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"proton therapy"

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
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
Penny Fang, Wen Jiang, Rajayogesh Davuluri, Cai Xu, Sunil Krishnan, Radhe Mohan, Albert C Koong, Charles C Hsu, Steven H Lin
BACKGROUND AND PURPOSE: Neoadjuvant chemoradiation (nCRT) can reduce tumor infiltrating lymphocytes. We examined absolute lymphocyte count (ALC) nadir during nCRT for esophageal cancer (EC) and pathologic complete response (pCR). MATERIALS AND METHODS: Patients with stage I-IVA EC (n = 313) treated 2007-2013 with nCRT followed by surgery were analyzed. ALC was obtained before, during/weekly, and one month after CRT. pCR was defined as no viable tumor cells at surgery...
March 9, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
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
Fada Guan, Christopher Peeler, Lawrence Bronk, Changran Geng, Reza Taleei, Sharmalee Randeniya, Shuaiping Ge, Dragan Mirkovic, David Grosshans, Radhe Mohan, Uwe Titt
No abstract text is available yet for this article.
March 2018: Medical Physics
Yunhe Xie, Christopher Ainsley, Lingshu Yin, Wei Zou, James McDonough, Timothy D Solberg, Alexander Lin, Boon-Keng Kevin Teo
A major source of uncertainty in proton therapy is the conversion of Hounsfield unit (HU) to proton stopping power ratio relative to water (SPR). In this study, we measured and quantified the accuracy of a stoichiometric dual energy CT (DECT) SPR calibration. We applied a stoichiometric DECT calibration method to derive the SPR using CT images acquired sequentially at [Formula: see text] and [Formula: see text]. The dual energy index was derived based on the HUs of the paired spectral images and used to calculate the effective atomic number (Zeff ), relative electron density ([Formula: see text]), and SPRs of phantom and biological materials...
March 7, 2018: Physics in Medicine and Biology
Veronica Ferrero, Elisa Fiorina, Matteo Morrocchi, Francesco Pennazio, Guido Baroni, Giuseppe Battistoni, Nicola Belcari, Niccolo' Camarlinghi, Mario Ciocca, Alberto Del Guerra, Marco Donetti, Simona Giordanengo, Giuseppe Giraudo, Vincenzo Patera, Cristiana Peroni, Angelo Rivetti, Manuel Dionisio da Rocha Rolo, Sandro Rossi, Valeria Rosso, Giancarlo Sportelli, Sara Tampellini, Francesca Valvo, Richard Wheadon, Piergiorgio Cerello, Maria Giuseppina Bisogni
Particle therapy exploits the energy deposition pattern of hadron beams. The narrow Bragg Peak at the end of range is a major advantage but range uncertainties can cause severe damage and require online verification to maximise the effectiveness in clinics. In-beam Positron Emission Tomography (PET) is a non-invasive, promising in-vivo technique, which consists in the measurement of the β+ activity induced by beam-tissue interactions during treatment, and presents the highest correlation of the measured activity distribution with the deposited dose, since it is not much influenced by biological washout...
March 6, 2018: Scientific Reports
Baozhou Sun, Dao Lam, Deshan Yang, Kevin Grantham, Tiezhi Zhang, Sasa Mutic, Tianyu Zhao
PURPOSE: Clinical treatment planning systems for proton therapy currently do not calculate monitor units (MUs) in passive scatter proton therapy due to the complexity of the beam delivery systems. Physical phantom measurements are commonly employed to determine the field-specific output factors (OFs) but are often subject to limited machine time, measurement uncertainties and intensive labor. In this study, a machine learning based approach was developed to predict output (cGy/MU) and derive MUs, incorporating the dependencies on gantry angle and field size for a single-room proton therapy system...
March 3, 2018: Medical Physics
Riccardo Via, Fabian Hennings, Giovanni Fattori, Aurora Fassi, Alessia Pica, Antony Lomax, Damien Charles Weber, Guido Baroni, Jan Hrbacek
PURPOSE: Over the last four decades, Ocular Proton Therapy has been successfully used to treat patients affected by intraocular lesions. For this, treatment geometry verification is routinely performed using radiographic images to align a configuration of fiducial radiopaque markers implanted on the sclera outer surface. This paper describes the clinical application of an alternative approach based on optical eye tracking for three-dimensional non-invasive and automatic eye localization...
March 1, 2018: Medical Physics
Xiaoqiang Li, Peyman Kabolizadeh, Di Yan, An Qin, Jun Zhou, Ye Hong, Thomas Guerrero, Inga Grills, Craig Stevens, Xuanfeng Ding
BACKGROUND: To evaluate spot-scanning proton arc therapy (SPArc) and multi-field robust optimized intensity modulated proton therapy (RO-IMPT) in treating stage III non-small-cell lung cancer (NSCLC) patients. METHODS: Two groups of stage IIIA or IIIB NSCLC patients (group 1: eight patients with tumor motion less than 5 mm; group 2: six patients with tumor motion equal to or more than 5 mm) were re-planned with SPArc and RO-IMPT. Both plans were generated using robust optimization to achieve an optimal coverage with 99% of internal target volume (ITV) receiving 66 Gy (RBE) in 33 fractions...
February 27, 2018: Radiation Oncology
Beat Bojaxhiu, Frank Ahlhelm, Marc Walser, Lorenzo Placidi, Ulrike Kliebsch, Lorentzos Mikroutsikos, Petra Morach, Alessandra Bolsi, Tony Lomax, Alessia Pica, Damien C Weber
PURPOSE: To assess the rate of radiation necrosis (RN) and white matter lesions (WMLs) in pediatric patients with primary brain tumors treated with pencil beam scanning (PBS) proton therapy (PT) with or without concomitant chemotherapy at the PSI. METHODS AND MATERIALS: Between 1999 and 2015, 171 pediatric patients (age <18 years) were treated with PT. Median age at diagnosis was 3.3 years (range, 0.3-17.0 years), and the median delivered dose was 54 Gy (relative biological effectiveness) (range, 40...
March 15, 2018: International Journal of Radiation Oncology, Biology, Physics
Michael T Prusator, Salahuddin Ahmad, Yong Chen
For passive scattering proton therapy systems, neutron contamination is the main concern both from an occupational and patient safety perspective. The Mevion S250 compact proton therapy system is the first of its kind, offering an in-room cyclotron design which prompts more concern for shielding assessment. The purpose of this study was to accomplish an in-depth evaluation of both the shielding design and in-room neutron production at our facility using both Monte Carlo simulation and measurement. We found that the shielding in place at our facility is adequate, with simulated annual neutron ambient dose equivalents at 30 cm outside wall/door perimeter ranging from background to 0...
February 22, 2018: Journal of Applied Clinical Medical Physics
Amanda F Saltzman, Nicholas G Cost
PURPOSE OF REVIEW: Rhabdomyosarcoma (RMS) is the most common sarcoma diagnosed in the first 20 years of life; bladder/prostate (BP) RMS accounts for 5% of all cases. Through efforts from multiple cooperative study groups, survival has improved significantly. This article aims to review the complex RMS classification system and treatment of BP RMS, with a focus on developing aspects of treatment. RECENT FINDINGS: Recent advancements in technology are responsible for most of the progress in RMS treatment...
February 22, 2018: Current Urology Reports
Jinsoo Uh, Matthew J Krasin, Chia-Ho Hua
PURPOSE: To evaluate the feasibility of using on-treatment magnetic resonance imaging (MRI) to detect proton range changes during treatment courses. METHODS: MRI-based virtual computed tomography (vCT) was generated to calculate water-equivalent path length (WEPL) at the distal surface of a clinical target volume. T2-weighted MR images with and without fat suppression were processed by thresholding and fuzzy c-mean clustering to assign a bulk HU (Hounsfield Unit) to each segment of fat, water, and air...
February 21, 2018: Medical Physics
Seán Walsh, Erik Roelofs, Peter Kuess, Yvonka van Wijk, Ben Vanneste, Andre Dekker, Philippe Lambin, Bleddyn Jones, Dietmar Georg, Frank Verhaegen
We present a methodology which can be utilized to select proton or photon radiotherapy in prostate cancer patients. Four state-of-the-art competing treatment modalities were compared (by way of an in silico trial) for a cohort of 25 prostate cancer patients, with and without correction strategies for prostate displacements. Metrics measured from clinical image guidance systems were used. Three correction strategies were investigated; no-correction, extended-no-action-limit, and online-correction. Clinical efficacy was estimated via radiobiological models incorporating robustness (how probable a given treatment plan was delivered) and stability (the consistency between the probable best and worst delivered treatments at the 95% confidence limit)...
February 18, 2018: Cancers
Ye Zhang, Isabel Huth, Damien Charles Weber, Antony John Lomax
BACKGROUND AND PURPOSE: Different scanned proton therapy systems provide different scanning scenarios, directly changing the temporal interference between sequential beam delivery and tumour motion. We aim here to quantify the interplay effects and compare motion mitigation performance among different PBS scanning systems. MATERIALS AND METHODS: Using 6 4DCT(MRI) datasets of liver tumours with irregular motions greater than 10 mm, 4D treatments with single- and double-field plans, and assuming various doses and motion mitigation approaches, were simulated for 8 PBS scenarios including spot or raster scanning, layered or volumetric rescanning, gating, constant or varying beam current and cyclotron or synchrotron beam sources...
February 16, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Clarissa Gillmann, Antony J Lomax, Damien C Weber, Oliver Jäkel, Christian P Karger
PURPOSE: To derive the dose-response curve for temporal lobe reactions (TLRs) after proton therapy and to compare the resulting relative biological effectiveness (RBE)-weighted tolerance doses based on an RBE of 1.1 with published values for carbon ions, which were calculated by the two versions of the local effect model (LEM I or IV). METHODS AND MATERIALS: 62 patients treated with protons for skull base tumors were analyzed for TLRs using magnetic resonance imaging...
February 16, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
C Hague, B Foran, E Hall, S Guild, O Joseph, R Moule, C Nutting, S Parsons, R Prestwich, N Slevin, C West, D Thomson
No abstract text is available yet for this article.
February 16, 2018: Clinical Oncology: a Journal of the Royal College of Radiologists
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