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Proton Beam

Jeong-Eun Rah, Gwe-Ya Kim, Do Hoon Oh, Tae Hyun Kim, Jong Won Kim, Dae Yong Kim, Sung Yong Park, Dongho Shin
BACKGROUND: The purpose of this study is to evaluate the dosimetric benefits of a proton arc technique for treating tumors of the para-aortic lymph nodes (PALN). METHOD: In nine patients, a proton arc therapy (PAT) technique was compared with intensity modulated radiation therapy (IMRT) and proton beam therapy (PBT) techniques with respect to the planning target volume (PTV) and organs at risk (OAR). PTV coverage, conformity index (CI), homogeneity index (HI) and OAR doses were compared...
October 21, 2016: Radiation Oncology
P Adamson, I Anghel, A Aurisano, G Barr, M Bishai, A Blake, G J Bock, D Bogert, S V Cao, T J Carroll, C M Castromonte, R Chen, S Childress, J A B Coelho, L Corwin, D Cronin-Hennessy, J K de Jong, S De Rijck, A V Devan, N E Devenish, M V Diwan, C O Escobar, J J Evans, E Falk, G J Feldman, W Flanagan, M V Frohne, M Gabrielyan, H R Gallagher, S Germani, R A Gomes, M C Goodman, P Gouffon, N Graf, R Gran, K Grzelak, A Habig, S R Hahn, J Hartnell, R Hatcher, A Holin, J Huang, J Hylen, G M Irwin, Z Isvan, C James, D Jensen, T Kafka, S M S Kasahara, G Koizumi, M Kordosky, A Kreymer, K Lang, J Ling, P J Litchfield, P Lucas, W A Mann, M L Marshak, N Mayer, C McGivern, M M Medeiros, R Mehdiyev, J R Meier, M D Messier, W H Miller, S R Mishra, S Moed Sher, C D Moore, L Mualem, J Musser, D Naples, J K Nelson, H B Newman, R J Nichol, J A Nowak, J O'Connor, M Orchanian, R B Pahlka, J Paley, R B Patterson, G Pawloski, A Perch, M M Pfützner, D D Phan, S Phan-Budd, R K Plunkett, N Poonthottathil, X Qiu, A Radovic, B Rebel, C Rosenfeld, H A Rubin, P Sail, M C Sanchez, J Schneps, A Schreckenberger, P Schreiner, R Sharma, A Sousa, N Tagg, R L Talaga, J Thomas, M A Thomson, X Tian, A Timmons, J Todd, S C Tognini, R Toner, D Torretta, G Tzanakos, J Urheim, P Vahle, B Viren, A Weber, R C Webb, C White, L Whitehead, L H Whitehead, S G Wojcicki, R Zwaska
We report results of a search for oscillations involving a light sterile neutrino over distances of 1.04 and 735 km in a ν_{μ}-dominated beam with a peak energy of 3 GeV. The data, from an exposure of 10.56×10^{20} protons on target, are analyzed using a phenomenological model with one sterile neutrino. We constrain the mixing parameters θ_{24} and Δm_{41}^{2} and set limits on parameters of the four-dimensional Pontecorvo-Maki-Nakagawa-Sakata matrix, |U_{μ4}|^{2} and |U_{τ4}|^{2}, under the assumption that mixing between ν_{e} and ν_{s} is negligible (|U_{e4}|^{2}=0)...
October 7, 2016: Physical Review Letters
Adepitan A Owosho, SaeHee K Yom, Zhiqiang Han, Kevin Sine, Nancy Y Lee, Joseph M Huryn, Cherry L Estilo
OBJECTIVE: The purpose of this study was to compare the dosimetric distribution of ipsilateral proton beam radiation therapy (PBRT) with intensity-modulated radiation therapy (IMRT) in the tooth-bearing region of the mandible in patients with head and neck cancer (HNC). STUDY DESIGN: The mandibular dosimetric distribution in patients with head and neck cancer treated with ≥60 Gy relative biologic equivalent PBRT was evaluated. The mean radiation doses were calculated in 5 regions: ipsilateral molar, ipsilateral premolar, anterior, contralateral premolar, and contralateral molar (CM) regions...
November 2016: Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Emmanuel Jouglar, Antoine Wagner, Grégory Delpon, Loïc Campion, Philippe Meingan, Valérie Bernier, Charlotte Demoor-Goldschmidt, Marc-André Mahé, Thomas Lacornerie, Stéphane Supiot
OBJECTIVES: Late abdominal irradiation toxicity during childhood included renal damage, hepatic toxicity and secondary diabetes mellitus. We compared the potential of conformal radiotherapy (CRT), helical tomotherapy (HT) and proton beam therapy (PBT) to spare the abdominal organs at risk (pancreas, kidneys and liver- OAR) in children undergoing abdominal irradiation. METHODS: We selected children with abdominal tumors who received more than 10 Gy to the abdomen...
2016: PloS One
Rajeev Kumar, Rajendra G Sonkawade, Anil K Pandey, Madhavi Tripathi, Nishikant A Damle, Praveen Kumar, Chandra S Bal
OBJECTIVE: The aim of this article was to share 10 years of operational experience of medical cyclotron and to provide working knowledge on the same. This experience has helped us gain working knowledge on cyclotron operation with practical points, which may help in improving F yield, minimizing the breakdown time, and help in the prevention of the occurrence of unusual events. MATERIALS AND METHODS: Our facility has a self-shielded radioisotope delivery system eclipse 111 medical cyclotron with an 11 MeV proton beam in use for the past 10 years to produce positron emitters - namely, F, N, and F-2 gas - for PET imaging...
October 13, 2016: Nuclear Medicine Communications
Arun D Singh, William J Dupps, Charles V Biscotti, John H Suh, Kira L Lathrop, John P Nairn, Helen Shih
PURPOSE: To report the outcome after limbal stem cell preservation during proton beam irradiation for diffuse iris melanoma. METHODS: This is a single-case report of diffuse iris melanoma that was managed with proton beam radiation (53 Gy), wherein preemptively harvested superior and inferior limbal stem cells before radiation were replaced after irradiation. Regeneration of the palisades of Vogt and the limbal stem cells was documented by an optical coherence tomography-based imaging protocol...
October 14, 2016: Cornea
Pietro Valerio Foti, Antonio Longo, Michele Reibaldi, Andrea Russo, Giuseppe Privitera, Corrado Spatola, Luigi Raffaele, Vincenzo Salamone, Renato Farina, Stefano Palmucci, Andrea Musumeci, Rosario Caltabiano, Marco Ragusa, Cesare Mariotti, Teresio Avitabile, Pietro Milone, Giovanni Carlo Ettorre
PURPOSE: The purpose of this prospective study was to investigate the proton-beam-induced changes in apparent diffusion coefficient (ADC) values of ocular melanoma treated with proton-beam therapy (PBT) in patients undergoing long-term magnetic resonance imaging (MRI) follow-up and to assess whether variations in ADC constitute a reliable biomarker for predicting and detecting the response of ocular melanoma to PBT. METHODS: Seventeen patients with ocular melanoma treated with PBT were enrolled...
October 17, 2016: La Radiologia Medica
Daniel Sanchez-Parcerisa, Maura Kirk, Marcus Fager, Brendan Burgdorf, Malorie Stowe, Tim Solberg, Alejandro Carabe
The development of rotational proton therapy plans based on a pencil-beam-scanning (PBS) system has been limited, among several other factors, by the energy-switching time between layers, a system-dependent parameter that ranges between a fraction of a second and several seconds. We are investigating mono- and bi-energetic rotational proton modulated arc therapy (PMAT) solutions that would not be affected by long energy switching times. In this context, a systematic selection of the optimal proton energy for each arc is vital...
October 14, 2016: Physics in Medicine and Biology
Brent F B Huisman, J M Létang, É Testa, D Sarrut
There is interest in the particle therapy community in using prompt gammas (PGs), a natural byproduct of particle treatment, for range verification and eventually dose control. However, PG production is a rare process and therefore estimation of PGs exiting a patient during a proton treatment plan executed by a Monte Carlo (MC) simulation converges slowly. Recently, different approaches to accelerating the estimation of PG yield have been presented. Sterpin et al (2015 Phys. Med. Biol. 60 4915-46) described a fast analytic method, which is still sensitive to heterogeneities...
October 14, 2016: Physics in Medicine and Biology
Ei-Ichiro Takaoka, Jun Miyazaki, Hitoshi Ishikawa, Koji Kawai, Tomokazu Kimura, Ryutaro Ishitsuka, Takahiro Kojima, Reiko Kanuma, Daichi Takizawa, Toshiyuki Okumura, Hideyuki Sakurai, Hiroyuki Nishiyama
OBJECTIVE: We retrospectively elucidated the oncological outcomes, prognostic factors and toxicities of proton beam therapy in trimodal bladder-preserving therapy for muscle-invasive bladder cancer at our institution. METHODS: From 1990 to 2015, 70 patients with cT2-3N0M0 muscle-invasive bladder cancer underwent trimodal bladder-preserving therapy consisting of maximal transurethral resection of the bladder tumor, small pelvis photon irradiation, intra-arterial chemotherapy and proton beam therapy...
October 13, 2016: Japanese Journal of Clinical Oncology
Joseph Frankl, Cassi Grotepas, Baldassare Stea, G Michael Lemole, Alexander Chiu, Rihan Khan
BACKGROUND: Chordoma is a rare invasive bone tumor that may occur anywhere along the neuraxis. A total of three primary histological varieties have been identified: conventional, chondroid, and dedifferentiated. CASE PRESENTATION: We report a case of an 8-year-old white girl who presented with conventional chordoma, was treated with surgical resection and mixed proton and photon beam therapy, and had a recurrence in the resection cavity 2.5 years later with dedifferentiated morphology...
October 12, 2016: Journal of Medical Case Reports
Ye Zhang, Isabel Huth, Martin Wegner, Damien Charles Weber, Antony John Lomax
BACKGROUND AND PURPOSE: The treatment quality of pencil beam scanned (PBS) proton therapy to mobile tumour treatments can be compromised due to interplay effects. The aim of this work is to systematically evaluate the effectiveness of rescanning for liver tumour treatments for a commercial PBS delivery system. MATERIALS AND METHODS: Plans were calculated to patient specific ITV's (2GyRBE), using spot spacings of 4 and 8mm for 1- and 3-field plans. 4D dose calculations were performed using regular and irregular motion extracted from nine 4DCT(MRI) liver datasets with 4 different starting phases...
October 7, 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
J Konheiser, B Naumann, A Ferrari, C Brachem, S E Müller
Calculations of the shielding and estimates of soil activation for a medical cyclotron are presented in this work. Based on the neutron source term from the (18)O(p,n)(18)F reaction produced by a 28 MeV proton beam, neutron and gamma dose rates outside the building were estimated with the Monte Carlo code MCNP6 (Goorley et al 2012 Nucl. Technol. 180 298-315). The neutron source term was calculated with the MCNP6 code and FLUKA (Ferrari et al 2005 INFN/TC_05/11, SLAC-R-773) code as well as with supplied data by the manufacturer...
October 11, 2016: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
L Witthauer, M Dieterle, S Abt, P Achenbach, F Afzal, Z Ahmed, J R M Annand, H J Arends, M Bashkanov, R Beck, M Biroth, N S Borisov, A Braghieri, W J Briscoe, F Cividini, S Costanza, C Collicott, A Denig, E J Downie, P Drexler, M I Ferretti-Bondy, S Gardner, S Garni, D I Glazier, D Glowa, W Gradl, M Günther, G M Gurevich, D Hamilton, D Hornidge, G M Huber, A Käser, V L Kashevarov, S Kay, I Keshelashvili, R Kondratiev, M Korolija, B Krusche, A B Lazarev, J M Linturi, V Lisin, K Livingston, S Lutterer, I J D MacGregor, J Mancell, D M Manley, P P Martel, V Metag, W Meyer, R Miskimen, E Mornacchi, A Mushkarenkov, A B Neganov, A Neiser, M Oberle, M Ostrick, P B Otte, D Paudyal, P Pedroni, A Polonski, S N Prakhov, A Rajabi, G Reicherz, G Ron, T Rostomyan, A Sarty, C Sfienti, M H Sikora, V Sokhoyan, K Spieker, O Steffen, I I Strakovski, Th Strub, I Supek, A Thiel, M Thiel, A Thomas, M Unverzagt, Yu A Usov, S Wagner, N K Walford, D P Watts, D Werthmüller, J Wettig, M Wolfes, L Zana
The double polarization observable E and the helicity dependent cross sections σ_{1/2} and σ_{3/2} were measured for η photoproduction from quasifree protons and neutrons. The circularly polarized tagged photon beam of the A2 experiment at the Mainz MAMI accelerator was used in combination with a longitudinally polarized deuterated butanol target. The almost 4π detector setup of the Crystal Ball and TAPS is ideally suited to detect the recoil nucleons and the decay photons from η→2γ and η→3π^{0}...
September 23, 2016: Physical Review Letters
Anna M Stagner, Frederick A Jakobiec, Aaron Fay
Synovial sarcoma (SS) is a soft tissue sarcoma of the extremities developing in young adults that has rarely been reported in the orbit. SS is associated with a unique translocation, resulting in an SYT-SSX fusion gene. We analyze seven published periocular cases, together with the current one, to gain a better appreciation of the features of the tumor in this location and to compare the findings with those derived from non-ophthalmic studies. A 31-year-old woman developed an inferior orbital mass after experiencing periorbital and hemifacial pain for more than a decade...
September 30, 2016: Survey of Ophthalmology
Kosj Yamoah, Peter As Johnstone
Proton beam therapy has recently become available to a broader population base. There remains much controversy about its routine use in prostate cancer. We provide an analysis of the existing literature regarding efficacy and toxicity of the technique. Currently, the use of proton beam therapy for prostate cancer is largely dependent on continued reimbursement for the practice. While there are potential benefits supporting the use of protons in prostate cancer, the low risk of toxicity using existing techniques and the high cost of protons contribute to lower the value of the technique...
2016: OncoTargets and Therapy
Michael D Sevilla, David Becker, Anil Kumar, Amitava Adhikary
The focus of our laboratory's investigation is to study the direct-type DNA damage mechanisms resulting from γ-ray and ion-beam radiation-induced free radical processes in DNA which lead to molecular damage important to cellular survival. This work compares the results of low LET (γ-) and high LET (ion-beam) radiation to develop a chemical track structure model for ion-beam radiation damage to DNA. Recent studies on protonation states of cytosine cation radicals in the N1-substituted cytosine derivatives in their ground state and 5-methylcytosine cation radicals in ground as well as in excited state are described...
November 2016: Radiation Physics and Chemistry
T Inaniwa, N Kanematsu
The stopping power ratio (SPR) of body tissues relative to water depends on the particle energy. For simplicity, however, most analytical dose planning systems do not account for SPR variation with particle energy along the beam's path, but rather assume a constant energy for SPR estimation. The range error due to this simplification could be indispensable depending on the particle species and the assumed energy. This error can be minimized by assuming a suitable energy referred to as an 'effective energy' in SPR estimation...
October 3, 2016: Physics in Medicine and Biology
Weiguang Yao, Thomas E Merchant, Jonathan B Farr
The lateral homogeneity assumption is used in most analytical algorithms for proton dose, such as the pencil-beam algorithms and our simplified analytical random walk model. To improve the dose calculation in the distal fall-off region in heterogeneous media, we analyzed primary proton fluence near heterogeneous media and propose to calculate the lateral fluence with voxel-specific Gaussian distributions. The lateral fluence from a beamlet is no longer expressed by a single Gaussian for all the lateral voxels, but by a specific Gaussian for each lateral voxel...
October 3, 2016: Physics in Medicine and Biology
Nan Qin, Pablo Botas, Drosoula Giantsoudi, Jan Schuemann, Zhen Tian, Steve B Jiang, Harald Paganetti, Xun Jia
Monte Carlo (MC) simulation is commonly considered as the most accurate dose calculation method for proton therapy. Aiming at achieving fast MC dose calculations for clinical applications, we have previously developed a graphics-processing unit (GPU)-based MC tool, gPMC. In this paper, we report our recent updates on gPMC in terms of its accuracy, portability, and functionality, as well as comprehensive tests on this tool. The new version, gPMC v2.0, was developed under the OpenCL environment to enable portability across different computational platforms...
October 3, 2016: Physics in Medicine and Biology
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