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Proton Beam

Valery Radchenko, Jonathan W Engle, Dmitri G Medvedev, Joel M Maassen, Cleo M Naranjo, George A Unc, Catherine A L Meyer, Tara Mastren, Mark Brugh, Leonard Mausner, Cathy S Cutler, Eva R Birnbaum, Kevin D John, F Meiring Nortier, Michael E Fassbender
Scandium-44g (half-life 3.97h) shows promise for application in positron emission tomography (PET), due to favorable decay parameters. One of the sources of (44g)Sc is the (44)Ti/(44g)Sc generator, which can conveniently provide this radioisotope on a daily basis at a diagnostic facility. Titanium-44 (half-life 60.0 a), in turn, can be obtained via proton irradiation of scandium metal targets. A substantial (44)Ti product batch, however, requires high beam currents, long irradiation times and an elaborate chemical procedure for (44)Ti isolation and purification...
April 7, 2017: Nuclear Medicine and Biology
Joo-Young Jung, Do-Kun Yoon, Brendan Barraclough, Heui Chang Lee, Tae Suk Suh, Bo Lu
The aim of this study is to compare between proton boron fusion therapy (PBFT) and boron neutron capture therapy (BNCT) and to analyze dose escalation using a Monte Carlo simulation. We simulated a proton beam passing through the water with a boron uptake region (BUR) in MCNPX. To estimate the interaction between neutrons/protons and borons by the alpha particle, the simulation yielded with a variation of the center of the BUR location and proton energies. The variation and influence about the alpha particle were observed from the percent depth dose (PDD) and cross-plane dose profile of both the neutron and proton beams...
February 25, 2017: Oncotarget
Ye Zhang, Isabel Huth, Martin Wegner, Damien C Weber, Antony J Lomax
This simulation study investigated the dosimetric effectiveness and treatment efficiency of surface motion guided gating of pencil beam scanning (PBS) proton therapy for liver tumour treatments. Dedicated 4D dose calculations were performed for simulating gated treatments using 4DCT data for six patients derived from 4DMRI (4DCT(MRI)). Surface motion as a surrogate for tumour motion was extracted from the 4DMRI images and a linear internal-external correlation model applied to derive amplitude-based gating windows (GWs) of 10 and 5 mm...
April 20, 2017: Physics in Medicine and Biology
Ulrich W Langner, John G Eley, Lei Dong, Katja Langen
PURPOSE: Commissioning beam data for proton spot scanning beams are compared for the first two Varian ProBeam sites in the United States, at the Maryland Proton Treatment Center (MPTC) and Scripps Proton Therapy Center (SPTC). In addition, the extent to which beams can be matched between gantry rooms at MPTC is investigated. METHOD: Beam data for the two sites were acquired with independent dosimetry systems and compared. Integrated depth dose curves (IDDs) were acquired with Bragg peak ion chambers in a 3D water tank for pencil beams at both sites...
April 19, 2017: Journal of Applied Clinical Medical Physics
Tae Wan Kim, Euncheol Choi, Jeonghoon Park, Dong-Ho Shin, Su Kyung Jung, Susie Seok, Kwan Ho Cho, Joo-Young Kim, Dae Yong Kim, Tae Hyun Kim, Yang Kwon Suh, Yeon Joo Kim, Sung Ho Moon
Purpose: This study retrospectively evaluated the clinical outcomes and complications of proton beam therapy (PBT) in a single institution in Korea and quantitatively analyzed the change in tumor volume after PBT using magnetic resonance imaging (MRI). Materials and Methods: Twenty-four treatment-naïve patients who underwent PBT for choroidal melanoma between 2009 and 2015 were reviewed. Dose fractionation was 60-70 CGE over 5 fractions. Orbital MRIs were taken at baseline and 3, 6, and 12 months after PBT and annually thereafter...
April 19, 2017: Cancer Research and Treatment: Official Journal of Korean Cancer Association
Bo Yang, Rui Qiu, Jinlong Jiao, Wei Lu, Zhimeng Zhang, Weimin Zhou, Chi Ma, Hui Zhang, Junli Li
Current short-pulse high-intensity lasers can accelerate electrons and proton/ions to energies of giga-electron volts. For certain advanced applications, laser-accelerated electrons and protons are optimised for high-energy X-ray and neutron generation at the XG-III picosecond (ps) laser beamline. These energetic X-ray and neutron beams can significantly affect radiation safety at the facility; therefore, proper evaluation of the radiological hazards induced by laser-driven X-ray and neutron sources is required...
April 13, 2017: Radiation Protection Dosimetry
Anuj Goenka, Neil B Newman, Hiral Fontanilla, Oren Cahlon, Brian Chon, Henry Tsai, Eugen Hug, Carl Brown, Carlos Vargas, Rahul R Parikh
BACKGROUND: In the present study, we assessed the effect of prostate gland size on patient-assessed genitourinary and gastrointestinal (GI) quality of life (QOL) after definitive treatment of prostate adenocarcinoma with proton beam therapy. PATIENTS AND METHODS: As a part of a prospective outcome tracking protocol, 81 patients treated at a single center between with proton beam therapy completed the Expanded Prostate Cancer Index Composite (EPIC) questionnaire before treatment and at the follow-up examinations...
March 18, 2017: Clinical Genitourinary Cancer
Alexander R Delaney, Max Dahele, Jim P Tol, Ingrid T Kuijper, Ben J Slotman, Wilko F A R Verbakel
BACKGROUND AND PURPOSE: Patient selection for proton therapy by comparing proton/photon treatment plans is time-consuming and prone to bias. RapidPlan™, a knowledge-based-planning solution, uses plan-libraries to model and predict organ-at-risk (OAR) dose-volume-histograms (DVHs). We investigated whether RapidPlan, utilizing an algorithm based only on photon beam characteristics, could generate proton DVH-predictions and whether these could correctly identify patients for proton therapy...
April 12, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
T Tessonnier, A Mairani, S Brons, T Haberer, J Debus, K Parodi
At the Heidelberg Ion Beam Therapy Center, scanned helium and oxygen ion beams are available in addition to the clinically used protons and carbon ions for physical and biological experiments. In this work, a study of the basic dosimetric features of the different ions is performed in the entire therapeutic energy range. Depth dose distributions are investigated for pencil-like beam irradiation, with and without a modulating ripple filter, focusing on the extraction of key Bragg curve parameters, such as the range, the peak-width and the distal 80%-20% fall-off...
April 13, 2017: Physics in Medicine and Biology
Steven E Vigdor, Alexander Klyachko, Keith Solberg, Mark Pankuch
In order to address dosimetry demands during proton therapy treatments utilizing pencil beam scanning and/or pulsed beam accelerators, we have developed a xenon-filled Gas Scintillation Detector (GSD) that can monitor delivered dose and two-dimensional beam centroid position pulse-by-pulse in real time, with high response linearity up to high instantaneous dose rates. We present design considerations for the GSD and results of beam tests carried out at operating proton therapy clinics. In addition to demonstrating spatial resolution with σ of a few hundred microns in each transverse dimension and relative dose precision better than 1% over large treatment areas, the test beam results also reveal the dependence of the GSD dose normalization on dose rate, beam energy, and gas impurities...
April 12, 2017: Physics in Medicine and Biology
Mehmet Dogrusöz, Martine J Jager, Bertil Damato
Approximately 90% of uveal melanoma develop in the choroid, with the remainder arising in the ciliary body or the iris. The treatment of uveal melanoma is aimed at conserving the eye and useful vision, and, if possible, preventing metastatic disease. Enucleation is now reserved for tumors that are large and/or involve the optic disc, having largely been replaced by various forms of radiotherapy (plaque brachy-therapy, proton beam or stereotactic radiotherapy) and laser therapy. Whereas iridectomy and iridocyclectomy are widely performed, transscleral exoresection of choroidal tumors is performed only in a few centers because it requires special skills and hypotensive anesthesia...
March 2017: Asia-Pacific Journal of Ophthalmology
Roger Harrison
Out-of-field doses in radiotherapy have been increasingly studied in recent years because of the generally improved survival of patients who have received radiotherapy as part of their treatment for cancer and their subsequent risk of a second malignancy. This short article attempts to identify some current problems, challenges and opportunities for dosimetry developments in this field. Out-of-field doses and derived risk estimates contribute to general knowledge about radiation effects on humans as well as contributing to risk-benefit considerations for the individual patient...
April 6, 2017: Physica Medica: PM
A Portz, M Baur, C R Gebhardt, A J Frank, P Neuderth, M Eickhoff, M Dürr
The influence of the chemical nature of the cluster constituents on the desorption/ionization process was investigated for desorption/ionization induced by neutral SO2 clusters (DINeC). The polar clusters act as a transient matrix in which the desorbed analyte molecules are dissolved during the desorption process. For drop-cast samples, the desorption/ionization efficiency was found to be largely independent of the pH value of the initial solution the samples were prepared from; positive ions were almost always dominant and no multiply charged negative ions were observed...
April 7, 2017: Journal of Chemical Physics
Vivek Verma, Jean-Claude M Rwigema, Sebastian Adeberg, Charles B Simone
No abstract text is available yet for this article.
March 16, 2017: Clinical Lung Cancer
Andrea Mairani, Giuseppe Magro, Thomas Tessonnier, Till Boehlen, Silvia Molinelli, Alfredo Ferrari, Katia Parodi, Juergen Debus, Thomas Haberer
Models able to properly predict relative biological effectiveness (RBE) values are needed for an accurate determination of the biological effect with proton and <sup>4</sup>He ion beams. This is particularly important for including RBE calculations in treatment planning studies comparing biologically optimized proton and <sup>4</sup>He ion plans. In this work, we have tailored the predictions of the modified Microdosimetric Kinetic Model (MKM), which is clinically applied for carbon ion beam therapy in Japan, to reproduce RBE with proton and <sup>4</sup>He ion beams...
April 6, 2017: Physics in Medicine and Biology
Scott Penfold, Rafał Zalas, Margherita Casiraghi, Mark Brooke, Yair Censor, Reinhard Schulte
A split feasibility formulation for the inverse problem of intensity-modulated radiation therapy treatment planning with dose-volume constraints included in the planning algorithm is presented. It involves a new type of sparsity constraint that enables the inclusion of a percentage-violation constraint in the model problem and its handling by continuous (as opposed to integer) methods. We propose an iterative algorithmic framework for solving such a problem by applying the feasibility-seeking CQ-algorithm of Byrne combined with the automatic relaxation method that uses cyclic projections...
April 5, 2017: Physics in Medicine and Biology
M Niklas, M Henrich, O Jäkel, J Engelhardt, A Abdollahi, S Greilich
Fluorescent nuclear track detectors (FNTDs) allow for visualization of single-particle traversal in clinical ion beams. The point spread function of the confocal readout has so far hindered a more detailed characterization of the track spots-the ion's characteristic signature left in the FNTD. Here we report on the readout of the FNTD by optical nanoscopy, namely stimulated emission depletion microscopy. It was firstly possible to visualize the track spots of carbon ions and protons beyond the diffraction limit of conventional light microscopy with a resolving power of approximately 80 nm (confocal: 320 nm)...
April 5, 2017: Physics in Medicine and Biology
Hans Jan Thomas Buitenhuis, Faruk Diblen, Karol Brzezinski, Sytze Brandenburg, Peter Dendooven
In-vivo dose delivery verification in proton therapy can be performed by positron emission tomography (PET) of the positron-emitting nuclei produced by the proton beam in the patient. A PET scanner installed in the treatment position of a proton therapy facility that takes data with the beam on will see very short-lived nuclides as well as longer-lived nuclides. The most important short-lived nuclide for proton therapy is <sup>12</sup>N (Dendooven <i>et al</i> 2015), which has a half-life of 11 ms...
April 5, 2017: Physics in Medicine and Biology
Sergey V Kutsaev, Brahim Mustapha, Peter N Ostroumov, Jerry Nolen, Albert Barcikowski, Michael Pellin, Abdellatif Yacout
A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials...
March 2017: Review of Scientific Instruments
V A Skalyga, I V Izotov, A V Sidorov, S V Golubev, S V Razin
Plasma of electron cyclotron resonance (ECR) discharge sustained by millimeter wave radiation is widely used for production of ion beams of different kind. The main trend in ECR ion sources development nowadays is an increase of frequency and power of microwave heating. The most advanced systems use gyrotrons in 24-60 GHz frequency range. In previous studies at IAP RAS it was demonstrated that ECR source SMIS 37 (Simple Mirror Ion Source) with 37.5 GHz heating operating in quasigasdynamic regime of plasma confinement is able to produce proton and deuteron beams with ion current density about 700 mA/cm(2)...
March 2017: Review of Scientific Instruments
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