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To address the issue of eye lens dosimetry in nuclear industry, we initiated the project to quantify the beta and gamma-ray source term in CANDU power plants and to convert this source term into dosimetric quantities of interest, such as eye lens dose and personal dose equivalents H p (10), H p (0.07). This way, the eye lens dose can be compared with dosimetric operational quantities to evaluate whether independent dosimetry is required for eye lens protection, or present dosimetry is adequate.

The International Commission on Radiation Units and Measurements is considering revising the definitions of the operational dose quantities used for personal monitoring. This paper investigates the impacts of the proposed changes on the Public Health England two-element β/γ personal thermoluminescence dosemeter (TLD), in terms of its energy and angle dependences of responses for both skin and whole-body dose assessments. In general, the photon response of the skin element would be unaffected by the proposal, though technical issues may arise during calibration. For body photon doses, the current TLD design still produces acceptable response characteristics in some circumstances, but in general it will need to be redesigned to better match the requirements of the new operational quantity; to that end, a simple adaption is demonstrated that might provide a partial solution. For electron/beta exposures, matching the combined responses of both the body and skin elements to the dose quantities may be more challenging. The performance criteria against which dosemeters are judged may also need to be revised to reflect the proposed change.

Esta pesquisa propõe estudar as leishmanioses visceral (LV) e tegumentar (LT), em Ipatinga, município do leste mineiro, endêmico para a doença, analisando o perfil epidemiológico, distribuição temporal espacial e a interferência dos fatores climáticos da doença, no período de 2011 a 2017. O trabalho também visa correlacionar a evolução clínica e imunológica da leishmaniose humana visceral (LHV) entre os anos 2015 a 2017, por consulta a prontuários hospitalares e pela dosagem das citocinas: interleucina 6 (IL-6), interleucina 10 (IL-10), fator de necrose tumoral alfa (TNF-α), interferon gama (INF-ϒ) e fator de crescimento transformante beta (TGF-β). O trabalho mostrou que as leishmanioses visceral e tegumentar ocorreram em diferentes regiões geográficas, enquanto a menor intensidade de ventos e a baixa umidade foram relacionadas ao aumento de casos de LV no município. A presença de reservatórios infectados antecedendo a ocorrência de casos humanos foi demonstrada pela alta correlação entre a fração de cães infectados e os casos humanos no município. O comportamento clínico - imunológico da leishmaniose humana visceral evidenciou que crianças portadoras de LV de até 3 anos responderam imunologicamente à doença com maior produção de citocinas do que as demais idades de portadores da leishmaniose visceral, como mostraram os dados clínicos e laboratoriais. This research proposes to study visceral (LV) and cutaneous (LT) leishmaniasis in Ipatinga, eastern Minas Gerais, endemic to the disease, analyzing the epidemiological profile, spatial temporal distribution and the interference of climatic factors of the disease in 2011. to 2017. The study also aims to correlate the clinical and immunological evolution of visceral human leishmaniasis (LHV) between the years 2015 to 2017, by consulting the hospital records and the dosage of cytokines: interleukin 6 (IL-6), interleukin 10 (IL -10), tumor necrosis factor alpha (TNF-α), interferon gamma (INF-ϒ) and transforming growth factor beta (TGF-β). The work showed that visceral and cutaneous leishmaniasis occurred in different geographic regions while the lower wind intensity and low humidity were related to the increase of VL cases in the municipality. The presence of infected reservoirs preceding the occurrence of human cases was demonstrated by the high correlation between the fraction of infected dogs and human cases in the municipality. The clinical and immunological behavior of visceral human leishmaniasis showed that children with VL up to 3 years of age responded immunologically to the disease with higher cytokine production than other ages of visceral leishmaniasis patients, as shown by clinical and laboratory data.

Targeted radionuclide therapy, known as molecular radiotherapy is a novel therapeutic module in cancer medicine. β-radiating radionuclides have definite impact on target cells via interference in cell cycle and particular signalings that can lead to tumor regression with minimal off-target effects on the surrounding tissues. Radionuclides play a remarkable role not only in apoptosis induction and cell cycle arrest, but also in the amelioration of other characteristics of cancer cells. Recently, application of novel β-radiating radionuclides in cancer therapy has been emerged as a promising therapeutic modality. Several investigations are ongoing to understand the underlying molecular mechanisms of β-radiating elements in cancer medicine. Based on the radiation dose, exposure time and type of the β-radiating element, different results could be achieved in cancer cells. It has been shown that β-radiating radioisotopes block cancer cell proliferation by inducing apoptosis and cell cycle arrest. However, physical characteristics of the β-radiating element (half-life, tissue penetration range, and maximum energy) and treatment protocol determine whether tumor cells undergo cell cycle arrest, apoptosis or both and to which extent. In this review, we highlighted novel therapeutic effects of β-radiating radionuclides on cancer cells, particularly apoptosis induction and cell cycle arrest.

Targeted therapies for multiple myeloma (MM) include the anti-CD38 antibody daratumumab, which, in addition to its inherent cytotoxicity, can be radiolabeled with tracers for imaging and with β- and α-emitter radionuclides for radioimmunotherapy. Methods: We have compared the potential therapeutic efficacy of β- versus α-emitter radioimmunotherapy using radiolabeled DOTA-daratumumab in a preclinical model of disseminated multiple myeloma. Multiple dose levels were investigated to find the dose with the highest efficacy and lowest toxicity. Results: In a dose–response study with the β-emitter (177)Lu-DOTA-daratumumab, the lowest tested dose, 1.85 MBq, extended survival from 37 to 47 d but did not delay tumor growth. Doses of 3.7 and 7.4 MBq extended survival to 55 and 58 d, respectively, causing a small equivalent delay in tumor growth, followed by regrowth. The higher dose, 11.1 MBq, eradicated the tumor but had no effect on survival compared with untreated controls, because of whole-body toxicity. In contrast, the α-emitter (225)Ac-DOTA-daratumumab had a dose-dependent effect, in which 0.925, 1.85, and 3.7 kBq increased survival, compared with untreated controls (35 d), to 47, 52, and 73 d, respectively, with a significant delay in tumor growth for all 3 doses. Higher doses of 11.1 and 22.2 kBq resulted in equivalent survival to 82 d but with significant whole-body toxicity. Parallel studies with untargeted (225)Ac-DOTA-trastuzumab conferred no improvement over untreated controls and resulted in whole-body toxicity. Conclusion: We conclude, and mathematic modeling confirms, that maximal biologic doses were achieved by targeted α-therapy and demonstrated (225)Ac to be superior to (177)Lu in delaying tumor growth and decreasing whole-body toxicity.

Purpose: To investigate the influence of changes in α/β ratio (range 1.5-3 Gy) on iso-effective doses, with varying treatment time, in spinal cord and central nervous system tissues with comparable radio-sensitivity. It is important to establish if an α/β ratio of 2 Gy, the accepted norm for neuro-oncology iso-effect estimations, can be used. Methods: The rat spinal cord irradiation data of Pop et al. provided ED50 values for radiation myelopathy for treatment times that varied from minutes to ∼6 days. Analysis using biphasic repair kinetics, allowing for variable dose-rates, provided the best fit with repair half-times of 0.19 and 2.16 hr, each providing ∼50% of overall repair; with an α/β ratio 2.47 Gy (CI 1.5-3.95 Gy). Using the above data set, graphical methods were used to investigate changes in the repair parameters for differing fixed α/β ratios between 1.5 and 3.0 Gy. Two different intermittent dose delivery equations were used to evaluate the implications in a radiosurgery setting. Results: Changes in the α/β ratio (1.5-3.0 Gy) have a minor effect on equivalent doses for radiation myelopathy for treatment durations of a few hours. Changing the α/β value from 2 Gy to 2.47 Gy, modified equivalent single doses by < 1% when overall treatment times ranged from 0.1 to 5.0 hr. Significant changes were only found for treatment times longer than 5-10 hr. These two α/β ratios were also compared in a practical radiosurgery situation, using two different models for estimating BED, again there was no significant loss of accuracy. Conclusions: It is reasonable to use an α/β ratio of 2 Gy for CNS tissue, with the same repair half-times as published in the original publication by Pop et al., in situations where the assessment of the BED in radiosurgery is used with other form of radiotherapy. In radiosurgery, the variation in BED with treatment duration (for a fixed physical dose) is very similar, but absolute BED values depend on the α/β value. In radiosurgery, clinical recommendations obtained using BED calculations using the originally proposed α/β ratio of 2.47 Gy are still appropriate. For calculations involving a combination of radiosurgery and other modalities, such as fractionated radiotherapy, it would be appropriate in all cases to apply a value of 2 Gy, the accepted norm in neuro-oncology, without significant loss of accuracy in the radio-surgical component. This may have important applications in retreatment situations.

Treatment of advanced metastatic castration-resistant prostate cancer after failure of approved therapy options remains challenging. Prostate-specific membrane antigen (PSMA)-targeting β- and α-emitters have been introduced, with promising response rates. Here, we present the first-to our knowledge-clinical data for PSMA-targeted α-therapy (TAT) using

Particle radioactivity is a property of airborne particles caused by the presence of naturally occurring or anthropogenic radionuclides. Recent studies have found associations between particle radioactivity and adverse health outcomes, including changes in blood pressure and lung function. However, the spatiotemporal distribution of particle radioactivity and factors influencing its variability have not been extensively studied. We address these knowledge gaps using measurements of gross beta activity, collected at seven Environmental Protection Agency (EPA) RadNet monitors located in and around Massachusetts. We apply back-trajectory analysis to identify prevailing air mass trajectories and find that these trajectories strongly influence seasonal trends in beta activity. We also evaluate the effects of different meteorological predictors on daily beta activity concentrations using a mixed-effect model. Important predictors of beta activity include air mass trajectories, temperature, and relative humidity. Finally, we create a series of random forest models to impute missing beta activity concentrations at each RadNet monitor for use in future health studies. This is the first study to analyze spatiotemporal trends in particle radioactivity using measurements from the EPA RadNet system.

Performance evaluation is typically assessed as part of the approval procedure to verify that a dosimetry system fulfils specified national or international type-test requirements under representative exposure conditions that are expected to mimic workplace fields from the radiological activities being monitored. The International Atomic Energy Agency Radiation Safety Technical Services Laboratory has recently implemented an integrated radiophotoluminescence (RPL) personal dosimetry system developed by Chiyoda Technol Corporation. This paper reports on the successful verification of dosimetric performance properties of the RPL dosimetry system to IEC 62387:2020, in which the badges were exposed to a range of radiation energies and angles of incidence as well as other influence parameters. Characteristics under test included the coefficient of variation, non-linearity of response due to dose dependence as well as the energy and angular response to photon and beta radiation.

Radiometals possess an exceptional breadth of decay properties and have been applied to medicine with great success for several decades. The majority of current clinical use involves diagnostic procedures, which use either positron-emission tomography (PET) or single-photon imaging to detect anatomic abnormalities that are difficult to visualize using conventional imaging techniques (e.g., MRI and X-ray). The potential of therapeutic radiometals has more recently been realized and relies on ionizing radiation to induce irreversible DNA damage, resulting in cell death. In both cases, radiopharmaceutical development has been largely geared toward the field of oncology; thus, selective tumor targeting is often essential for efficacious drug use. To this end, the rational design of four-component radiopharmaceuticals has become popularized. This Review introduces fundamental concepts of drug design and applications, with particular emphasis on bifunctional chelators (BFCs), which ensure secure consolidation of the radiometal and targeting vector and are integral for optimal drug performance. Also presented are detailed accounts of production, chelation chemistry, and biological use of selected main group and rare earth radiometals.

Growth factors play a crucial role in wound healing in general and are promising tools for the treatment of chronic wounds as they can restore the physiological wound healing process. In growth factor-loaded wound dressings, human epidermal growth factor (EGF) is released in a burst and washed out quickly. The developed matrix consists of recombinant EGF produced in transgenic silkworms as a fusion protein with the fibroin light chain. The covalent linkage prevents EGF from draining into the surrounding tissue while presenting the growth factor on the surface. EGF-functionalized silk membranes and nonwovens lead to a 2.5-fold increase in the cell number of fibroblasts, while retaining full bioactivity even after e-beam sterilization. EGF is long-term presented without burst release and significantly reduces the wound area by 15% in an in vitro wound model. Hence, the cost-effective production of a biomaterial using transgenic silkworm larvae in combination with a growth factor paves the way for a promising new multifactorial wound cover for chronic wound healing. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2643-2652, 2018.

Purpose: Dose and dose rate are both appropriate for estimating risk from internally deposited radioactive materials. We investigated the role of dose rate on lung cancer induction in Beagle dogs following a single inhalation of strontium-90 (90Sr), cerium-144 (144Ce), yttrium-91 (91Y), or yttrium-90 (90Y). As retention of the radionuclide is dependent on biological clearance and physical half-life a representative quantity to describe this complex changing dose rate is needed. Materials and methods: Data were obtained from Beagle dog experiments from the Inhalation Toxicology Research Institute. The authors selected the dose rate at the effective half-life of each radionuclide (DRef). Results: Dogs exposed to DRef (1–100 Gy/day) died within the first year after exposure from acute lung disease. Dogs exposed at lower DRef (0.1–10 Gy/day) died of lung cancer. As DRef decreased further (

Kinetic analysis of PET data requires continuous measurement of radioactivity in the arterial blood throughout the acquisition time, termed the arterial input function. The arterial input function is used as an input to compartmental modeling, which can be a better predictor of disease progression than SUV measurements from static PET images. Current common methods of measuring blood concentrations include image-derived, population-based, and manual sampling. These all have challenges due to logistical and technologic issues, as well as patient burden. The aim of this study was to design, develop, and assess a device that is practical and effective for the routine measurement of β-emitting radiotracer concentration in blood without the drawbacks of current methods and for which metabolite analysis is not required. Methods: Designs that integrated a scintillating fiber and a silicon photomultiplier with a general-purpose venous access catheter for in vivo measurement were considered. Other design requirements included miniaturization, high sampling rates, and stopping power for β-particles. Preliminary prototypes were designed to test the feasibility of the concept. Phantom tests were developed to mimic human vasculature. Tests of linearity, sensitivity, signal-to-noise ratios, the impact of vein diameter, and the influence of γ-radiation were conducted. Results: Prototype sensors were constructed using 2 different diameters of polystyrene-based scintillating fibers. Fibers were custom-polished and fixed to a silicon photomultiplier. Sensor output was linear, with R2 = 0.999 over the range from 0.037 to 9.25 MBq/mL. Absolute sensitivity was approximately 450 counts per second per MBq/mL. Measured signal-to-noise ratios ranged from 1.2:1 to 3.2:1 using a blood-to-tissue concentration ratio of 1:1. Sensor output increased with vein diameter and showed no sensitivity to γ-radiation. Conclusion: In experiments with phantom models, the prototype provided accurate measurements of β-emitting radiotracer concentration. The design will be refined for in vivo testing. The ability to routinely gather blood input function data would facilitate the adoption of kinetic modeling of PET data.

The computer code VARSKIN, version 5.3, is widely used to calculate superficial dose caused by the routine handling of radioactive substances or in skin contamination incidents. It allows a variety of source configurations, points, volume, surface and syringe-like (cylindrical) and a variety of exposure situations such as direct skin contact or exposure through clothing. However, there is a need for more benchmarking data of VARSKIN, especially for beta particles, with complex irradiation geometries. Dose calculations using MCNP5 and VARSKIN 5.3 for a variety of mass-less point beta-emitting sources were performed. Both programs gave comparable results that are in good agreement with published dose rate conversion factors for sources on contact with the skin or with fabric. However, important differences appear, with VARSKIN 5.3 values as much as 40% below the Monte Carlo results, when an air gap of a few mm is introduced between the fabric and skin.

A scintillating fiber array detector for measuring gross beta counting is developed to monitor the real-time radioactivity in drinking water. The detector, placed in a stainless-steel tank, consists of 1096 scintillating fibers, both sides of which are connected to a photomultiplier tube. The detector parameters, including working voltage, background counting rate and stability, are tested, and the detection efficiency is calibrated using standard potassium chloride solution. Water samples are measured with the detector and the results are compared with those by evaporation method. The results show consistency with those by evaporation method. The background counting rate of the detector is 38.131 ± 0.005 cps, and the detection efficiency for β particles is 0.37 ± 0.01 cps/(Bq/l). The MDAC of this system can be less than 1.0 Bq/l for β particles in 120 min without pre-concentration.