Radiation research最新文献

{"title":"A Murine Model of Radionuclide Lung Contamination for the Evaluation of Americium Decorporation Treatments.","authors":"Trevor Arino, Alexia G Cosby, Jennifer Alvarenga-Vasquez, Kirsten E Martin, Alex Rigby, Adrianna Reece-Newman, Shereen Aissi, Ethan Hallick, Isaac Jaro, Rebecca J Abergel","doi":"10.1667/RADE-25-00001.1","DOIUrl":"https://doi.org/10.1667/RADE-25-00001.1","url":null,"abstract":"<p><p>The hydroxypyridinone ligand 3,4,3-LI(1,2-HOPO) (HOPO), has been previously characterized as a promising chelating agent for in vivo decorporation of actinides, with decorporation being the removal of internally deposited contaminants from the body after exposure. The large majority of relevant literature reports have detailed the efficacy profile of HOPO as a decorporation agent in rodent models, where controlled radionuclide contamination is conducted via intravenous injection. However, this method of contamination does not necessarily reflect an accurate predictive model of the most probable biodistribution of free metal in the body. In the event of a radiological dispersal device or nuclear power plant accident scenario, it is most likely that first responders, military personnel, and victims of the event will be contaminated via air and water transmission. Therefore, research into the efficacy of chelating agents to treat lung-contaminated in vivo models needs to be carried out. Here, we establish a murine model with controlled, reproducible lung contamination using two different radionuclides, 89Zr and 241Am, for orthogonal biodistribution validation by positron emission tomography and ex vivo radioanalysis, respectively. In addition, we report effective chelation treatment of 241Am-contaminated lungs using HOPO, which improves decorporation by up to 40% compared to Ca-DTPA, the current standard of care.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143812139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation Between DNA Double-Strand Break Distribution in 3D Genome and Ionizing Radiation-Induced Cell Death.","authors":"Ankang Hu, Wanyi Zhou, Xiyu Luo, Rui Qiu, Junli Li","doi":"10.1667/RADE-24-00277.1","DOIUrl":"https://doi.org/10.1667/RADE-24-00277.1","url":null,"abstract":"<p><p>The target theory is the most classical hypothesis explaining radiation-induced cell death, yet the physical or biological nature of the \"target\" remains ambiguous. This study hypothesizes that the distribution of DNA double-strand breaks (DSBs) within the 3D genome is a pivotal factor affecting the probability of radiation-induced cell death. We propose that clustered DSBs in DNA segments with high-interaction frequencies are more susceptible to leading to cell death than isolated DSBs. Topologically associating domains (TAD) can be regarded as the reference unit for evaluating the impact of DSB clustering in the 3D genome. To quantify this correlation between the DSB distribution in 3D genome and radiation-induced effect, we developed a simplified model considering the DSB distribution across TADs. Utilizing track-structure Monte Carlo codes to simulate the electron and carbon ion irradiation, and we calculated the incidence of each DSB case across a variety of radiation doses and linear energy transfers (LETs). Our simulation results indicate that DSBs in TADs with frequent interactions (case 3) are significantly more likely to induce cell death than clustered DSBs within a single TAD (case 2). Moreover, case 2 is significantly more likely to induce cell death than isolated DSBs (case 1). The curves of the incidence of cases 2 and 3 compared with LETs have a similar shape to the radiation quality factor (Q) used in radiation protection. This indicates that these two cases are also associated with the stochastic effects induced by high-LET radiation. Our study underscores the crucial significance of the 3D genome structure in the fundamental mechanisms of radiobiological effects. The hypothesis in our research offers novel perspectives on the mechanisms that regulate radiobiological effects. Moreover, it serves as a valuable reference for the establishment of mechanistic models that can predict cell survival under different doses and LETs.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143812092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The EGFR Pathway as a Potential Therapeutic Target for Modulation of Radiation-induced Liver Injury.","authors":"Satoshi Omiya, Juan Dalo, Yuki Ueda, Uma Shankavaram, Elisa Baldelli, Valerie Calvert, Michelle Bylicky, Emanuel F Petricoin, Molykutty J Aryankalayil","doi":"10.1667/RADE-24-00203.1","DOIUrl":"https://doi.org/10.1667/RADE-24-00203.1","url":null,"abstract":"<p><p>Radiation exposure can result in various complications influenced by factors such as dose, the amount of tissue exposed, and the type of tissue exposed. Radiation-induced liver injury (RILI) is a concern in cancer patients receiving thoracic and upper abdominal radiation, but it can also be a risk for civilians exposed to radiation in a nuclear event. RILI can lead to organ dysfunction or death; a deeper understanding of how radiation causes damage to normal tissue could pave the way for new treatments. In our study, we focused on the effects of radiation on the two main liver cell types: liver sinusoidal endothelial cells (LSECs) and hepatocytes. We exposed these cells to different doses of radiation (2, 4 or 8 Gy) as well as a sham irradiation (0 Gy) control. Proteins were extracted at 30 min, 6 h and 24 h postirradiation and analyzed using reverse phase protein array (RPPA). We observed changes to the Hepatic fibrosis signaling pathway, IL-8 signaling, and S100 family signaling pathways across multiple doses and time points in LSECs. In hepatocytes, radiation affected different pathways; we see changes in the Th1 and Th2 signaling pathways and the IL-10 signaling pathway. These pathways are critical in mediating the immune response, with Th1 being associated with pro-inflammatory responses and Th2 with anti-inflammatory responses. Hub proteins from protein-protein interaction (PPI) networks across all time points for both LSECs and hepatocytes highlighted EGFR as a top-ranked protein, indicating the potential role in mitigating radiation damage in liver cells. Herein, we showed alterations in protein expression after radiation-induced liver injury using RPPA at early time points (hours to days) to determine potentially targetable molecular pathways. We further highlighted potential therapeutic protein markers, including EGFR, as an example of the potential utility of RPPA in target discovery.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143804182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Combined Therapy of Pegylated G-CSF with Ciprofloxacin Mitigates Damage Induced by Lethal Ionizing Radiation to the Bone Marrow, Spleen, and Ileum by Increasing AKT Activation but Decreasing IL-18, C3, and miR-34a.","authors":"Juliann G Kiang, Georgetta Cannon, Min Zhai, Matthew G Olson, Akeylah K Woods, Katherine S Cleveland, Hengying Ellery, Feng Xu, Mang Xiao","doi":"10.1667/RADE-24-00266.1","DOIUrl":"https://doi.org/10.1667/RADE-24-00266.1","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Ciprofloxacin (CIP) was found to enhance pegylated G-CSF therapy (PEG, Neulasta®)-induced survival from 30% to 85% after ionizing radiation exposure. This combined therapy significantly mitigated radiation-induced brain hemorrhage through its capability to improve platelet recovery. This study tested whether this combined treatment also mitigated gastrointestinal damage from radiation. B6D2F1 female mice were exposed to 60Co γ radiation. CIP was fed daily to mice for up to 14 days. PEG was injected on day 1, and then weekly up to day 14. For the early time point study, blood, femurs, spleen, and ileum were collected on days 2, 4, 9, and 15 postirradiation. Bone marrow cells were counted; spleen weights and splenocyte counts were measured; and ileum histopathology was examined and analyzed. AKT, ERK, JNK, p38, claudin 2, NF-kB, Bax, Bcl-2, and gasdermin D were measured in ileum lysates using Western blotting while miR-34a was measured by reverse transcription followed by real-time-PCR, and citrulline was measured by colorimetric assay. In serum, interleukin-18 (IL-18) was measured by Luminex assay and complement protein 3 (C3) was detected by ELISA. The bacterial DNA load in livers was measured by real-time PCR. Radiation depleted bone marrow cells in femurs beginning day 2 through day 15 postirradiation, which was mitigated by PEG or CIP+PEG on day 9 through day 15 and by CIP on day 15, respectively. Radiation exposure led to decreased spleen weight on day 2 through day 15, while PEG or CIP+PEG significantly mitigated the reduction on day 9 through day 15. Radiation exposure reduced splenocyte counts on day 2 through day 15 postirradiation, but that was mitigated by PEG or CIP+PEG on day 15. Ileum histology showed that radiation decreased villus height on day 2 through day 15; CIP mitigated the reduction on day 15, whereas PEG+CIP mitigated it on day 2 through 15. Villus widths were increased on day 2 through day 15, while PEG+CIP effectively decreased them on day 4 through day 15. Crypt depth was reduced by radiation on day 2, but returned to the baseline on day 4 through 15. CIP or CIP+PEG transiently increased the depth only on day 4. Crypt counts were reduced by radiation on days 2 and 4, but returned to the baseline on days 9 and 15, regardless of individual drugs or combinations. Citrulline data confirmed the villus height recovery. Radiation significantly increased pro-inflammatory cytokine IL-18 on days 4 and 9, which was mitigated by PEG alone or PEG+CIP, but not by CIP alone. Radiation increased C3 on day 9 in ileum and serum. The serum C3 was positively associated with the serum IL-18 levels and negatively correlated with the crypt depth. Radiation-induced decreases in claudin 2 (a tight junction marker) in ileum and increases in bacterial DNA in livers were mitigated by PEG+CIP. Radiation did not reduce NF-kB and its activation but reduced Bcl-2 expression, which was not significantly recovered by any individual drug or combinat","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143781102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Symbolic Regression: A Versatile Approach for Constructing Phenomenological Models of Radiobiological Effects.","authors":"Ankang Hu, Wanyi Zhou, Rui Qiu, Junli Li","doi":"10.1667/RADE-24-00213.1","DOIUrl":"https://doi.org/10.1667/RADE-24-00213.1","url":null,"abstract":"<p><p>The development of quantitative models that correlate physical, chemical, and biological parameters with radiobiological effects is imperative in the domains of radiotherapy and radiation protection. Due to the challenges associated with quantifying underlying mechanisms, phenomenological models are frequently established in preference to mechanistic models. However, the lack of a universal methodology for constructing phenomenological models presents a significant challenge in the field. We employ symbolic regression as a method for constructing phenomenological models. We attempt to develop models for the survival fraction, microdosimetric parameters, the radiation oxygen effect, and the FLASH effect. Additionally, we compare the results obtained from our symbolic regression approach with existing formulas in the scientific literature to assess the efficacy and validity of our method. Symbolic regression yields multiple simple formulas for each modeling task undertaken. These formulas demonstrate a comparable ability to predict radiobiological effects as the formulas presented in previous scientific publications. Our findings propose that symbolic regression is an automated and flexible strategy for constructing phenomenological models of radiobiological effects. Additionally, they underscore that the interpretability of a model is as crucial as its goodness of fit, as symbolic regression can identify various distinct formulas that adequately fit the provided data points.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143754348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparations for Ultra-High Dose Rate 25-90 MeV Electron Radiation Experiments with a Compact, High-Peak-Current, X-band Linear Accelerator.","authors":"Haytham H Effarah, Trevor Reutershan, Michael W L Seggebruch, Martin Algots, Alexander Amador, Janet Baulch, Olivia G G Drayson, Frederic V Hartemann, Yoonwoo Hwang, Agnese Lagzda, Ferenc Raksi, Charles L Limoli, Christopher P J Barty","doi":"10.1667/RADE-24-00120.1","DOIUrl":"10.1667/RADE-24-00120.1","url":null,"abstract":"<p><p>The Distributed Charge Compton Source (DCCS) developed by Lumitron Technologies, Inc. has produced a 25-MeV electron beam with 1.7-nC macrobunches at a 100-Hz repetition rate from a compact, high-gradient X-band (11.424 GHz) accelerator. The DCCS is currently being commissioned to produce 100-MeV-class electrons, well within the very high energy electron (VHEE) energy regime, with macrobunch charges of up to 25 nC at repetition rates up to 400 Hz. The DCCS is also designed to produce imaging X rays through Laser Compton scattering. This work aims to describe the preparations for the first dosimetry experimental campaign using this accelerator system at energies ranging from 25 MeV to 90 MeV through hardware development and Monte Carlo (TOPAS) simulation studies. A significant goal of these preparations is to configure the machine so that it can be used to both image with X rays and subsequently treat with VHEEs without movement of the animal model under study. At ultra-high dose rates, this X-ray image-guided electron source could be used to investigate dose-rate dependent differential sparing of normal and malignant biological tissue, known as the FLASH effect. An indium-tin-oxide-coated, 100-μm-thick diamond window was obtained and installed in a custom flange assembly to act as the electron/X-ray vacuum exit window. Simulations at 25 MeV suggest that a scattering foil and collimator can shape the output of the accelerator to produce a 12-mm-diameter, flat-field, circular beam with a 1.7-nC macrobunch charge. This corresponds to an entrance dose of 10 Gy in less than 100 ms. These initial results highly motivate an experimental campaign toward investigating VHEE FLASH using the DCCS at Lumitron Technologies, Inc.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":"223-235"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143625791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occupational Exposure to Low Dose Ionizing Radiation and the Incidence of Surgically Removed Cataracts and Glaucoma in a Cohort of Ontario Nuclear Power Plant Workers.","authors":"Paul J Villeneuve, Brianna Frangione, Robert Talarico, Tim Prendergast, Chenchung Yu, Gagan Gill, Lydia Zablotska","doi":"10.1667/RADE-24-00050.1","DOIUrl":"10.1667/RADE-24-00050.1","url":null,"abstract":"<p><p>Ionizing radiation is a human carcinogen and has been shown to increase the risk of non-cancerous ocular disorders. Specifically, findings from epidemiological studies suggest that ionizing radiation leads to the development of cataracts and to a lesser extent glaucoma, however, there are uncertainties of these risks at lower exposures. We analyzed data from a cohort of 60,874 Ontario Nuclear Power Plant (NPP) workers within the Canadian National Dose Registry (NDR). These workers were monitored for whole-body exposure to ionizing radiation using dosimeters, with exposure estimates derived for each year of employment. Incident cases of surgically removed cataracts and glaucoma were identified through the record linkage of occupational histories to administrative health data for Ontario between 1991 and 2022. We compared the incidence of surgically removed cataracts and glaucoma in the cohort to Ontario's general population using indirect age- and sex-standardization with matching by place of residence. We evaluated exposure-response relationships with internal cohort comparisons using age-, sex-, and calendar-period-adjusted Poisson regression. The relative risks of cataract and glaucoma were estimated across categorical measures of whole-body dose [Hp(10)] from exposure to radiation (lagged 5 years). In total, 32,855 of the 60,874 workers (58%) had a positive cumulative dose exceeding the minimum reportable threshold. Among these workers, the mean cumulative whole-body lifetime dose at end of follow-up was 23.7 mSv (interquartile range: 1.1-26.4 mSv, maximum = 959.3 mSv). Overall, 4,401 (7.2%) of workers developed glaucoma, while 2,939 (4.8%) underwent cataract-removal surgery. There was no evidence of a dose-response relationship between cumulative whole-body dose ionizing radiation (lagged 5 years) and glaucoma, but some for surgically removed cataracts. Specifically, among workers with a cumulative exposure of greater than 50 mSv relative to those with an exposure of less than 0.25 mSv, the relative risks of incident glaucoma and cataract removal surgery were 0.91 (95% CI: 0.81-1.05) and 1.13 (95% CI: 0.97-1.33), respectively. The linear excess risks per 100 mSv (lagged 5 years) for cataract removal surgery was 0.055 (95% CI: -0.042 to 0.163). Our findings provide some evidence that ionizing radiation increases the risk of cataracts but not glaucoma in an occupational cohort whose lifetime cumulative dose rarely exceeded 30 mSv.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":"271-283"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143449665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasmid DNA Strand Breaks Are Dose Rate Independent at Clinically Relevant Proton Doses and Under Biological Conditions.","authors":"Louis V Kunz, Robert Schaefer, Houda Kacem, Jonathan Ollivier, Michele Togno, Flore Chappuis, Damien Weber, Anthony Lomax, Charles L Limoli, Serena Psoroulas, Marie-Catherine Vozenin","doi":"10.1667/RADE-24-00118.1","DOIUrl":"10.1667/RADE-24-00118.1","url":null,"abstract":"<p><p>We investigated the effect of proton FLASH radiation on plasmid DNA. Purified supercoiled pBR322 plasmids were irradiated with clinical doses (≤10 Gy) of protons at ultra-high and conventional dose rates using the Paul Scherrer Institute (PSI) isochronous cyclotron. The proton beam in this clinical facility has been validated to produce the FLASH effect in preclinical models. Plasmid samples were irradiated under various oxygen tensions, scavenger levels, pH conditions and Fe (II) concentrations as these biochemical parameters vary across tissues and tumors. Over the range of doses used, plasmid DNA strand breaks were found to be dose rate independent at all conditions investigated. Irradiation within the Bragg peak and spread-out Bragg peak increased clustered strand breaks, except in the presence of scavengers. With this model system, we demonstrate conclusively that plasmid DNA strand breakage is dose rate independent at doses below 10 Gy and does not constitute a high throughput assay endpoint predictive of the biological effect of FLASH.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":"214-222"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143516355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What's in a Proton FLASH Beam? Characterizing Ultra-High Dose Rate Protons Using a Commercial Plastic Scintillator.","authors":"Yannick Poirier, Kevin E Byrne, Gulakhshan Hamad, François Therriault-Proulx, Kai Jiang, Wei Deng, Amit Sawant, Sina Mossahebi","doi":"10.1667/RADE-24-00117.1","DOIUrl":"10.1667/RADE-24-00117.1","url":null,"abstract":"<p><p>While biological studies of the FLASH effect in proton beams have mainly been performed in the plateau region at maximum beam energy and current, this type of delivery has limited clinical applications. Naturally, it is anticipated that plans to treat patients clinically with FLASH-radiotherapy (FLASH-RT) will capitalize on the Bragg peak. However, as the proton spot widens with depth, the time required to deliver the entire dose to any single point increases. This decreases the dose rate, making the ultra-high dose rates required to trigger the FLASH effect harder to achieve over large areas. Importantly, the dose rate is difficult to measure directly. Time and dose linearity of a fast-resolving commercial plastic scintillation detector were characterized against an ionization chamber. The percent depth dose of a 250 MeV proton beam scanned across a small area (3.5 × 3.5 cm2) was measured at depths of 3-40 cm in solid water. The plastic scintillation detector was used to evaluate the instantaneous and voxel-averaged dose rates as a function of depth for conventional (2 nA nozzle current) and ultra-high dose rate (100 nA) beams. The response of the plastic scintillation detector was shown to be linear with time (±2.5 ms) and absorbed dose (±2%). The scintillator and ionization chamber measurements agreed well as a function of depth (and therefore energy) within 2% for depths <34 cm. Beyond 34 cm, expected quenching effects were observed in the plastic scintillation detector. The voxel-averaged dose rate varied from 52.7 Gy/s at the entrance to 29.3 Gy/s at mid-depth, to 70.4 Gy/s near the Bragg peak, while the maximum instantaneous dose rate decreased from 472 Gy/s near the entrance to 236 Gy/s at the Bragg peak. The plastic scintillation detector has proven useful for investigators to evaluate the complex relationship between dose rate and pencil-beam scanning ultra-high dose rate beam characteristics. There is a loss of dose rate near the Bragg peak due to spot widening, which may acutely impact our ability to exploit the FLASH effect for sparing normal tissues upstream of the intended treatment area. A thorough preclinical investigation of whether the FLASH effect is maintained near the Bragg peak is necessary before this technique can begin translation to the clinic.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":"201-213"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143616807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Systematic Study of Silicon Carbide Detectors and Beam Current Transformer Signals for UHDR Single Electron Pulse Monitoring.","authors":"C Okpuwe, G Milluzzo, D Coves, T Delaviere, D Del Sarto, M De Napoli, F Di Martino, G Felici, L Lanzanò, L Masturzo, J Pensavalle, E Touzain, M Camarda, F Romano","doi":"10.1667/RADE-24-00139.1","DOIUrl":"10.1667/RADE-24-00139.1","url":null,"abstract":"<p><p>The use of ultra-high dose rate beams (UHDR) (> 40 Gy/s) for radiotherapy, despite its advantage of exhibiting the FLASH effect that improves the sparing of healthy tissues, faces challenges in dosimetry and beam monitoring since standard dosimeters like the ionization chamber experience saturation effects at such high dose rates. Silicon carbide (SiC) detectors have recently been demonstrated to be dose-rate independent with low-energy pulsed electron beams up to an instantaneous dose rate of 5.5 MGy/s, and has emerged as a reliable alternative technology for dosimetry in FLASH-RT. This study explored the suitability of using the SiC detector for measuring intra-pulse instantaneous dose rates, which are necessary for monitoring fluctuations within the pulse of UHDR pulsed electron beams. The experiments reported were conducted using UHDR electron beams accelerated at 9 MeV by an ElectronFlash linac and using varying different beam parameters, such as the beam current (i.e., different dose per pulse) and pulse width settings. The temporal single pulse shape signals were measured with a 10 µm thick, 4.5 mm2 area SiC detector for different configurations and compared with a well-characterized AC current transformer (ACCT) (which served as the standard monitoring system of the accelerator), and with a second ACCT placed at the same location as the SiC detector (i.e., after the applicator at the irradiation point). The results show a high level of agreement between the signals of the SiC detector and ACCT placed after the applicator at around the irradiation point. This underscores the potential of the SiC detector and the ACCT to be used for monitoring instantaneous dose rates within a pulse. Furthermore, since use of the SiC detector and ACCT are based on different physical principles, they can provide complementary beam information. A combination of the two has the potential to provide insight about a variety of variables of interest for UHDR beams. However, some discrepancies were observed when comparing the SiC signals with the ACCT installed in the LINAC, which increased linearly with decreasing dose per pulse. Further studies are required to better understand these observations.</p>","PeriodicalId":20903,"journal":{"name":"Radiation research","volume":" ","pages":"236-245"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143493400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}