Radiation And Environmental Biophysics[JOURNAL]
Sun
200 papers
Cross-modality validation of quantitative Y imaging using a custom hepatopulmonary shunt phantom and patient data.
Yeyin N, Abuqbeitah M, Demir M … +7 more , Akyol S, Kayaokay DT, Kesmezacar FF, Günay O, ALMisned G, Issa B, Tekin HO
Radiat Environ Biophys · 2026 Jul · PMID 42390595 · Publisher ↗
In this study the discrepancies in dose estimations from a Y-filled hepatopulmonary shunt phantom (HPSP) were analyzed using SPECT/CT, PET/CT, and PET/MR modalities. The dose variability was also evaluated among randomly...
In this study the discrepancies in dose estimations from a Y-filled hepatopulmonary shunt phantom (HPSP) were analyzed using SPECT/CT, PET/CT, and PET/MR modalities. The dose variability was also evaluated among randomly selected individuals undergoing Y-microsphere therapy. The HPSP comprised a right lung of 1,101 cm³, a left lung of 863 cm³, a healthy liver parenchyma of 690 cm³, and two intrahepatic tumours of 202 cm³ and 9.5 cm³. Y-chloride activity was diluted in water and injected into the phantom. SPECT/CT, PET/CT, and PET/MR were acquired with the phantom immersed in water. Absorbed dose was calculated for phantom compartments and for patients with liver tumours who were treated with Y-glass microspheres. The calculated lung shunt fraction (LSF) (12.0%) from the PET/MR images was closest to the actual LSF (11.03%), followed by PET/CT with 12.2% and SPECT/CT with 13.4% LSF. The deviation between the actual dose estimates and Y-PET/MR was - 0.1% for the large tumour (202 cm³), -10.5% for the small tumour (9.5 cm³), -7.5% for the healthy liver parenchyma, and 6.1% for the lung. For Y-PET/CT, the deviation was 4.8% for the large tumour, -7.5% for the small tumour, -15.5% for the healthy liver parenchyma, and 7.6% for the lung. In contrast, a significant disparity was observed in the Y-SPECT/CT modality, with deviations of -6.3% for the large tumour, -65.3% for the small tumour, -10.7% for the healthy liver parenchyma, and 18.2% for the lung. In the patient study, the doses from Tc-MAA SPECT/CT and Y-PET/MR images were comparable, whereas Y-SPECT/CT yielded significantly lower dose estimates. The findings obtained demonstrate that Y-SPECT/CT generates significant inaccuracies in absorbed dose estimates mainly for small tumours. All modalities overestimated LSF and lung dose by less than 10% except SPECT/CT (18%). It is concluded that implementing an optimal imaging technique with robust scatter correction would mitigate the dose underestimate. Y-PET/CT and Y-PET/MR are the preferred methods for reliable dosimetry and precise dose-response assessment, especially owing to their robust correlation with Tc-MAA SPECT/CT simulation.
Correction: Assessment of radiotherapy effect and toxicity using tissue-associated DNA methylation markers in cell-free DNA: a study on prostate cancer.
Bahtiyar N, Mermut O, Firtina S … +4 more , Ozaydin A, Suleymanova A, Isikgil B, Onaran İ
Radiat Environ Biophys · 2026 Jun · PMID 42340384 · Publisher ↗
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Stereolithography-printed BiO-reinforced photopolymer nanocomposite samples with antibacterial and radiation shielding properties.
Özkan İ, Aydın NM, Akman F
Radiat Environ Biophys · 2026 Jun · PMID 42340383 · Publisher ↗
Stereolithography (SLA) is an additive manufacturing technique that allows the production of polymer composite samples with high accuracy and smooth surface quality. This makes SLA suitable for functional surface applica...
Stereolithography (SLA) is an additive manufacturing technique that allows the production of polymer composite samples with high accuracy and smooth surface quality. This makes SLA suitable for functional surface applications. In this study, photopolymer nanocomposite surfaces reinforced with bismuth oxide (BiO) nanoparticles were produced by SLA and evaluated in terms of surface structure, antibacterial activity, electrical properties, electromagnetic shielding, and ionizing radiation shielding performance. BiO nanoparticles were added to a commercial UV-curable photopolymer resin at contents of 1, 3, and 5 wt% and printed layer by layer with a layer thickness of 50 μm. Surface structure and particle distribution were examined by SEM-EDS. The results showed good particle distribution at low BiO contents, while particle accumulation occurred at higher contents due to settling during printing. Antibacterial activity was tested according to ISO 22,196, and all BiO-reinforced surfaces showed more than 99% reduction against Escherichia coli and Staphylococcus aureus after 24 h. Surface resistivity measurements performed according to TS EN 1149-1 showed values higher than 10 Ω, indicating strong electrical insulation. Electromagnetic shielding effectiveness values remained below 5 dB in the 8-12 GHz frequency range. In addition, ionizing radiation shielding parameters, including mass attenuation coefficient, linear attenuation coefficient, half-value layer, and radiation protection efficiency, were theoretically calculated using WinXCOM and EpiXS. The results showed that increasing BiO content improved photon attenuation, especially at low energies. Overall, Bi2O-reinforced SLA nanocomposites provide strong antibacterial performance, electrical insulation, and improved ionizing radiation shielding, making them suitable for multifunctional surface applications.
Protective and remineralizing capacity of biosilicate, chitosan-based material, and fluoride on demineralized and irradiated enamel.
Molena KF, Mattos VS, de Castro Neto JC … +5 more , de Paula-Silva FWG, de Oliveira HF, Palma-Dibb RG, de Carvalho Panzeri F, de Queiroz AM
Radiat Environ Biophys · 2026 Jun · PMID 42334591 · Publisher ↗
This study aimed to investigate the protective and remineralizing capabilities of biosilicate, chitosan, and fluoride on demineralized enamel, pre- and post-radiotherapy (RT). Enamel samples (n = 180) underwent artificia...
This study aimed to investigate the protective and remineralizing capabilities of biosilicate, chitosan, and fluoride on demineralized enamel, pre- and post-radiotherapy (RT). Enamel samples (n = 180) underwent artificial caries process (ACP) and 70 Gy irradiation. They were divided into ten groups (n = 18): Biosilicate Suspension Pre-RT (G1), Post-RT (G2); Biosilicate Gel Pre-RT (G3), Post-RT (G4); Chitosan Gel Pre-RT (G5), Post-RT (G6); Fluoridated Gel Pre-RT (G7), Post-RT (G8); Caries Control + RT (G9); No Caries Control + RT (G10). Knoop microhardness and surface roughness were measured pre- and post-ACP and post-treatment. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) evaluated topography. Energy Dispersive X-ray Spectroscopy (EDS) and Raman Spectroscopy assessed chemical composition. ACP caused enamel prism disruption. G10 had the highest microhardness and lowest roughness (p < 0.05). G3 and G5 performed better pre-RT; G4 and G8 performed better post-RT. SEM and AFM showed surface protection and particle deposition in the treated groups. No significant chemical differences were found in EDS and Raman analyses. Biosilicate and partially preserved enamel microhardness and offered protective effects, alongside fluoride. These materials may benefit head and neck cancer patients by forming a protective layer and preventing radiation-related enamel demineralization.
Methodology for estimating intake from an unknown mixture of radioactive compounds.
Halder S, Nadar MY, Yadav J … +2 more , Sawant P, Chaudhury P
Radiat Environ Biophys · 2026 Jun · PMID 42334590 · Publisher ↗
In this study, a methodology is provided for estimation of intake due to inhalation of mixture of radioactive compounds of different solubility types. A systemic approach is presented for evaluating intake with help of s...
In this study, a methodology is provided for estimation of intake due to inhalation of mixture of radioactive compounds of different solubility types. A systemic approach is presented for evaluating intake with help of statistical techniques using different measurement datasets, modified retention and daily urinary excretion fractions. For a single or multiple types of monitoring datasets, intake estimation is performed, considering the varying fractions of compounds. For this purpose, chi square and autocorrelation analysis has been used. A Python program has been written for computation of intake. A case has been taken from the IAEA/IDEAS Intercomparison Exercise on Internal Dose Assessment for validation of the methodology for the estimation of the unknown fractions of compounds as well as of the intake.
Assessing the variation of DNA damage response of individual human cells exposed to photon radiation.
Płódowska M, Drzazga D, Węgierek-Ciuk A … +6 more , Szyc P, Brzozowska B, Wołowiec P, Meher PK, Lisowska H, Wojcik A
Radiat Environ Biophys · 2026 Jun · PMID 42301301 · Publisher ↗
Individual cells of the same type and in the same position in the cell cycle show stochastic cell-to-cell variability (noise) in gene and protein expression, even under the same environmental conditions. The aim of the s...
Individual cells of the same type and in the same position in the cell cycle show stochastic cell-to-cell variability (noise) in gene and protein expression, even under the same environmental conditions. The aim of the study was to test if radiation-induced DNA damage response of cells shows noise, on top of the randomly distributed DNA damage. This was tested by comparing the frequency of DNA repair foci in sister nuclei of binucleated cells (intra BNC variability) and nuclei of two BNC (inter BNC variability). Inter cell variability was also measured for mononucleated cells (MNC). Binucleation was induced in U2OS cells by cytochalasin B. Cells were exposed to 2 Gy of photons, 53BP1 and γH2AX foci were visualised and counted in nuclei of binucleated and mononucleated cells 30, 60, 120 and 180 min post exposure. Coefficients of variation were calculated as indicators of variability. For both types of foci, the frequencies observed in sister nuclei within BNC were positively correlated and exhibited significantly lower variation compared to the variability measured between single nuclei from randomly paired BNC. The contribution of noise to the total variability was 28% for 53BP1 foci and 50% for γH2AX foci. The results demonstrate that the variability of focus frequency observed in nuclei of BNC results from a combination of noise and random damage variability.
Quantifying measurement uncertainties in diode-based in-vivo dosimetry for Cobalt-60 high dose rate brachytherapy.
Lobo D, Sunny J, Pooja MS … +5 more , Srinivas C, Athiyamaan MS, Banerjee S, Krishna A, Simon P
Radiat Environ Biophys · 2026 Jun · PMID 42301300 · Publisher ↗
High-dose-rate (HDR) brachytherapy provides a highly conformal cancer treatment modality by exploiting steep dose gradients, and achieving excellent tumour control while minimising radiation exposure to healthy tissues....
High-dose-rate (HDR) brachytherapy provides a highly conformal cancer treatment modality by exploiting steep dose gradients, and achieving excellent tumour control while minimising radiation exposure to healthy tissues. In-vivo dosimetry (IVD) serves as an essential quality assurance tool, offering independent verification of delivered dose. However, its accuracy can be affected by several measurement-related uncertainties. This study aimed to characterise diode-based IVD for Co-60 HDR brachytherapy and quantify the uncertainties influencing detector performance. A Co-60 HDR afterloading system (SagiNova) was used along with a diode-based in-vivo detector. Calibration was performed using a Polymethyl Methacrylate PMMA phantom. A custom-designed acrylic phantom was fabricated to ensure reproducible detector positioning and fixed geometry during irradiation. Detector linearity and uniformity were assessed by delivering known doses from 1 to 8 Gy in 1 Gy increments. Since conventional brachytherapy treatment planning systems do not account for tissue heterogeneity, additional measurements were performed by placing materials simulating bone (Teflon), lung (cork), and soft tissue (acrylic) of 1-3 cm thickness between the source and detector. The diode exhibited excellent stability, with repeatability showing < 2% relative standard deviation. Sensitivity across cumulative absorbed doses demonstrated < 2.5% variation, confirming strong consistency. A linear response was observed throughout the tested dose range. Heterogeneity analysis revealed notable dose perturbations: as expected, bone-equivalent material produced the highest attenuation, while lung-equivalent material resulted in the least, underscoring the importance of accounting for tissue density variations in IVD measurements. Although IVD offers valuable real-time dose verification in HDR brachytherapy, its widespread clinical adoption remains limited by challenges such as detector size and the steep dose gradients surrounding the source. Comprehensive commissioning-including evaluation of linearity, reproducibility, geometric dependence, and heterogeneity effects-is critical for understanding detector behaviour under clinical conditions. It is concluded that accurate characterisation of these uncertainties enhances the reliability of diode-based IVD systems and supports their integration into routine brachytherapy practice for improved patient safety and treatment precision.
K-edge optimization of PMMA-based metal oxide shields for dental X-ray protection using Geant4 Monte Carlo simulations.
Alabsy MT, El-Kaliuoby MI, El-Khatib AM … +1 more , Khalil AM
Radiat Environ Biophys · 2026 Jun · PMID 42301299 · Publisher ↗
This study investigates PMMA-based composites enhanced with high-Z metal oxides (SnO₂, La₂O₃, Sm₂O₃, Er₂O₃, WO₃, and PbO) for dental diagnostic X-ray shielding. The oxides were selected for their K-edge energies lying wi...
This study investigates PMMA-based composites enhanced with high-Z metal oxides (SnO₂, La₂O₃, Sm₂O₃, Er₂O₃, WO₃, and PbO) for dental diagnostic X-ray shielding. The oxides were selected for their K-edge energies lying within the 20-90 keV range relevant to dental radiology. PbO was included only as a benchmark material, while the other oxides were evaluated as safer, eco-friendly alternatives. Geant4 Monte Carlo simulations, validated against NIST XCOM with < 1% deviation, were employed to calculate key shielding parameters including linear attenuation coefficient (LAC), mean free path (MFP), half-value layer (HVL), tenth-value layer (TVL), effective atomic number (Z), and effective electron density (N). The results demonstrate that each oxide significantly improves PMMA's attenuation capability, particularly at photon energies just above its K-edge. In the investigated energy range, sharp enhancements in LAC, Z, and N, along with reductions in MFP, HVL, and TVL, were observed. Specifically, the maximum LAC values reached 15.309 cm⁻¹ for PMMA-Sn at 30 keV, 10.356 cm⁻¹ for PMMA-La at 40 keV, 7.353 cm⁻¹ for PMMA-Sm at 50 keV, 5.761 cm⁻¹ for PMMA-Er at 60 keV, 4.204 cm⁻¹ for PMMA-W at 70 keV, and 3.300 cm⁻¹ for PMMA-Pb at 90 keV, corresponding closely to the K-edge energies of the respective elements. Notably, all composites outperformed PbO in attenuation efficiency within their respective K-edge regions. These findings highlight the potential of strategically exploiting K-edge absorption to design lightweight, non-toxic PMMA-based shielding materials optimized for specific dental imaging modalities.
First analysis of associations between residential radon exposure and cancer risks in the CONSTANCES cohort.
Henyoh AMS, Lequy E, Cléro E … +13 more , Gréau C, Vignaud C, Ancelet S, Mukakalisa C, Ribet C, Coeuret-Pellicer M, Kab S, Mandin C, Sauce J, Ielsch G, Goldberg M, Zins M, Laurent O
Radiat Environ Biophys · 2026 May · PMID 42295407 · Publisher ↗
Radon exposure is an established risk factor for lung cancer, but its potential role in risks of other cancers remains unclear. A recent systematic review recommended more in-depth studies of specific cancer sites as pot...
Radon exposure is an established risk factor for lung cancer, but its potential role in risks of other cancers remains unclear. A recent systematic review recommended more in-depth studies of specific cancer sites as potential long-term effects of radon exposure, especially during childhood. Here we investigated the association between lifelong residential radon exposure and the risks of various cancers, and the potential role of age at exposure. Study participants were selected from the French population-based CONSTANCES cohort recruited at adult age over the period 2012-2019. Radon exposure was reconstructed by linking lifelong residential histories with estimated municipality-level indoor radon concentrations. We fitted for each cancer site studied a time-dependent Cox proportional hazards model to assess the association between cumulative annual average residential radon exposure and the age at diagnosis of specific primary incident cancer, expressed as a Hazard Ratio per 1000 Bq.m-years exposure and the corresponding 95% confidence interval. The models were adjusted for birth cohort, diploma, time-varying region of residence, and where appropriate, time-varying smoking status. At the end of follow-up in year 2022, 7433 (12%) participants over 61,366 were diagnosed with incident primary cancer. The median age at time of censoring was 55 years old (Q1, Q3 = 44, 65). Based on current follow-up, no robust association was observed between radon exposure and any of the targeted cancers. The main limitations of this study to date are the semi-ecological approach used for exposure reconstruction which should be improved in the future, and the still limited duration of follow-up after inclusion. The richness of the CONSTANCES cohort combined with extended follow-up and planned improvements in radon exposure assessment will further increase the potential of future investigations.
Validation of dosimetric characteristics of the GammaMed Plus Ir HDR brachytherapy source using the GATE Monte Carlo code.
Slimani A, Khallouqi A, Mlouk LA … +5 more , Elaouam HA, Nassar H, Sekkat H, Halimi A, El Rhazouani O
Radiat Environ Biophys · 2026 Jun · PMID 42257907 · Publisher ↗
This study aimed to validate the dosimetric parameters of the Ir GammaMed Plus source used in high-dose-rate (HDR) brachytherapy, using the Monte Carlo simulation code GATE (version 9.3), in accordance with the American...
This study aimed to validate the dosimetric parameters of the Ir GammaMed Plus source used in high-dose-rate (HDR) brachytherapy, using the Monte Carlo simulation code GATE (version 9.3), in accordance with the American Association of Physics in Medicine (AAPM) TG-43 protocol recommendations. The source was modelled inside a 40 cm diameter water-filled spherical phantom to accurately replicate clinical conditions. The dose rate constant, radial dose function g(r), anisotropy function [Formula: see text], and the two-dimensional dose rate distribution matrix were calculated using the DoseActors modules. The results showed excellent agreement with reference data: the dose rate constant was [Formula: see text], with a maximum difference from values reported in the literature of 0.76%, and average deviations of 1.2% and 1.4% for g(r) and [Formula: see text], respectively. These findings suggest that GATE provides reliable and accurate dosimetric estimations and may be a useful tool for dosimetric validation in research settings, particularly in heterogeneous media.
NORM dust intake: comparison of personal air sampling and bioassays.
Hewson GS, Ralph MI, Cattani M
Radiat Environ Biophys · 2026 Jun · PMID 42257906 · Publisher ↗
Intake of naturally occurring radioactive materials (NORM), particularly the inhalation of thorium-bearing dust in mineral sand operations, has traditionally been assessed via personal air sampling (PAS). However, data f...
Intake of naturally occurring radioactive materials (NORM), particularly the inhalation of thorium-bearing dust in mineral sand operations, has traditionally been assessed via personal air sampling (PAS). However, data from bioassay studies suggest that the actual intake determined via PAS may be underestimated. This review integrates thorium intake estimates derived from historical bioassay datasets, such as urine, faeces, lung counting, and thoron-in-breath tests, with historical PAS data. The findings indicated that bioassay-based predictions of intake were consistently greater, with mean bioassay-to-PAS intake ratios ranging from 2.6 to 4.2. The contributing factors to this discrepancy include biokinetic model uncertainties, potential dust sampler bias, the PAS strategy, high variability of exposure within similar exposure groups (SEGs), self-absorption of alpha particles during the radiometric analysis of filtered dust samples, and nonaccounting for respiratory protection. This review suggests improvements to current PAS-based dose assessments, including sampling and analysis protocols. We recommend that PAS be supplemented by targeted bioassay monitoring, where feasible, to improve dose estimation and worker protection in NORM industries.
Towards a phantom-based quantitative assessment of dose reduction and image-quality trade-offs in half- and full-rotation dental CBCT protocols: a thermoluminescent dosimetry approach with clinical insight.
Amasya H, Günay O, Kesmezacar FF … +8 more , Akdoğan ET, Tunçman Kayaokay D, Karaçam SÇ, Yeyin N, Demir M, Orhan K, ALMisned G, Tekin HO
Radiat Environ Biophys · 2026 Jun · PMID 42257905 · Publisher ↗
This study aimed to compare full- (360°) and half-rotation (180°) dental cone-beam computed tomography (CBCT) protocols in terms of effective dose (ED) and quantitative image quality for the maxilla and mandible regions....
This study aimed to compare full- (360°) and half-rotation (180°) dental cone-beam computed tomography (CBCT) protocols in terms of effective dose (ED) and quantitative image quality for the maxilla and mandible regions. An Alderson Radiation Therapy phantom was imaged using a Hyperion X9 Pro (Cefla, Imola) CBCT device with a 10 × 6 cm field of view. Both anatomical regions were acquired using full- and half-rotation protocols. A total of 67 thermoluminescence dosimeters were positioned in the phantom for ED calculations. Quantitative image-quality assessment was performed using axial slices extracted from each volume, and signal-to-noise ratio (SNRs) and contrast-to-noise ratio (CNRs) were calculated. The EDs were 406.33 µSv (full-rotation) and 208.29 µSv (half-rotation) for the maxilla, and 248.94 µSv (full-rotation) and 73.63 µSv (half-rotation) for the mandible. These doses corresponded to dose reductions of 48.74% in the maxilla and 70.42% in the mandible. SNRs and CNRs decreased by 36.69% and 34.74% in the maxilla, and by 49.95% and 50.28% in the mandible, respectively. Dose reduction was more pronounced in the mandible than in the maxilla, and this was accompanied by a greater loss in SNR and CNR. It is concluded that protocol selection should be guided by diagnostic requirements and adherence to the "As Low as Diagnostically Acceptable being Indication-oriented and Patient-specific (ALADAIP) principle.
Temporal and spatial patterns of γH2AX signaling in different human cells after exposure to X-rays and UV-C light.
Guardamagna I, Lonati L, Iaria O … +12 more , Mentana A, Parodi D, Peterlin G, Semerano R, Riani C, Previtali A, Tricarico A, de Fatis PT, Ivaldi GB, Perucca P, Cazzalini O, Baiocco G
Radiat Environ Biophys · 2026 May · PMID 42171732 · Full text
The phosphorylation of H2AX at serine 139 (γH2AX) is a marker of DNA damage response, well characterized after ionizing radiation (IR) exposure. In this work we compared γH2AX activation in different human cell lines exp...
The phosphorylation of H2AX at serine 139 (γH2AX) is a marker of DNA damage response, well characterized after ionizing radiation (IR) exposure. In this work we compared γH2AX activation in different human cell lines exposed to X-rays, up to 5 Gy, or UV-C light (below ionization threshold), up to 40 J/m. We selected HeLa, Caco-2 and HaCaT cells as models with different origins and radiosensitivity, conventionally screened with the clonogenic assay. We integrated data from fluorescence microscopy and flow cytometry. Results highlight that γH2AX spatial pattern is determined by the genotoxic agent: X-rays induce discrete, countable foci (associated with DNA double-strand breaks), while UV-C leads to pan-nuclear signal distributions. Instead, dose-response curves are strongly dependent on the cell-line, showing linear or saturating trends, not attributable to the readout technique. After 5 Gy X-rays, γH2AX signal peaks within 1 hour. The residual intensity at 24 hours is compatible with the control for all cell lines; however, cells show different clonogenic survival fractions at 7 days. The kinetics of γH2AX positive cells following 20 J/m UV-C exposure is completely different, with a slower accumulation and persistent signaling from viable cells (not restricted to the S-phase) up to 24 hours, but with a loss of clonogenic potential in the long-term. These findings emphasize that γH2AX marker may be considered as a functional sensor of DNA damage response rather than a marker of specific DNA lesions, and that both radiation quality and cellular context must be considered for its correct interpretation.
Biokinetic modelling of the exhalation of Rn gas and its airborne progeny from patients undergoing treatment with Ra-dichloride and effective dose estimation for caregivers.
Katzdobler L, Delker A, Giussani A … +5 more , Hürkamp K, Kuttler C, Meisenberg O, Ziegler S, Li WB
Radiat Environ Biophys · 2026 May · PMID 42149170 · Full text
The radiopharmaceutical 223Ra-dichloride (Xofigo®) has been approved for palliative treatment of metastatic castration-resistant prostate cancer. During the treatment and caregiving, patients who received 223Ra-dichlorid...
The radiopharmaceutical 223Ra-dichloride (Xofigo®) has been approved for palliative treatment of metastatic castration-resistant prostate cancer. During the treatment and caregiving, patients who received 223Ra-dichloride can exhale the progeny 219Rn, a radioactive gas. This causes a potential risk for medical staff and caregivers who might inhale the 219Rn gas and its airborne decay products. As an addition to the strategies of developing devices for measuring 219Rn gas and its daughter nuclides in treatment rooms, this work tried to estimate the amount of exhaled 219Rn and of its airborne progeny using biokinetic modelling. The biokinetic models and parameters for 223Ra and its progeny 219Rn, as published by the International Commission of Radiological Protection, were adopted for this analysis. Without consideration of room ventilation, the model predicted that the amount of 219Rn gas in the room air can reach a maximum activity of 5.8∙10− 2 Bq at approximately 1.5 min after infusion of one Bq of 223RaCl2. The summed activities of 219Rn and its airborne progeny do not exceed 1.2∙10− 1 Bq per infused Bq of 223RaCl2. In the breathing air of the patients, the activities at 1 and 5 min after the infusion were estimated to be approximately 2∙10− 2 Bq and 1.8∙10− 2 Bq per Bq of 223RaCl2, respectively. The values at 1 min are comparable to the measured results reported in the literature. The effective dose from inhalation of 219Rn gas and its airborne progeny due to a treatment of 4015 kBq of 223RaCl2, was estimated to be 232.6 nSv for medical staff and 7.5 µSv for caregivers.
Evaluation of the absorbed-dose response of EBT3, EBT4, HD-V2, MD-V3, and RTQA2 gafchromic films as a function of photon energy.
Khosravani M, Baghani HR, Shamsabadi R
Radiat Environ Biophys · 2026 May · PMID 42108325 · Publisher ↗
The Energy dependence of the dose response is a primary characteristic of a radiation dosimeter. Although an ideal dosimeter should exhibit an independent energy response over the range of use, all types of dosimeters sh...
The Energy dependence of the dose response is a primary characteristic of a radiation dosimeter. Although an ideal dosimeter should exhibit an independent energy response over the range of use, all types of dosimeters show some energy dependence. The current study aimed to evaluate this energy dependence of some gafchromic films in a photon field through Monte Carlo (MC) simulations using the MCNPX code. Five gafchromic films including EBT3, EBT4, HD-V2, MD-V3, and RTQA2 were considered and the energy dependence was evaluated for monochromatic and some polychromatic clinical photon beams. The results showed that all considered films show an energy dependent dose response. Specifically, the energy dependence was highly evident at photon energies below 60 keV. Among the studied films, the EBT4 and MD-V3 films showed the least and most energy dependence, respectively. Changing from monochromatic nature of photon beam to a polychromatic clinical beam changed film energy dependence response at keV energy range. Although considered gafchromic films are characterized as dosimeters with energy-independent response, all studied films showed a degree of absorbed-dose energy dependence. This observed energy dependence may be of concern in absorbed dose measurements, especially at low photon energies.
Assessing cumulative radon decay products in blood samples as a biological proxy for lung cancer risk: a matched case-control study in babylon, Iraq.
Essa HO
Radiat Environ Biophys · 2026 May · PMID 42108324 · Publisher ↗
Lung cancer is the most common malignancy among Iraqi males, yet comprehensive radon exposure data remain scarce. This matched case-control study investigated the cumulative burden of long-lived radon decay products (²¹⁰...
Lung cancer is the most common malignancy among Iraqi males, yet comprehensive radon exposure data remain scarce. This matched case-control study investigated the cumulative burden of long-lived radon decay products (²¹⁰Pb/²¹⁰Po) in dried blood samples as a biological proxy for radon exposure in Babylon Governorate, Iraq. Blood samples were collected from 38 lung cancer patients and 38 age- and sex-matched healthy controls, lyophilized, and analyzed using CR-39 solid-state nuclear track detectors over a 120-day exposure period. Linear mixed-effects modelling, accounting for the matched design and potential confounders, revealed significantly higher radon decay product concentrations in cases compared to controls (adjusted mean difference: 67.95 Bq/m³; 95% confidence interval (CI): 57.43-78.46; p < 0.001). Age was positively associated with concentration (7.56 Bq/m³ per year; p < 0.001), reflecting cumulative environmental exposure. Male smokers showed significantly higher concentrations than male non-smokers (24.9 Bq/m³; p = 0.039), while no significant smoking-related difference was observed in females. These findings validate dried blood samples with CR-39 detectors as a sensitive tool for assessing cumulative radon progeny burden and underscore the urgent need for targeted radon mitigation strategies in Iraq, particularly for smokers and older populations.
Naturally occurring radionuclides (NOR) and rare earth elements (REE) in soil and cereals in a high background area, Fen complex, Norway.
Haanes H, Gjelsvik R, Hoftuft J … +1 more , Brown J
Radiat Environ Biophys · 2026 May · PMID 42080919 · Full text
Some areas of the world have high natural background levels of naturally occurring radionuclides (NOR) and/or rare earth elements (REE). With high background radiation risk, knowledge about, for example, uptake by crops...
Some areas of the world have high natural background levels of naturally occurring radionuclides (NOR) and/or rare earth elements (REE). With high background radiation risk, knowledge about, for example, uptake by crops is required in the process of assessing radiation doses to humans. In the Fen complex, in Norway, underlying bedrock has elevated levels of both NOR and REE. In Mining hill where these bedrocks surface and there are also legacy mines, soils also have high background levels. Most of Fen complex is, however, covered by thick Holocene deposits but some of its agricultural soils are situated near the areas of surfacing carbonatite bedrock and legacy mines. We assess whether there has been any influence on the levels in the agricultural soils within the Fen complex from the areas with high NOR and REE soil background. We also determine uptake from soils by cereals into grain or grain with hull, and present concentration ratios (CR) for NOR and REE in this high background area. In particular, the REE CRs are an important augmentation to existing sparse datasets. We furthermore assess whether uptake can be biased by any soil particles adhering to cereal grain or grain with hull. We investigate whether washing (or not washing) and use of different acids for dissolution may affect ICP-MS results on common elements. We also address soil mass in cereal samples using Scandium and Titanium as tracers for soil particles and assess the potential magnitude of bias CR.
Effects of ionizing radiation on earthworms under long-term exposure: a review.
Maystrenko T, Rybak A
Radiat Environ Biophys · 2026 May · PMID 42043533 · Publisher ↗
Our review includes well-known works as well as relatively new experimental articles (published from 2015 to 2024) addressing the impact of prolonged exposure to soil with elevated radionuclide levels on earthworm popula...
Our review includes well-known works as well as relatively new experimental articles (published from 2015 to 2024) addressing the impact of prolonged exposure to soil with elevated radionuclide levels on earthworm populations, as well as organismal, cellular, and molecular parameters in individuals. It was shown that the negative influence of ionizing radiation on earthworms was not recorded in all studies. The reasons for this could be both the relatively high overall radioresistance of members of the taxon or non-ideal habitat conditions for earthworm populations in the studied areas (contaminated or reference). Yet, negative effects at individual and sub-individual levels in organisms from the contaminated areas or subjected to low-dose long-term radiation were often noted in the absence of any changes in population endpoints. Damages to tissues and cells were observed in earthworms inhabiting areas with enhanced concentrations of technologically enhanced natural radioactive materials (TENORM) in the soil. Overall, the results of studies on the effects of radionuclide-contaminated soil on soil invertebrates indicate a high potential for survival and maintenance of earthworm populations even with short-term disruptions to their age structure and reproductive capacity. The use of -omics technologies in such studies makes it possible to identify new biomarkers that respond to sub-chronic and chronic radiation exposure, to uncover complex mechanisms of radionuclide detoxification, radiation resistance, and adaptation to long-term radiation exposure, and to provide a more accurate assessment of the consequences for wildlife.
A novel paradigm in radiotherapy planning techniques comparison for dosimetric and secondary cancer risk assessment in right-sided modified radical mastectomy.
Jose A, George A, Singh AP … +1 more , Ladia DD
Radiat Environ Biophys · 2026 May · PMID 42026345 · Publisher ↗
Radiotherapy for right-sided modified radical mastectomy (MRM) patients carries a risk of secondary malignancies due to radiation exposure to nearby organs-at-risk (OARs). Techniques such as 3D-CRT, IMRT (sliding window)...
Radiotherapy for right-sided modified radical mastectomy (MRM) patients carries a risk of secondary malignancies due to radiation exposure to nearby organs-at-risk (OARs). Techniques such as 3D-CRT, IMRT (sliding window), and VMAT differ in their dose distribution to these OARs. This retrospective study analyzed dose-volume histograms from 25 female patients with right-sided MRM to compare the three techniques in terms of dosimetric parameters, radiobiological outcomes, and secondary cancer risks. Mean doses to key OARs-the heart, contralateral lung, ipsilateral lung, and contralateral breast-were evaluated, and NTCP calculations were used to quantify radiation-induced secondary malignancy risks. 3D-CRT delivered lower mean doses to contralateral OARs, reducing secondary cancer risks compared to IMRT and VMAT, but was associated with higher NTCP in the ipsilateral lung. VMAT achieved superior target conformity but increased low-dose exposure to contralateral OARs, raising secondary cancer risks. These findings highlight the importance of individualized treatment planning for right-sided MRM patients. Overall, 3D-CRT appears favorable for minimizing secondary cancer risks in contralateral organs, despite higher ipsilateral lung NTCP. This study provides a framework for integrating dosimetric, radiobiological, and secondary cancer risk assessments in radiotherapy planning, supporting future strategies to optimize both efficacy and safety.
Mathematical modelling of time-dependent radiobiological effects in radiotherapy using In vivo tumour dynamics.
Nakano H, Shiinoki T, Utsunomiya S … +3 more , Tanabe S, Kaidu M, Ishikawa H
Radiat Environ Biophys · 2026 May · PMID 42026344 · Publisher ↗
In the present study the impact of a prolonged dose-delivery time on tumour control was evaluated by using a mathematical tumour model calibrated with in vivo tumour volume data. While in vitro studies have reported redu...
In the present study the impact of a prolonged dose-delivery time on tumour control was evaluated by using a mathematical tumour model calibrated with in vivo tumour volume data. While in vitro studies have reported reduced radiobiological effects with extended dose-delivery time, the in vivo relevance remains uncertain. Here, such effects were explored across various fractionation protocols and temporal delivery conditions. A biologically based mathematical model was developed using tumour volume data from CT26 murine models subjected to different radiation protocols (5 × 2 Gy, 1 × 7 Gy, and 3 × 4 Gy). The model integrated microdosimetric kinetic modelling (MKM) and ordinary differential equations to simulate tumour dynamics. Simulations were conducted for dose-delivery times of 0, 10, 30, 60, and 120 min, and the changes in tumour volume relative to instantaneous delivery (0 min) were evaluated. All protocols exhibited increased tumour volumes with longer delivery times. The 1 × 7 Gy protocol showed the highest effect, with a 5% increase in tumour volume at approximately 42.5 min. The 5 × 2 Gy protocol maintained tumour volumes within 5% even at delivery times exceeding 100 min. These dose-delivery time thresholds for a 5% volume increase differed between early (1 day post-irradiation) and late (30 days) evaluations. Prolonged dose-delivery time could compromise tumour control, with its impact varying by fractionation protocol. The results obtained provide a framework to quantify time sensitivity in radiotherapy, and they support the use of mathematical tumour models to assess the impact of potential dose uncertainties arising from prolonged dose-delivery times on tumour control.
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