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Proton beam therapy

Luke Pater, Brian Turpin, Anthony Mascia
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood with 250-350 cases diagnosed annually in the United States. Biliary tract rhabdomyosarcoma is rare, representing <1% of the RMS cases. Due to its location, resection is clinically challenging, and functional complications exist and persist from biliary obstruction. The anatomical location of this tumor presents both opportunities and challenges for pencil beam scanning proton therapy. Proton therapy offers a dosimetric and clinical advantage by sparing the healthy liver, stomach, contra-lateral kidney and bowel...
October 5, 2017: Curēus
Cristina Garibaldi, Barbara Alicja Jereczek-Fossa, Giulia Marvaso, Samantha Dicuonzo, Damaris Patricia Rojas, Federica Cattani, Anna Starzyńska, Delia Ciardo, Alessia Surgo, Maria Cristina Leonardi, Rosalinda Ricotti
Radiotherapy (RT) is very much a technology-driven treatment modality in the management of cancer. RT techniques have changed significantly over the past few decades, thanks to improvements in engineering and computing. We aim to highlight the recent developments in radiation oncology, focusing on the technological and biological advances. We will present state-of-the-art treatment techniques, employing photon beams, such as intensity-modulated RT, volumetric-modulated arc therapy, stereotactic body RT and adaptive RT, which make possible a highly tailored dose distribution with maximum normal tissue sparing...
2017: Ecancermedicalscience
Pablo Botas, Clemens Grassberger, Gregory Sharp, Harald Paganetti
The purpose of this study was to investigate Internal Tumor Volume (ITV) density overwrite strategies to minimize Intensity Modulated Proton Therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. IGTV and ICTV structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the Average Intensity Projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement...
December 8, 2017: Physics in Medicine and Biology
Sandrine Lacombe, Erika Porcel, Emanuele Scifoni
Cancer radiation therapy with charged particle beams, called particle therapy, is a new therapeutic treatment presenting major advantages when compared to conventional radiotherapy. Because ions have specific ballistic properties and a higher biological effectiveness, they are superior to x-rays. Numerous medical centres are starting in the world using mostly protons but also carbon ions as medical beams. Several investigations are attempting to reduce the cost/benefit ratio and enlarge the range of therapeutic indications...
2017: Cancer Nanotechnology
Ulrich W Langner, Michelle Mundis, Dan Strauss, Mingyao Zhu, Sina Mossahebi
OBJECTIVE: Analytical dose calculation algorithms for Eclipse and Raystation treatment planning systems (TPS), as well as a Raystation Monte Carlo model are compared to corresponding measured point doses. METHOD: The TPS were modeled with the same beam data acquired during commissioning. Thirty-five typical plans were made with each planning system, 31 without range shifter and four with a 5 cm range shifter. Point doses in these planes were compared to measured doses...
December 4, 2017: Journal of Applied Clinical Medical Physics
Evgeny V Khmelevsky, Irina N Kancheli, Vladimir S Khoroshkov, Andrey D Kaprin
Aim: This study evaluated the frequency and long-term dynamics of early and late post irradiation damage after proton-photon or photon therapy for locally advanced prostate cancer. Background: The results of a randomized study of proton-photon or photon therapy using several fractionation regimes were analyzed in 272 patients with high and intermediate risk of progression. Materials and methods: Three variants of proton boost fractionation were studied sequentially: 3...
January 2018: Reports of Practical Oncology and Radiotherapy
Emmanuel Kammerer, Jennifer Le Guevelou, Abdulhamid Chaikh, Serge Danhier, Julien Geffrelot, Christelle Levy, Eric Saloux, Jean-Louis Habrand, Juliette Thariat
BACKGROUND: Radiation therapy plays a major role in the management of adjuvant breast cancer with nodal involvement, with an iatrogenic increase of cardio-vascular risk. Photon therapy, even with intensity modulation, has the downsides of high mean heart dose and heterogeneous target coverage, particularly in the case of internal mammary irradiation. This systematic review of the literature aims to evaluate proton therapy in locally advanced breast cancer. MATERIAL AND METHODS: PubMed was searched for original full-text articles with the following search terms: «Proton Therapy» and «Breast Cancer»...
November 24, 2017: Cancer Treatment Reviews
C Bäumer, D Geismar, B Koska, P H Kramer, J Lambert, M Lemke, S Plaude, L Pschichholz, S Qamhiyeh, A Schiemann, B Timmermann, X Vermeren
PURPOSE: To commission the treatment planning system (TPS) RayStation for proton therapy including beam models for spot scanning and for uniform scanning. METHODS: Tests consist of procedures from ESTRO booklet number 7, the German DIN for constancy checks of TPSs, and extra tests checking the dose perturbation function. The dose distributions within patients were verified in silico by a comparison of 65 clinical treatment plans with the TPS XiO. Dose-volume parameters, dose differences, and three-dimensional gamma-indices serve as measures of similarity...
November 2017: Physica Medica: PM
Sebastian Adeberg, Semi B Harrabi, Vivek Verma, Denise Bernhardt, Nicole Grau, Jürgen Debus, Stefan Rieken
The rapid rise of particle therapy across the world necessitates evidence to justify its ever-increasing utilization. This narrative review summarizes the current status of these technologies on treatment of both meningiomas and gliomas, the most common benign and malignant primary brain tumors, respectively. Proton beam therapy (PBT) for meningiomas displays high rates of long-term local control, low rates of symptomatic deterioration, along with the potential for safe dose-escalation in select (but not necessarily routine) cases...
December 1, 2017: Radiation Oncology
Meei-Ling Jan, Ming-Wei Lee, Hsuan-Ming Huang
Compton-based prompt gamma (PG) imaging has been proposed for in vivo range verification in proton therapy. However, several factors degrade the image quality of PGs, some of which are due to inherent properties of a Compton camera such as spatial resolution and energy resolution. Moreover, Compton-based PG imaging has a spatially variant resolution loss. In this study, we investigate the performance of the list-mode ordered subset expectation maximization algorithm with a shift-variant point spread function model (LM-OSEM-SV-PSF)...
November 30, 2017: Physics in Medicine and Biology
Anastasia Velalopoulou, Shampa Chatterjee, Ralph A Pietrofesa, Cynthia Koziol-White, Reynold A Panettieri, Liyong Lin, Stephen Tuttle, Abigail Berman, Constantinos Koumenis, Melpo Christofidou-Solomidou
Radiation therapy for the treatment of thoracic malignancies has improved significantly by directing of the proton beam in higher doses on the targeted tumor while normal tissues around the tumor receive much lower doses. Nevertheless, exposure of normal tissues to protons is known to pose a substantial risk in long-term survivors, as confirmed by our work in space-relevant exposures of murine lungs to proton radiation. Thus, radioprotective strategies are being sought. We established that LGM2605 is a potent protector from radiation-induced lung toxicity and aimed in the current study to extend the initial findings of space-relevant, proton radiation-associated late lung damage in mice by looking at acute changes in human lung...
November 25, 2017: International Journal of Molecular Sciences
Daniel Diaz-Aguilar, Sergei Terterov, Rudi Scharnweber, Harsimran Brara, Alex Tucker, Catherine Merna, Stephanie Wang, Shayan Rahman
Background: Chordomas are uncommon malignant bone tumors that are often minimally symptomatic for several years. By the time they are diagnosed, these lesions are typically large, involve major neural, bony, and vascular structures, and are no longer readily resectable. This leads to a high recurrence rate. Case Description: In this case report, we present a 67-year-old male with nonmechanical axial back pain, neurogenic claudication, and a large mass centered at the L3 level on magnetic resonance imaging consistent with a locally invasive chordoma...
2017: Surgical Neurology International
Macarena Cubillos-Mesías, Michael Baumann, Esther G C Troost, Fabian Lohaus, Steffen Löck, Christian Richter, Kristin Stützer
BACKGROUND: Proton beam therapy is promising for the treatment of head and neck cancer (HNC), but it is sensitive to uncertainties in patient positioning and particle range. Studies have shown that the planning target volume (PTV) concept may not be sufficient to ensure robustness of the target coverage. A few planning studies have considered irradiation of unilateral HNC targets with protons, but they have only taken into account the dose on the nominal plan, without considering anatomy changes occurring during the treatment course...
November 28, 2017: Radiation Oncology
N Arians, K Lindel, J Krisam, K Herfarth, D Krug, S Akbaba, J Oelmann-Avendano, J Debus
BACKGROUND: The prognosis for patients with cervical or endometrial cancer has improved over the last decades. Thus, reducing therapy-related toxicity and impact on quality of life have become more and more important. With the development of new radiotherapy techniques like IMRT (Intensity-modulated radiotherapy) the incidence of acute and chronic toxicities has already been reduced. Nevertheless, rates of complications requiring medical treatment range from 0.7-8% according to literature...
November 28, 2017: Radiation Oncology
Francesca Fiorini, Niek Schreuder, Frank Van den Heuvel
PURPOSE: Cyclotron-based pencil beam scanning (PBS) proton machines represent nowadays the majority and most affordable choice for proton therapy facilities, however their representation in Monte Carlo (MC) codes is more complex than passively scattered proton system or synchrotron based PBS machines. This is because degraders are used to decrease the energy from the cyclotron maximum energy to the desired energy, resulting in a unique spot size, divergence and energy spread depending on the amount of degradation...
November 27, 2017: Medical Physics
W D Newhauser, C Schneider, L Wilson, S Shrestha, W Donahue
External-beam radiation therapy is safe, effective and widely used to treat cancer. With 5-year cancer survival for adults above 70%, increasingly research is focusing on quantifying and reducing treatment-related morbidity. Reducing exposures to healthy tissues is one strategy, which can be accomplished with advanced-technology radiotherapies, such as intensity-modulated photon therapy and proton therapy. Both of these modalities provide good conformation of the therapeutic dose to the tumor volume, but they also deliver stray radiation to the whole body that increases the risk of radiogenic second cancers...
November 21, 2017: Radiation Protection Dosimetry
Abdelkhalek Hammi, Lorenzo Placidi, Damien Charles Weber, Antony John Lomax
To exploit the full potential of proton therapy, accurate and on-line methods to verify the patient positioning and the proton range during the treatment are desirable. Here we propose and validate an innovative technique for determining patient misalignment uncertainties through the use of a small number of low dose, carefully selected proton pencil beams ('Range Probes') with sufficient energy that their residual Bragg peak position and shape can be measured on exit. Since any change of the patient orientation in relation to these beams will result in changes of the density heterogeneities through which they pass, our hypothesis is that patient misalignments can be deduced from measured changes in BP shape and range...
November 24, 2017: Physics in Medicine and Biology
Ž Kneževic, I Ambrozova, C Domingo, M De Saint-Hubert, M Majer, I Martínez-Rovira, S Miljanic, N Mojzeszek, P Porwol, O Ploc, M Romero-Expósito, L Stolarczyk, S Trinkl, R M Harrison, P Olko
Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target...
November 18, 2017: Radiation Protection Dosimetry
Ana María Barragán Montero, Kevin Souris, Daniel Sánchez Parcerisa, Edmond Sterpin, John Aldo Lee
PURPOSE: Analytical algorithms have a limited accuracy when modelling very heterogeneous tumor sites. This work addresses the performance of a hybrid dose optimizer that combines both Monte Carlo (MC) and pencil beam (PB) dose engines to get the best trade-off between speed and accuracy for proton therapy plans. METHODS: The hybrid algorithm calculates the optimal spot weights (w) by means of an iterative optimization process where the dose at each iteration is computed by using a precomputed dose influence matrix based on the conventional PB plus a correction term c obtained from a MC simulation...
November 21, 2017: Medical Physics
Maura Kirk, Gary Freedman, Thorsten Ostrander, Lei Dong
This report aims to propose and present an evaluation of a robust pencil beam scanning proton multi-field optimized treatment planning technique for postmastectomy radiation of breast cancer patients with implanted tissue expanders containing an internal metal port. Field-specific split targets were created for optimization to prevent spots from traveling through the metal port, while providing uniform coverage of the target with the use of a multi-field intensity modulated optimization approach. Two beam angles were strategically selected to provide complementary target coverage and plan robustness...
September 18, 2017: Curēus
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