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https://www.readbyqxmd.com/read/29457751/intra-and-inter-fraction-uncertainties-during-igrt-for-wilms-tumor
#1
Filipa Guerreiro, Enrica Seravalli, Geert O Janssens, Cees P van de Ven, Marry M van den Heuvel-Eibrink, Bas W Raaymakers
BACKGROUND AND PURPOSE: To assess intra- and inter-fraction motion uncertainties, due to displacements of the tumor bed (TB) and organs at risk (OAR), as well as intra- and inter-fraction patient set-up uncertainties, due to positioning variations, during image-guided radiation therapy (IGRT) in children with Wilms' tumor. MATERIAL AND METHODS: Four-dimensional computed tomography (4D-CT) and daily pre- and post-treatment cone-beam CT (CBCT)-scans of 15 patients (average 4, range 1-8 years) undergoing flank irradiation after nephrectomy were analyzed...
February 19, 2018: Acta Oncologica
https://www.readbyqxmd.com/read/29453744/low-serum-ige-is-a-sensitive-and-specific-marker-for-common-variable-immunodeficiency-cvid
#2
Monica G Lawrence, Thamiris V Palacios-Kibler, Lisa J Workman, Alexander J Schuyler, John W Steinke, Spencer C Payne, Emily C McGowan, James Patrie, Ramsay L Fuleihan, Kathleen E Sullivan, Patricia L Lugar, Camellia L Hernandez, Douglas E Beakes, James W Verbsky, Thomas A E Platts-Mills, Charlotte Cunningham-Rundles, John M Routes, Larry Borish
Although small prior studies have suggested that IgE can be low in common variable immunodeficiency (CVID), the workup for patients with recurrent infections and suspected hypogammaglobulinemia does not include the routine measurement of serum IgE. We sought to test the hypothesis that low/undetectable serum IgE is characteristic of CVID by comparing the frequency of low/undetectable serum IgE in healthy controls and patients with CVID. We measured total serum IgE in a large multi-center cohort of patients with CVID (n = 354) and compared this to large population-based cohorts of children and adults...
February 17, 2018: Journal of Clinical Immunology
https://www.readbyqxmd.com/read/29452872/urolift-as-a-surrogate-for-fiducial-markers-in-igrt-planning-of-prostate-cancer-in-bph-patients
#3
Nrusingh C Biswal, Beth Swann, Michael G McKenna, Rachana Singh
No abstract text is available yet for this article.
December 24, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/29447260/optimal-dose-reduction-algorithm-using-an-attenuation-based-tube-current-modulation-method-for-cone-beam-ct-imaging
#4
Kihong Son, Jieun Chang, Hoyeon Lee, Changhwan Kim, Taewon Lee, Seungryong Cho, Sohyun Park, Jin Sung Kim
To reduce the radiation dose given to patients, a tube current modulation (TCM) method has been widely used in diagnostic CT systems. However, the TCM method has not yet been applied to a kV-CBCT system on a LINAC machine. The purpose of this study is to investigate if a TCM method would be desirable in a kV-CBCT system for image-guided radiation therapy (IGRT) or not. We have developed an attenuation-based TCM method using prior knowledge from planning CT images of patients. The TCM method can provide optimized dose reductions without degrading image quality for kV-CBCT imaging...
2018: PloS One
https://www.readbyqxmd.com/read/29439305/strategic-application-of-radiotherapy-for-hepatocellular-carcinoma
#5
Seo Hee Choi, Jinsil Seong
With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT...
February 14, 2018: Clinical and Molecular Hepatology
https://www.readbyqxmd.com/read/29426589/determination-of-the-effective-dose-delivered-by-image-guided-radiotherapy-in-head-neck-and-breast-treatments
#6
Mireille Conrad, Grégory Bolard, Marie Nowak, Berardino De Bari, Wendy Jeanneret-Sozzi, Jean Bourhis, Jean-François Germond, François Bochud, Raphaël Moeckli
PURPOSE: Image guided radiotherapy (IGRT) improves patient positioning for treatment delivery at the cost of an additional dose. This work aimed to calculate the effective dose (as an indicator of dose) for head & neck (H&N) and breast IGRT treatments by implementing dose calculation models to determine the dose distributions. METHODS: The kV dose-models were created for the IGRT systems of Elekta Synergy (XVI) and Varian Clinac (OBI) linear accelerators within Philips Pinnacle TPS...
February 6, 2018: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/29423883/prescribing-immunoglobulin-replacement-therapy-for-patients-with-non-classical-and-secondary-antibody-deficiency-an-analysis-of-the-practice-of-clinical-immunologists-in-the-uk-and-republic-of-ireland
#7
John David M Edgar, Alex G Richter, Aarnoud P Huissoon, Dinakantha S Kumararatne, Helen E Baxendale, Claire A Bethune, Tomaz Garcez, Siraj A Misbah, Ricardo U Sorensen
BACKGROUND: Immunologists are increasingly being asked to assess patients with non-classical and secondary antibody deficiency to determine their potential need for immunoglobulin replacement therapy (IGRT). Immunoglobulin is a limited, expensive resource and no clear guidance exists for this broad patient group. The purpose of this survey is to establish what factors influence the decision to commence IGRT in adult patients, when diagnostic criteria for primary antibody deficiency are not fulfilled...
February 8, 2018: Journal of Clinical Immunology
https://www.readbyqxmd.com/read/29398152/radiotherapy-for-prostate-cancer-does-daily-image-guidance-with-tighter-margins-improve-patient-reported-outcomes-compared-to-weekly-orthogonal-verified-irradiation-results-from-a-randomized-controlled-trial
#8
Hanne Tøndel, Jo-Åsmund Lund, Stian Lydersen, Anne D Wanderås, Bjørg Aksnessæther, Christer Andre Jensen, Stein Kaasa, Arne Solberg
BACKGROUND: Novel cancer drugs are subject to strict scientific evaluation of safety and efficacy and usually undergo a cost effectiveness analysis before approval for use in clinical practice. For new techniques in radiotherapy (RT) such as image-guided radiotherapy (IGRT), this is often not the case. We performed a randomized controlled trial to compare daily cone beam computer tomography (CBCT) IGRT with reduced planning target volume (PTV) margins vs weekly orthogonal portal imaging with conventional PTV margins...
February 2, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29384731/real-time-volumetric-relative-dosimetry-for-magnetic-resonance-image-guided-radiation-therapy-mr-igrt
#9
Hannah Jungeun Lee, Mo Kadbi, Gary Bosco, Geoffrey S Ibbott
The integration of magnetic resonance imaging (MRI) with linear accelerators (linac) has enabled the use of 3D MR-visible gel dosimeters for real-time verification of volumetric dose distributions. Several iron-based radiochromic 3D gels were created in-house then imaged and irradiated in a pre-clinical 1.5 T - 7 MV MR-Linac. MR images were acquired using a range of balanced-fast field echo (b-FFE) sequences during irradiation to assess the contrast and dose response in irradiated regions and to minimize the presence of MR artifacts...
January 31, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29372691/prediction-of-radiation-necrosis-in-a-rodent-model-using-magnetic-resonance-imaging-apparent-transverse-relaxation-formula-see-text
#10
Jean-Guy Belliveau, Michael D Jensen, James M P Stewart, Igor Solovey, L Martyn Klassen, Glenn S Bauman, Ravi S Menon
BACKGROUND AND PURPOSE: Radiation necrosis remains an irreversible long-term side-effect following radiotherapy to the brain. The ability to predict areas that could ultimately develop into necrosis could lead to prevention and management of radiation necrosis. MATERIALS AND METHODS: Fischer 344 rats were irradiated using two platforms (micro-CT irradiator and x-Rad 225 IGRT) with radiation up to 30 Gy for the micro-CT and 40 Gy for the xRAD-224 to half the brain...
January 26, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29372290/patient-positioning-in-head-and-neck-cancer-setup-variations-and-safety-margins-in-helical-tomotherapy
#11
Christina Leitzen, Timo Wilhelm-Buchstab, Thomas Müdder, Martina Heimann, David Koch, Christopher Schmeel, Birgit Simon, Sabina Stumpf, Susanne Vornholt, Stephan Garbe, Fred Röhner, Felix Schoroth, Hans Heinz Schild, Heinrich Schüller
OBJECTIVE: To evaluate the interfractional variations of patient positioning during intensity-modulated radiotherapy (IMRT) with helical tomotherapy in head and neck cancer and to calculate the required safety margins (sm) for bony landmarks resulting from the necessary table adjustments. MATERIALS AND METHODS: In all, 15 patients with head and neck cancer were irradiated using the Hi-Art II tomotherapy system between April and September 2016. Before therapy sessions, patient position was frequently checked by megavolt computed tomography (MV-CT)...
January 25, 2018: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/29338305/safety-and-feasibility-of-prostate-stereotactic-ablative-radiotherapy-using-multimodality-imaging-and-flattening-filter-free
#12
Aileen Duffton, Azmat Sadozye, Lynsey Devlin, Nicholas MacLeod, Carolynn Lamb, Suzanne Currie, Philip McLoone, Marimuthu Sankaralingam, John Foster, Stephanie Paterson, Stefanie Keatings, David Dodds
OBJECTIVE: To investigate feasibility and safety of stereotactic ablative radiotherapy in the management of prostate cancer while employing MR/CT fusion for delineation, fiducial marker seeds for positioning and Varian RapidArc with flattening filter free (FFF) delivery. METHODS: 41 patients were treated for low-intermediate risk prostate cancer with initial prostate-specific antigen of ≤20 ng ml-1, Gleason score 6-7. Patients had MR/CT fusion for delineation of prostate ±seminal vesicles...
February 1, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29332447/a-projection-quality-driven-tube-current-modulation-method-in-cone-beam-ct-for-igrt-proof-of-concept
#13
Kuo Men, Jianrong Dai
PURPOSE: To develop a projection quality-driven tube current modulation method in cone-beam computed tomography for image-guided radiotherapy based on the prior attenuation information obtained by the planning computed tomography and then evaluate its effect on a reduction in the imaging dose. MATERIALS AND METHODS: The QCKV-1 phantom with different thicknesses (0-400 mm) of solid water upon it was used to simulate different attenuation (μ). Projections were acquired with a series of tube current-exposure time product (mAs) settings, and a 2-dimensional contrast to noise ratio was analyzed for each projection to create a lookup table of mAs versus 2-dimensional contrast to noise ratio, μ...
December 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/29282134/small-field-dosimetry-for-the-small-animal-radiotherapy-research-platform-sarrp
#14
Mihaela Ghita, Stephen J McMahon, Hannah F Thompson, Conor K McGarry, Raymond King, Sarah O S Osman, Jonathan L Kane, Amanda Tulk, Giuseppe Schettino, Karl T Butterworth, Alan R Hounsell, Kevin M Prise
BACKGROUND: Preclinical radiation biology has become increasingly sophisticated due to the implementation of advanced small animal image guided radiation platforms into laboratory investigation. These small animal radiotherapy devices enable state-of-the-art image guided therapy (IGRT) research to be performed by combining high-resolution cone beam computed tomography (CBCT) imaging with an isocentric irradiation system. Such platforms are capable of replicating modern clinical systems similar to those that integrate a linear accelerator with on-board CBCT image guidance...
December 28, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/29249526/curative-radiation-therapy-at-time-of-progression-under-active-surveillance-compared-with-up-front-radical-radiation-therapy-for-prostate-cancer
#15
Alejandro Berlin, Ardalan E Ahmad, Melvin L K Chua, Fabio Y Moraes, Haiyan Jiang, Maria Komisarenko, Narhari Trimilshina, Hamid Raziee, Ali Hosni, Jure Murgic, Peter Chung, Robert G Bristow, Antonio Finelli
PURPOSE: To describe and compare outcomes in men with initially presumed indolent prostate cancer receiving definitive radiation therapy after active surveillance (AS) versus those in a risk-matched cohort undergoing up-front radiation therapy. METHODS AND MATERIALS: Men prospectively enrolled in an AS program between 1992 and 2014 and subsequently undergoing curative radiation therapy (ie, image guided radiation therapy [IGRT] or low-dose-rate brachytherapy [LDR-BT]) were identified...
March 1, 2018: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/29219117/prediction-of-radiation-necrosis-in-a-rodent-model-using-magnetic-resonance-imaging-apparent-transverse-relaxation-r-sub-2-sub-sup-sup
#16
Jean-Guy Belliveau, Michael D Jensen, James M P Stewart, Igor Solovey, Martyn L Klassen, Glenn S Bauman, Ravi S Menon
Radiation necrosis remains an irreversible long-term side-effect following radiotherapy to the brain. The ability to predict areas that could ultimately develop into necrosis could lead to prevention and management of radiation necrosis. Materials and Methods: Fischer 344 rats were irradiated using two platforms (micro-CT irradiator and x-RAD 225 IGRT) with radiation up to 30 Gy for the micro-CT and 40 Gy for the xRAD-224 to half the brain. Animals were subsequently imaged using a 9.4T MRI scanner every 2-4 weeks for up to 28 weeks using a 7-echo gradient echo sequence...
December 8, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29184684/impact-of-sarcopenia-on-outcomes-of-locally-advanced-esophageal-cancer-patients-treated-with-neoadjuvant-chemoradiation-followed-by-surgery
#17
Gilbert Z Murimwa, Puja S Venkat, William Jin, Susan Leuthold, Kujtim Latifi, Khaldoun Almhanna, Jose M Pimiento, Jacques-Pierre Fontaine, Sarah E Hoffe, Jessica M Frakes
Background: Sarcopenia is an independent predictor of clinical outcomes in multiple gastrointestinal cancers. Total psoas area (TPA), as measured on a single cross-sectional CT image at the L4 vertebral body level, has been correlated with sarcopenia. We sought to evaluate whether TPA was predictive of acute grade ≥3 toxicity, pathologic response, and overall survival in patients with locally advanced esophageal cancer receiving tri-modality therapy. Methods: An institutional database of esophageal cancer patients treated with neoadjuvant chemoradiation followed by surgery was queried...
October 2017: Journal of Gastrointestinal Oncology
https://www.readbyqxmd.com/read/29181556/oligometastases-in-prostate-cancer-metabolic-response-in-follow-up-psma-pet-cts-after-hypofractionated-igrt
#18
René Baumann, Mark Koncz, Ulf Luetzen, Fabian Krause, Juergen Dunst
BACKGROUND: Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMAPET/CT) is a new and evolving diagnostic method in prostate cancer with special impact on treatment planning in image-guided radiotherapy (IGRT). Initial results of metabolic response in repeated PSMA PET/CTs after hypofractionated IGRT for metastatic lesions are reported here. MATERIALS AND METHODS: Of 280 patients investigated with 68Ga-PSMA PET/CT in the period from 01/2014 through 12/2016 in the authors' department, patients were selected according to the following criteria: oligometastatic disease at initial PSMA PET/CT defined as not more than five metastatic lesions, hypofractionated IGRT to all lesions, no systemic therapy in the last 6 months and during follow-up, and at least one follow-up PSMA PET after radiotherapy...
November 27, 2017: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/29154259/evaluation-of-coefficients-to-derive-organ-and-effective-doses-from-cone-beam-ct-cbct-scans-a-monte-carlo-study
#19
Abdullah Abuhaimed, Colin J Martin
Regular imaging is used throughout image guided radiation therapy (IGRT) to improve treatment delivery. In order for treatment procedures to be optimized, the doses delivered by imaging exposures should be taken into account. CT dosimetry methods based on the CT dose index (CTDI), measured with a 100 mm long pencil ionization chamber (CTDI<sub>100</sub>) in standard phantoms, are not designed for the cone beam CT (CBCT) imaging systems used in radiotherapy, therefore a modified version has been proposed for CBCT by the International Electrotechnical Commission (CTDI<sub>IEC</sub>)...
November 20, 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/29136287/quantification-of-mri-visibility-and-artefacts-at-3t-of-liquid-fiducial-marker-in-a-pancreas-tissue-mimicking-phantom
#20
Sergej Schneider, Rasmus Irming Jølck, Esther Gera Cornelia Troost, Aswin Louis Hoffmann
PURPOSE: X-ray based position verification of the target volume in image-guided radiation therapy (IGRT) of patients with pancreatic ductal adenocarcinoma (PDAC) is currently performed on solid fiducial markers that are implanted under endoscopic ultrasonography. A new biodegradable liquid fiducial marker has recently been introduced. To assess its potential use for magnetic resonance imaging (MRI) guided photon or proton radiotherapy of PDAC, the MRI visibility and artefacts of this marker were quantified and compared against solid gold markers...
November 14, 2017: Medical Physics
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