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Linear Accelerator - Crossref

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Last Updated: 22 August 2022

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Concept of Neutron Source Creation for Nuclear Medicine on the Basis of Linear Electron Accelerator

We review the current state of epithermal neutron capture therapy, a promising form of malignant tumor therapy based on reactors and accelerators. The target containing the fissile material is shown by the method. The source prototype for the production of thermal and epithermal neutrons using the delayed neutrons generated with the support of a linear electron accelerator is the source prototype. In nuclear medicine, and in particular in neutron capture therapy in cancer treatment, such a neutron beam can be used in neutron capture therapy. When treating patients, neutron capture therapy must address both the intensity and the energy spectrum of the neutron flux, which is an important step in the development of neutron capture therapy. To solve this issue, a former development of activation-type neutron ball spectrometer can be used, which will allow for optimization of various aspects of the shaper, collimator, and filters in order to get the most accurate neutron fluxes.

Source link: https://doi.org/10.26565/2312-4334-2021-4-21


Preclinical validation and treatment of volumetric modulated arc therapy based total bone marrow irradiation in Halcyon™ ring gantry linear accelerator

Abstract Aim This study is intended to present preclinical evidence, as well as the first clinical application of total bone marrow and lymph nodal irradiation using Volumetric modulated arc therapy in Halcyon-E ring gantry linear accelerator. For TMI/TMLI, two female and two male with body weights of 116 kg, 52 kg, 64 kg, and 62 kilograms; two male and two male with chronic myeloid leukemia, one each with acute lymphoblastic leukemia, and acute myeloid leukemia were modelled and planned. From head to knee and knee to toe, head and Feet first supine CT scans were conducted from head to knee and foot. With a uniform margin of 6 mm over the total bone marrow/bone lymph nodes, the planning target volume was set. Both HFS and FFS PTVs were optimized independently using 6MV unflatten energy for 12 Gy in 6 fractions, according to the users. For dose feathering between arcs between adjacent isocenters, a junction dose gradient system was used. Conclusions Only one female patient who was AML received the TMLI therapy, while the other three patients died as a result of medical difficulties and comorbidities that occurred in the time between simulation and therapy. PTV's 95% dose was normalized to 95% volume, with PTV's 73 percent receiving 3. 3 percent of the total number. Total lung mean and V12Gy were 1048. 6 cGy and 19. 5 percent, with 19. 5 % at u00b1 107. 1 cGy and V12Gy 1048. 6%. 18. The median number of isocenters was 17, while the average MU/Dose ratio per isocenter was 2. 28 0. 3 — 0. 30 0. 3.

Source link: https://doi.org/10.1186/s13014-022-02109-z


Clinical utility of a 1.5 T magnetic resonance imaging-guided linear accelerator during conventionally fractionated and hypofractionated prostate cancer radiotherapy

Purpose: We'll explore our first encounter with a 1. 5 T magnetic resonance imaging linear accelerator in prostate cancer radiotherapy in terms of its use in a radiation oncology clinic. The medical records of 14 prostate cancer patients treated with MRI-guided radiotherapy were retrospectively reviewed. The fraction of time, adapt-to-position:adapt-to-shape, machine-associated treatment interruption rate, median gamma pass rate, the percentage of planning target volume receiving at least 95% of the prescription dose coverage value of each ATS fraction, the effects of the learning curve on the fraction time, and radiation-related acute gastrointestinal and genitourinary toxicities were investigated. Three patients were treated with moderately hypofractionated ironically fractionated, five patients were routinely fractionated, and three patients were treated with ultra-hypofractionated radiotherapy regimens. Conclusion 1. 5 The MRI-LINAC unit could be used as a conventional LINAC unit if the radiotherapy center's conditions are appropriate.

Source link: https://doi.org/10.3389/fonc.2022.909402


Dosimetric characterization of hypofractionated Gamma Knife radiosurgery of large or complex brain tumors versus linear accelerator–based treatments

OBJECTIVE Noninvasive Gamma Knife platforms, such as the relocatable frame and on-board imaging, have resulted in hypofractionated GK radiosurgery of large or complex brain tumors. METHODS TEN patients were selected for the study at the authors' institution for large brain tumors were chosen for the study. On the Varian TrueBeam device, Multiplan V4. 5 for the CyberKnife VSI System, and Leksell GammaPlan V10. 2 for the Gamma Knife Perfexion system, treatment planning was carried out using Eclipse External Beam Planning V11 for VMAT on the Varian TrueBeam system, Leksell GammaPlan V10. 2 for the Gamma Knife Perfexion system. The percentage of the PTV receiving at least the prescription dose was standardized across all platforms for individual cases. For all of the cases, the PTV, conformity index, Paddick gradient index, mean and maximum doses for organs at risk, and healthy brain dose were determined. RESULTS The mean Paddick gradient index was 2. 6 0. 2, 3. 2 0. 5, and 4. 3 1. 0 for GK, CK, and VMAT, respectively, with a 1. 0. In addition, the mean V5 measurements for GK and CK were similar at 71. 9 cm 3 and 73. 3 cm 3, respectively, much lower than the mean V5 value of 124. 6 cm 3 for VMAT, which were statistically lower than the mean V5 of 67. 1 cm 3 for VMAT. CONCLUSIONS For hypofractionated GK radiosurgery versus linear accelerator based therapies, hypofractionated GK radiosurgery was noted significantly higher near-target brain sparing was observed.

Source link: https://doi.org/10.3171/2016.7.gks16881


Changing practice patterns of Gamma Knife versus linear accelerator-based stereotactic radiosurgery for brain metastases in the US

OBJECT Single-fraction stereotactic radiosurgery is a critical component in the diagnosis of limited brain metastases from non-small cell lung cancer. In the absence of clear prospective studies comparing the efficacy and toxicities of treatment between the two methods, nonclinical factors may play a larger role in determining which radiosurgery system a facility may choose to use. This report is the first to investigate national trends of GK SRS versus LINAC SRS use in order to determine which risk factors may be associated with the adoption of these radiosurgery tools, according to the authors' knowledge. METHODS The National Cancer Data Base was used to find patients > 18 years old with NSCLC who were treated with single-fraction SRS to the brain between 2003 and 2011. RESULTS This report included 1780 patients, of whom 1371 received GK SRS and 409 underwent LINAC SRS. The number of patients receiving LINAC SRS has gradually increased from 3. 2 percent in 2003 to 38 percent in 2011, and 32 percent in 2011. Using multivariable analysis, 4 new determinants of increased LINAC SRS use emerged, including year of diagnosis in 2008-2013 versus 2003-2007, community versus academic institution type, non-West versus West geographic location, and distance from the cancer reporting center of 20 miles versus u2265 20 miles versus u265 20 miles versus u265 20 miles versus u2165 20 miles versus u201307 20 miles versus vance v a v v2 versus e a &r augmentation e vs versus a vs versus vseta versus vs versus t versus t u2013 versus t versus ot versus u201320 miles u2013 vsra20 miles versus a20 miles versus t versus vs u2013206520 miles v CONCLUSIONS GK remains the most commonly used single-fraction SRS modality for NSCLC brain metastases in the United States, with CONCLUSIONS GK being the most commonly used single-fraction SRS modality for NSCLC brain metastases. The distribution of GK and LINAC SRS cases remains uneven geographically diverse.

Source link: https://doi.org/10.3171/2015.4.jns1573


Diffusion tractography imaging–guided frameless linear accelerator stereotactic radiosurgical thalamotomy for tremor: case report

Essential tremor and Parkinson's disease-u2013-associated tremor are extremely common in the field of mobility disorders. These types of tremors are treated with both a neuromodulatory and neuroablative target. The authors explore the case of a patient with tremor-dominant Parkinson's disease, whose lack of tremor improvement with medications, who was given a LINAC-based thalamotomy. Using probabilistic tractography, the VIM thalamic nucleus was determined using diffusion tensor imaging u2013-based segmentation of FSL using probabilistic tractography. The patient underwent continuous right upper-extremity resting tremor improvement from ten months to complete resolution at 22 months of follow-up. A frameless LINAC-based thalamic segmentation assisted by DTI-based thalamic segmentation is a fast and effective method for treating tremors by radiosurgical lesions of the VIM thalamus.

Source link: https://doi.org/10.3171/2016.10.jns161603


Linear accelerator radiosurgery for vestibular schwannomas

Object Radiosurgery has become a common treatment for small vestibular schwannomas. Methods Between July 1988 and August 2005, 390 patients with VSs were treated with LINAC-based radiosurgery at the authors' U2019 facility. Both one- and two-year actuarial control rates were 98%, and the 5-year actuarial control rate was 90 percent. After radiosurgery, seventeenteen patients expressed facial pain, and 14 patients complained of facial numbness, and 14 patients complained of facial pain after radiosurgery. With increasing tumor volume or an increasing radiosurgical dose to the tumor periphery, the risk of these disorders has increased. Conclusions: Radiosurgery is a safe and efficient therapeutic alternative to surgery for small VSs.

Source link: https://doi.org/10.3171/jns.2006.105.5.657


Treatment of arteriovenous malformations with linear accelerator–based radiosurgery compared with Gamma Knife surgery

Object of study The authors wanted to compare the outcomes of patients with arteriovenous malformations treated by Gamma Knife surgery with those of patients treated by linear accelerator radiosurgery. The median age was 33 years in the LINAC cohort was 16 Gy; the median treated AVM volume was 5. 5 cm 3 ; and 46% of patients in this group were treated after hemorrhage. Twelve patients who underwent LINAC radiosurgery underwent withdrawal from GKS and one was retreated with LINAC radiosurgery, and one was retreated with LINAC radiosurgery. In the GKS group and 6. 2% in the LINAC group, hemorrhage during the time of risk before AVM obliteration was 13% in the GKS group and 6. 2% in the LINAC group. Conclusions The treatment of patients with AVMs by using LINAC radiosurgery and GKS therapy results in high obliteration rates in the patients treated, which also pose a long-term radiation risk.

Source link: https://doi.org/10.3171/sup.2006.105.7.58


Efficient plasma electron accelerator driven by linearly chirped multi-10-TW laser pulses

Laser pulse chirp can play a significant role in wakefield and plasma bubble formation, as well as electron injection and related electron acceleration. We experimentally demonstrate the control of a relativistic electron beam's generation efficiency with a focus on maximum electron energy, new, and reproducibility by simply changing the chirp value of a multi-TW laser pulse. In comparison to unchirped or negatively chirped pulses, positively chirped laser pulses, i. e. pulses with instantaneous frequency increasing with time, propel electrons in the order of 100 MeV more efficiently. Our findings, in addition to expanding the validity of similar studies published for PW laser pulses, provide the foundation for investigating the subtle dynamics of an effective plasma electron accelerator driven by chirped laser pulses.

Source link: https://doi.org/10.21203/rs.3.rs-1926085/v1

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions