Low-dose Radiation Research Articles

Хемилюминесцентные характеристики периферической крови при облучении in vitro в диапазоне доз 100–500 мГр

Abstract. Nowadays a lot of examinations are dedicated to determination of radiobiological effects under low doses of ionising radiation. It is known that ionising radiation in the cells of an organism increases generation of reactive oxygen species (ROS). The purpose of the work is to determine basic parameters of chemiluminescent kinetics of ROS in peripheral blood under in vitro radiation in the range of 100–500 mGy doses. The research will extend the knowledge of the impact degree of ionising radiation in low doses on organism tissue of farm animals. Scientific novelty is that the results of the research will allow to predict radiobiological effects of low doses in a multicellular organism. The research is included in practical and fundamental directions of radiobiology. Research methods. In vitro radiation of blood samples in the range of 100–500 mGy doses. The kinetics of generation of ROS is registered on 36-channel chemiluminometer 3604-PC. Results. The doses in the range of 100–300 mGy accelerated the time of the first peak of spontaneous and activated generation of radicals, under 500 mGy dose the formation of the first peak of spontaneous and activated generation of primary ROS decelerated. Under the impact of low absorbed doses maximum intensity of primary and secondary radicals generation decreased. The inhibition of primary radicals spontaneous production occurred under 100–300 mGy doses, the inhibition of antigen activated generation of primary ROS was under 400 mGy. The reduction of the amount of spontaneous secondary ROS was registered under 100 mGy dose. The decrease of antigen activated secondary radicals production occurred under 100–300 mGy doses. 500 mGy dose inhibited a reaction ability of blood cells to generate primary radicals. The external in vitro gamma radiation in the range of 100–500 mGy had a negative impact on peripheral blood cells showing an acceleration of chemiluminescent reaction as well as decrease of maximum intensity of the first peak of spontaneous and antigen activated primary and secondary radicals production. As a consequence, a decrease of the amount of primary and secondary radicals production was revealed.

Low-Dose Radiation Associated Mortality Risks of Site-Specific Solid Tumors in U.S. Shipyard Workers.

U.S. nuclear capable shipyard workers have increased potential for occupational radiation exposure. to examine solid tumor mortality risks at low doses. 437,937 workers working from 1957 to 2004 at eight U.S. shipyards were studied. Radiation workers with a median life-time dose at 0.82 mSv had a significantly lower solid tumor mortality risk [Relative risk (RR): 0.96, 95% confidence interval (CI): 0.94-0.98] than non-radiation workers. Among 153,930 radiation workers., the RRs of solid tumors increased with increasing dose categories without statistical significance. The dose category >0- < 25 mSv had significantly lower RR (0.95, 95% CI: 0.91-0.99) vs. 0 dose and the Excess Relative Risk was 0.05/100 mSv (95% CI: 0.01-0.08). Solid tumor risk might increase with radiation dose, but not linearly at low doses. Actual mortality risk may be dependent on dose received.

Abstract 5743: Liposome platform enables X-ray induced photodynamic therapy treatment against human triple negative breast cancer cells

Abstract In this study, we employed X-ray induced photodynamic therapy (X-PDT) for the treatment on triple negative breast cancer (TNBC) cells. To do this, we rationally developed a liposome delivery system co-loaded with protoporphyrin IX (PPIX) and perfluorooctyl bromide (PFOB). Low-dose X-ray at 2Gy was employed to activate PPIX for reactive oxygen species (ROS) generation, and the co-loading of PFOB provided additional oxygen to augment ROS production. The highly toxic ROS triggered TNBC cell death. In vitro X-PDT effects including intracellular ROS generation, cytotoxicity, cell viability and apoptosis/necrosis assay in TNBC cells were studied. Our results indicate that the nanocarriers effectively induced X-PDT effect with very low dose radiation, which makes it possible to damage cancer cells. Our strategy may offer a paradigm-shifting treatment alternative for TNBC patients who need neoadjuvant radiotherapy but wish to avoid long term detrimental effect on functional outcome by undergoing X-PDT using only a fraction of the conventional radiotherapy. Citation Format: Biyao Yang, Rui Sang, Yi Li, Ewa Goldys, Wei Deng. Liposome platform enables X-ray induced photodynamic therapy treatment against human triple negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5743.

Abstract 6642: Exploring the x-ray psoralen activated cancer therapy mechanism of action in a genetically engineered mouse model of soft tissue sarcoma

Abstract BACKGROUND: Psoralen is a natural ultraviolet activated compound that has been used for over 70 years to treat skin cancer, psoriasis, and vitiligo. Recently, to expand its use beyond external treatment, a novel therapeutic called X-PACT (X-ray psoralen activated cancer therapy) was created to treat internal tumors. A combination of 8-methoxypsoralen and phosphors that convert low doses of x-ray radiation to ultraviolet (UV) light are injected into solid tumors and subsequently activated by x-ray photons with considerable antineoplastic effect. Notably, canine clinical trials have observed significant abscopal effects of X-PACT therapy on metastatic lesions throughout patients, but the immunomodulatory mechanisms of action are unclear (Nolan et al, in submission). Here, we present preliminary data investigating the immune response to X-PACT therapy in a murine soft tissue sarcoma (STS) model. METHODS: Six mice of the inducible KrasG12D/+; p53flox/flox (KP) murine STS model with palpable, gastrocnemius tumors were used in this initial study. Four mice underwent treatment with X-PACT. In this group, psoralen was mixed with energy converters and injected into the tumor. The mice then received low-level radiation to activate the drug. Treatment was performed five times over a 15-day period and the animals were sacrificed within 48 hours of final treatment. The other two mice with induced tumors received no treatment prior to sacrifice. For both groups, a cardiac blood draw was performed at the time of sacrifice to obtain plasma serum for analysis. Luminex xMAP technology was used for multiplexed quantification of 45 mouse cytokines, chemokines and growth factors. RESULTS: There were five markers that showed significantly different levels between the treated and control groups. Results indicated significantly higher (p = 0.006) plasma concentrations of macrophage derived chemokine (MDC) following five rounds of treatment with X-PACT therapy. Additionally, the treated mice displayed significantly lower concentrations of granulocyte colony-stimulating factor (G-CSF, p = 0.003), eotaxin (p = 0.016), tissue inhibitor of matrix metalloproteinase 1 (TIMP1, p = 0.024), and interleukin-1β (IL-1β, p = 0.033) compared to untreated mice with STS. CONCLUSION: In humans, MDC levels are associated with longer survival and lower cancer severity. G-CSF, eotaxin, TIMP1, and IL-1β are upregulated in cancer patients and correlate with disease severity. Together, the lower concentrations of G-CSF, Eotaxin, TIMP1, and IL-1β suggest a softening of cancer severity following X-PACT treatment. Further studies and larger sample sizes are necessary to confirm and expand upon these preliminary findings. Citation Format: Beatrice Schleupner, Alexandra Hunter Aitchison, Elle MacAlpine, Nicole Cantor, Jason Somarelli, Brian Brigman, Julia Visgauss, Michael Monument, William Eward. Exploring the x-ray psoralen activated cancer therapy mechanism of action in a genetically engineered mouse model of soft tissue sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6642.

Abstract 1178: Tissue nanomechanics as a novel, clinically translatable predictive early biomarker of response in combination immunotherapy

Abstract Background: Recently, the successful integration of immunotherapy with other treatment modalities has demonstrated its efficacy in enhancing immune activation and suppressing tumors in solid cancers. The most promising of such efforts include the use of low dose radiation (LD-XRT) to prime the tumor microenvironment and enhance the T cell infiltration and activation [Barsoumian HB, et al., 2020; Patel RR, et al., 2021; He K, et al., 2023]. With these advancements, there is an urgent need to develop clinical biomarkers to predict response and optimize treatment decisions. Recent evidence underscores the importance of nanomechanical alterations within the tumor microenvironment as mechanistic indicators of aggressiveness [Plodinec M, et al., 2012]. This study aims to demonstrate the value of ARTIDIS nanomechanical signature as early predictor of elucidate of response to combination LD-XRT/immune checkpoint inhibitors (ICI). Our measurement protocol in mice follows the same settings for biopsies acquired in routine biopsy collection protocol, thus supporting prompt clinical translation and integration. Methods: We established a mouse model of 344SQ lung adenocarcinoma tumors that exhibited resistance to anti-PD1 treatment in 129Sv/Ev mice. These mice underwent treatment protocols involving a combination of anti-PD1 and anti-CTLA4 antibodies, both with and without LD-XRT pre-treatment. Throughout the study, we closely monitored survival rates and tumor growth across diverse experimental groups. Employing the ARTIDIS platform, a cutting-edge technology that integrates atomic force microscopy with proprietary artificial intelligence algorithms, we extracted a multiparametric nanomechanical signature and we evaluated its outcome prediction value. This signature was then complemented by histopathology, multiplex immunofluorescence, and Nanostring assays to elucidate mechanisms of stroma remodulation and immune infiltration. Results: This study identifies the unique nanomechanical signature predictive of response to immunotherapy alone or in combination with radiation. Using the tissue nanomechanical signature as a predictive biomarker, we achieved precise differentiation between responders and non-responders, boasting a 90% sensitivity, 99.1% specificity, and a 96% AUC. To our knowledge, this study is the first to demonstrate the response-predicting power of a tissue derived nanomechanical signature for immune checkpoint inhibitors administered in combination with LD-XRT. These findings support clinical translation of the ARTIDIS nanomechanical signature as a pivotal tool for clinically predicting and evaluating responses to integrated radiation and immunotherapy approaches. Citation Format: Gitika Srivastava, Sara Nizzero, Mark Wasley, Mingee Kim, Kathleen Graham, Papa Diogop Ndiaye, Mariam Gachechiladze, Nahum Puebla-Osorio, Philipp Oertle, Tobias Appenzeller, Vittorio Cristini, Marko Loparic, Marija Plodinec, James W. Welsh. Tissue nanomechanics as a novel, clinically translatable predictive early biomarker of response in combination immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1178.

The effects of electromagnetic field radiation of extremely low frequency on growth parameters and nucleotide substitutions in L. minor clones

Current technologies have become a source of electromagnetic pollution resulting from artificially generated electromagnetic radiation (EMR). To understand the influence of the EMR on living organisms, we investigated the long-term effects of EMR of 50 Hz frequency on duckweed (Lemna minor) clones. Experimental groups of duckweed were treated directly and indirectly by changing EMR generating magnetic flux (MF) starting from 2 µT (0–11 weeks from the beginning of the experiment) and switching to 300 µT (12–48 weeks) MF density during the second part of the experiment. The growth parameters (plant growth, frond area, and frond number) and the point mutations appearing at the antioxidant genes DNA sequences [ascorbate peroxidase (APx), glutathione peroxidase (GPx), and catalase (Cat)] were analyzed. The significantly enhanced number of nucleotide substitutions in DNA sequences of L. minor clones directly affected by LF EMR in comparison to indirectly affected clones was revealed at the introns of APx, GPx, and Cat genes starting from the 10th week of the experiment. The results indicate that even low-dose chronic electromagnetic radiation may contribute to the changes in growth parameters and generation of point mutations in antioxidant gene sequences, especially in the intron regions.

Distinguish response of low-dose radiation with different dose-rate on gene expression of human coronary artery endothelial cells: a bioinformatic study based on transcriptomic sequencing

Purpose People are exposed to low-dose radiation in medical diagnosis, occupational, or life circumstances, but the effect of low-dose radiation on human health is still controversial. The biological effects of radiation below 100 mGy are still unproven. In this study, we observed the effects of low-dose radiation (100 mGy) on gene expression in human coronary artery endothelial cells (HCAECs) and its effect on molecular signaling. Materials and methods HCAECs were exposed to 100 mGy ionizing radiation at 6 mGy/h (low-dose-rate) or 288 mGy/h (high-dose-rate). After 72 h, total RNA was extracted from sham or irradiated cells for Quant-Seq 3'mRNA-Seq, and bioinformatic analyses were performed using Metascape. Gene profiling was validated using qPCR. Results Compared to the non-irradiated control group, 100 mGy of ionizing radiation at 6 mGy/h altered the expression of 194 genes involved in signaling pathways related to heart contraction, blood circulation, and cardiac myofibril assembly differentially. However, 100 mGy at 288 mGy/h altered expression of 450 genes involved in cell cycle-related signaling pathways, including cell division, nuclear division, and mitosis differentially. Additionally, gene signatures responding to low-dose radiation, including radiation dose-specific gene profiles (HIST1H2AI, RAVER1, and POTEI) and dose-rate-specific gene profiles (MYL2 for the low-dose-rate and DHRS9 and CA14 for the high-dose-rate) were also identified. Conclusions We demonstrated that 100 mGy low-dose radiation could alter gene expression and molecular signaling pathways at the low-dose-rate and the high-dose-rate differently. Our findings provide evidence for further research on the potential impact of low-dose radiation on cardiovascular function.

Public knowledge, sentiments, and perceptions of low dose radiation (LDR) and power production, with special reference to reactor accidents

Public knowledge, sentiments, and perceptions of low dose radiation (LDR) and power production, with special reference to reactor accidents

A potential novel technique for measurement of pulp volume on periapical radiography: A pilot study.

Pulp volume can be assessed during dental treatment. Three-dimensional imaging techniques are not routinely used for this purpose because of high radiation doses. This study aimed to develop a novel method to measure pulp volume using periapical radiography. In this study, cone-beam computed tomography (CBCT) was used as a reference method. Periapical radiography and CBCTs obtained from the same patients (n = 32) were recorded. Pulp volume was determined by observing the density differences between the pulp and peripheral structures using ImageJ. A method of graph and volume calculation was developed for each tooth. The Shapiro-Wilk test and Mann-Whitney U test were used to show normality and non-normal distributions. The Bland-Altman plot was used to show the scattering of the mean versus difference values of the measurements of the two methods used to calculate the pulp volume. Normality was evaluated using the Shapiro-Wilk test. CBCT measurements are normally distributed (p = 0.307), while ImageJ is not normally distributed (p = 0.027). Therefore, the mean difference between the two groups was analyzed using the nonparametric Mann-Whitney U test. There was a statistically significant difference between the CBCT and ImageJ measurements (p = 0.01). According to Spearman's correlation analysis, the results obtained from the novel method were moderately correlated with those obtained from the reference method (r = 0.444). The results of this study indicated that a novel method-based Java software can be used to calculate pulp volume using low-dose radiation containing periapical radiography.

Proteomic changes in the hippocampus of large mammals after total-body low dose radiation.

There is a growing interest in low dose radiation (LDR) to counteract neurodegeneration. However, LDR effects on normal brain have not been completely explored yet. Recent analyses showed that LDR exposure to normal brain tissue causes expression level changes of different proteins including neurodegeneration-associated proteins. We assessed the proteomic changes occurring in radiated vs. sham normal swine brains. Due to its involvement in various neurodegenerative processes, including those associated with cognitive changes after high dose radiation exposure, we focused on the hippocampus first. We observed significant proteomic changes in the hippocampus of radiated vs. sham swine after LDR (1.79Gy). Mass spectrometry results showed 190 up-regulated and 120 down-regulated proteins after LDR. Western blotting analyses confirmed increased levels of TPM1, TPM4, PCP4 and NPY (all proteins decreased in various neurodegenerative processes, with NPY and PCP4 known to be neuroprotective) in radiated vs. sham swine. These data support the use of LDR as a potential beneficial tool to interfere with neurodegenerative processes and perhaps other brain-related disorders, including behavioral disorders.

194MO Phase II study of low-dose radiation (LDRT) plus durvalumab (D) and etoposide/platinum (EP) as first-line treatment in ES-SCLC (LEAD): Efficacy and safety results

194MO Phase II study of low-dose radiation (LDRT) plus durvalumab (D) and etoposide/platinum (EP) as first-line treatment in ES-SCLC (LEAD): Efficacy and safety results

Technical feasibility of novel immunostimulatory low-dose radiation for polymetastatic disease with CBCT-based online adaptive and conventional approaches.

A workflow/planning strategy delivering low-dose radiation therapy (LDRT) (1Gy) to all polymetastatic diseases using conventional planning/delivery (Raystation/Halcyon="conventional") and the AI-based Ethos online adaptive RT (oART) platform is developed/evaluated. Using retrospective data for ten polymetastatic non-small cell lung cancer patients (5-52 lesions each) with PET/CTs, gross tumor volumes (GTVs) were delineated using PET standardized-uptake-value (SUV) thresholding. A 1cm uniform expansion of GTVs to account for setup/contour uncertainty and organ motion-generated planning target volumes (PTVs). Dose optimization/calculation used the diagnostic CT from PET/CT. Dosimetric objectives were: Dmin,0.03cc ≥ 95% (acceptable variation (Δ) ≥ 90%), V100% ≥ 95% (Δ ≥ 90%), and D0.03cc ≤ 120% (Δ ≤ 125%). Additionally, online adaptation was simulated. When available, subsequent diagnostic CT was used to represent on-treatment CBCT. Otherwise, the CT from PET/CT used for initial planning was deformed to simulate clinically representative changes. All initial plans generated, both for Raystation and Ethos, achieved clinical goals within acceptable variation. For all patients, Dmin,0.03cc ≥ 95%, V100% ≥ 95%, and D0.03cc ≤ 120% goals were achieved for 84.8%/99.5%, 97.7%/98.7%, 97.4%/92.3%, in conventional/Ethos plans, respectively. The ratio of 50% isodose volume to PTV volume (R50% ), maximum dose at 2cm from PTV (D2cm ), and the ratio of the 100% isodose volume to PTV volume (conformity index) in Raystation/Ethos plans were 7.9/5.9; 102.3%/88.44%; and 0.99/1.01, respectively. In Ethos, online adapted plans maintained PTV coverage whereas scheduled plans often resulted in geographic misses due to changes in tumor size, patient position, and body habitus. The average total duration of the oART workflow was 26:15 (min:sec) ranging from 6:43 to 57:30. The duration of each oART workflow step as a function of a number of targets showed a low correlation coefficient for influencer generation and editing (R2 =0.04 and 0.02, respectively) and high correlation coefficient for target generation, target editing and plan generation (R2 =0.68, 0.63 and 0.69, respectively). This study demonstrates feasibility of conventional planning/treatment with Raystation/Halcyon and highlights efficiency gains when utilizing semi-automated planning/online-adaptive treatment with Ethos for immunostimulatory LDRT conformally delivered to all sites of polymetastatic disease.

ASO Visual Abstract: Low-Dose Radiation Yields Lower Rates of Pathologic Response in Esophageal Cancer Patients.

ASO Visual Abstract: Low-Dose Radiation Yields Lower Rates of Pathologic Response in Esophageal Cancer Patients.

Soil Microbes and Plant-Associated Microbes in Response to Radioactive Pollution May Indirectly Affect Plants and Insect Herbivores: Evidence for Indirect Field Effects from Chernobyl and Fukushima.

The biological impacts of the nuclear accidents in Chernobyl (1986) and Fukushima (2011) on wildlife have been studied in many organisms over decades, mainly from dosimetric perspectives based on laboratory experiments using indicator species. However, ecological perspectives are required to understand indirect field-specific effects among species, which are difficult to evaluate under dosimetric laboratory conditions. From the viewpoint that microbes play a fundamental role in ecosystem function as decomposers and symbionts for plants, we reviewed studies on microbes inhabiting soil and plants in Chernobyl and Fukushima in an attempt to find supporting evidence for indirect field-specific effects on plants and insect herbivores. Compositional changes in soil microbes associated with decreases in abundance and species diversity were reported, especially in heavily contaminated areas of both Chernobyl and Fukushima, which may accompany explosions of radioresistant species. In Chernobyl, the population size of soil microbes remained low for at least 20 years after the accident, and the abundance of plant-associated microbes, which are related to the growth and defense systems of plants, possibly decreased. These reported changes in microbes likely affect soil conditions and alter plant physiology. These microbe-mediated effects may then indirectly affect insect herbivores through food-mass-mediated, pollen-mediated, and metabolite-mediated interactions. Metabolite-mediated interactions may be a major pathway for ecological impacts at low pollution levels and could explain the decreases in insect herbivores in Fukushima. The present review highlights the importance of the indirect field effects of long-term low-dose radiation exposure under complex field circumstances.

Finite-Sample Bias of the Linear Excess Relative Risk in Cohort Studies of Computed Tomography-Related Radiation Exposure and Cancer.

The linear excess relative risk (ERR) is the most commonly reported measure of association in radiation epidemiological studies, when individual dose estimates are available. While the asymptotic properties of the ERR estimator are well understood, there is evidence of small sample bias in case-control studies of treatment-related radiation exposure and second cancer risk. Cohort studies of cancer risk after exposure to low doses of radiation from diagnostic procedures, e.g., computed tomography (CT) examinations, typically have small numbers of cases and risks are small. Therefore, understanding the properties of the estimated ERR is essential for interpretation and analysis of such studies. We present results of a simulation study that evaluates the finite-sample bias of the ERR estimated by time-to-event analyses and its confidence interval using simulated data, resembling a retrospective cohort study of radiation-related leukemia risk after CT examinations in childhood and adolescence. Furthermore, we evaluate how the Firth-corrected estimator reduces the finite-sample bias of the classical estimator. We show that the ERR is overestimated by about 30% for a cohort of about 150,000 individuals, with 42 leukemia cases observed on average. The bias is reduced for higher baseline incidence rates and for higher values of the true ERR. As the number of cases increases, the ERR is approximately unbiased. The Firth correction reduces the bias for all cohort sizes to generally around or under 5%. Epidemiological studies showing an association between radiation exposure from pediatric CT and cancer risk, unless very large, may overestimate the magnitude of the relationship, while there is no evidence of an increased chance for false-positive results. Conducting large studies, perhaps by pooling individual studies to increase the number of cases, should be a priority. If this is not possible, Firth correction should be applied to reduce small-sample bias.

Low-dose radiation therapy for COVID-19

Background. Radiation therapy is one of the most effective treatments in patients with malignant neoplasms, it also plays an important role in the treatment of non-oncological di­seases. The coronavirus disease 2019 (COVID-19) pandemic has prompted a review of the long-forgotten idea of using low-dose radiation therapy (LDRT) in patients with lobar and interstitial pneumonia. Historically, from 1905 to the mid-1940s, LDRT was used to treat pneumonia, and evidence suggests that it might improve survival and provide rapid relief of respiratory symptoms. The purpose was to summarize current information about ­using low-dose radiation therapy in the treatment of patients with ­COVID-19. Materials and methods. A selection of publications was carried out, which covered information on the possibilities of using low-dose radiation therapy in the treatment of patients with COVID-19. At the first stage, a search was conducted for lite­rary sources using the keywords: COVID-19, low-dose radiation therapy. At the second stage, summaries of articles were studied and publications that did not meet the research criteria were excluded. At the third stage, the full texts of the selected articles were studied for compliance with the criteria for inclusion in the reference list and research relevance. Results. As of August 1, 2023, according to ClinicalTrials.gov, among 9,244 clinical trials associated with COVID-19, sixteen are currently being conduc­ted. They examine the effectiveness of LDRT in the treatment of patients with COVID-19 and already involve 1,038 patients. The largest number of studies is conducted in European countries. It has been shown that LDRT selectively attenuates oxidative stress to an inflammatory stimulus and inhibits the nitric oxide production pathway. This may contribute to its anti-inflammatory and vascular effects. At the same time, heme oxygenase 1 and other antioxidants are induced, they are mediated by Nrf2, which is the main regulator of endogenous antioxidant, anti-stress, analgesic reactions, and is also closely related to nicotinamide adenine dinucleotide phosphate and the metabolic pathway of pentose phosphate. Nrf2 may be critical for pain relief associated with edema formation and possibly plays a major role in the effects of LDRT, whereas direct functional effects of low-dose radiation on the autonomic nervous system and nociception are likely to be smaller. Conclusions. From 1905 to 1946, researchers published the results of more than 15 clinical studies on the effectiveness of radiotherapy for inflammatory lung diseases, which included more than 850 patients and demonstrated the high therapeutic effectiveness of radiation therapy in the indicated pathology. Today, there are 16 ongoing clinical trials in the world devoted to the study of LDRT effectiveness in the treatment of patients with COVID-19, in which 1,038 patients have already been involved. The risk of radiation-induced lung and breast cancer in a 25-year-old woman exposed to 1 Gy whole chest radiation may be as high as 5.9 and 5.5 %, respectively.

Identification of DNA methylation biomarkers for evaluating cardiovascular disease risk from epigenome profiles altered by low-dose ionizing radiation

BackgroundEnvironmental exposure, medical diagnostic and therapeutic applications, and industrial utilization of radionuclides have prompted a growing focus on the risks associated with low-dose radiation (< 100 mGy). Current evidence suggests that such radiation can induce epigenetic changes. Nevertheless, whether exposure to low-dose radiation can disrupt endothelial cell function at the molecular level is unclear. Because endothelial cells play crucial roles in cardiovascular health and disease, we aimed to investigate whether low-dose radiation could lead to differential DNA methylation patterns at the genomic level in endothelial cell (EC) lines.MethodsWe screened for changes in DNA methylation patterns in primary human aortic (HAECs) and coronary artery endothelial cells following exposure to low-dose ionizing radiation. Using a subset of genes altered via DNA methylation by low-dose irradiation, we performed gene ontology (GO) analysis to predict the possible biological network mediating the effect of low-dose radiation. In addition, we performed comprehensive validation using methylation and gene expression analyses, and ChIP assay to identify useful biomarkers among candidate genes for use in detecting low-dose radiation exposure in human primary normal ECs.ResultsLow-dose radiation is sufficient to induce global DNA methylation alterations in normal EC lines. GO analysis demonstrated that these hyper- or hypo-methylated genes were linked to diverse biological pathways. Our findings indicated a robust correlation between promoter hypermethylation and transcriptional downregulation of four genes (PGRMC1, UNC119B, RERE, and FNDC3B) in response to low-dose ionizing radiation in HAECs.ConclusionsBased on these findings, the identified genes can serve as potential DNA methylation biomarkers for the assessment of cardiovascular risk upon exposure to low-dose radiation.

Determination of radiosensitivity from chest X-ray on human breast cancer cell line MDA-MB-231 in terms of cell morphology and cell proliferation

Chest X-rays are used to assess diagnostic conditions for patients with breast cancer. The aim of this research was to study the radiation dose from chest X-ray on the response of breast cancer cells. In this research, the proliferation and cell numbers of the MDA-MB-231 cell line were studied at 1, 24, 48, 72 and 96 h after 0.42–0.82 mGy of chest X-ray irradiation. The results showed that the cell morphology of breast cancer cells did not change after irradiation. In contrast, it was found that the radiation dose from chest X-ray inhibited cell growth and the cell viability of MDA-MB-231. It can be seen that the changes at the cellular level occur within cancer cells from low-dose radiation.

Evaluasi Nilai Diagnostic Reference Level (DRL) pada pemeriksaan CT Scan Thorax Kontras klinis tumor paru di RS X Jakarta

A contrast thorax CT scan is a CT scan procedure in the chest area (thorax) that uses a contrast agent to improve visualization of organs and structures in the chest. Lung tumors are the growth of abnormal lumps in lung tissue which can be benign or malignant. Awareness of the potential and increasing radiation dose in all CT scan examinations encourages radiographers to want and be able to minimize radiation exposure as the main goal in radiological examinations and also strive for radiation protection during examinations. CT scan radiation dose accounts for 70% of the total dose received from medical imaging. High or low doses of radiation received can increase the risk of cancer. The large dose of radiation received by a patient during a CT scan, therefore regulations are needed that will guarantee monitoring of the radiation dose received by the patient to ensure that the dose received is commensurate with medical purposes. The radiation dose to the patient needs to be optimized by applying the Diagnostic Reference Level (DRL) to optimize medical exposure protection for the patient. Dosage evaluation in clinical contrast chest CT scan examinations for lung tumors and the application of DRL in these examinations have never been carried out at RS X Jakarta. Objective: This study aims to determine the DRL value in clinical contrast thorax CT scan examination of lung tumors at RS CTDIvol and DLP values from clinical contrast Thorax CT Scan examination of lung tumors. The DRL value is calculated at Quartile 3 (75 percentile) using the descriptive frequency test and Wilcoxon test in the SPSS application, then compared with the latest IDRL value. Results: Quartile 3 value (75 percentile) from CTDIvol and DLP CT scan chest contrast clinical lung tumors, namely The CTDIvol value was 12.55 mGy and the DLP was 439 mGy.cm. Conclusion: The DRL value in the clinical contrast thorax CT scan for lung tumors at Hospital X Jakarta. is still below the recommended standard, which shows that the radiation output dose in this examination practice is within normal limits and is classified as safe.

Exaggeration of consequences of low-dose radiation exposures with special reference to cataracts

Publications overestimating the medical and ecological sequels of a slight anthropogenic increase in the radiation background have been reviewed recently with examples of different organs and pathological conditions. The overestimation contributed to the strangulation of atomic energy. The use of nuclear energy for electricity production is on the agenda today due to the increasing energy needs of humankind. Apparently, certain scientific writers acted in the interests of fossil fuel producers. Health risks and environmental damage are maximal for coal and oil, lower for natural gas, and much lower for atomic energy. This letter is an addition to previously published materials, this time focused on studies of cataracts in radiation-exposed populations in Russia. Selection and self-selection bias are of particular significance. Apparently, the self-reporting rate correlates with dose estimates and/or with professional awareness about radiation-related risks among nuclear workers or radiologic technologists, the latter being associated with their work experience/duration and hence with the accumulated dose. Individuals informed of their higher doses would more often seek medical advice and receive more attention from medics. As a result, lens opacities are diagnosed in exposed people earlier than in the general population. This explains dose-effect correlations proven for the incidence of cataracts but not for the frequency of cataract surgeries. Along the same lines, various pathological conditions are more often detected in exposed people. Ideological bias and the trimming of statistics have not been unusual in the Russian medical sciences. It is known that ionizing radiation causes cataracts; however, threshold levels associated with risks are understudied. In particular, thresholds for chronic and fractionated exposures are uncertain and may be underestimated.