Read by QxMD icon Read


E C Simpson
PURPOSE: Positron emitting isotopes such as (11)C and (10)C can be used for vital dose verification in hadron therapy. These isotopes are produced when the high energy (12)C primary beam particles undergo nuclear reactions within the patient. METHODS: We discuss a model for calculating cross sections for the production (11)C in (12)C+(12)C collisions, applicable at hadron therapy energies. RESULTS: Good agreement with the available cross section measurements is found for (12)C(-1n), though more detailed, systematic measurements would be very valuable...
October 11, 2016: Physica Medica: PM
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
Constantin Dreher, Christian Scholz, Mira Pommer, Stephan Brons, Hannah Prokesch, Swantje Ecker, Jürgen Debus, Oliver Jäkel, Stephanie E Combs, Daniel Habermehl
BACKGROUND: The aim of the thesis is to improve treatment plans of carbon ion irradiation by integrating the tissues' specific [Formula: see text]-values for patients with locally advanced pancreatic cancer (LAPC). MATERIAL AND METHODS: Five patients with LAPC were included in this study. By the use of the treatment planning system Syngo RT Planning (Siemens, Erlangen, Germany) treatment plans with carbon ion beams have been created. Dose calculation was based on [Formula: see text]-values for both organs at risk (OAR) and the tumor...
2016: PloS One
Clara Ferreira, Daniel Johnson, Karl Rasmussen, Clinton Leinweber, Salahuddin Ahmad, Jae Won Jung
PURPOSE: To develop a novel conformal superficial brachytherapy (CSBT) device as a treatment option for the patient-specific radiation therapy of conditions including superficial lesions, postsurgical positive margins, Dupuytren's contractures, keloid scars, and complex anatomic sites (eyelids, nose, ears, etc.). METHODS AND MATERIALS: A preliminary CSBT device prototype was designed, built, and tested using readily available radioactive seeds. Iodine-125 ((125)I) seeds were independently guided to the treatment surface to conform to the target...
October 3, 2016: Brachytherapy
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
Travis Shaffer, Charles M Drain, Jan Grimm
Nuclear medicine utilizes ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including X-rays, beam therapy, brachytherapy, and various injected radionuclides. While positron emission tomography and single-photon emission computed tomography remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative...
September 29, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
J T Taylor, C Waltham, T Price, N M Allinson, P P Allport, G L Casse, A Kacperek, S Manger, N A Smith, I Tsurin
For many years, silicon micro-strip detectors have been successfully used as tracking detectors for particle and nuclear physics experiments. A new application of this technology is to the field of particle therapy where radiotherapy is carried out by use of charged particles such as protons or carbon ions. Such a treatment has been shown to have advantages over standard x-ray radiotherapy and as a result of this, many new centres offering particle therapy are currently under construction around the world today...
September 21, 2016: Nuclear Instruments & Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
D Chuard, V Anthonipillai, R Dendale, C Nauraye, E Khan, C Mabit, L De Marzi, L Narici
Particle therapy provides an opportunity to study the human response to space radiation in ground-based facilities. On this basis, a study of light flashes analogous to astronauts' phosphenes reported by patients undergoing ocular proton therapy has been undertaken. The influence of treatment parameters on phosphene generation was investigated for 430 patients treated for a choroidal melanoma at the proton therapy centre of the Institut Curie (ICPO) in Orsay, France, between 2008 and 2011. 60% of them report light flashes, which are predominantly (74%) blue...
August 2016: Life Sciences in Space Research
S Incerti, M Douglass, S Penfold, S Guatelli, E Bezak
Emerging radiotherapy treatments including targeted particle therapy, hadron therapy or radiosensitisation of cells by high-Z nanoparticles demand the theoretical determination of radiation track structure at the nanoscale. This is essential in order to evaluate radiation damage at the cellular and DNA level. Since 2007, Geant4 offers physics models to describe particle interactions in liquid water at the nanometre level through the Geant4-DNA Package. This package currently provides a complete set of models describing the event-by-event electromagnetic interactions of particles with liquid water, as well as developments for the modelling of water radiolysis...
September 19, 2016: Physica Medica: PM
Vivek Verma, Steven H Lin, Charles B Simone, Minesh P Mehta
BACKGROUND: Proton beam radiotherapy (PBT) is frequently shown to be dosimetrically superior to photon radiotherapy (RT), though supporting data for clinical benefit are severely limited. Because of the potential for toxicity reduction in gastrointestinal (GI) malignancies, we systematically reviewed the literature on clinical outcomes (survival/toxicity) of PBT. METHODS: A systematic search of PubMed, EMBASE, abstracts from meetings of the American Society for Radiation Oncology, Particle Therapy Co-Operative Group, and American Society of Clinical Oncology was conducted for publications from 2000-2015...
August 2016: Journal of Gastrointestinal Oncology
Marco Durante, Harald Paganetti
Charged particle therapy has been largely driven and influenced by nuclear physics. The increase in energy deposition density along the ion path in the body allows reducing the dose to normal tissues during radiotherapy compared to photons. Clinical results of particle therapy support the physical rationale for this treatment, but the method remains controversial because of the high cost and of the lack of comparative clinical trials proving the benefit compared to x-rays. Research in applied nuclear physics, including nuclear interactions, dosimetry, image guidance, range verification, novel accelerators and beam delivery technologies, can significantly improve the clinical outcome in particle therapy...
September 2016: Reports on Progress in Physics
Silvia Muraro, Giuseppe Battistoni, Francesco Collamati, Erika De Lucia, Riccardo Faccini, Fernando Ferroni, Salvatore Fiore, Paola Frallicciardi, Michela Marafini, Ilaria Mattei, Silvio Morganti, Riccardo Paramatti, Luca Piersanti, Davide Pinci, Antoni Rucinski, Andrea Russomando, Alessio Sarti, Adalberto Sciubba, Elena Solfaroli-Camillocci, Marco Toppi, Giacomo Traini, Cecilia Voena, Vincenzo Patera
The interaction of the incoming beam radiation with the patient body in hadrontherapy treatments produces secondary charged and neutral particles, whose detection can be used for monitoring purposes and to perform an on-line check of beam particle range. In the context of ion-therapy with active scanning, charged particles are potentially attractive since they can be easily tracked with a high efficiency, in presence of a relatively low background contamination. In order to verify the possibility of exploiting this approach for in-beam monitoring in ion-therapy, and to guide the design of specific detectors, both simulations and experimental tests are being performed with ion beams impinging on simple homogeneous tissue-like targets (PMMA)...
2016: Frontiers in Oncology
Conor H McFadden, Timothy M Hallacy, David B Flint, Dal A Granville, Aroumougame Asaithamby, Narayan Sahoo, Mark S Akselrod, Gabriel O Sawakuchi
PURPOSE: Understanding the DNA damage and repair induced by hadron therapy (HT) beams is crucial for developing novel strategies to maximize the use of HT beams to treat cancer patients. However, spatiotemporal studies of DNA damage and repair for beam energies relevant to HT have been challenging. We report a technique that enables spatiotemporal measurement of radiation-induced damage in live cells and colocalization of this damage with charged particle tracks over a broad range of clinically relevant beam energies...
September 1, 2016: International Journal of Radiation Oncology, Biology, Physics
Vivek Verma, Charles B Simone, Andrew O Wahl, Sushil Beriwal, Minesh P Mehta
BACKGROUND: Proton beam therapy (PBT) is increasingly being used globally to treat a variety of malignancies. This is the first review assessing PBT for gynecologic neoplasms. Dose distribution to organs-at-risk (OARs), particularly bone marrow (BM), is addressed. Clinical outcomes and toxicity data are detailed. MATERIAL AND METHODS: Systematic searches of PubMed, EMBASE, abstracts from meetings of the American Society for Radiation Oncology, Particle Therapy Co-Operative Group, and American Society of Clinical Oncology were conducted for publications...
November 2016: Acta Oncologica
Ivana Dokic, Andrea Mairani, Martin Niklas, Ferdinand Zimmermann, Naved Chaudhri, Damir Krunic, Thomas Tessonnier, Alfredo Ferrari, Katia Parodi, Oliver Jäkel, Jürgen Debus, Thomas Haberer, Amir Abdollahi
The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival...
August 1, 2016: Oncotarget
P Cambraia Lopes, J Bauer, A Salomon, I Rinaldi, V Tabacchini, T Tessonnier, P Crespo, K Parodi, D R Schaart
Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong (15)O signal due to its relatively short half-life (~2 min) and high oxygen content in biological tissues, enabling shorter scans that are less sensitive to biological washout. This paper presents the first performance tests of a scaled-down in situ time-of-flight (TOF) PET system based on digital photon counters (DPCs) coupled to Cerium-doped Lutetium Yttrium Silicate (LYSO:Ce) crystals, providing quantitative results representative of a dual-head tomograph that complies with spatial constraints typically encountered in clinical practice (2  ×  50°, of 360°, transaxial angular acceptance)...
August 21, 2016: Physics in Medicine and Biology
A Modiri, X Gu, A Hagan, R Bland, P Iyengar, R Timmerman, A Sawant
A critical aspect of highly potent regimens such as lung stereotactic body radiation therapy (SBRT) is to avoid collateral toxicity while achieving planning target volume (PTV) coverage. In this work, we describe four dimensional conformal radiotherapy using a highly parallelizable swarm intelligence-based stochastic optimization technique. Conventional lung CRT-SBRT uses a 4DCT to create an internal target volume and then, using forward-planning, generates a 3D conformal plan. In contrast, we investigate an inverse-planning strategy that uses 4DCT data to create a 4D conformal plan, which is optimized across the three spatial dimensions (3D) as well as time, as represented by the respiratory phase...
August 21, 2016: Physics in Medicine and Biology
Michael I Tribelsky, Yasuhide Fukumoto
We consider the general problem of laser pulse heating of a spherical dielectric particle embedded in a liquid. The discussed range of the problem parameters is typical for medical and biological applications. We focus on the case, when the heat diffusivity in the particle is of the same order of magnitude as that in the fluid. We perform quantitative analysis of the heat transfer equation based on interplay of four characteristic scales of the problem, namely the particle radius, the characteristic depth of light absorption in the material of the particle and the two heat diffusion lengths: in the particle and in the embedding liquid...
July 1, 2016: Biomedical Optics Express
Ester Orlandi, Nicola Alessandro Iacovelli, Maria Bonora, Anna Cavallo, Piero Fossati
Salivary gland cancers (SGCs) are rare diseases and their treatment depends upon histology, stage and site of origin. Radical surgery is the mainstay of treatment but radiotherapy (RT) plays a key role in both the postoperative and the inoperable setting, as well as in recurrent disease. In the absence of prospective randomized trials, a wide retrospective literature suggests postoperative RT (PORT) in patients with high risk pathological features. SGCs, and adenoid cystic carcinoma (ACC) in particular, are known to be radio-resistant tumors and should therefore respond well to particle beam therapy...
September 2016: Oral Oncology
Alexander S Pasciak, Laurentia Nodit, Austin C Bourgeois, Ben E Paxton, Patricia N Coan, Christopher T Clark, M Katherine Tolbert, Joleen K Adams, Aravind Arepally, Yong C Bradley
: In (90)Y radioembolization, non-target embolization (NTE) to the stomach or small bowel can result in gastrointestinal injury, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of (90)Y radioembolization in a porcine model at different absorbed dose endpoints. METHODS: Six female pigs underwent transfemoral angiography and infusion of (90)Y resin microspheres into arteries supplying part of the gastric wall...
July 7, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"