Search Results (54)

Extensive research is being carried out on the application of $\alpha$ particles for cancer treatment. A key challenge in $\alpha$ therapy is how to deliver the $\alpha$ emitters to the tumour. In AlphaGlue, a novel treatment delivery concept, the $\alpha$ emitters are suspended in a thin layer of glue that is put on top of the tumour. In principle, this should be an easy and safe way to apply $\alpha$ therapy. In this study, the effectiveness of AlphaGlue is evaluated using GEANT4 and GEANT4-DNA simulations to calculate the DNA damage as a function of depth. Two radionuclides are considered in this work, ²¹¹At and ²²⁴Ra. The results indicate that, as a concept, the method offers a promising hypothesis for treating superficial tumours, such as skin cancer, when ²²⁴Ra is applied directly on the tissue and stabilized with a glue layer. This results in 2$\times {10}^{-5}$ complex double strand breaks and 5$\times {10}^{-5}$ double strand breaks at 5 mm depth per applied ²²⁴Ra atom. When applying a ²²⁴Ra atom concentration of $(4.35\pm 0.2)\times {10}^{11}/$cm² corresponding to an activity of $(21.8\pm 1)\mathsf{\mu }$Ci/cm² on the skin surface, the RBE weighted dose exceeds 20 Gy at 5 mm depth. Hence, there is significant cell death at 5 mm into the tissue; a depth matching clinical requirements for skin cancer treatment. Given the rapidly falling weighted dose versus depth curve, the treatment depth can be tuned with good precision. The results of this study show that AlphaGlue is a promosing treatment and open the pathway towards the next stage of the research, which includes in-vitro studies. Full article

Positron emission tomography (PET) imaging targeting glypican-3 (GPC3) holds promise for improving the detection and characterization of hepatocellular carcinoma (HCC). Preclinical and early clinical studies have largely utilized high-molecular-weight antibodies radiolabeled with isotopes such as ⁸⁹Zr and ¹²⁴I, demonstrating high affinity and tumor uptake but suffering from prolonged circulation times and suboptimal signal-to-background ratios. To address these limitations, interest has shifted toward low-molecular-weight vectors—synthetic peptides and small antibody fragments—labeled with shorter-lived radionuclides (e.g., ⁶⁸Ga and ¹⁸F) to enable rapid pharmacokinetics and same-day imaging protocols. Emerging platforms such as affibodies and aptamers offer further advantages in target affinity and reduced immunogenicity. However, clinical translation requires rigorous validation: larger, histologically confirmed cohorts, head-to-head comparison with CT/MRI, and correlation with hard clinical endpoints. Moreover, leveraging GPC3 expression as a biomarker could guarantee a deeper knowledge of tumor biology—differentiation grade and vascular invasion risk—and guide theranostic strategies. While β-emitters (⁹⁰Y, ¹⁷⁷Lu) have been explored for GPC3-directed therapy, their efficacy is influenced by oxygenation and cell-cycle status, whereas α-emitters (²²⁵Ac) may overcome these constraints, albeit with challenges in radionuclide selection and daughter nuclide management. Finally, dual-targeting probes combining GPC3 and prostate-specific membrane antigen (PSMA) have demonstrated superior uptake and retention in murine models, suggesting a versatile approach for future clinical diagnostics and therapy planning. Full article

This study investigated the spatial distribution and radiological risks of naturally occurring radionuclides (²²⁶Ra, ²³²Th, ⁴⁰K) in 37 soil samples from Zacatecas, located in north-central Mexico, using high-resolution gamma spectrometry. Results revealed ⁴⁰K concentrations (mean: 736.81 Bq kg⁻¹), nearly double the global average, while ²²⁶Ra (29.96 Bq kg⁻¹) and ²³²Th (29.72 Bq kg⁻¹) aligned with worldwide norms. Geoaccumulation indices identified moderate ⁴⁰K accumulation at 22 sites, with El Capulín classified as moderately contaminated (I_geo = 1.07). Radiological risk indices showed absorbed dose rates (62.52 nGy h⁻¹) and excess lifetime cancer risk (0.330 × 10⁻³) exceeding global thresholds by 4% and 14%, respectively. Multivariate analyses demonstrated strong Spearman correlations (ρ = 0.75–1.00) among risk indices, while spatial interpolation identified southern/western regions as high-risk zones. These findings emphasize the necessity of integrating spatial analysis with multivariate statistical techniques in environmental radioprotection frameworks. While most of the study area complies with international safety standards, the identified zones exceeding dose thresholds warrant prioritized management to mitigate potential cumulative health risks. Full article

This study focused on identifying Th-, Nb-Ta-, Zr-, and REE-bearing minerals with a multivariate statistical approach in alkaline syenite to evaluate their radiological risks, at Nikeiba, Egypt. Through microchemical analyses, by utilizing electron probe microanalysis, horite, microlite, monazite, zircon, columbite, and fergusonite were shown to bear uranium and thorium. These minerals have played an important role in higher radioactive zones in the studied alkaline syenite. REE-minerals comprising bastnäsite, monazite, and fluorite and apatite are well recorded. The total rare earth elements (TREE₂O₃) reveal higher concentrations in bastnäsite than monazite, with averages 74.87 and 63.8 wt%. Ce is considered the most predominant LREE in the analyzed bastnäsite and monazite. The mean values of radionuclide activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K are 108 ± 20 Bq/kg, 107 ± 9 Bq/kg, and 1255 ± 166 Bq/kg, respectively. Radiological assessments revealed a radium equivalent activity of 357 Bq/kg, below global limits, but an air-absorbed dose rate (166 nGy/h) and annual effective doses (0.81 mSv/y indoors, 0.20 mSv/y outdoors) exceeding safe thresholds. Additionally, the excess lifetime cancer risk (ELCR) was calculated at 0.00071, surpassing the acceptable limit of 0.00029, making these rocks unsafe for construction use. Statistical analyses further underscored the relationships between radionuclide concentrations and associated risks, highlighting the necessity for continuous monitoring and mitigation. Full article

Soil samples were collected from a college campus in Taiwan to measure the levels of radionuclides, contributing to the sustainable management of campus environments. A high-resolution HPGe gamma spectrometry system was utilized to measure the activity concentrations of natural radionuclides (²²⁶Ra, ²³²Th, and ⁴⁰K) and artificial radionuclide (¹³⁷Cs). The activity concentrations of ¹³⁷Cs were not detected in the campus soils, suggesting that artificial radionuclides did not contaminate the soil, supporting sustainable soil quality. However, the average concentrations of ²³²Th and ⁴⁰K with mean values of 53.4 ± 5.1 and 504.5 ± 75.4 Bq/kg dw were higher than the global soil average of 45 and 420 Bq/kg dw, respectively. Meanwhile, the average concentration of ²²⁶Ra with a mean value of 30.1 ± 3.0 Bq/kg dw was similar to the global soil average of 32 Bq/kg. The average outdoor absorbed gamma dose rate (D_ex) and annual effective doses (AED_ex), with a mean of 67.2 nGy/h and 82.4 μSv/y, were found to be higher than the average world levels of 57 nGy/h and 70 μSv/y, respectively. Despite these findings, the radium equivalent activity Ra_eq and external hazard index H_ex, with average values of 145.2 Bq/kg and 0.39, respectively, were below the recommended limit values of 370 Bq/kg and 1.0, respectively. This study provides useful information on the background radioactivity of the study campus, which is crucial for developing sustainable strategies to ensure a safe and healthy environment, indicating that there are no radiological hazards in the soil. Full article

The formation of an aluminosilicate gel structure made of alkali-activated materials (AAMs) was conducted through an alkali-activation reaction of the solid precursors (fly ash, metakaolin, and wood ash). Fly and wood ash are by-products of the burning process of coal and wood, respectively. Alkali-activated materials of aluminosilicate origin, made from the different ashes, fly and wood, are very attractive research targets and can be applied in various technological fields due to their thermal stability, resistance to thermal shock, high porosity, high sustainability, and finally, low energy loss during production. In this paper, we evaluate physico-chemical properties, microstructure, and radiological environmental impacts when wastes that contain elevated levels of naturally occurring radionuclides (NORs) such as fly ash and wood ash are made into “green cements” such as AAMs. The determination of radionuclide content was performed by means of gamma-ray spectrometry. Results showed that the AAMs have a lower value in the activity concentration of radionuclides than raw materials. The external absorbed gamma dose rate was 74.7–107.3 nGy/h, and the external radiation hazard index values were in range of 0.445–0.628 Bq/kg. The results of the activity concentration measurements for alkali-activated materials indicate the potential of their safe application in building construction. In terms of the structural characterizations, the obtained alkali-activated materials were examined using XRD, DRIFT, FESEM, and TEM analyses. Full article

The combination of high and low LET radionuclides has been tested in several patient studies to improve treatment response. Radionuclide mixtures can also be released in nuclear power plant accidents or nuclear bomb deployment. This study investigated the DNA damage response and DNA double-strand break (DSB) repair in peripheral blood mononuclear cells (PBMCs) after internal exposure of blood samples of 10 healthy volunteers to either no radiation (baseline) or different radionuclide mixtures of the α- and β-emitters [²²³Ra]RaCl₂ and [¹⁷⁷Lu]LuCl₃, i.e., 25 mGy/75 mGy, 50 mGy/50 mGy and 75 mGy/25 mGy, respectively. DSB foci and γ-H2AX α-track enumeration directly after 1 h of exposure or after 4 h or 24 h of repair revealed that radiation-induced foci (RIF) and α-track induction in 100 cells was similar for mixed α/β and pure internal α- or β-irradiation, as were the repair rates for all radiation qualities. In contrast, the fraction of unrepaired RIF (Q_β) in PBMCs after mixed α/β-irradiation (50% ²²³Ra & 50% ¹⁷⁷Lu: Q_β = 0.23 ± 0.10) was significantly elevated relative to pure β-irradiation (50 mGy: Q_{β, pure} = 0.06 ± 0.02), with a similar trend being noted for all mixtures. This α-dose-dependent increase in persistent foci likely relates to the formation of complex DNA damage that remains difficult to repair. Full article

Chiang Mai province of Thailand is known for having the highest natural background radiation in the country, as well as being recognized as one of the world’s most polluted cities for air quality. This represents the major contributor to the development of lung cancer. This research aims to estimate the comprehensive dose of both internal and external exposure due to natural background radiation and related health perspectives in the highly polluted area of Chiang Mai. The average values of indoor radon and thoron concentrations in 99 houses over 6 months were 40.8 ± 22.6 and 17.8 ± 16.3 Bq/m³, respectively. These results exceed the worldwide value for indoor radon and thoron (40 and 10 Bq/m³), respectively. During burning season, the average values of indoor radon (56.7 ± 20 Bq/m³) and thoron (20.8 ± 20.4 Bq/m³) concentrations were higher than the world-wide averages. The radon concentration in drinking water (56 samples) varied from 0.1 to 91.9 Bq/L, with an average value of 9.1 ± 22.8 Bq/L. Most of the drinking water samples (87%) fell below the recommended maximum contamination limit of 11.1 Bq/L. The average values of natural radionuclide (²²⁶Ra, ²³²Th and ⁴⁰K) in 48 soil samples were 47 ± 20.9, 77.9 ± 29.7 and 700.1 ± 233 Bq/kg, respectively. All values were higher than the worldwide average of 35, 30 and 400 Bq/kg, respectively. The average value of outdoor absorbed gamma dose rate (98 ± 32.5 nGy/h) exceeded the worldwide average of 59 nGy/h. Meanwhile, the average activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in 25 plant food samples were 2.7 ± 0.1, 3.2 ± 1.6 and 1000.7 ± 1.9 Bq/kg, respectively. The ⁴⁰K concentration was the most predominant in plant foods. The highest concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were found in Chinese cabbage, celery and cilantro, respectively. The total annual effective dose for residents in the study area varied from 0.6 to 4.3 mSv, with an average value of 1.4 mSv. This indicates a significant long-term public health hazard due to natural background radiation and suggests a heightened radiation risk for the residents. The excess lifetime cancer risk value (5.4) associated with natural background radiation was found to be higher than the recommended value. Moreover, the number of lung cancer cases per year per million average of 25.2 per million persons per year was in the limit range 170–230 per million people. Overall, our results will be used for future decision making in the prevention of lung cancer risk associated with natural background radiation. Full article

Transarterial chemoembolization (TACE) is currently the standard of care in patients with unresectable hepatocellular carcinoma (HCC), and selective internal radionuclide therapy (SIRT) with ⁹⁰Y microspheres is mainly used as an alternative modality in patients considered poor candidates for TACE. Treatment with sorafenib is the recommended option for patients with progressive disease after TACE. This study aims to evaluate the safety and efficacy of SIRT with glass microspheres in patients with progressive HCC after repeated TACE who are not eligible for treatment with sorafenib. Forty-seven patients with progressive HCC after a median of three TACE sessions (range 2–14) underwent SIRT (3.5 ± 1.5 GBq; liver target dose 110–120 Gy). Toxicity was recorded 4 and 12 weeks after treatment and reported according to the Common Terminology Criteria for Adverse Events Version 5.0. Treatment response was assessed three months after SIRT using multiphase computed tomography and modified criteria in solid tumors (mRECIST). Survival analyses were performed using Kaplan–Meier curves and a Cox proportional hazards model for uni- and multivariate analyses. Significant but reversible hepatotoxicity (≥grade 3) occurred in five patients (11%). No radioembolization-induced liver disease (REILD) was observed. The number of previous TACE sessions and cumulative administered activity did not predict the incidence of post-SIRT significant hepatotoxicity. Treatment responses consisted of partial responses in 26 (55%), stable disease in 12 (26%), and progressive disease in 9 (19%) patients. The median overall survival (OS) was 11 months (95% confidence interval (CI), 9–13), and objective responses to SIRT were associated with a longer OS (p = 0.008). Significant hepatotoxicity (≥grade 3) after SIRT was a contributor to impaired survival (median OS 6 months (95% CI, 4–8) vs. 12 months (95% CI, 10–14), p < 0.001). SIRT with glass microspheres is a safe and effective salvage treatment for patients with progressive HCC refractory to TACE who are considered poor candidates for sorafenib treatment. Full article

Background: The combination of platinum-containing cytostatic drugs with different radiation qualities has been studied for years. Despite their massive side effects, these drugs still belong to the therapeutic portfolio in cancer treatment. To overcome the disadvantages of cisplatin, our study investigated the cytotoxic effects of combining radionuclides with cisplatin. Methods: FaDu cells were treated with cisplatin (concentration ≈ 2 µM) and additionally irradiated after two hours with the alpha-emitter ²²³Ra, the beta-emitter ¹⁸⁸Re as well as external X-rays using dose ranges of 2–6 Gy. Cell survival was followed by colony formation assays and plotted against cisplatin concentration and radiation dose. The results were interpreted by isobolograms. Results: Isobolographic analyses revealed a supra-additive cytotoxic effect for the combination of cisplatin and ²²³Ra. A sub-additive effect was observed for the combination of cisplatin and ¹⁸⁸Re, whereas a protective effect was found for the combination with X-rays. Conclusions: The combination of cisplatin and ²²³Ra may have the potential to create a successfully working therapy scheme for various therapy approaches, whereas the combination with ¹⁸⁸Re as well as single-dose X-ray treatment did not lead to a detectable radiosensitizing effect. Thus, the combination with alpha-emitters might be advantageous and, therefore, should be followed in future studies when combined with cytostatic drugs. Full article

A novel solid-phase synthetic approach was developed to produce a mineral-like composite ceramic based on strontium titanate (SrTiO₃) and yttrium titanate (Y₂Ti₂O₇) matrices for immobilizing radionuclides such as ⁹⁰Sr and its daughter product ⁹⁰Y, as well as lanthanides and actinides, via reactive spark plasma sintering technology (SPS-RS). Using XRD, SEM, and EDS analyses, the sintering kinetics of the initial mixed oxide reactants of composition Y_xSr_1–1.5xTiO₃ (x = 0.2, 0.4, 0.6 and 1) and structure-phase changes in the ceramics under SPS-RS conditions were investigated as a function of Y³⁺ content. In addition, a detailed study of phase transformation kinetics over time as a function of the heating temperature of the initial components (SrCO₃, TiO₂, and Y₂O₃) was conducted via in situ synchrotron XRD heating experiments. The composite ceramic achieved relatively high physicomechanical properties, including relative density between 4.92–4.64 g/cm³, Vickers microhardness of 500–800 HV, and compressive strength ranging from 95.5–272.4 MPa. An evaluation of hydrolytic stability and leaching rates of Sr²⁺ and Y³⁺ from the matrices was performed, demonstrating rates did not exceed 10⁻⁵–10⁻⁶ g·cm⁻²·day⁻¹ in compliance with GOST R 50926-96 and ANSI/ANS 16.1 standards. The leaching mechanism of these components was studied, including the calculation of solution penetration depth in the ceramic bulk and ion diffusion coefficients in the solution. These findings show great promise for radioactive waste conditioning technologies and the manufacturing of radioisotope products. Full article

Microbial life can thrive in the most inhospitable places, such as nuclear facilities with high levels of ionizing radiation. Using direct meta-analyses, we have previously highlighted the presence of bacteria belonging to twenty-five different genera in the highly radioactive water of the cooling pool of an operating nuclear reactor core. In the present study, we further characterize this specific environment by isolating and identifying some of these microorganisms and assessing their radiotolerance and their ability to decontaminate uranium. This metal is one of the major radioactive contaminants of anthropogenic origin in the environment due to the nuclear and mining industries and agricultural practices. The microorganisms isolated when sampling was performed during the reactor operation consisted mainly of Actinobacteria and Firmicutes, whereas Proteobacteria were dominant when sampling was performed during the reactor shutdown. We investigated their tolerance to gamma radiation under different conditions. Most of the bacterial strains studied were able to survive 200 Gy irradiation. Some were even able to withstand 1 kGy, with four of them showing more than 10% survival at this dose. We also assessed their uranium uptake capacity. Seven strains were able to remove almost all the uranium from a 5 µM solution. Four strains displayed high efficiency in decontaminating a 50 µM uranium solution, demonstrating promising potential for use in bioremediation processes in environments contaminated by radionuclides. Full article

Peptide receptor radionuclide therapy (PRRT) has been applied to the treatment of neuroendocrine tumors (NETs) for over two decades. However, improvement is still needed, and targeted alpha therapy (TAT) with alpha emitters such as lead-212 (²¹²Pb) represents a promising avenue. A series of ligands based on octreotate was developed. Lead-203 was used as an imaging surrogate for the selection of the best candidate for the studies with lead-212. ^203/212Pb radiolabeling and in vitro assays were carried out, followed by SPECT/CT imaging and ex vivo biodistribution in NCI-H69 tumor-bearing mice. High radiochemical yields (≥99%) and purity (≥96%) were obtained for all ligands. [²⁰³Pb]Pb-eSOMA-01 and [²⁰³Pb]Pb-eSOMA-02 showed high stability in PBS and mouse serum up to 24 h, whereas [²⁰³Pb]Pb-eSOMA-03 was unstable in those conditions. All compounds exhibited a nanomolar affinity (2.5–3.1 nM) for SSTR2. SPECT/CT images revealed high tumor uptake at 1, 4, and 24 h post-injection of [²⁰³Pb]Pb-eSOMA-01/02. Ex vivo biodistribution studies confirmed that the highest uptake in tumors was observed with [²¹²Pb]Pb-eSOMA-01. [²¹²Pb]Pb-eESOMA-01 displayed the highest absorbed dose in the tumor (35.49 Gy/MBq) and the lowest absorbed dose in the kidneys (121.73 Gy/MBq) among the three tested radioligands. [²¹²Pb]Pb-eSOMA-01 is a promising candidate for targeted alpha therapy of NETs. Further investigations are required to confirm its potential. Full article

The main purpose of this study was to determine the natural radioactivity level of raw radionuclides in the metal tailings of a mine in Lhasa, Tibet, and to conduct sampling and detection in 17 typical metal tailing mines in Lhasa, Tibet. The specific activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in the samples were calculated. The total αβχγ radiation, radon concentration, and outdoor absorbed dose rate in the air 1.0 m above the ground were measured. The γ radiation levels affecting miners and their surrounding residents were assessed. The results show that the radiation dose ranges from 0.08 μSv/h to 0.26 μSv/h, and the radon concentration ranges from 10.8 Bq/m³ to 29.6 Bq/m³, which does not exceed the national radiation-related standards, and the environmental hazard risk is low. The specific activity concentration of ²²⁶Ra ranged from 8.91 Bq/kg to 94.61 Bq/kg, the specific activity concentration of ²³²Th ranged from 2.90 Bq/kg to 89.62 Bq/kg, and the specific activity concentration of ⁴⁰K was less than MDA to 762.89 Bq/kg. The average absorbed dose rate (DO) of the 17 mining areas was 39.82 nGy/h, the average annual effective dose rate (EO) was 0.057 mSv/y. The average external risk index of the 17 mining areas was 0.24, the average internal risk index was 0.34, and the average γ index was 0.31, all of which were less than the maximum permissible limit. This means that the metal tailings from all 17 mining areas were within the limit for γ radiation and, therefore, can be used in bulk as major building materials without posing a significant radiation threat to the residents of the study area. Full article

In Korea, when replacing or discarding parts of a medical linear accelerator (linac), self-disposal is required in the consideration of the activity, but there is no standard regulation to manage radioactive waste. The aim of this study is to check the activity of each part to determine the disposal time according to the clearance level for self-disposal. The results of measuring the components of the linac head parts of the disposed Varian, Elekta, and Siemens equipment were reflected in the Monte Carlo simulation to confirm the radionuclide change according to the presence or absence of impurities. To confirm the degree of activation of the linac, the main radionuclides according to the time after the linac shutdown, considering the workloads of 40/80 Gy/day of 10/15 MV linac irradiated with beams for 10 years in the results of the simulation of the linac parts, and the radionuclide concentration was confirmed. As a result of applying the clearance level for self-disposal in the notice of the Korean Nuclear Safety (KINS) to each linac head part, most parts of the 10 MV linac could be dismantled after 1 month, and 15 MV target and primary collimators were stored after a long period of time before being dismantled. Although additional radionuclides were identified according to the presence or absence of impurities, the disposal timing for each part did not change significantly. In this study, the clearance level for self-disposal for each radionuclide was applied to activated parts by three manufacturers to confirm the self-disposal timing and predict the timing at which workers are not exposed to radiation during dismantling/disposal. Full article