Sökresultat

Filtyp

Din sökning på "*" gav 530613 sökträffar

A treatment planning comparison of contemporary photon-based radiation techniques for breast cancer

Background and purpose: Adjuvant radiation therapy (RT) of the whole breast (WB) is still the standard treatment for early breast cancer. A variety of radiation techniques is currently available according to different delivery strategies. This study aims to provide a comparison of six treatment planning strategies commonly adopted for breast-conserving adjuvant RT and to use the Pareto concept in

The Advantage of FLASH Radiotherapy Confirmed in Mini-pig and Cat-cancer Patients

Purpose: Previous studies using FLASH radiotherapy (RT) in mice showed a marked increase of the differential effect between normal tissue and tumors. To stimulate clinical transfer, we evaluated whether this effect could also occur in higher mammals. Experimental Design: Pig skin was used to investigate a potential difference in toxicity between irradiation delivered at an ultrahigh dose rate call

Long-term neurocognitive benefits of FLASH radiotherapy driven by reduced reactive oxygen species

Here, we highlight the potential translational benefits of delivering FLASH radiotherapy using ultra-high dose rates (>100 Gy·s−1). Compared with conventional dose-rate (CONV; 0.07–0.1 Gy·s−1) modalities, we showed that FLASH did not cause radiation-induced deficits in learning and memory in mice. Moreover, 6 months after exposure, CONV caused permanent alterations in neurocognitive end points, wh

Dosimetric and preparation procedures for irradiating biological models with pulsed electron beam at ultra-high dose-rate

Purpose: Preclinical studies using a new treatment modality called FLASH Radiotherapy (FLASH-RT) need a two-phase procedure to ensure minimal uncertainties in the delivered dose. The first phase requires a new investigation of the reference dosimetry lying outside the conventional metrology framework from national metrology institutes but necessary to obtain traceability, repeatability, and stabil

Exploration of clinical preferences in treatment planning of radiotherapy for prostate cancer using Pareto fronts and clinical grading analysis

Introduction: Radiotherapy treatment planning is a multi-criteria problem. Any optimization of the process produces a set of mathematically optimal solutions. These optimal plans are considered mathematically equal, but they differ in terms of the trade-offs involved. Since the various objectives are conflicting, the choice of the best plan for treatment is dependent on the preferences of the radi

Understanding High-Dose, Ultra-High Dose Rate, and Spatially Fractionated Radiation Therapy

The National Cancer Institute's Radiation Research Program, in collaboration with the Radiosurgery Society, hosted a workshop called Understanding High-Dose, Ultra-High Dose Rate and Spatially Fractionated Radiotherapy on August 20 and 21, 2018 to bring together experts in experimental and clinical experience in these and related fields. Critically, the overall aims were to understand the biologic

Ultra-high-dose-rate FLASH and Conventional-Dose-Rate Irradiation Differentially Affect Human Acute Lymphoblastic Leukemia and Normal Hematopoiesis

Purpose: Ultra-high-dose-rate FLASH radiation therapy has been shown to minimize side effects of irradiation in various organs while keeping antitumor efficacy. This property, called the FLASH effect, has caused enthusiasm in the radiation oncology community because it opens opportunities for safe dose escalation and improved radiation therapy outcome. Here, we investigated the impact of ultra-hig

Hypofractionated FLASH-RT as an effective treatment against glioblastoma that reduces neurocognitive side effects in mice

Purpose: Recent data have shown that single-fraction irradiation delivered to the whole brain in less than tenths of a second using FLASH radiotherapy (FLASH-RT), does not elicit neurocognitive deficits in mice. This observation has important clinical implications for the management of invasive and treatment-resistant brain tumors that involves relatively large irradiation volumes with high cytoto

Monitoring electron energies during FLASH irradiations

When relativistic electrons are used to irradiate tissues, such as during FLASH pre-clinical irradiations, the electron beam energy is one of the critical parameters that determine the dose distribution. Moreover, during such irradiations, linear accelerators (linacs) usually operate with significant beam loading, where a small change in the accelerator output current can lead to beam energy reduc

Development of Ultra-High Dose Rate (FLASH) Particle Therapy

Research efforts in FLASH radiotherapy have increased at an accelerated pace recently. FLASH radiotherapy involves ultra-high dose rates and has shown to reduce toxicity to normal tissue while maintaining tumor response in pre-clinical studies when compared to conventional dose rate radiotherapy. The goal of this review is to summarize the studies performed to-date with proton, electron, and heavy

Irradiation at Ultra-high (FLASH) Dose Rates Reduces Acute Normal Tissue Toxicity in the Mouse Gastrointestinal System

Purpose: Preclinical studies using ultra-high dose rate (FLASH) irradiation have demonstrated reduced normal tissue toxicity compared with conventional dose rate (CONV) irradiation, although this finding is not universal. We investigated the effect of temporal pulse structure and average dose rate of FLASH compared with CONV irradiation on acute intestinal toxicity. Materials and Methods: Whole ab

Intracavitary Electron FLASH Radiotherapy in a Canine Cancer Patient With Oral Malignant Melanoma

PURPOSE/OBJECTIVE(S): Studies of electron FLASH radiotherapy (FLASH-RT) in companion animals are being conducted at several institutions. High energy electron beams are generally suitable for treatment of superficial cancers, but of limited use for deep-seated tumors. In this case report, the feasibility of intracavitary electron FLASH-RT is demonstrated.MATERIALS/METHODS: A canine cancer patient

Distal cholangiocarcinoma - from novel biomarkers to clinical management and outcome

Cholangiocarcinoma is an aggressive malignacy arising from the biliary tree. Anatomical subtypes ofcholangiocarcinoma differs in tumor biology and clinical management. Distal cholangiocarcinoma (dCCA)originates from the common bile duct. Radical resection is the only curative treatment, for dCCA it entails apancreatoduodenectomy (Whipple procedure). Other periampullary cancers treated with pancrea

Watching soot inception via online Raman spectroscopy

In this work, online spontaneous Raman spectroscopy was applied to study the soot inception and growth zones of a low pressure premixed ethylene/oxygen flame. Firstly, we measured online Raman spectrum of aerosol soot extracted from the flame. The spectrum was compared to ex situ Raman measurements of the same soot after being deposited on a window. In the aerosol soot particles, the presence of a

A “patient-industry complex”? Investigating the financial dependency of UK patient organisations on drug company funding

We examined the minimum extent of dependency of UK patient organisations on pharmaceutical industry funding using drug company disclosure reports and patient organisation financial accounts from 2012 to 2016. We used linear regression to explain the overall share of industry funding (‘general dependency’) and top donor funding (‘company-specific dependency’) in organisations’ income. Predictors in

Just or Unjust : Assessment of rainfall-related flood damage in a Swedish context

Climate change has led to an increase in heavy summer rainfalls, and climate projections for Sweden indicate that there will be more sudden rainfall in the future. While the exact locations and time for this rainfall are unknown, it is known that there will be damages to buildings, cars, and people when the rainfall occurs. It is thus important to evaluate past events to understand the resulting fClimate change has led to an increase in heavy summer rainfalls, and climate projections for Sweden indicate that there will be more sudden rainfall in the future. While the exact locations and time for this rainfall are unknown, it is known that there will be damages to buildings, cars, and people when the rainfall occurs. It is thus important to evaluate past events to understand the resulting f

Water level management of wetlands in response to current and future RCP climate change scenarios : A mesocosm experiment within climate control chambers

Wetlands are integral components of our natural environment since they provide many critical ecosystem services to humanity, such as water purification, climate change mitigation, flood control, and biodiversity. Although wetlands can convey resilience to some degree of changes, they might be vulnerable to climate change. Altered hydrology and rising temperatures can turn the wetland services into

Test Optimization for Core-based System-on-Chip

The semiconductor technology has enabled the fabrication of integrated circuits (ICs), which may include billions of transistors and can contain all necessary electronic circuitry for a complete system, so-called System-on-Chip (SOC). In order to handle design complexity and to meet short time-to-market requirements, it is increasingly common to make use of a modular design approach where an SOC i