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Proton Beam

Christian Baeumer, Martin Janson, Beate Timmermann, Jörg Wulff
AIM: To assess if apertures shall be mounted upstream or downstream of a range shifting block if these field-shaping devices are combined with the pencil-beam scanning delivery technique (PBS). The lateral dose fall-off served as a benchmark parameter. Both options realizing PBS-with-apertures were compared to the uniform scanning mode. We also evaluated the difference regarding the out-of-field dose caused by interactions of protons in beam-shaping devices.
 Methods: The potential benefit of the downstream configuration over the upstream configuration was estimated analytically...
March 19, 2018: Physics in Medicine and Biology
(no author information available yet)
The use of proton beam therapy (PBT) offers the opportunity to improve greater conformality of radiotherapy treatment delivery in some patients. However, it is associated with a high capital cost and the need to build new dedicated facilities. We discuss how the global radiotherapy community can respond to the challenge of producing high-quality evidence of clinical benefit from PBT in adult patients. In the UK, the National Cancer Research Institute-funded Clinical and Radiotherapy Translational group has established the PBT Clinical Trial Strategy Group...
March 15, 2018: Clinical Oncology: a Journal of the Royal College of Radiologists
Dibyasree Choudhury, Susanta Lahiri
The 1-2 GeV proton induced spallation reaction on the high Z materials like Hg, or lead bismuth eutectic (LBE), popularly known as converter targets, will produce strong flux of fast neutrons which would further react with fissile materials to produce intense radioactive ion beam (RIB). LBE offers suitability for use as converters over Hg but it suffers from the demerit of radiotoxic polonium production. These targets may be viewed as a store house of clinically important and other exotic radionuclides. For application of those radionuclides, radiochemical separation from bulk target material is of utmost importance...
March 10, 2018: Applied Radiation and Isotopes
Lorenzo Placidi, Michele Togno, Damien C Weber, Antony J Lomax, Jan Hrbacek
PURPOSE: Wedge phantoms coupled with a CCD camera are suggested as a simple means to improve the efficiency of quality assurance for pencil beam scanning (PBS) proton therapy, in particular to verify energy/range consistency on a daily basis. The method is based on the analysis of an integral image created by a pencil beam (PB) pattern delivered through a wedge. We have investigated the reproducibility of this method and its dependence on setup and positional beam errors for a commercially available phantom (Sphinx® , IBA Dosimetry) and CCD camera (Lynx® , IBA Dosimetry) system...
March 13, 2018: Zeitschrift Für Medizinische Physik
Hans G Rinderknecht, H-S Park, J S Ross, P A Amendt, D P Higginson, S C Wilks, D Haberberger, J Katz, D H Froula, N M Hoffman, G Kagan, B D Keenan, E L Vold
The structure of a strong collisional shock front forming in a plasma is directly probed for the first time in laser-driven gas-jet experiments. Thomson scattering of a 526.5 nm probe beam was used to diagnose temperature and ion velocity distribution in a strong shock (M∼11) propagating through a low-density (ρ∼0.01  mg/cc) plasma composed of hydrogen. A forward-streaming population of ions traveling in excess of the shock velocity was observed to heat and slow down on an unmoving, unshocked population of cold protons, until ultimately the populations merge and begin to thermalize...
March 2, 2018: Physical Review Letters
Hsuan-Ming Huang, Chih-Chieh Liu, Meei-Ling Jan, Ming-Wei Lee
The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton-nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton range because PG rays, particularly characteristic ones, have strong correlations with the distribution of the proton dose. However, accurate image reconstruction from characteristic PGs is challenging because the detector efficiency and resolution are generally low. Our previous study showed that point spread functions can be incorporated into the reconstruction process to improve image resolution...
March 16, 2018: Physics in Medicine and Biology
Mark T Corkum, Wei Liu, David A Palma, Glenn S Bauman, Robert E Dinniwell, Andrew Warner, Mark V Mishra, Alexander V Louie
BACKGROUND: Cancer patients frequently search the Internet for treatment options, and hospital websites are seen as reliable sources of knowledge. Guidelines support the use of proton radiotherapy in specific disease sites or on clinical trials. This study aims to evaluate direct-to-consumer advertising content and claims made by proton therapy centre (PTC) websites worldwide. METHODS: Operational PTC websites in English were identified through the Particle Therapy Co-Operative Group website...
March 15, 2018: Radiation Oncology
Atallah Baydoun, Neha Vapiwala, Lee E Ponsky, Musaddiq Awan, Ali Kassaee, David Sutton, Tarun K Podder, Yuxia Zhang, Donald Dobbins, Raymond F Muzic, Bryan Traughber, Mitchell Machtay, Rodney Ellis
PURPOSE: We conducted this dosimetric analysis to evaluate the feasibility of a multi-center stereotactic body radiation therapy (SBRT) trial for renal cell carcinoma (RCC) using different SBRT platforms. MATERIALS/METHODS: The computed tomography (CT) simulation images of 10 patients with unilateral RCC previously treated on a Phase 1 trial at Institution 1 were anonymized and shared with Institution 2 after IRB approval. Treatment planning was generated through five different platforms aiming a total dose of 48 Gy in three fractions...
March 14, 2018: Journal of Applied Clinical Medical Physics
Takashi Baba, J Larry Campbell, J C Yves Le Blanc, Paul R S Baker, Kazutaka Ikeda
We report a method for comprehensive structural characterization of lipids in animal tissues using a combination of differential Ion mobility spectrometry (DMS) with electron-impact excitation of ions from organics (EIEIO) mass spectrometry. Singly charged lipid ions in protonated or sodiated forms were dissociated by an electron beam having a kinetic energy of 10 eV in a branched radio-frequency ion trap. We established a comprehensive set of diagnostics to characterize structures of glycerophospholipids, sphingolipids, and acylglycerols, including glycosylated, plasmalogen, and ester forms...
March 14, 2018: Journal of Lipid Research
Keiji Kobashi, Anussara Prayongrat, Takuya Kimoto, Chie Toramatsu, Yasuhiro Dekura, Norio Katoh, Shinichi Shimizu, Yoichi M Ito, Hiroki Shirato
Modern radiotherapy technologies such as proton beam therapy (PBT) permit dose escalation to the tumour and minimize unnecessary doses to normal tissues. To achieve appropriate patient selection for PBT, a normal tissue complication probability (NTCP) model can be applied to estimate the risk of treatment-related toxicity relative to X-ray therapy (XRT). A methodology for estimating the difference in NTCP (∆NTCP), including its uncertainty as a function of dose to normal tissue, is described in this study using the Delta method, a statistical method for evaluating the variance of functions, considering the variance-covariance matrix...
March 12, 2018: Journal of Radiation Research
Satoshi Shibata, Shigeyuki Takamatsu, Kazutaka Yamamoto, Miu Mizuhata, Sayuri Bou, Yoshitaka Sato, Mariko Kawamura, Satoko Asahi, Yuji Tameshige, Yoshikazu Maeda, Makoto Sasaki, Tomoyasu Kumano, Satoshi Kobayashi, Hiroyasu Tamamura, Toshifumi Gabata
We evaluated the effectiveness and toxicity of proton beam therapy (PBT) for hepatocellular carcinomas (HCC) >5 cm without fiducial markers using four-dimensional CT (4D-CT) planning. The subjects were 29 patients treated at our hospital between March 2011 and March 2015. The median total dose was 76 Cobalt Gray Equivalents (CGE) in 20 fractions (range; 66-80.5 CGE in 10-32 fractions). Therapy was delivered with end-expiratory phase gating. An internal target volume (ITV) margin was added through the analysis of respiratory movement with 4D-CT...
March 14, 2018: Cancers
Lorenzo Manganaro, Germano Russo, Faiza Bourhaleb, Federico Fausti, Simona Giordanengo, Vincenzo Monaco, Roberto Sacchi, Anna Vignati, Roberto Cirio, Andrea Attili
One major rationale for the application of heavy ion beams in tumour therapy is their increased relative biological effectiveness (RBE). The complex dependencies of the RBE on dose, biological endpoint, position in the field etc. require the use of biophysical models in treatment planning and clinical analysis. This study aims at introducing a new software, named "Survival", to facilitate the radiobiological computations needed in ion therapy. The simulation toolkit was written in C++ and it was developed with a modular architecture in order to easily incorporate different radiobiological models...
March 14, 2018: Physics in Medicine and Biology
Fatima Padilla-Cabal, Dietmar Georg, Hermann Fuchs
PURPOSE: The feasibility of Magnetic Resonance Image (MRI) based proton therapy is based, among several other factors, on the implementation of appropriate extensions on current dose calculation methods. This work aims to develop a pencil beam algorithm (PBA) for dose calculation of proton beams within magnetic field regions of up to 3T. METHODS: Monte Carlo (MC) simulations using the GATE 7.1/GEANT4.9.4p02 toolkit were performed to generate calibration and benchmarking data for the PBA...
March 12, 2018: Medical Physics
Yoshikazu Maeda, Yoshitaka Sato, Hiroki Minami, Yutaka Yasukawa, Kazutaka Yamamoto, Hiroyasu Tamamura, Satoshi Shibata, Sayuri Bou, Makoto Sasaki, Yuji Tameshige, Kyo Kume, Hiroshi Ooto, Shigeru Kasahara, Yasuhiro Shimizu, Yusuke Saga, Akira Omoya, Makoto Saitou
PURPOSE: To evaluate the effectiveness of CT image-guided proton radiotherapy for prostate cancer by analyzing the positioning uncertainty and assessing daily dose change due to anatomical variations. MATERIALS AND METHODS: Patients with prostate cancer were treated by opposed lateral proton beams based on a passive scattering method using an in-room CT image-guided system. The system employs a single couch for both CT scanning and beam delivery. The patient was positioned by matching the boundary between the prostate and the rectum's anterior region identified in the CT images to the corresponding boundary in the simulator images after bone matching...
March 12, 2018: Medical Physics
A Crellin
Proton Beam Therapy is one of the key elements in a major improvement in access to advanced radiotherapy in the UK. An overseas programme has treated significant numbers of children and young adults and skull base tumours since 2008. A major government investment has resulted in building two proton centres in England sited in academic major cancer centres. A weak evidence base for most adult indications means that the NHS will use clinical trials and studies to explore the future role of Protons.
March 9, 2018: Clinical Oncology: a Journal of the Royal College of Radiologists
Felipe Fantuzzi, Benedikt Rudek, Wania Wolff, Marco Antonio Chaer Nascimento
In free-radical halogenation of aromatics singly-charged ions are usually formed as intermediates. These stable species can be easily observed by time-of-flight mass spectrometry (TOF-MS). Here we used electron and proton beams to ionize chlorobenzene (C6 H5Cl) and investigate the ions stability by TOF-MS. Additionally to the singly-charged parent ion and its fragments we find a significant yield of doubly- and triply- charged parentions not previously reported. In order to characterize these species we used high-level theoretical methods based on Density Functional Theory (DFT), Coupled-Cluster (CC)and Generalized Valence Bond (GVB) to calculate the structure, relative stabilities, and bonding of these dications and trications...
March 12, 2018: Journal of the American Chemical Society
Agata Tobola-Galus, Jan Swakon, Pawel Olko
The aim of these studies was to investigate depth dose distribution of a 60 MeV proton beam formed by a set of dedicated mesh-formed collimators. The set of mini-beams formed by the mesh is scattered in the tissue and lead to uniform energy deposition in the target volume. The rationale is to protect the eyelid skin from complications after hypofractionated radiation therapy. The experimental verification of the depth dose distribution for collimators of 1-3 mm mesh size was performed in solid state and water phantoms on 60 MeV proton beam from the AIC-144 cyclotron...
February 24, 2018: Radiation Protection Dosimetry
Anussara Prayongrat, Kikuo Umegaki, Arjen van der Schaaf, Albert C Koong, Steven H Lin, Thomas Whitaker, Todd McNutt, Naruhiro Matsufuji, Edward Graves, Masahiko Mizuta, Kazuhiko Ogawa, Hiroyuki Date, Kensuke Moriwaki, Yoichi M Ito, Keiji Kobashi, Yasuhiro Dekura, Shinichi Shimizu, Hiroki Shirato
Particle beam therapy (PBT), including proton and carbon ion therapy, is an emerging innovative treatment for cancer patients. Due to the high cost of and limited access to treatment, meticulous selection of patients who would benefit most from PBT, when compared with standard X-ray therapy (XRT), is necessary. Due to the cost and labor involved in randomized controlled trials, the model-based approach (MBA) is used as an alternative means of establishing scientific evidence in medicine, and it can be improved continuously...
February 24, 2018: Journal of Radiation Research
Hiroki Shirato
No abstract text is available yet for this article.
March 8, 2018: International Journal of Clinical Oncology
Daniele Marchioni, Angelo Musumeci, Cristoforo Fabbris, Stefano De Rossi, Davide Soloperto
BACKGROUND: The clivus is a region characterized by complex anatomy, with vascular and neural structures that are located in close proximity. Different pathologies can affect this area, and traditional surgical approaches were open approaches. Recently, the endoscopic transnasal technique has been introduced, and currently represents a good alternative for the surgical management of these lesions. This is a preliminary report on patients treated endoscopically for clival lesions by the authors' Skull Base Team...
March 8, 2018: European Archives of Oto-rhino-laryngology
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