Radiation Technology Research Articles

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.

Infrared radiation denoising model of “sub-region-Gaussian kernel function” in the process of sandstone loading and fracture

Rock damage and fracture are the basic and common scientific problems that mostly happen during the extraction of minerals and construction engineering projects in a rock mass environment. These problems can cause dynamic coal mine catastrophes such as coal and gas explosions, rock bursts, and mine water inrush. The accurate and effective monitoring of these problems can provide reliable information for early warning of coal mine dynamic disasters, surrounding rock fractures process, and water inrush in mining face. Furthermore, these challenges can be effectively monitored using infrared radiation technology. However, the infrared radiation data can be affected in the presence of noises which can cause ineffective monitoring of the aforementioned problems. Therefore, it is essential to denoise the associated noises to enhance the infrared radiation characteristics effectively for the development of better monitoring and early warning system. This paper analyzed the characteristics of sandstone's infrared radiation noise curve under biaxial loading. The infrared radiation temperature curve's subregion denoising technique uses the correlation coefficient of a polynomial fitting function as an assessment index. As a result, the infrared radiation energy is suggested and presented as an infrared radiation index to establish the threshold of the Gaussian kernel function. A new model of “sub-region-Gaussian kernel function” average infrared radiation temperature denoising is established, which solves the problem of infrared radiation temperature distortion in the sandstone loading and fracture process. The findings of this research will lay down a theoretical and experimental foundation for the application of infrared monitoring technology to the effective monitoring and early warning of engineering projects such as coal mining, tunnel excavation and stability analysis of slope.

Joint patient selection and scheduling under no‐shows: Theory and application in proton therapy

We study how to admit and schedule heterogeneous patients by using simple, interpretable, yet effective policies when capacity is scarce, no‐show behavior is patient‐ and time‐dependent, service duration and reward are deterministic but patient‐dependent, and overtime is costly. Our work is motivated by the aforementioned operational challenges that typically face adopters of new technologies in the healthcare sector. We anchor our study on a partnership with the proton therapy center of Massachusetts General Hospital (MGH), which offers a new radiation technology for cancer patients. We formulate the problem as a nonlinear integer optimization problem. However, as the solution to this formulation lacks both tractability and interpretability, to be relevant to practice, we limit our study to simple and interpretable policies. In particular, we propose a simple index‐based rule and derive analytical performance guarantees for it. We also calibrate our model using empirical data from our partner hospital, and conduct a series of experiments to evaluate the performance of our proposed policy under practical circumstances. The analytical performance guarantees and our numerical experiments demonstrate (a) the strong performance of the proposed policies, and (b) their robustness to various practical considerations (e.g., to potential misspecification of no‐show probabilities). Our results show that our proposed policy, despite being a simple and interpretable index‐based rule, is capable of improving performance by about 20% at an organization such as MGH, and of delivering results that are not far from being optimal across a wide range of parameters that might vary between organizations. This suggests that the proposed policy can be viewed as an effective “one‐fits‐all” capacity allocation rule that can be used in a variety of environments in which operational challenges such as no‐shows and overtime costs need to be navigated using simple and interpretable rules.

Astrazon Red FBL Çözeltisinin Gama Işınlarıyla Renk Giderimi ve Detoksifikasyonu

In this study, decoloration and detoxification of Astrazon Red FBL dye solutions using gamma rays have been examined at different environments (air, O2 saturated, 2.6 mM H2O2). In this context, the decoloration, mineralization, detoxification, pH, COD and BOD5 parameters were followed. Biodegradability ( 5 days of biological oxygen demand/ chemical oxygen demand -BOD5/COD-) ratio has been improved up on 2 kGy irradiation for all solutions. Optimum irradiation conditions were found to be 5 kGy pH 9 for air, 5 kGy pH 11 for O2 saturated, 7 kGy pH 11 for 2.6 mM H2O2 to provide mineralization and decoloration of Astrazon Red FBL solutions. Microtox bioluminescent test was conducted to measure the toxicity of Astrazon FBL solutions treated with high energetic rays. Toxicity reduction has been achieved at 5, 5 and 7 kGy in the range of 81.2, 86.7 and 56.3 % for air, O2 saturated and H2O2 solutions, respectively. As a result of study, it is found that Astrazon Red FBL dye could be treated by irradiation technology.

Investigation of cytotoxic cadmium in aquatic green algae by synchrotron radiation-based Fourier transform infrared spectroscopy: Role of dissolved organic matter

The heavy metal Cd can cause severe toxicity on aquatic algae, but there are few studies on the cytotoxicity of heavy metal on algae based on synchrotron radiation technology. In this study, synchrotron radiation-based Fourier transform infrared spectromicroscopy (SR-FTIR) was used to characterize in vivo the toxic effects of Cd on Cosmarium sp. cells, emphasizing the influence of dissolved organic matter (DOM) on Cd toxicity. Results showed that, in the absence of DOM, obvious growth inhibition, cell volume reduction, and photosynthesis disruption could be observed with increasing Cd concentrations (0–500 μg/L). Based on the SR-FTIR imaging and functional group quantification, it was shown that the biosynthesis of biomolecules such as proteins, lipids, and carbohydrates was inhibited in algal cells. However, the addition of DOM caused significant heterogeneities in biomacromolecule biosynthesis that an increased biosynthesis of carbohydrates and structural lipids but an inhibited biosynthesis of proteins and storage lipids were observed. Furthermore, the correlation analysis and principal component analysis showed a good correlation between v(C-OH)/Amide II and biochemical parameters, indicating that changes of carbohydrates could be used as the biomarker to indicate the cytotoxicity of heavy metals to algal cells. These findings provide insight into the mechanisms of heavy metal cytotoxicity to aquatic algae and systematic cytotoxicity assessment under various aquatic conditions.

Attitude and Motivation of Medical Professors in the Use of Virtual Simulation Technology of Radiotherapy in Clinical Teaching Context in Chongqing Medical University

Virtual simulation technology of radiotherapy has completely changed the way we teach and learn. In the context of medical school education, the technology bridges the gap between abstract knowledge and ordinary life. Technology advances the possibilities available to mankind and are essential to medical professors in the teaching. However, educators are faced with the challenge of guiding students through this transition and ensuring they don’t lose valuable time using their devices. The rise of technology in learning has also carried some disadvantages with it, some of which might be overlooked. This study aimed to determine the attitude and motivation of medical professors to adopt virtual simulation technology of radiotherapy in clinical teaching context. Descriptive statistics, t-test analysis, one-way ANOVA, Pearson-r correlation, and chi-squared test were used in this study. It is recommended to upskill the technological and pedagogical knowledge and skills of faculty member, crucial especially in the context of a post-pandemic education

Attitude and Motivation of Medical Professors in the Use of Virtual Simulation Technology of Radiotherapy in Clinical Teaching Context in Chongqing Medical University

Virtual simulation technology of radiotherapy has completely changed the way we teach and learn. In the context of medical school education, the technology bridges the gap between abstract knowledge and ordinary life. Technology advances the possibilities available to mankind and are essential to medical professors in the teaching. However, educators are faced with the challenge of guiding students through this transition and ensuring they don’t lose valuable time using their devices. The rise of technology in learning has also carried some disadvantages with it, some of which might be overlooked. This study aimed to determine the attitude and motivation of medical professors to adopt virtual simulation technology of radiotherapy in clinical teaching context. Descriptive statistics, t-test analysis, one-way ANOVA, Pearson-r correlation, and chi-squared test were used in this study. It is recommended to upskill the technological and pedagogical knowledge and skills of faculty member, crucial especially in the context of a post-pandemic education.

MRI-LINAC: A transformative technology in radiation oncology.

Advances in radiotherapy technologies have enabled more precise target guidance, improved treatment verification, and greater control and versatility in radiation delivery. Amongst the recent novel technologies, Magnetic Resonance Imaging (MRI) guided radiotherapy (MRgRT) may hold the greatest potential to improve the therapeutic gains of image-guided delivery of radiation dose. The ability of the MRI linear accelerator (LINAC) to image tumors and organs with on-table MRI, to manage organ motion and dose delivery in real-time, and to adapt the radiotherapy plan on the day of treatment while the patient is on the table are major advances relative to current conventional radiation treatments. These advanced techniques demand efficient coordination and communication between members of the treatment team. MRgRT could fundamentally transform the radiotherapy delivery process within radiation oncology centers through the reorganization of the patient and treatment team workflow process. However, the MRgRT technology currently is limited by accessibility due to the cost of capital investment and the time and personnel allocation needed for each fractional treatment and the unclear clinical benefit compared to conventional radiotherapy platforms. As the technology evolves and becomes more widely available, we present the case that MRgRT has the potential to become a widely utilized treatment platform and transform the radiation oncology treatment process just as earlier disruptive radiation therapy technologies have done.

Characterization of Biodegradable Food Contact Materials under Gamma-Radiation Treatment.

Radiation is an example of one of the techniques used for pasteurization and sterilization in various packaging systems. There is a high demand for the evaluation of the possible degradation of new composites, especially based on natural raw materials. The results of experimental research that evaluated the impact of radiation technology on biodegradable and compostable packaging materials up to 40 kGy have been presented. Two commercially available flexible composite films based on aliphatic-aromatic copolyesters (AA) were selected for the study, including one film with chitosan and starch (AA-CH-S) and the other with thermoplastic starch (AA-S). The materials were subjected to the influence of ionizing radiation from 10 to 40 kGy and then tests were carried out to check their usability as packaging material for the food industry. The results showed that the mechanical properties of AA-S films improved due to the radiation-induced cross-linking processes, while in the case of AA-CH-S films, a considerable decrease in the elongation at break was observed. The results also showed a decrease in the WVTR in the case of AA-S and no changes in barrier properties in the case of AA-CH-S. Both materials revealed no changes in the odor analyzed by sensory analysis. In the case of the AA-S films, the higher the radiation dose, the faster the biodegradation rate. In the case of the AA-CH-S film, the radiation did not affect biodegradation. The performed research enables the evaluation of the materials intended for direct contact with food. AA-CH-S was associated with unsatisfactory parameters (exceeding the overall migration limit and revealing color change during storage) while AA-S showed compliance at the level of tests carried out. The study showed that the AA-CH-S composite did not show a synergistic effect due to the presence of chitosan.

Aerosol delivered irradiated Escherichia coli confers serotype-independent protection and prevents colibacillosis in young chickens

Escherichia coli causes colibacillosis in chickens, which has severe economic and public health consequences. For the first time, we investigated the efficacy of gamma-irradiated E. coli to prevent colibacillosis in chickens considering different strains and application routes. Electron microscopy, alamarBlue assay and matrix assisted laser desorption/ionization time-of- flight mass spectrometry showed that the cellular structure, metabolic activity and protein profiles of irradiated and non-treated E. coli PA14/17480/5-ovary (serotype O1:K1) were similar. Subsequently, three animal trials were performed using the irradiated E. coli and clinical signs, pathological lesions and bacterial colonization in systemic organs were assessed.In the first animal trial, the irradiated E. coli PA14/17480/5-ovary administered at 7 and 21 days of age via aerosol and oculonasal routes, respectively, prevented the occurrence of lesions and systemic bacterial spread after homologous challenge, as efficient as live infection or formalin-killed cells. In the second trial, a single aerosol application of the same irradiated strain in one-day old chickens was efficacious against challenges with a homologous or a heterologous strain (undefined serotype). The aerosol application elicited better protection as compared to oculonasal route. Finally, in the third trial, efficacy against E. coli PA15/19103–3 (serotype O78:K80) was shown. Additionally, previous results of homologous protection were reconfirmed. The irradiated PA15/19103–3 strain, which also showed lower metabolic activity, was less preferred even for the homologous protection, underlining the importance of the vaccine strain. In all the trials, the irradiated E. coli did not provoke antibody response indicating the importance of innate or cell mediated immunity for protection.In conclusion, this proof-of-concept study showed that the non-adjuvanted single aerosol application of irradiated “killed but metabolically active” E. coli provided promising results to prevent colibacillosis in chickens at an early stage of life. The findings open new avenues for vaccine production with E. coli in chickens using irradiation technology.

A systematic review on the strategies of reducing asphalt pavement temperature

Under the action of repeated load of vehicles, asphalt pavement tends to suffer rutting and other failures at high temperatures, which shortens the service life of the pavement. Meanwhile, asphalt pavement aggravates the urban heat island (UHI) effect, reducing the livability of the city. Research shows that lower road temperatures can mitigate the UHI effect. For this reason, researchers have launched lots of studies to cool asphalt pavement under high temperatures, such as reflective pavement and phase change pavement, etc. Although these technologies are effective at reducing the temperature of asphalt pavement, there are still some limitations. This paper mainly discusses the latest development of asphalt pavement temperature reduction strategies, classifies them according to different action mechanisms, and discusses the advantages and limitations of each strategy in detail. Suggestions for future research are given to address the limitations of each strategy, such as passive radiation technology can provide new ideas for reflective pavement, planting trees should consider plant physiological parameters and spatial distribution of planting, and phase change materials can be encapsulated by high thermal conductivity materials, etc. This study can provide a guidance for further development of asphalt pavement cooling technologies.