Radiation Technology Research Articles

Antimicrobial 405nm violet-blue light treatment of ex vivo human platelets leads to mitochondrial metabolic reprogramming and potential alteration of Phospho-proteome.

Continued efforts to reduce the risk of transfusion-transmitted infections (TTIs) through blood and blood components led to the development of ultraviolet (UV) light irradiation technologies known as pathogen reduction technologies (PRT) to enhance blood safety. While these PRTs demonstrate germicidal efficiency, it is generally accepted that these photoinactivation techniques have limitations as they employ treatment conditions shown to compromise the quality of the blood components. During ex vivo storage, platelets having mitochondria for energy production suffer most from the consequences of UV irradiation. Recently, application of visible violet-blue light in the 400-470nm wavelength range has been identified as a relatively more compatible alternative to UV light. Hence, in this report, we evaluated 405nm light-treated platelets to assess alterations in energy utilization by measuring different mitochondrial bioenergetic parameters, glycolytic flux, and reactive oxygen species (ROS). Furthermore, we employed untargeted data-independent acquisition mass spectrometry to characterize platelet proteomic differences in protein regulation after the light treatment. Overall, our analyses demonstrate that ex vivo treatment of human platelets with antimicrobial 405nm violet-blue light leads to mitochondrial metabolic reprogramming to survive the treatment, and alters a fraction of platelet proteome.

Novel insight into the self-lubricating mechanism of Cu–Pb bearing alloy during sliding friction with the guidance of molecular dynamics

The self-lubricating mechanism of Cu–Pb bearing alloy is discussed by molecular dynamics (MD). MD friction tests are conducted on the pure Cu and Cu–Pb models. The Pb-rich secondary phases (PSPs) melt due to the frictional heat. The solid–liquid phase transition of Pb is characterized by the radial distribution function (RDF) and the potential energy. An obvious drop of motion resistance of the abrasive debris is observed in Cu–Pb alloy once the debris moves close to the soft PSP which protect the matrix from abrasion by embedding the debris and promoting the formation of a liquid lubricant film. The synchrotron radiation technology is employed to in-situ observe the phase transition of Pb, and the MD results match the experimental results well.

Trimodal organ‑preserving treatment of muscle‑invasive bladder cancer

Purpose of the study. Generalization of the world experience of organ‑preserving treatment in muscle‑invasive bladder cancerMaterials and methods. The literature was searched in Medline, Cochrane Library, Elibrary and PubMed systems. Publications describing the modern possibilities of organ‑preserving treatment of muscle‑invasive bladder cancer were included, 58 of which were used to write this review.Results. The review highlights the results of international randomized and significant non‑randomized studies of organ‑preserving treatment in muscle‑invasive bladder cancer. Special attention is paid to the description of a modern combination of treatment methods to achieve its maximum effectiveness while maintaining the quality of life of patients. The analysis of the world literature was carried out, confirming the prospects of organ‑preserving treatment with careful selection of patients.Conclusion. Organ-preserving trimodal therapy for muscle‑invasive bladder cancer remains an alternative treatment strategy. Careful selection of patients plays a key role. The modern approach to trimodal therapy (TMT) is as follows: complete transurethral resection of the bladder (TURB), neoadjuvant or adjuvant chemotherapy, subsequent assessment of the response to treatment (re‑staging with TURB) should be performed; with a complete pathomorphological response, a course of remote radiation therapy up to TFD 60–66 Gy in the case of traditional fractionation (focal radiation therapy and the use of hypofractionation modes are also possible), using modern irradiation technologies (IGRT, IMRT). In case of an incomplete response, the implementation of the radical cystectomy (RCE) is shown. If a relapse occurs during follow‑up after treatment in the volume of TMT, a life‑saving RCE is shown.If the above conditions are met, the oncological results of treatment with TMT are equivalent to those during RCE, but require further study.

Impact of X-ray irradiation as an equivalent alternative to gamma for sterilization of single-use bioprocessing polymers.

Irradiation sterilization of polymeric pharmaceutical processing systems and medical devices, an essential healthcare technology, is facing critical business continuity challenges, driving the need to qualify equivalent alternative irradiation technologies, such as X-ray. Whereas the underlying there is a paucity of cross-industry published data evaluating X-ray irradiation effects on plastics as compared to gamma irradiation. That leads to regulatory uncertainty in the levels of costly validation data regulators will require and overall apprehension in the rate of X-ray irradiation adoption. The present study evaluates the impact of X-ray versus gamma irradiation on a wide range of polymers with more than 36 single-use (SU) components, using a comprehensive set of industry aligned methods for characterization of bioprocess polymers. Whereas many of these techniques readily demonstrate changes in polymer properties following irradiation, all of the polymers evaluated demonstrated that the impact of X-ray irradiation was to the same degree or less as compared to gamma. Increased publication of studies evaluating the impact to polymers of X-ray versus gamma irradiation is critical to leveraging extensive, existing validation packages on bioprocess systems and medical devices obtained following gamma irradiation, and essential in qualifying X-ray irradiation as an equivalent technology (i.e., materials are impacted to the same extent or less than gamma) that can overcome business continuity challenges to ensure continued availability of critical patient therapies.

Studies on the comparative effectiveness of X-rays, gamma rays and electron beams to inactivate microorganisms at different dose rates in industrial sterilization of medical devices

The radiation resistance of Bacillus pumilus spores to gamma rays, X-rays, and electron beam (e-beam) was investigated using industrial irradiators operating at various dose rates. The dose rates were as follows: gamma 1 and 10 kGy/h; X-ray 10 and 200 kGy/h; e-beam 2000 kGy/h. The regression analysis showed that survivor curves were log10 linear for all three sources within the investigated absorbed dose range of 1–6 kGy, irrespective of the dose rate applied. All irradiation technologies were equally efficient to inactivate the spores, which is reflected in their comparable D-values (p > 0.05), and dose rate had no impact on the microbicidal efficacy. These results suggest that wherever a specified minimum dose is delivered, the sterilization dose can be transferred between irradiation technologies in industrial sterilization of medical devices without any impact on product sterility. These findings from a novel single study encompassing all available industrial radiation technologies for the purpose of medical devices sterilization, advance our understanding of microbial destruction as related to exposure to important sterilization modalities, which will help inform future applicability of these technologies for emerging industry opportunities.

Metastasis-Directed Local Therapy of Hepatic Oligometastasis from Colorectal Cancer and Future Perspective in Radiation Therapy.

Introduction of the concept for oligometastasis led to wide application of metastasis-directed local ablative therapies for metastatic colorectal cancer (CRC). By application of the metastasis-directed local ablative therapies including surgical resection, radiofrequency ablation (RFA), and stereotactic ablative body radiotherapy (SABR), the survival outcomes of patients with metastatic CRC have improved. The liver is the most common distant metastatic site in CRC patients, and recently various metastasis-directed local therapies for hepatic oligometastasis from CRC (HOCRC) are widely used. Surgical resection is the first line of metastatic-directed local therapy for HOCRC, but its eligibility is very limited. Alternatively, RFA can be applied to patients who are ineligible for surgical resection of liver metastasis. However, there are some limitations such as inferior local control (LC) compared with surgical resection and technical feasibility based on location, size, and visibility on ultrasonography of the liver metastasis. Recent advances in radiation therapy technology have led to an increase in the use of SABR for liver tumors. SABR is considered complementary to RFA for patients with HOCRC who are ineligible for RFA. Furthermore, SABR can potentially result in better LC for liver metastases > 2-3 cm compared with RFA. In this article, the previous studies regarding curative metastasis-directed local therapies for HOCRC based on the radiation oncologist's and surgeon's perspective are reviewed and discussed. In addition, future perspectives regarding SABR in the treatment of HOCRC are suggested.

Evolutionary development of radiotherapy technologies in locally advanced cervical cancer

За последние два десятилетия парадигмы лучевой терапии полностью перешли от двумерного подхода (2D), основанного исключительно на анатомических костных ориентирах, к трехмерному (3D) индивидуальному дозиметрическому планированию под визуальным контролем, принимая во внимание различия в размере, положении опухоли и органов риска (ОР) для более точного подведения очаговых доз к клиническим мишеням с одновременным максимальным щажением ОР. В данной статье кратко представлены достижения в области дистанционной лучевой терапии (ДЛТ) и автоматизированной брахитерапии (БТ) для лечения местнораспространенного рака шейки матки. При этом, акцентировано внимание на исторической эволюции от технологий 2D-лучевой терапии к 3D-конформной лучевой терапии (3D CRT) с последующим переходом к лучевой терапии с модулированной интенсивностью (IMRT), которая в настоящее время становится стандартом планирования и реализации ДЛТ. Обсуждены достижения БТ, в частности, эволюция от манчестерской системы БТ в условиях низкой мощности дозы излучения до внедряемой в настоящее время адаптивной БТ под трехмерным визуальным контролем (3D-IGABT). В этом контексте уделено внимание недавно проведенным крупным когортным исследованиям, которые показали значительное улучшение местного контроля (МК) и снижение токсичности, связанной с применением технологии 3D-IGABT. Наконец, кратко отмечены и другие технологические достижения в лучевой терапии инвазивного местнораспространенного рака шейки матки.

γ–radiolytic degradation of rosuvastatin in the air–saturated aqueous solution

Widespread environmental occurrence and persistence of pharmaceuticals have attracted great concern due to their incomplete removal by conventional wastewater treatment technologies. The use of radiation technology has proven to be a good and successful alternative where highly reactive species lead to high degradation level of pharmaceuticals. Among the most commonly prescribed pharmaceuticals is rosuvastatin (ROSU), cholesterol-lowering agent, which has been detected as a contaminant in wastewater and natural waters. The aim of the present study was to investigate the γ-radiolytic degradation of ROSU in aqueous solutions under different conditions. The focus was given to the most applicable conditions, the degradation of ROSU in air, where dominant reactions of •OH radicals with ROSU are expected. Therefore, the reaction rate constant of ROSU with •OH radicals (2.15 ± 0.07 × 1010 M−1 s−1) was determined by laser flash photolysis. By combined γ-radiolysis and mass spectrometry study, the reaction mechanism of radiation degradation of ROSU was proposed and the radiolytic products were identified.

Abstract ED8-2: The role of advanced radiation technology in reducing toxicity

Abstract Over the past decade, breast cancer radiotherapy has increasingly focused on techniques to improve treatment precision and limit toxicity. Surface guided radiotherapy and respiratory gating has allowed for improved cardiac sparing and the elimination of permanent skin tattoos in women receiving breast radiation, while rapid developments in the technological delivery of radiation via both volumetric arc therapy and proton beam radiation have shown promise in further improving target coverage and normal tissue sparing for breast cancer patients. Cutting edge innovations, including MR-guided radiotherapy and FLASH technology are now being explored as means to further improve treatment precision and decrease toxicity. The purpose of this talk is to highlight and discuss these advances in radiotherapy, review the existing evidence to support their use in the treatment of breast cancer, and detail specific patient populations that are most likely to benefit. Discussion will also focus on ongoing and future research aimed at improving our understanding and utilization of these novel advances in care. Citation Format: Melissa Mitchell. The role of advanced radiation technology in reducing toxicity [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr ED8-2.

Fluorescence and molecular weight dependence of disinfection by-products formation from extracellular organic matter after ultrasound irradiation

Algal blooms have a negative impact on the safety of drinking water. Ultrasonic radiation technology is an “environment-friendly” technology that is widely used in algae removal. However, this technology leads to the release of intracellular organic matter (IOM), which is an important precursor of disinfection by-products (DBPs). This study investigated the relationship between the release of IOM in Microcystis aeruginosa and the generation of DBPs after ultrasonic radiation as well as analyzed the generation mechanism of DBPs. Results showed that the content of extracellular organic matter (EOM) in M. aeruginosa increased in the order of 740 kHz >1120 kHz >20 kHz after 2 min of ultrasonic radiation. Organic matter with a molecular weight (MW) greater than 30 kDa increased the most, including protein-like, phycocyanin (PC) and chlorophyll a, followed by small-molecule organic matter less than 3 kDa, mainly humic-like substances and protein-like. DBPs with an organic MW range of less than 30 kDa were dominated by trichloroacetic acid (TCAA), while those with an MW greater than 30 kDa had the highest trichloromethane (TCM) content. Ultrasonic irradiation changed the organic structure of EOM, affected the amount and type of DBPs, and tended to generate TCM.

Dosimetric Comparison of 3-Dimensional Conformal Radiotherapy (3DCRT), Intensity Modulated Radiotherapy (IMRT) and Volumetric-Arc Radiotherapy (VMAT) in Cervical Cancer Treatment

Background: Cervical cancer being the fourth most frequently diagnosed cancer, concurrent chemoradiation forms the mainstay of the treatment from stage IB3 to IVA. As we witnessed advancement in radiotherapy technologies, attempts had been taken to reduce the dose to the OARs without compromising the tumor coverage. In this study we will compare the PTV coverage, conformity index and doses received by the OARs (urinary bladder, rectum, bowel bag, bilateral head of femur) by all the three techniques namely 3DCRT, IMRT and VMAT for carcinoma cervix patients undergoing concurrent Chemoradiotherapy (CRT) at our institution and further implement the results in our clinical practice. Material and Methods: Forty-five of biopsy-proven carcinoma cervix in stage IIA to IIIB were taken up for the study. Following imaging, contouring was carried out using the principal clinical findings and conventional RTOG recommendations. Dose prescription to the cervix was 50 Gy in 25 fraction and planned with all three modalities, 3DCRT, IMRT and VMAT. The patient was treated with the 3DCRT plan and the IMRT and VMAT plans were made for dosimetric purpose only. Results: Quantitative dose evaluation performed of three techniques V40, V45, V50, Dmean for Bladder and Rectum, Dmean and D100 for Femur, V30, V40, D195 CC, Dmean for Bowel. Results show that VMAT plan is preferable than IMRT for sparing Bladder and rectum. Conclusion: IMRT and VMAT both could be advocated for practice was tumor coverage was almost similar in both of them and decision could be made on patient specific logistics.

Stereotactic Radiation for Oligometastatic and Oligoprogressive Stage IV Breast Cancer: A Case-Based Review.

For decades, the distant progression of breast cancer has been the purview of systemic therapy alone or with low to moderate-dose radiation therapy intended for the palliation of symptomatic metastases. However, for decades there have been anecdotes of long-term disease-free survival with more aggressive local treatment of one or more metastases. The hypothesis of oligometastases is that the treatment of a clinically limited number of distant metastases can change the natural history of stage IV breast cancer. The advance in the technology of stereotactic body radiation (SBRT) has made it more possible to offer a non-invasive, yet potentially disease-modifying, metastases-directed ablative treatment in place of surgery or a palliative radiation regimen. Although there are promising local control and survival outcomes in phase I/II trials, there is still a lack of phase III evidence of ablative SBRT results showing any change in the natural history of metastatic breast cancer. Limited oligometastases may call for an ablative approach with SBRT when definitive long-term local control is needed for the best palliation against symptomatic progression in challenging locations. Some oligometastases that have progression on a certain systemic regimen, while others remain stable or in remission, may also be treated with SBRT in the hopes of prolonging the use of that regimen. Whether SBRT should represent the standard management for stage IV breast cancer of a limited number or of limited progression requires confirmation by phase III data. This review will discuss the data from key clinical trials as it applies to decision making in typical clinical cases considered for potentially ablative SBRT for oligometastases or oligoprogression.

Advancing Methods for Fusion Neutronics: An Overview of Workflows and Nuclear Analysis Activities at UKAEA

Global research programs seeking to achieve a commercially viable model of a fusion power plant are being accelerated at an unprecedented rate. One critical element to the design and licensing is an accurate understanding of the radiation environment throughout the plant lifetime and subsequent decommissioning phase. The radiation field, which results from the nuclear fusion reaction, gives rise to highly complex phenomena such as flux leakage, materials activation, and decay gamma fields. Demonstration of compliance with limits, the integrity of components, and the permissibility of operations are all fundamental to regulatory approval and the overall safety of a nuclear device. As such, neutronics, which is used in the general sense to refer to the mapping of radiation fields in nuclear devices, is a critical design driver. The Applied Radiation Technology group at the United Kingdom Atomic Energy Authority is a world leader in this field, developing new methods and deploying state-of-the-art codes to conduct nuclear analysis. As well as applied neutronics in areas spanning fusion reactors, medical applications, spallation neutron sources, and nuclear fission, there is an extensive parallel experimental program undertaking critical radiation field characterization and conducting measurements using an array of bespoke particle detection systems. This paper highlights recent technical developments made by this group in the context of outstanding challenges in this field, as well as providing an overview of current methods and capabilities for the broader interest of the community.

Health Physics in Applications of Radiation Technology

Health Physics in Applications of Radiation Technology

Thermal Energy Feedback Regulation of Human Life System Based on Photon Radiation

To solve the problem of the long execution time of the traditional thermalenergy feedback regulation mechanism of human life system, a method ofanalyzing the thermal energy feedback regulation mechanism of human lifesystem based on photonic radiation was proposed. The energy responseentropy of human living system is calculated by analyzing the change ofhuman living system’s thermal energy. The photonic counter is designedby using photonic radiation technology to extract the weak optical signal ofthermal energy of the system and output energy accumulation. The quadraticprogramming algorithm is used to solve the optimal solution of thermalenergy, and the neural network model is combined with the energy accu-mulation of photon counter to realize the thermal feedback regulation. So far,the design of energy feedback regulation mechanism of human living systemhas been completed. The experimental results show that compared withthe traditional feedback control mechanism, the designed energy feedbackcontrol mechanism based on photonic radiation has a shorter implementationtime and is suitable for practical engineering.

Enhancement of TOC removal efficiency of sulfamethoxazole using catalysts in the radiation treatment: Effects of band structure and electrical properties of radiocatalysts

Photocatalysts in AOP have been used for the decomposition of recalcitrant organic pollutants. However, several technical issues associated with energy band gap of catalysts still limit the practical application of photocatalysts with sunlight and UV. Some catalysts with large energy band gap have been successfully used in the radiocatalytic systems using gamma radiation and electron beam. However, there has been little systematic studies for band structure and electrical properties of an appropriate radiocatalyst in the radiation treatment. Kinetic studies were conducted to evaluate the properties (conduction band, valence band, energy band gap, electron mobility, and stability) of catalysts suitable for the radiocatalytic system using high energy sources and the radiocatalytic oxidation performance for sulfamethoxazole (SMX). The lower the CB potential and/or the higher the VB potential was, the higher the oxidation performance of a catalyst was. Unlike the photocatalytic process (activating the catalysts with energy band gaps lower than 6.2 eV), the radiation system using a gamma ray could activate the catalyst with a comparatively large energy band gap (<1,240 keV). TOC removal efficiency for SMX (30 mg/L) with Al2O3 (2 g/L) as a radiocatalyst was enhanced up to 83.9 % at an absorbed dose of 5 kGy, compared to the control (radiation treatment without catalysts) showing 6.6 % TOC removal efficiency at the same condition. The stabilities of metal oxide catalysts were much higher (low self-degradation of 0.0006–0.01 % at 50 kGy) than those (0.07–0.44 % at 50 kGy) of metal sulfide catalysts. Since S2− is less electronegative than O2−, the VB holes of metal sulfide catalyst are more prone to self-degradation. The radiation technology has a wide range of selection for catalysts, and can be an effective alternative-treatment system for the mineralization of recalcitrant organic chemicals.

Treatment of extranodal NK/T-cell lymphoma: From past to future.

Extranodal NK/T-cell lymphoma (ENKTCL) is the most common subtype of T/NK-cell lymphoma in Asia and Latin America, but very rare in North American and Europe. Patient survival has improved significantly over the past two decades. However, standard treatment has not yet been established, although dozens of prospective trials have been conducted. To help understand how the treatment of ENKTCL has evolved in the past and what trends lie ahead, we have comprehensively reviewed the treatment of this aggressive malignancy, with a particular focus on neglected or unanswered issues, such as the optimal staging method, the best partner of asparaginase (Asp), the individualized administration of Asp, the preferred sequence of CT and RT and so on. Overall, the 5-year overall survival (OS) of patients with Ann Arbor stage I/II disease increased from < 50% in the early 20th century to > 80% in recent years, and the median OS of patients with Ann Arbor stage III/IV disease increased from < 1 year to more than 3 years. The improvement in patient survival is largely attributable to advances in radiation technology and the introduction of Asp and anti-PD-1/PD-L1 immunotherapy into practice. Radiotherapy is essential for patients with early-stage disease, while Asp-based chemotherapy (CT) and PD-1/PD-L1 inhibitors significantly improved the prognosis of patients with advanced-stage disease. ENKTCL management is trending toward simpler regimens, less toxicity, and higher efficacy. Novel drugs, such as manufactured T cells, monoclonal antibodies, and small molecule inhibitors, are being intensively investigated. Based on the fact that ENKTCL is highly resistant to cytotoxic drugs except Asp, and aggressive CT leads to higher toxicity rather than better outcomes, we recommend it is unnecessary to expend additional resources to compare different combinations of Asp with cytotoxic agents. Instead, more efforts should be made to optimize the use of Asp and immunotherapy to maximize efficacy and minimize toxicity, explore ways to overcome resistance to Asp and immunotherapy, identify novel treatment targets, and define subpopulations who may benefit more from specific treatments.

Radiation Technology for Food Irradiation

Radiation Technology for Food Irradiation

Sorption behavior and thermodynamic characteristics of stevia leaves as affected by freeze drying and gamma irradiation technologies

Sorption behavior and thermodynamic characteristics of stevia leaves as affected by freeze drying and gamma irradiation technologies

Equivalence study of extractables from single-use biopharmaceutical manufacturing equipment after X-ray or gamma irradiation

Single-use (SU) devices and assemblies used as manufacturing equipment in the biopharmaceutical industry require comprehensive qualifications. These qualifications include the assessment of compounds released from SU devices in contact with the process fluids, and how these leachable compounds potentially influence process performance, drug product quality, and patient safety. SU suppliers need to provide comprehensive qualification data for several parameters, for both new products and product changes, such as changes in the sterilization process applied to the SU device. The introduction of X-ray irradiation as an alternative to the currently used and established gamma irradiation of SU devices represents a situation where robust data is required to demonstrate equivalency between these two radiation technologies. Here, we present the results of a comprehensive extractables study for three SU components, bags, tubing, and sterilizing grade filters, evaluated after X-ray and gamma-ray irradiation. The selected study conditions were set up to allow a direct comparison of the results from the two sterilization methods, and to allow conclusions to be made on the impact of irradiation type on the polymers and their additives. Orthogonal analytical methods are applied to identify and quantify all organic compounds present. The data package provided here supports risk assessments for application of irradiated SU equipment in biopharmaceutical manufacturing. The formation of reaction products and the fundamental chemical pathways are discussed and found to be independent of the irradiation type. The results demonstrate the equivalency of both irradiation methods for extractables from plastic components used in pharmaceutical and biopharmaceutical manufacturing.