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https://www.readbyqxmd.com/read/29786861/temporally-feathered-intensity-modulated-radiation-therapy-a-planning-technique-to-reduce-normal-tissue-toxicity
#1
Juan Carlos López Alfonso, Shireen Parsai, Nikhil Joshi, Andrew Godley, Chirag Shah, Shlomo A Koyfman, Jimmy J Caudell, Clifton D Fuller, Heiko Enderling, Jacob G Scott
PURPOSE: Intensity modulated radiation therapy (IMRT) has allowed optimization of three-dimensional spatial radiation dose distributions permitting target coverage while reducing normal tissue toxicity. However, radiation-induced normal tissue toxicity is a major contributor to patients' quality of life and often a dose-limiting factor in the definitive treatment of cancer with radiation therapy. We propose the next logical step in the evolution of IMRT using canonical radiobiological principles, optimizing the temporal dimension through which radiation therapy is delivered to further reduce radiation-induced toxicity by increased time for normal tissue recovery...
May 22, 2018: Medical Physics
https://www.readbyqxmd.com/read/29786614/a-novel-optimization-framework-for-vmat-with-dynamic-gantry-couch-rotation
#2
Qihui Lyu, Victoria Y Yu, Dan Ruan, Ryan Neph, Daniel O'Connor, Ke Sheng
Existing Volumetric Modulated Arc Therapy (VMAT) optimization using coplanar arcs is highly efficient but usually dosimetrically inferior to intensity modulated radiation therapy (IMRT) with optimized non-coplanar beams. To achieve both dosimetric quality and delivery efficiency, we proposed in this study, a novel integrated optimization method for non-coplanar VMAT (4πVMAT). 4πVMAT with Direct Aperture Optimization (DAO) was achieved by utilizing a least square dose fidelity objective, along with an anisotropic total variation term for regularizing the fluence smoothness, a single segment term for imposing simple apertures, and a group sparsity term for selecting beam angles...
May 22, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29785839/optimization-of-a-secondary-voi-protocol-for-lung-imaging-in-a-clinical-ct-scanner
#3
Thomas C Larsen, Vissagan Gopalakrishnan, Jianhua Yao, Catherine P Nguyen, Marcus Y Chen, Joel Moss, Han Wen
We present a solution to meet an unmet clinical need of an in-situ "close look" at a pulmonary nodule or at the margins of a pulmonary cyst revealed by a primary (screening) chest CT while the patient is still in the scanner. We first evaluated options available on current whole-body CT scanners for high resolution screening scans, including ROI reconstruction of the primary scan data and HRCT, but found them to have insufficient SNR in lung tissue or discontinuous slice coverage. Within the capabilities of current clinical CT systems, we opted for the solution of a secondary, volume-of-interest (VOI) protocol where the radiation dose is focused into a short-beam axial scan at the z position of interest, combined with a small-FOV reconstruction at the xy position of interest...
May 21, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29785725/density-scaling-of-phantom-materials-for-a-3d-dose-verification-system
#4
Kensuke Tani, Yukio Fujita, Akihisa Wakita, Ryohei Miyasaka, Ryuzo Uehara, Takumi Kodama, Yuya Suzuki, Ako Aikawa, Norifumi Mizuno, Jiro Kawamori, Hidetoshi Saitoh
In this study, the optimum density scaling factors of phantom materials for a commercially available three-dimensional (3D) dose verification system (Delta4) were investigated in order to improve the accuracy of the calculated dose distributions in the phantom materials. At field sizes of 10 × 10 and 5 × 5 cm2 with the same geometry, tissue-phantom ratios (TPRs) in water, polymethyl methacrylate (PMMA), and Plastic Water Diagnostic Therapy (PWDT) were measured, and TPRs in various density scaling factors of water were calculated by Monte Carlo simulation, Adaptive Convolve (AdC, Pinnacle3 ), Collapsed Cone Convolution (CCC, RayStation), and AcurosXB (AXB, Eclipse)...
May 21, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29785411/low-dose-ct-perfusion-of-the-liver-using-reconstruction-of-difference
#5
Saeed Seyyedi, Eleni Liapi, Tobias Lasser, Robert Ivkov, Rajeev Hatwar, J Webster Stayman
Liver CT perfusion (CTP) is used in the detection, staging, and treatment response analysis of hepatic diseases. Unfortunately, CTP radiation exposures is significant, limiting more widespread use. Traditional CTP data processing reconstructs individual temporal samples, ignoring a large amount of shared anatomical information between temporal samples, suggesting opportunities for improved data processing. We adopt a prior-image-based reconstruction approach called Reconstruction of Difference (RoD) to enable low-exposure CTP acquisition...
May 2018: IEEE Transactions on Radiation and Plasma Medical Sciences
https://www.readbyqxmd.com/read/29784552/-new-calculation-algorithms-in-brachytherapy-for-iridium-192-treatments
#6
C Robert, I Dumas, F Martinetti, C Chargari, C Haie-Meder, D Lefkopoulos
Since 1995, the brachytherapy dosimetry protocols follow the methodology recommended by the Task Group 43. This methodology, which has the advantage of being fast, is based on several approximations that are not always valid in clinical conditions. Model-based dose calculation algorithms have recently emerged in treatment planning stations and are considered as a major evolution by allowing for consideration of the patient's finite dimensions, tissue heterogeneities and the presence of high atomic number materials in applicators...
May 18, 2018: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
https://www.readbyqxmd.com/read/29784460/review-of-real-time-3-dimensional-image-guided-radiation-therapy-on-standard-equipped-cancer-radiation-therapy-systems-are-we-at-the-tipping-point-for-the-era-of-real-time-radiation-therapy
#7
Paul J Keall, Doan Trang Nguyen, Ricky O'Brien, Pengpeng Zhang, Laura Happersett, Jenny Bertholet, Per R Poulsen
PURPOSE: To review real-time 3-dimensional (3D) image guided radiation therapy (IGRT) on standard-equipped cancer radiation therapy systems, focusing on clinically implemented solutions. METHODS AND MATERIALS: Three groups in 3 continents have clinically implemented novel real-time 3D IGRT solutions on standard-equipped linear accelerators. These technologies encompass kilovoltage, combined megavoltage-kilovoltage, and combined kilovoltage-optical imaging. The cancer sites treated span pelvic and abdominal tumors for which respiratory motion is present...
April 14, 2018: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/29784026/effects-of-ionizing-radiation-on-the-viability-and-proliferative-behavior-of-the-human-glioblastoma-t98g-cell-line
#8
Hossam Murad, Yaman Alghamian, Abdulmunim Aljapawe, Ammar Madania
OBJECTIVE: Radiotherapy is the traditional therapy for glioma patients. Glioma has poor response to ionizing radiation (IR). Studying radiation-induced cell death can help in understanding the cellular mechanisms underlying its radioresistance. T98G cell line was irradiated with Co60 source by 2 or 10 Gy. MTT assay was used to calculate the surviving fraction. Cell viability, cell cycle distribution and apoptosis assays were conducted by flow cytometry for irradiated and control cells for the 10 Gy dose...
May 21, 2018: BMC Research Notes
https://www.readbyqxmd.com/read/29782597/low-dose-radiation-18f-fluoride-pet-ct-in-the-assessment-of-unilateral-condylar-hyperplasia-of-the-mandible-preliminary-results-of-a-single-centre-experience
#9
G M Lima, S Diodato, E Costabile, G Cicoria, S Civollani, C Marchetti, P L Guidalotti, C Pettinato, C Nanni, S Fanti
Background: Unilateral condylar hyperplasia (UCH) of the mandible, or Hypercondylia, is a pathological condition that determines an abnormal growth of the affected condyle.Bone SPECT with Tc99m-diphosphonates is a successful tool in the diagnosis of UCH. EANM guidelines also suggest the use of 18F-NaF PET/CT, though it leads to a higher radiation exposure. Aim: As UCH patients are young, we aimed to develop a low dose 18F-Fluoride PET/CT protocol and compare it to a standard injected activity scan, to assess if the image quality remains unchanged...
2018: European journal of hybrid imaging
https://www.readbyqxmd.com/read/29782301/lymphangioma-circumscriptum-post-radiotherapy-for-penile-cancer-treated-with-co%C3%A2-laser
#10
Dietmar Schulz, Andreas Lein, Ancuta Proca Nicula, Katrin Schierle, Caius Solovan
Lymphangioma circumscriptum (LC) is a rare, benign condition, predominantly characterized by the malformation of lymphatic skin vessels. Its onset may be congenital or due to secondary causes such as radiotherapy, infections, or surgical procedures. We present the case of a 55-year-old patient with a pathologic history of squamous cell carcinoma of the penis followed by radical penectomy. Due to metastasis to the locoregional lymph nodes, the entire affected area was subsequently treated with radiation therapy, receiving a total dose of 55...
April 2018: Acta Dermatovenerologica Croatica: ADC
https://www.readbyqxmd.com/read/29782043/stereotactic-radiation-therapy-for-the-treatment-of-functional-pituitary-adenomas-associated-with-feline-acromegaly
#11
Tiffany L Wormhoudt, Mary-Keara Boss, Katharine Lunn, Lynn Griffin, Del Leary, Kristy Dowers, Sangeeta Rao, Susan M LaRue
BACKGROUND: Conventional fractionated radiotherapy has been shown to be partially effective for management of pituitary tumors in cats that cause acromegaly and diabetes mellitus (DM), but, the efficacy and safety of stereotactic radiation therapy (SRT) as a treatment for acromegalic cats has not been described. HYPOTHESIS: Stereotactic radiation therapy is an effective and safe treatment for controlling acromegaly associated with pituitary adenomas in cats. Additionally, SRT-treated acromegalic cats with DM will experience a decrease in insulin requirements after radiation therapy...
May 21, 2018: Journal of Veterinary Internal Medicine
https://www.readbyqxmd.com/read/29781993/murine-salivary-functional-assessment-via-pilocarpine-stimulation-following-fractionated-radiation
#12
Jomy J Varghese, Isaac L Schmale, Mollie Eva Hansen, Shawn D Newlands, Danielle S W Benoit, Catherine E Ovitt
Hyposalivation is commonly observed in the autoimmune reaction of Sjögren's syndrome or following radiation injury to the major salivary glands. In these cases, questions remain regarding disease pathogenesis and effective interventions. An optimized technique that allows functional assessment of the salivary glands is invaluable for investigating exocrine gland biology, dysfunction, and therapeutics. Here, we present a step by step approach to performing pilocarpine stimulated saliva secretion, including tracheostomy and the dissection of the three major murine salivary glands...
May 4, 2018: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29781766/significant-suppression-of-ct-radiation-induced-dna-damage-in-normal-human-cells-by-the-prc-210-radioprotector
#13
Frank Jermusek, Chelsea Benedict, Emma Dreischmeier, Michael Brand, Michael Uder, Justin J Jeffery, Frank N Ranallo, William E Fahl
While computed tomography (CT) is now commonly used and considered to be clinically valuable, significant DNA double-strand breaks (γ-H2AX foci) in white blood cells from adult and pediatric CT patients have been frequently reported. In this study to determine whether γ-H2AX foci and X-ray-induced naked DNA damage are suppressed by administration of the PrC-210 radioprotector, human blood samples were irradiated in a CT scanner at 50-150 mGy with or without PrC-210, and γ-H2AX foci were scored. X-ray-induced naked DNA damage was also studied, and the DNA protective efficacy of PrC-210 was compared against 12 other common "antioxidants...
May 21, 2018: Radiation Research
https://www.readbyqxmd.com/read/29781764/charged-iron-particles-found-in-galactic-cosmic-rays-are-potent-inducers-of-epithelial-ovarian-tumors
#14
Birendra Mishra, Gregory W Lawson, Ryan Ripperdan, Laura Ortiz, Ulrike Luderer
Astronauts traveling in deep space are exposed to high-charge and energy (HZE) particles from galactic cosmic rays. We have previously determined that irradiation of adult female mice with iron HZE particles induces DNA double-strand breaks, oxidative damage and apoptosis in ovarian follicles, causing premature ovarian failure. These effects occur at lower doses than with conventional photon irradiation. Ovarian failure with resultant loss of negative feedback and elevated levels of gonadotropin hormones is thought to play a role in the pathophysiology of ovarian cancer...
May 21, 2018: Radiation Research
https://www.readbyqxmd.com/read/29781071/wound-fluids-collected-from-patients-after-iort-treatment-activates-extrinsic-apoptotic-pathway-in-mcf7-breast-cancer-cell-line
#15
Katarzyna Ida Kulcenty, Igor Piotrowski, Karolina Zaleska, Dawid Murawa, Wiktoria Maria Suchorska
OBJECTIVES: Intraoperative radiotherapy (IORT) relates to irradiation of diseased tissue during the surgery within the tumor bed. The reason for this process is based on the fact that the increase in the radiation dose increases local tumor control. It was shown that postoperative fluids obtained from patients after breast cancer conserving surgery, stimulated motility and invasiveness of tumor cells in vitro. The results obtained from TARGIT clinical trial demonstrated that IORT significantly inhibits the stimulatory effect of wound fluids on tumor cells in vitro...
2018: Ginekologia Polska
https://www.readbyqxmd.com/read/29780829/the-effect-of-c-arm-mobility-and-field-of-vision-on-radiation-exposure-in-the-treatment-of-proximal-femoral-fractures-a-randomized-clinical-trial
#16
Mahmut Kalem, Kerem Başarır, Hakan Kocaoğlu, Ercan Şahin, Hakan Kınık
Objectives: To examine the effect of fluoroscopy devices with different sizes of image intensifier and C-arm maneuverability on operating time, fluoroscopy time, radiation dose and reduction, and fixation quality at intertrochanteric femoral fractures. Design: Single-center, randomized, prospective study. Setting: Academic Level I trauma hospital. Patients and Intervention: 34 patients treated with cephalomedullary nailing for a stable, intertrochanteric proximal femur fracture (OTA A1)...
2018: BioMed Research International
https://www.readbyqxmd.com/read/29780047/-evaluation-of-a-2d-diode-array-corresponding-to-flattening-filter-free-x-ray-beams
#17
Tomoko Kimura, Jun-Ichi Fukunaga, Taka-Aki Hirose, Ryota Hirayama
Recently, a medical linear accelerator with a flattening filter free (FFF) mode has led to the use of FFF X-ray beams at clinical sites. The usefulness of FFF X-ray beams in high-precision radiation therapy has been reported. Therefore, the quality assurance and quality control for FFF X-ray beams have become necessary. In this study, the characteristics of the detectors of a newly developed 2-D diode array (MapCHECK2, Sun Nuclear Corporation) for FFF X-ray beams, i.e., dose reproducibility, dose rate dependence, dose linearity, and output factor, were evaluated...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/29780046/-study-of-dose-recalculation-method-on-overriding-lung-density-using-cbct-image-in-the-thorax
#18
Hiroshi Watanabe, Shuichi Ozawa, Atsuyuki Ohashi, Koji Ikenaga, Kentaro Miki, Akito Saito, Teiji Nishio, Yuji Murakami, Yasushi Nagata
It is a useful method for the adaptive radiotherapy (ART) to calculate absorbed dose accurately on the image set taken by on-board cone beam computed tomography (CBCT) attached to linac for image-guided radiation therapy (IGRT). For this purpose, a simple and accurate calculation method is necessary. Several papers report that it is possible to calculate easily and accurately by using several methods of researches in the neck and prostate, but the lung density varies greatly depending on patient thorax condition...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/29780045/-screening-for-biological-marker-of-dose-optimization-in-cancer-radiotherapy
#19
Tatsuya Ueno, Satoru Monzen, Mitsuru Chiba, Yuki Morino, Yoichiro Hosokawa
PURPOSE AND METHODS: External radiotherapy of target regions using high-energy beams leads to excessive exposure along with individual variation in therapeutic and adverse effects. However, high-precision radiotherapy utilizes 3D-multi detector computed tomography to confirm both target position and administer radiation dose. To install the individual bioinformation in the radiotherapy plan (particularly, radiosensitivity into the target region and/or the around normal tissue), the investigation of biomarkers, which are able to estimate their radiosensitivity was performed...
2018: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/29780037/past-and-present-work-practices-of-european-interventional-cardiologists-in-the-context-of-radiation-protection-of-the-eye-lens-results-of-the-euraloc-study
#20
Joanna Karolina Domienik-Andrzejewska, Olivera Ciraj-Bjelac, Panagiotis Askounis, Peter Covens, Octavian Dragusin, Sophie Jacob, Jad Farah, Emilio Gianicolo, Renato Padovani, Pedro Manuel Peixoto Teles, Anders Widmark, Lara Struelens
This paper investigates over five decades of work practices in interventional cardiology with special emphasis on radiation protection. The analysis is based on the data from more than 400 cardiologists from different European countries recruited for EURALOC study collected in the period from 2014 to 2016. Information on the types of procedures performed and their annual mean number, fluoroscopy time, access site choice, X-ray units and radiation protection means used was collected using an occupational questionnaire...
May 21, 2018: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
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