ◽  
Mehmet Serdar Güzel ◽  
Özlem Dağli ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Bragg Peak ◽  
Energy Levels ◽  
Peak Position ◽  
Bone Thickness ◽  
Dose Rates ◽  
Tooth Plate ◽  
Acceptable Deviation ◽  
Different Depths ◽  
Selection Of

Purpose: In this study, the required dose rates for optimal treatment of tumoral tissues when using proton therapy in the treatment of defective tumours seen in mandibles has been calculated. We aimed to protect the surrounding soft and hard tissues from unnecessary radiation as well as to prevent complications of radiation. Bragg curves of therapeutic energized protons for two different mandible (molar and premolar) plate phantoms were computed and compared with similar calculations in the literature. The results were found to be within acceptable deviation values. Methods: In this study, mandibular tooth plate phantoms were modelled for the molar and premolar areas and then a Monte Carlo simulation was used to calculate the Bragg curve, lateral straggle/range and recoil values of protons remaining in the therapeutic energy ranges. The mass and atomic densities of all the jawbone layers were selected and the effect of layer type and thickness on the Bragg curve, lateral straggle/range and the recoil were investigated. As protons move through different layers of density, lateral straggle and increases in the range were observed. A range of energies was used for the treatment of tumours at different depths in the mandible phantom. Results: Simulations revealed that as the cortical bone thickness increased, Bragg peak position decreased between 0.47–3.3%. An increase in the number of layers results in a decrease in the Bragg peak position. Finally, as the proton energy increased, the amplitude of the second peak and its effect on Bragg peak position decreased. Conclusion: These findings should guide the selection of appropriate energy levels in the treatment of tumour structures without damaging surrounding tissues.

Theoretical Research and Development of a Clinical Setup Prototype for Online Monitoring of the Bragg Peak Position for the Prometheus Proton Therapy Complex

2018 ◽  
Vol 15 (7) ◽  
pp. 977-980
Author(s):  
V. E. Balakin ◽  
A. A. Pryanichnikov ◽  
F. N. Novoskoltsev ◽  
I. I. Degtyarev ◽  
E. V. Altukhova ◽  
...  
Keyword(s):  
Research And Development ◽  
Proton Therapy ◽  
Bragg Peak ◽  
Online Monitoring ◽  
Peak Position ◽  
Theoretical Research

scholarly journals Knowledge of endoscopic ultrasound-delivered fiducial composition and dimension necessary when planning proton beam radiotherapy

2018 ◽  
Vol 06 (06) ◽  
pp. E766-E768 ◽  
Author(s):  
Ferga Gleeson ◽  
Erik Tryggestad ◽  
Nicholas Remmes ◽  
Chris Beltran ◽  
Jon Kruse ◽  
...  
Keyword(s):  
Endoscopic Ultrasound ◽  
Proton Therapy ◽  
Bragg Peak ◽  
Carbon Composite ◽  
Proton Beam Radiotherapy ◽  
Spot Scanning ◽  
Dose Perturbation ◽  
The Impact ◽  
Dose Reductions ◽  
Selection Of

Abstract Background and study aims Little consideration has been given to selection of endoscopic ultrasound-guided fiducials for proton radiotherapy and the resulting perturbations in the therapy dose and pattern. Our aim was to assess the impact of perturbations caused by six fiducials of different composition and dimensions in a phantom gel model. Materials and methods The phantom was submerged in a water bath and irradiated with a uniform 10 cm × 10 cm field of 119.7 MeV monoenergetic spot scanning protons delivered through a 45 mm range shifter. The proton “Bragg Peak” was evaluated.  Results Dose perturbations manifesting as dose reductions up to 30 % were observed. A carbon composite (1 × 5 mm) and gold (0.4 × 10 mm) fiducial with backload potential rather than dedicated EUS pre-loaded gold fiducial needles had the best performance in terms of minimizing the dose perturbation. Conclusions Our data demonstrate that a carbon composite fiducial has a less untoward effect on proton therapy dose distribution than dedicated EUS pre-loaded gold fiducial needles. Such information is important to consider when selecting fiducials specifically for proton therapy.

scholarly journals Commissioning of a clinical pencil beam scanning proton therapy unit for ultra‐high dose rates (FLASH)

2021 ◽  
Author(s):  
Konrad P. Nesteruk ◽  
Michele Togno ◽  
Martin Grossmann ◽  
Anthony J. Lomax ◽  
Damien C. Weber ◽  
...  
Keyword(s):  
Proton Therapy ◽  
High Dose ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Dose Rates ◽  
Pencil Beam Scanning

scholarly journals Enhancement of the ionoacoustic effect through ultrasound and photoacoustic contrast agents

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julie Lascaud ◽  
Pratik Dash ◽  
Matthias Würl ◽  
Hans-Peter Wieser ◽  
Benjamin Wollant ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Bragg Peak ◽  
Ion Beam ◽  
External Beam Radiotherapy ◽  
Local Treatment ◽  
Signal Amplitude ◽  
Peak Position ◽  
Photon Absorption ◽  
India Ink

AbstractThe characteristic depth dose deposition of ion beams, with a maximum at the end of their range (Bragg peak) allows for local treatment delivery, resulting in better sparing of the adjacent healthy tissues compared to other forms of external beam radiotherapy treatments. However, the optimal clinical exploitation of the favorable ion beam ballistic is hampered by uncertainties in the in vivo Bragg peak position. Ionoacoustics is based on the detection of thermoacoustic pressure waves induced by a properly pulsed ion beam (e.g., produced by modern compact accelerators) to image the irradiated volume. Co-registration between ionoacoustics and ultrasound imaging offers a promising opportunity to monitor the ion beam and patient anatomy during the treatment. Nevertheless, the detection of the ionoacoustic waves is challenging due to very low pressure amplitudes and frequencies (mPa/kHz) observed in clinical applications. We investigate contrast agents to enhance the acoustic emission. Ultrasound microbubbles are used to increase the ionoacoustic frequency around the microbubble resonance frequency. Moreover, India ink is investigated as a possible mean to enhance the signal amplitude by taking advantage of additional optical photon absorption along the ion beam and subsequent photoacoustic effect. We report amplitude increase of up to 200% of the ionoacoustic signal emission in the MHz frequency range by combining microbubbles and India ink contrast agents.

scholarly journals Preselection Tool for the Model-Based Selection of Head and Neck Cancer Patients for Proton Therapy

2019 ◽  
Vol 105 (1) ◽  
pp. E384
Author(s):  
M. Tambas ◽  
H.P. van der Laan ◽  
A.V.D. Hoek ◽  
H.P. Bijl ◽  
M. Dieters ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Head And Neck ◽  
Cancer Patients ◽  
Neck Cancer ◽  
Proton Therapy ◽  
Model Based ◽  
Selection Of

scholarly journals Evaluation of the effect of soft tissue composition on the characteristics of spread-out Bragg peak in proton therapy

2016 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
SayyedBijan Jia ◽  
Mahdi Ghorbani ◽  
Mohsen Khosroabadi ◽  
HamidReza Sadoughi ◽  
Courtney Knaup
Keyword(s):  
Soft Tissue ◽  
Proton Therapy ◽  
Bragg Peak ◽  
Tissue Composition ◽  
Soft Tissue Composition ◽  
Spread Out Bragg Peak

scholarly journals Radiation Sterilization: Dose Is Dose

2020 ◽  
Vol 54 (s1) ◽  
pp. 45-52
Author(s):  
Joyce M. Hansen ◽  
Niki Fidopiastis ◽  
Trabue Bryans ◽  
Michelle Luebke ◽  
Terri Rymer
Keyword(s):  
Energy Level ◽  
Energy Levels ◽  
Radiation Energy ◽  
Biological Indicators ◽  
High Energy ◽  
Microbial Inactivation ◽  
Radiation Sterilization ◽  
Dose Rates ◽  
Radiation Sources ◽  
Radiation Sterilization Dose

Abstract In the radiation sterilization arena, the question often arises as to whether radiation resistance of microorganisms might be affected by the energy level of the radiation source and the rate of the dose delivered (kGy/time). The basis for the question is if the microbial lethality is affected by the radiation energy level and/or the rate the dose is delivered, then the ability to transfer dose among different radiation sources could be challenged. This study addressed that question by performing a microbial inactivation study using two radiation sources (gamma and electron beam [E-beam]), two microbial challenges (natural product bioburden and biological indicators), and four dose rates delivered by three energy levels (1.17 MeV [gamma], 1.33 MeV [gamma], and 10 MeV [high-energy E-beam]). Based on analysis of the data, no significant differences were seen in the rate of microbial lethality across the range of radiation energies evaluated. In summary, as long as proof exists that the specified dose is delivered, dose is dose.

1.37 - 2.90 Micron Intersubband Transitions in GaN/AlN Superlattices

2006 ◽  
Vol 955 ◽  
Author(s):  
Eric Anthony DeCuir ◽  
Emil Fred ◽  
Omar Manasreh ◽  
Jinqiao Xie ◽  
Hadis Morkoc ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Bound States ◽  
Energy Levels ◽  
Three Dimensional ◽  
Blue Shift ◽  
Bound State ◽  
Peak Position ◽  
Multiple Quantum ◽  
Intersubband Transitions ◽  
Photovoltaic Mode

ABSTRACTIntersubband transitions in the spectral range of 1.37-2.90 °Cm is observed in molecular beam epitaxy grown Si-doped GaN/AlN multiple quantum wells using a Fourier-transform spectroscopy technique. A blue shift in the peak position of the intersubband transition is observed as the well width is decreased. A sample with a well width in the order of 2.4 nm exhibited the presence of three bound states in the GaN well. The bound state energy levels are calculated using a transfer matrix method. An electrochemical capacitance voltage technique is used to obtain the three dimensional carrier concentrations in these samples which further enable the calculation of the Fermi energy level position. Devices fabricated from these GaN/AlN quantum wells are found to operate in the photovoltaic mode.

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