Search

Purpose: This study aimed to develop a user-friendly prediction formula for dose rate adjustment after initial 177Lu-Dotatate therapy from a prospective observational study of patients. Materials and methods: This study included consenting patients in a prospective observational study who underwent their first treatment in four cycles of 177Lu-Dotatate treatment at our hospital between January 2022 and February 2024. All patients received 7.4 GBq of 177Lu-Dotatate. The prediction formula was derived from the regression analysis of tumor-related factors and renal function. Creatinine clearance was estimated using the Cockcroft–Gault equation in this study for renal function. Results: Among the 13 patients (seven males, six females, median age: 59 years), logarithmically transformed total tumor volume (cc) and maximum tumor diameter (mm) of primary tumors or metastases showed strong correlations (p < 0.001, R2 = 0.897). As such, the maximum tumor diameter was used as the tumor parameter in the prediction formula. Additionally, maximum tumor diameter and creatinine clearance showed strong (p < 0.001, R2 = 0.768) and moderate (p = 0.013, R2 = 445) correlations, respectively, with the ratio of the dose rate 5.5-h post-administration to the dose rate immediately post-administration (%) at 1 m from the body surface. The resulting formula, 51.4 + 0.360 × maximum tumor diameter (mm) − 0.212 × creatinine clearance (ml/min), demonstrated an extremely strong correlation (p < 0.001, R2 = 0.937). Conclusion: The present study showed that the maximum tumor diameter and renal function affected the declining the dose rate of patients surface after 177Lu-Dotatate, which can inform post-administration dose rate management and potentially facilitate outpatient treatment in Japan. [ABSTRACT FROM AUTHOR]

Purpose: To propose a straightforward and time‐efficient quality assurance (QA) approach of beam time delay for respiratory‐gated radiotherapy and validate the proposed method on typical respiratory gating systems, Catalyst™ and AlignRT™. Methods: The QA apparatus was composed of a motion platform and a Winston‐Lutz cube phantom (WL3) embedded with metal balls. The apparatus was first scanned in CT‐Sim and two types of QA plans specific for beam on and beam off time delay, respectively, were designed. Static reference images and motion testing images of the WL3 cube were acquired with EPID. By comparing the position differences of the embedded metal balls in the motion and reference images, beam time delays were determined. The proposed approach was validated on three linacs with either Catalyst™ or AlignRT™ respiratory gating systems. To investigate the impact of energy and dose rate on beam time delay, a range of QA plans with Eclipse (V15.7) were devised with varying energy and dose rates. Results: For all energies, the beam on time delays in AlignRT™ V6.3.226, AlignRT™ V7.1.1, and Catalyst™ were 92.13 ±$ \pm $ 5.79 ms, 123.11 ±$ \pm $ 6.44 ms, and 303.44 ±$ \pm $ 4.28 ms, respectively. The beam off time delays in AlignRT™ V6.3.226, AlignRT™ V7.1.1, and Catalyst™ were 121.87 ±$ \pm $ 1.34 ms, 119.33 ±$ \pm $0.75 ms, and 97.69 ±$ \pm $ 2.02 ms, respectively. Furthermore, the beam on delays decreased slightly as dose rates increased for all gating systems, whereas the beam off delays remained unaffected. Conclusions: The validation results demonstrate the proposed QA approach of beam time delay for respiratory‐gated radiotherapy was both reproducible and time‐efficient to practice for institutions to customize accordingly. [ABSTRACT FROM AUTHOR]

AbstractDose rate assessment is of utmost importance in fusion reactors because of the maintenance operations that these facilities will require. The standard way to perform this assessment in ITER is use of the Direct 1-Step (D1S) methodology, which consists of performing neutron transport simulation, material activation, and decay photon transport simulation in one step and thus in one simulation only. Usually, implementation of the D1S methodology requires changing the source files in a reference Monte Carlo code. The purpose of the present work is to develop an easy-to-implement method for Monte Carlo codes to help calculate the dose rate in fusion reactors. To do so, the proposal is to act on nuclear data only and not on source files of the simulation codes. This is done by replacing prompt photon production in evaluation files by suitable decay photon production, taking into account radioactive decays of radionuclides and irradiation history. This study was to be applied first on the TRIPOLI-4® Monte Carlo code for the sake of simplicity. TRIPOLI-4 is the reference code for particle transport at CEA. The verification and validation process relies first on a comparison to the reference Rigorous 2-Step (R2S) methodology and then on an experiment, the so-called Frascati Neutron Generator (FNG) dose experiment. The nuclear database to be changed is of the ENDF-6 format, a recurrent format in neutronics studies. The analysis studied both neutron and photon responses to check if the simulation was performing normally in a physical way and to compare the results with references provided by simulations based on the R2S methodology or by the FNG dose experiment. The simulations have proven to be in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Background: This study investigates the impact of varying dose rates on dosimetric parameters and pretreatment quality assurance (QA) accuracy in intensity-modulated radiotherapy (IMRT) planning using anthropomorphic phantoms. The research explores the dosimetric effects of different dose rates ranging from 100 to 600 monitor units per minute (MU/min) on parameters such as Homogeneity Index (HI), Conformity Index (CI), and dose to organs at risk (OAR). Method: Anthropomorphic phantoms, mimicking human tissues, were employed for simulation. Treatment plans were generated using the Eclipse Treatment Planning System, and dosimetric evaluations were conducted using cumulative dose-volume histograms (DVH). Furthermore, pretreatment patient-specific QA was performed using EPID portal dosimetry and Delta4 dosimetry system. Result: Treatment plans adhere to institutional protocol, ensuring the target receives =95% of the prescription dose while meeting OAR constraints. All plans maintain target homogeneity and conformality, keeping maximum doses within the target below 107%. Low dose plans exhibit superior target coverage, conformality, and homogeneity compared to higher doses. However, increased dose rates elevate delivered Monitor Units and maximum doses to critical structures. Gamma passing rates vary with dose rates, with the lowest at 100 MU/min and the highest at 400 MU/min for 1% 1mm criteria. Dosimetric evaluations using Delta 4 and EPID QA methods confirm plan validity across different dose rates. Conclusion: Low dose rate dosimetry is superior to higher rates for target and organ-at-risk (OAR) delivery, albeit prolonging delivery time and affecting internal organ motion. Portal dosimetry offers a faster, more convenient tool for IMRT pretreatment quality assurance (QA). Optimal results are achieved at 400 MU/min, enhancing gamma agreement between calculated and measured portal doses for complex fields. This improvement in QA enhances IMRT treatment delivery quality. However, patient-specific QA using the DELTA4 dosimetry system and ICRU 83 recommendations are insufficient for discussing dosimetric differences relevant to patient treatment. [ABSTRACT FROM AUTHOR]

Abstract Background and purpose Rare but severe toxicities of the optic apparatus have been observed after treatment of intracranial tumours with proton therapy. Some adverse events have occurred at unusually low dose levels and are thus difficult to understand considering dose metrics only. When transitioning from double scattering to pencil beam scanning, little consideration was given to increased dose rates observed with the latter delivery paradigm. We explored if dose rate related metrics could provide additional predicting factors for the development of late visual toxicities. Materials and methods Radiation-induced intracranial visual pathway lesions were delineated on MRI for all index cases. Voxel-wise maximum dose rate (MDR) was calculated for 2 patients with observed optic nerve toxicities (CTCAE grade 3 and 4), and 6 similar control cases. Additionally, linear energy transfer (LET) related dose enhancing metrics were investigated. Results For the index cases, which developed toxicities at low dose levels (mean, 50 GyRBE), some dose was delivered at higher instantaneous dose rates. While optic structures of non-toxicity cases were exposed to dose rates of up to 1 to 3.2 GyRBE/s, the pre-chiasmatic optic nerves of the 2 toxicity cases were exposed to dose rates above 3.7 GyRBE/s. LET-related metrics were not substantially different between the index and non-toxicity cases. Conclusions Our observations reveal large variations in instantaneous dose rates experienced by different volumes within our patient cohort, even when considering the same indications and beam arrangement. High dose rate regions are spatially overlapping with the radiation induced toxicity areas in the follow up images. At this point, it is not feasible to establish causality between exposure to high dose rates and the development of late optic apparatus toxicities due to the low incidence of injury.

Natural background gamma rays and their effects on human health are essential components of both radiation protection and public concern. In the frame of these aspects, the mapping of the natural gamma dose rate values of the Province of Asti is given. The Asti Fire Brigade Command approved a project relating to the mapping of gamma radiation from the natural background in the territory of Asti. The project engaged both the Nuclear, Biological, Chemical, and Radiological (NBCR) and Topography Applied to Rescue (TAS) components of the Asti Command. Skilled personnel, comprising level 1 TAS operators for data collection and level 2 TAS operators for cartographic analysis, were deployed across the six working days. The methodology involved the use of two digital handheld radiation G-M detectors, in conjunction with a portable GPS unit, including the Global Mapper software. One of the significant findings of this study is the observation that the natural gamma dose rate levels were 201.25% higher in the streets of the city center compared to other areas, predominantly because the building materials in these locations contain a higher amount of natural radionuclides. The results indicated that the level of natural gamma dose rates in the studied region is close to the global average value.

Background and purpose: Rare but severe toxicities of the optic apparatus have been observed after treatment of intracranial tumours with proton therapy. Some adverse events have occurred at unusually low dose levels and are thus difficult to understand considering dose metrics only. When transitioning from double scattering to pencil beam scanning, little consideration was given to increased dose rates observed with the latter delivery paradigm. We explored if dose rate related metrics could provide additional predicting factors for the development of late visual toxicities. Materials and methods: Radiation-induced intracranial visual pathway lesions were delineated on MRI for all index cases. Voxel-wise maximum dose rate (MDR) was calculated for 2 patients with observed optic nerve toxicities (CTCAE grade 3 and 4), and 6 similar control cases. Additionally, linear energy transfer (LET) related dose enhancing metrics were investigated. Results: For the index cases, which developed toxicities at low dose levels (mean, 50 GyRBE), some dose was delivered at higher instantaneous dose rates. While optic structures of non-toxicity cases were exposed to dose rates of up to 1 to 3.2 GyRBE/s, the pre-chiasmatic optic nerves of the 2 toxicity cases were exposed to dose rates above 3.7 GyRBE/s. LET-related metrics were not substantially different between the index and non-toxicity cases. Conclusions: Our observations reveal large variations in instantaneous dose rates experienced by different volumes within our patient cohort, even when considering the same indications and beam arrangement. High dose rate regions are spatially overlapping with the radiation induced toxicity areas in the follow up images. At this point, it is not feasible to establish causality between exposure to high dose rates and the development of late optic apparatus toxicities due to the low incidence of injury. [ABSTRACT FROM AUTHOR]

Recently, dose delivery technology has rapidly evolved with flattening filter-free beams (FFF), and the biological effects of high dose rates are a matter of interest. We hypothesized that FFF beams at different dose rates obtained with modern linear accelerators have different effects on the TME. The B16–F10 melanoma syngeneic tumor model was established, and mice were randomized to 2 different doses (2 Gy and 10 Gy) and 3 different dose rates (1 Gy/min, 6 Gy/min, and 14 Gy/min) along with the control group. Euthanasia was performed on the seventh day after RT, and intracardiac blood was collected for a comet assay. Tumors were harvested and examined histomorphologically and immunohistochemically. Statistical analyses were performed using SPSS software version 23 (SPSS Inc., Chicago, IL, USA). The daily growth rate was uniform, and no difference was observed between tumor volumes across all three dose rates for each dose. Deoxyribonucleic acid (DNA) damage in blood mononuclear cells was not affected by dose or dose rate. In the TME histomorphological examination, the number of mitosis is less in the 10 Gy arm, whereas the pleomorphism score was greater. Nevertheless, varying dose rates had no effect on the number of mitosis or the pleomorphism score. The severity of the inflammation, cell densities in the TME, and expression of immunohistochemical markers were comparable across all doses and dose rates. In our study involving the B16–F10 syngeneic tumor model, varying dose rates obtained with FFF beams had no effect on tumor volume, blood mononuclear cell DNA damage, or TME parameters. However, in order to fully understand the biological impacts of novel techniques, our study should be validated with alternative preclinical setups. • We built a syngeneic tumor model with B16–F10 malignant melanoma cells. • We investigated the impact of varying FFF dose rates (1-6-14 Gy/min) on TME. • There was no effect of dose or dose rate on DNA damage in blood mononuclear cells. • Low, moderate, and high dose rates showed no variation in tumor sizes. • No different effects were observed on TME. [ABSTRACT FROM AUTHOR]

In this study, the radiological impact of naturally occurring radionuclides (238U and 232Th) and fallout radionuclide (137Cs) in the soil around the Kaiga Generating Station (KGS), Kaiga, on the terrestrial non-human biota was investigated. Through the analysis of 113 soil samples collected from 2015 to 2021, the study determined mean activity concentrations of 2.9 ± 1.4, 19.6 ± 5.2, and 24.1 ± 4.3 Bq kg−1 d.w. for 137Cs, 238U, and 232Th, respectively, in surface soil samples. Utilizing the ERICA assessment tool (v2.0) and employing the Tier-2 approach, the study estimated radiological doses to reference organisms in the terrestrial ecosystem around Kaiga. Lichens and bryophytes exhibited the highest activity concentrations for 137Cs, 238U, and 232Th, while annelids showed the lowest activity for 137Cs, and for 238U and 232Th, amphibians exhibited the minimum activity. The total dose rates (internal + external) ranged from 1.9E−03 to 6.7E−01 µGy h−1. Despite the highest dose rate of 6.7E−01 µGy h−1 observed in lichen and bryophytes, all assessed dose rates remained below the ERICA screening level of 10 µGy h−1. Risk quotient values for all reference organisms were less than 1 (RQ < 1), indicating negligible risk to non-human biota. [ABSTRACT FROM AUTHOR]

Natural background gamma rays and their effects on human health are essential components of both radiation protection and public concern. In the frame of these aspects, the mapping of the natural gamma dose rate values of the Province of Asti is given. The Asti Fire Brigade Command approved a project relating to the mapping of gamma radiation from the natural background in the territory of Asti. The project engaged both the Nuclear, Biological, Chemical, and Radiological (NBCR) and Topography Applied to Rescue (TAS) components of the Asti Command. Skilled personnel, comprising level 1 TAS operators for data collection and level 2 TAS operators for cartographic analysis, were deployed across the six working days. The methodology involved the use of two digital handheld radiation G-M detectors, in conjunction with a portable GPS unit, including the Global Mapper software. One of the significant findings of this study is the observation that the natural gamma dose rate levels were 201.25% higher in the streets of the city center compared to other areas, predominantly because the building materials in these locations contain a higher amount of natural radionuclides. The results indicated that the level of natural gamma dose rates in the studied region is close to the global average value. [ABSTRACT FROM AUTHOR]

In the event of a postulated severe accident, fission products may leak into the reactor building through the containment wall, exerting a radiological impact on the emergency response team as they are tasked with performing mitigative missions. It is thus important to estimate the potential radiological consequences of the mission before taking action so that an optimized plan can be devised to avoid putting the team in harm's way unintentionally. Some of the most well-known accident simulation codes were attempted to do the estimation, but were found to be too time consuming to get the results, making them not suitable for emergency use. The problem evidently arises from the fact that there are too many (about 200) compartments in a typical reactor building. In this study, the software REMADA is developed to simulate fission product dispersion in a reactor building (with about 200 compartments) within a reasonable timeframe, and to estimate the radiation doses to those who are carrying out mitigative missions in the reactor building. The results show that the software is not only fast, but also informative, to provide support for well-informed emergency decision making. [ABSTRACT FROM AUTHOR]

OBJECTIVE: It seems that dose rate (DR) and photon beam energy (PBE) may influence the sensitivity and response of polymer gel dosimeters. In the current project, the sensitivity and response dependence of optimized PASSAG gel dosimeter (OPGD) on DR and PBE were assessed. MATERIALS AND METHODS: We fabricated the OPGD and the gel samples were irradiated with various DRs and PBEs. Then, the sensitivity and response (R2) of OPGD were obtained by MRI at various doses and post-irradiation times. RESULTS: Our analysis showed that the sensitivity and response of OPGD are not affected by the evaluated DRs and PBEs. It was also found that the dose resolution values of OPGD ranged from 9 to 33 cGy and 12 to 34 cGy for the evaluated DRs and PBEs, respectively. Additionally, the data demonstrated that the sensitivity and response dependence of OPGD on DR and PBE do not vary over various times after the irradiation. CONCLUSIONS: The findings of this research project revealed that the sensitivity and response dependence of OPGD are independent of DR and PBE. [ABSTRACT FROM AUTHOR]

Tb3+-doped sodium-silicate glasses, chemically defined as (73.2SiO2 -15.3Na2O-6MgO-2ZnO- 3.5CaO)1-x-(TbF3)x for x = 0, 5, 7, 9, 11, 13, and 15 wt%) were theoretically investigated for their radiation shielding and dosimetry potentials. The photon interaction parameters were estimated using the NIST-XCOM computational tool. The obtained results showed that the attenuation coefficient of the sodium-silicate glasses decreased from 7.2062 to 0.0210 cm2/g for x = 0, 10.5553 to 0.0221 cm2/g for x = 5 mol%, 11.8949 to 0.0225-cm2/g for x = 7 mol%,, 13.2346 to 0.0229cm2/g for x = 9 mol%, 14.5742 to 0.0233 cm2/g for x = 11 mol%, 15.9138 to 0.0238 cm2/g for x = 13 mol%, and 17.2534 to 0.0242 cm2/g for the x = 15 mol% sample, respectively, for γ-photon energy increase from 15 to 15,000 keV. For the same sample order, the mass energy absorption coefficient varied from 0.0161 to 7.4884, 0.0167 to 10.5009, 0.0169 to 11.7058, 0.0171 to 12.9108, 0.0174 to 14.1158, 0.0176 to 15.3208, and 0.0176 to 16.52582 cm2/g. The effective atomic number changed from 10.49 to 24.04, 10.62 to 27.69, 10.74 to 30.84, 10.87 to 33.57, 11.01 to 35.97, 11.15 to 38.10 for SNMZCT2, SNMZCT3, SNMZCT4, SNMZCT5, SNMZCT6, SNMZCT7, respectively. The minimum specific gamma constants for the investigated samples were obtained at 0.2 MeV with values of 5.435 Rm2/Cih, 6.102 Rm2/Cih, 6.770 Rm2/Cih, 7.437 Rm2/Cih and 8.772 Rm2/Cih for SNMZCT2, SNMZCT3, SNMZCT4, SNMZCT5, SNMZCT6 and SNMZCT7, respectively. Using the geometric fitting method, the computed buildup factors show significant variation with energy of incident gamma photons, number of glass mean free path (mfp), and the chemical composition (i.e., TbF3 content) of the glasses. Increasing the molar concentration of TbF3 in the glass system improves its photon shielding abilities and suppresses photon scattering in the glasses. [ABSTRACT FROM AUTHOR]

Objective(s): In systemic radionuclide therapy such as radioiodine (I-131) for differentiated thyroid cancer, post-therapy dosimetry is essential to verify pre-therapy predictions, which in turn informs the next treatment. However, post-therapy multi-time point dosimetry is resource intensive and unfeasible in many institutions. We devised a schema of rapid predictive dosimetry by circumventing post-First Strike multi-time point dosimetry with carefully assigned gestalt values of predicted kinetics to personalise the Second Strike prescription.Methods: Verification is performed after the First Strike. Patient-specific time-activity curve is plotted from serial measurements of whole body exposure rates to obtain its decay constant; its inverse is the whole body Time Integrated Activity Coefficient (TIAC). The percentage of whole body TIAC attributed to blood is carefully assigned by gestalt based on population kinetics tabulated in Part 1, adjusted by any metastasis on I-131 whole body scintigraphy. Marrow absorbed dose is calculated by EANM formularism. Lung safety threshold at 48h post-therapy is linearly scaled by height, where the patient’s risk of lung radiotoxicity is revealed from the whole body time-activity curve value at 48h. Predictive prescription for the second I-131 fraction (Second Strike) is by careful gestalt assessment based on predicted kinetics, remaining marrow and lung tolerance, marrow dose rate constraint per fraction (0.265 Gy/h), local regulatory and facility requirements in relation to radiation protection. Tumour dosimetry is obviated under the assumption of severe tumour absorbed dose heterogeneity. The final prescription for the Second Strike is usually the lowest I-131 activity amongst all clinical, dosimetric and regulatory constraints.Results: This schema is incorporated into a Predictive Calculator spreadsheet for rapid predictive dosimetry, and is freely available. Calculations may be completed within minutes to generate personalised predictive prescriptions, making it feasible for routine clinical implementation.Conclusion: Our innovative schema of rapid verification and predictive dosimetry bridges the technological gap between empiric vs theranostic prescription to help institutions modernise. Its expeditious design makes this schema feasible to be integrated into the routine clinical workflow. Its predictive estimates provide invaluable dosimetric insight to inform the next I-131 fraction, allowing every prescription to be scientifically rationalised and personalised according to individual circumstances.

Introduction: In radiology, low X-ray energies (<140 keV) are used to obtain an optimal image while in radiotherapy, higher X-ray energies (MeV) are used to eradicate tumor tissue. In radiation research, both these X-ray energies being used to extrapolate in vitro research to clinical practice. However, the energy deposition of X-rays depends on their energy spectrum, which might lead to changes in biological response. Therefore, this study compared the DNA damage response (DDR) in peripheral blood lymphocytes (PBLs) exposed to X-rays with varying beam quality, mean photon energy (MPE) and dose rate. Methods: The DDR was evaluated in peripheral blood lymphocytes (PBLs) by the ɣ-H2AX foci assay, the cytokinesis-block micronucleus assay and an SYTOX-based cell death assay, combined with specific cell death inhibitors. Cell cultures were irradiated with a 220 kV X-ray research cabinet (SARRP, X-Strahl) or a 6 MV X-ray linear accelerator (Elekta Synergy). Three main physical parameters were investigated: beam quality (V), MPE (eV) and dose rate (Gy/min). Additional copper (Cu) filtration caused variation in the MPE (78 keV, 94 keV, 118 keV) at SARRP; dose rates were varied by adjusting tube current for 220 kV X-rays (0.33–3 Gy/min) or water-phantom depth in the 6 MV set-up (3–6 Gy/min). Results: The induction of chromosomal damage and initial (30 min) DNA double-stranded breaks (DSBs) were significantly higher for 220 kV X-rays compared to 6 MV X-rays, while cell death induction was similar. Specific cell death inhibitors for apoptosis, necroptosis and ferroptosis were not capable of blocking cell death after irradiation using low or high-energy X-rays. Additional Cu filtration increased the MPE, which significantly decreased the amount of chromosomal damage and DSBs. Within the tested ranges no specific effects of dose rate variation were observed. Conclusion: The DDR in PBLs is influenced by the beam quality and MPE. This study reinforces the need for consideration and inclusion of all physical parameters in radiation-related studies. [ABSTRACT FROM AUTHOR]

A methodology for mapping the density of 137Cs contamination of agricultural land is proposed and tested. The methodology is based on data on gamma-dose rate measurements, gamma-logging results, and direct determination of 137Cs in soil samples, which were obtained by different organizations in different years. It allows to generalize all available information on 137Cs contamination of the lands and significantly improves the representativeness of estimates of the spatial distribution of the radionuclides at the mapping. [ABSTRACT FROM AUTHOR]

The concentration of natural radionuclides in the soil around the world has become an environmental concern for international and national authorities because of the harmful effect of radiation exposure on human health. The samples of soil used for this study were collected from Foron and Heipang districts of Barkin Ladi Local Government Area of Plateau State. The samples were analyzed using Canberra Model 727/727R Lead Shield Gamma-ray Spectrometer with NaI(Ti) detector. The result shows that 40K ranges from 301.91 ± 0.24 Bq/kg to 124.97 ± 0.31 Bq/kg from the mining spot to 400 m away from the mining spots. 226Ra ranges from 105.43 ± 1.76 Bq/Kg to 43.10 ± 0.62 Bq/Kg from mining spots to 400 m away from the mining spots, and 232Th also ranges from 92.79 ± 0.26 Bq/kg to 26.97 ± 0.39 Bq/kg respectively. The absorbed dose rate in the air (Dr) has a mean value of 82.88 nGh-1. The annual effective dose rate (AEDR) mean value was 0.1mSvy-1, and the radium equivalent (Ra eq) mean value was 180.23 Bq/kg, Hex and Hin have mean values of 0.49 and 0.69 respectively. The calculated excess lifetime cancer risk (ELCR) ranges from 0.0003 to 0.00039 with a mean value of 0.00035 in the soil samples. Therefore, this result suggested that the area under study could be termed radiologically unsafe for people living around or close to the area. [ABSTRACT FROM AUTHOR]

In this study, we quantify specific activity of 238U, 232Th, and 40K, from soils, water, and vegetables around limestone mining sites because of the dense urban settlement with high agricultural activities around the area. Annual effective dose (AED) was evaluated and used to estimate radiological hazard impact. Mean values of internal radiation hazard index (Hin) for soils, water, and vegetation are calculated and compared with those from literatures. The estimated mean excess lifetime cancer risk (ELCR) was obtained, too. The values of ELCR are under the world average value as recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) one of the world regulatory bodies. For this reason, health related issues may occur at long time of living in this environment. [ABSTRACT FROM AUTHOR]

The majority of total radiation dose received by the world population comes from background natural radiation. The distinguishing features of this radiation include relatively persistent exposure of a population at a specific place. The amount of background radiation that is generally present in the environment is greatly influenced by the inhalation of radon (Rn), thoron (Tn), and their offspring. In light of this, measurement of dose rate exposure due to granite flooring has been attempted in Bangalore. Fifteen different granite samples, used as flooring for construction in buildings, were examined for a period of three years. Solid state nuclear track detector-based dosimeters, can technique, and radiation survey meters have been used. All the experimental observations were made according to the standard protocols provided by the Bhabha Atomic Research Centre, Mumbai, India. The arithmetic mean dose rate varied between 1.39 ± 0.06 and 2.09 ± 0.10 mSv y-1. The values of dose rates were found to be higher in granite and lower in coarse-grained dolerite. All 15 types of granite samples have undergone a minimum of 30 measurements. The greater activity concentration of radionuclides found in granite samples leads to higher dose rates. [ABSTRACT FROM AUTHOR]

The purpose of this investigation is to determine how gamma radiation-induced oxidative stress impacts the reproductive system of adult chickens. In this study, we used 39-57 weeks old cocks' chickens to assess the significance of semen volume10-3liter per bird per ejaculation). Sperm count overall (108 cells per ejaculation) and count per milliliter (108 cells). The volume, concentration data, and sum sperm data of cock chickens all increased significantly with age, though not at all ages; rather, just at a select few ages that were considered to be the control (regulate) group. These data were found after 35 days of gamma radiation at soft dose rates (soft intensity) of at100, 120 and 130cm between cages of chickens and radioactive source with 0.402, 0.279 and 0.237 Gy/h respectively. This is a six-hour daily chronic dose rate (extended duration of radiation). As the soft dosage rate was gradually increased, a significant decline in the values was observed. The semen volume data drop ratio was calculated for each male chicken generation and compared to the control group using three chronic moderate doses of irradiation at doses ranging from around 4.8 to 13.6 percent and semen concentrations from roughly 4.9 to 14 percent. The average results from both groups showed that when the intensity of the gamma ray radiation increased, all metrics significantly declined. Using date seeds extract(Phoenix dactylifera L.) as a defense against oxidative stresses brought on by radiation exposure and to lower its percentage data, especially on particular sperm data qualities. Due to its availability in the Middle East, the use of date seeds extracts(Phoenix dactylifera L.) in this study proved beneficial in terms of both economic return and fertility-boosting effects on chickens, as evidenced by the positive results obtained when compared to other antioxidants under the same conditions. Due to its availability in the Middle East, the use of date seeds extracts(Phoenix dactylifera L.) in this study proved beneficial in terms of both economic return and fertility-boosting effects on chickens, as evidenced by the positive results obtained when compared to other antioxidants under the same conditions. [ABSTRACT FROM AUTHOR]

The Sentinel Lymph Node (SLN) or Sentinel Lymph Node Biopsy (SLNB) technique involves various professionals from different departments in clinical settings to manage breast cancer patients properly. Tracing the nodular involvement of breast cancer patients requires radiation source Tc99m labeled with colloidal albumin to be injected at the tumor site. The patient becomes a radiation source for a sufficient time, which concerns the Nuclear Medicine (NM) and surgical staff. The study aims to provide the radiation doses of staff in the NM department during the SLN scintigraphy procedure and obtain an empirical model for calculating the radiation doses to staff in the surgical department from that particular patient. Radiation doses in SLN technique for breast cancer patients are minimal, and a sufficient number of SLN biopsy procedures can be performed by hospital staff within the category of non-radiation workers.

An acute issue arises in relation to the operation of water-moderated water-cooled reactors (VVER), including KLT-40 type reactors, which are widely used nowadays on icebreakers and floating power units (FPU), which is the duration of safe operation of steam generators (SGs). The issue is related to the generation of microcracks in the water and steam line of the steam generator under normal power operation. 16N7 penetrates the steam line through those microcracks and its presence is evidence of an untight water and steam line of the SG secondary circuit. This effect, which was later called a "leak," was studied in a number of papers of the authors in relation to the conditions of cyclic operation of the water and steam mode of the SG. This paper focuses on the mathematical and physical analysis of the mechanisms causing the formation of microcracks in the SG steam line and occurring in the steam line area where steam and water pressures are balanced; and their effective length is assessed. The temperature distribution along the thickness of the steam pipeline in the steam and water transition part was calculated for the periodic water whipping of the area. It has been demonstrated that, depending on the time of the steam and water oscillation period, the radial temperature distribution along the tube thickness has a significant difference in the distribution under normal temperature on the outer surface of the tube. However, the maximum temperature difference is in the inner surface of the tube. The distribution of mechanical stresses arising in the tube metal is characterized by a linear dependence of stresses on temperature whose maximum value corresponds to the maximum temperature difference characteristic of the area of the inner surface of the tube. This allows us to conclude that the crack formation starts in the inner surface of the SG tube in the specified transitional area of the tube. [ABSTRACT FROM AUTHOR]

Radiotherapy (RT) is performed in approximately 75% of patients with cancer, and its efficacy is often hampered by the low tolerance of the surrounding normal tissues. Recent advancements have demonstrated the potential to widen the therapeutic window using “very short” radiation treatment delivery (from a conventional dose rate between 0.5 Gy/min and 2 Gy/min to more than 40 Gy/s) causing a significant increase of normal tissue tolerance without varying the tumor effect. This phenomenon is called “FLASH Effect (FE)” and has been discovered by using electrons. Although several physical, dosimetric, and radiobiological aspects need to be clarified, current preclinical “in vivo” studies have reported a significant protective effect of FLASH RT on neurocognitive function, skin toxicity, lung fibrosis, and bowel injury. Therefore, the current radiobiological premises lay the foundation for groundbreaking potentials in clinical translation, which could be addressed to an initial application of Low Energy Electron FLASH (LEE) for the treatment of superficial tumors to a subsequent Very High Energy Electron FLASH (VHEE) for the treatment of deep tumors. Herein, we report a clinical investigational scenario that, if supported by preclinical studies, could be drawn in the near future. [ABSTRACT FROM AUTHOR]

This report focuses on assessing the human health risks associated with radioactivity in the environment. It presents data on the concentration of radionuclides (Ra-226, Th-232, and K-40), as well as radon and thoron exhalation rates from agricultural soils in Punjab's Patiala and Fatehgarh Sahib Districts. The study found that the radionuclides present in the soil contribute significantly to inhalation doses. The concentration of these radionuclides in the soil affects indoor radon and thoron levels, as they are a source of indoor gas. Soil samples were collected from ten agricultural fields and analyzed using gamma spectroscopy technique. The results provide information on specific activity, radon exhalation rates, thoron surface exhalation rates, radium equivalent activity, external, and internal index, annual effective dose, and excess life time cancer risk. [ABSTRACT FROM AUTHOR]

The influence of meteorological conditions and the initial energy of gamma quanta on the results of the aerial radiation reconnaissance of a radioactively contaminated area is considered. The statistical distribution of atmospheric pressure, air temperature, and air moisture content is analyzed. Based on the results of mathematical simulations, the values of the coefficients inversely proportional to a decrease in the gamma radiation absorbed dose rate caused by the air layer between a flight level and an analyzed point on the ground were calculated for the aviation survey of a radioactively contaminated area with an initial energy of gamma quanta ranging from 50 to 3000 keV and an air density ranging from 0.9 to 1.7 kg/m3. It is shown that it is necessary to take into account the meteorological parameters and the energy composition of gamma radiation when performing an aerial radiation survey of an area. [ABSTRACT FROM AUTHOR]

This study measured 99mTc-MDP bone scintigraphy radiation risks, as low-dose radiation exposure is a growing concern. Dosimeter measurements were taken at four positions (left lateral, right lateral, anterior, and posterior) around the patients at 30, 60, 100, and 200 cm at 0, 1.5, and 3 h. The highest dose rates were recorded from 51% of the patients, who emitted ≥ 25 µSv/h up to 49.00 µSv/h at the posterior location at a distance of 30 cm. Additionally, at the anterior location at a distance of 30 cm, 42% of patients emitted ≥ 25 µSv/h up to 38.00 µSv/h. Furthermore, at 1.5 h after the tracer injection, 7% of the dose rates exceeded 25 µSv/h. There was a significant reduction in mean dose rates for all positions as distance and time increased (p-value < 0.05). As a result, radiation levels decreased with increased distance and time as a result of radiation decay, biological clearance, and distance from the source. In addition, increasing the distance from the patient for all positions reduced the radiation dose, as was substantiated via exponential regression analysis. Additionally, after completing the bone scintigraphy, the patients' dose rates on discharge were within the current guidelines, and the mean radiation doses from 99mTc-MDP were below occupational limits. Thus, medical staff received less radiation than the recommended 25 μSv/h. On discharge and release to public areas, the patients' mean dose rates were as follows: 1.13 µSv/h for the left lateral position, 1.04 µSv/h for the right lateral, 1.39 µSv/h for the anterior, and 1.46 µSv/h for the posterior. This confirms that if an individual was continuously present in an unrestricted area, the dose from external sources would not exceed 20 µSv/h. Furthermore, the patients' radiation doses were below the public exposure limit on discharge. [ABSTRACT FROM AUTHOR]

Radioactive contamination of the earth’s biosphere has always been a source of concern. From the health point of view, radiation exposure and dose delivered to human beings are of prime importance. Certain parts of coastal southwest districts of the state of Kerala in India namely Thiruvananthapuram (Trivandrum), Kollam (Quilon) and Alappuzha (Alleppey) are known high background radiation areas (HBRA) owing to the presence of rich quantities of thorium and uranium. Surface soil samples from these districts' HBRAs and adjoining regions were studied for their primordial radionuclide levels using NaI(Tl) based gamma-ray spectrometry. Specific activities of 226Ra, 232Th and 40K nuclides in soil samples from the whole study area were between 4.7 Bq/kg to 130 Bq/kg, 6.5 Bq/kg to 611 Bq/kg and 101 Bq/kg to 1852 Bq/ kg, respectively. Important dosimetric parameters namely radium equivalent activity (Raeq), absorbed gamma dose (D), Indoor and outdoor Annual Effective Dose equivalents (AEDin & AEDout), internal and external hazard indices (Hin & Hex) for gamma exposure, and Excess Lifetime Cancer Risk (ELCR) were also determined to assess probable health effects on human beings residing in these regions. A comparison of average specific radioactivities and average indoor annual effective doses between the HBRA and Normal background Radiation Area (NBRA) is presented. Results show that the neighbouring regions have considerably lower radiation dosimetric parameters. [ABSTRACT FROM AUTHOR]

Neutron induced damage in future nuclear materials can be studied using heavy ion beams only if the differences in the microstructure evolution are well understood. Large variations in the damage dose rate, caused by scanning of the ion beam, can alter the microstructure compared to steady-state irradiation. We study the effect of scanning on the microstructure by irradiating pure iron with a 10 MeV Fe ion beam to a dose of 0.2 dpa. The beam is scanned in one direction with frequencies of 200 Hz and 10 kHz. Different shapes of the beam are also used to study the effect of dose variation. All of the irradiations are conducted at room temperature using the DiFU chamber at RBI. TEM analysis shows differences between the narrow beam and defocused irradiation modes, including unusual void formation observed at 10 kHz. A wider beam reduces the effect of scanning speed and no voids are found in this scanning case.

The output constancy of the accelerator used for boron neutron capture therapy (BNCT) is essential to ensuring anti-tumor efficacy and safety. BNCT as currently practiced requires a wide variety of beam quality assessments to ensure that RBE dose errors are maintained within 5%. However, the necessity of maintaining a constant beam dose rate has not been fully discussed. We therefore clarified the effect of different physical dose rates of the accelerator BNCT on biological effects. SAS and A172 cells exposed to 10B-boronophenylalanine were irradiated using a neutron beam (normal operating current, 100 μA) at the Aomori Quantum Science Center. Thermal neutron flux was attenuated to 50.0 ± 0.96% under 50 μA irradiation compared to that under 100 μA irradiation. Cells were given physical doses of 1.67 and 3.36 Gy at 30 and 60 mC, respectively, and survival was significantly increased after 50 μA irradiation for both cell types (p = 0.0052 for SAS; p = 0.046 for A172, for 60 mC). Differences in accelerator BNCT beam dose rates have non-negligible effects on biological effects. Dose rate fluctuations and differences should not be easily permitted to obtain consistent biological effects.

To establish the high-pressure ionization chamber products for dose rate monitoring of the environmental level γ ray, the design from the aspects of ionization chamber shell, detector, electronic system, etc. are optimized, to improve the environmental adaptability, electromagnetic compatibility and reliability of the equipment. According to the standard method, the general quality characteristics test was carried out at a third party. The test results showed that the working and storage temperature range of the product was -10 ℃-45 ℃; Humidity range ≤93% RH; It has certain anti-vibration and impact capacity, and meets the requirements of the severity level 2M1 of transport environmental conditions in GB/T 8993—1998; Electrostatic discharge immunity and radio frequency electromagnetic field radiation immunity in electromagnetic compatibility shall meet the relevant requirements of GB/T 17626-2—2018 and GB/T 17626-3—2016; The reliability meets the requirement of MTBF≥1 000 h. The environmental adaptability, electromagnetic compatibility and reliability of this product meet the requirements of meter-level products. It can be used as a portable radiation dosimeter in climatefree places. High pressure ionization chamber can be used as a high accuracy work measuring instrument for ambient level air kerma to carry out radiation dose monitoring.

With the development of radiomedical technology, medical cyclotron proton accelerators have broad market prospects in China. China’s construction of medical cyclotron proton accelerator test room can improve the production efficiency of imported medical cyclotron proton accelerator. In order to ensure the radiation safety of the test room, this paper selects the 16 MeV cyclotron accelerator test room with a large proportion of imports as the research object, using FLUKA software to establish the target, shield and material model, setting the particle type, energy, beam intensity, beam loss rate and other parameters, and simulateing the radiation dose field distribution around the test room. The results show that the dose rate range of 30 cm outside the test room is 0.146~1.801 μSv/h, which meets the dose rate limit of 25 μSv/h. The research methods and results of this paper can provide reference for the radiation safety analysis of similar engineering.

Abstract Background Acrylamide poisoning is often reported as chronic poisoning presenting with peripheral neuropathy or carcinogenic action due to long-term exposure to low concentrations. However, there have been few reports of acute poisoning due to oral ingestion of acrylamide, where the symptoms appear a few hours after ingestion. Here, we report a case of acute acrylamide poisoning where a high concentration was ingested in a short time, resulting in a fatal outcome due to the rapid course of events. Case presentation The patient was an adolescent female who ingested 150 ml (148 g) of acrylamide with suicidal intent. A disorder of consciousness was observed when the emergency medical team arrived 36 min later. An hour later, tracheal intubation and intravenous access were performed at a hospital, and 2 h after that, she was transported to our hospital. After she arrived at the hospital, circulatory dynamics could not be maintained despite vasopressor and colloid osmotic infusion, and hemodialysis could not be introduced. Subsequently, cardiopulmonary arrest occurred, and the patient passed away 7 h after ingestion. In the present case, severe symptoms appeared shortly after acrylamide ingestion, unlike other reported cases. In previous report summarizing animal studies, there was a relationship among the symptoms of acute poisoning, the dose, and onset time. The data from this case were compared to those from previous reports, and we were able to predict the early appearance of severe symptoms based on this comparison. Conclusion The severity of acute acrylamide poisoning by oral ingestion was primarily dependent on the amount and rate of ingestion.

Objective(s): The traditional practice of empiric radioiodine (I-131) prescription is scientifically obsolete and inappropriate for inoperable metastatic differentiated thyroid cancer. However, theranostically guided prescription is still years away for many institutions. A personalized predictive method of radioiodine prescription that bridges the gap between empiric and theranostic methods is presented. It is an adaptation of the “maximum tolerated activity” method, where serial blood sampling is replaced by population kinetics carefully chosen by the user. It aims to maximize crossfire benefits within safety constraints to overcome tumour absorbed dose heterogeneity for a safe and effective first radioiodine fraction i.e., the First Strike.Methods: The EANM method of blood dosimetry was incorporated with population kinetics, marrow and lung safety constraints, body habitus and clinical assessment of metastatic extent. Population data of whole body and blood kinetics in patients with and without metastases, prepared by recombinant human thyroid stimulating hormone or thyroid hormone withdrawal, and the maximum safe marrow dose rate were deduced from published data. For diffuse lung metastases, the lung safety limit was linearly scaled by height and separated into lung and remainder-of-body components.Results: The slowest whole body Time Integrated Activity Coefficient (TIAC) amongst patients with any metastases was 33.5±17.0 h and the highest percentage of whole body TIAC attributed to blood was 16.6±7.9%, prepared by thyroid hormone withdrawal. A variety of other average radioiodine kinetics is tabulated. Maximum safe marrow dose rate was deduced to be 0.265 Gy/h per fraction, where blood TIAC is normalised to administered activity. An easy-to-use calculator was developed which only requires height, weight and gender to populate recommendations for personalized First Strike prescription. The user decides by clinical gestalt whether the prescription is to be constrained by marrow or lung, then selects an activity depending on how extensive the metastases are likely to be. A Standard Female with oligometastasis and good urine output without diffuse lung metastasis is expected to safely tolerate 8.03 GBq of radioiodine as the First Strike.Conclusion: This predictive method will help institutions rationalise the First Strike prescription based on radiobiologically sound principles, personalised to individual circumstances.

Background and Aim: We measured radiation emission from the patients undergoing myocardial perfusion scan after leaving nuclear medicine department to demonstrate how much radiation hospital staff or patients’ companions, in the vicinity of the patients would receive. We also evaluated the relationship of age, sex, and body mass index with the emitted radiation rate. Material and Methods: In this study 60 patients (41 females and 19 males) after undergoing 99mTc-sestamibi myocardial perfusion scan with a dose of 925±185 MBq, were selected randomly. The equivalent dose rate at distances of 0.25 m, 1 m and 2 m from the patients were measured by a survey meter before leaving nuclear medicine department and after 12 & 24 hours. Data were analyzed by T-test, Pearson correlation coefficient and ANOVA. Results: The mean equivalent dose rates in unit of microsievert per hour at distances of 0.25 m, 1 m and 2 m from the patients were (120.6 ± 24.1, 19.4 ± 3.8, 8.4 ± 1.3) at leaving time, (29.1 ± 8.7, 5.3 ± 1.2, 2.1 ± 0.8) after 12 hours and (4.3 ± 1.5, 0.8 ± 0.6, 0.3 ± 0.1) after 24 hours, respectively. The mean equivalent dose rate showed no relationship with gender and age, but it was inversely correlated with body mass index (P-value

Abstract Background F-18 FDG (fluorodeoxyglucose) PET/CT procedures are one of the most growing studies used for patient management in oncology, cardiology, neurology, and other indications, in which the challenges meet both patients and clinicians, especially when we are looking for the presence/absence of disease progression and cure. This study was conducted to assess the external radiation dose after 18FDG-PET/CT examination. In total, 117 patients were enrolled in the study. Radiation exposure was measured using a calibrated RadEye SPRD-ER personal radiation detector. The measurements were taken at 0, 30, 100, 150, and 200 cm distance from the patient. The time of measurement was immediately post-injection, 30 min, 60 min after injection, and at the time of releasing the patient. Results The result showed that the mean radiation equivalent dose rate at 0 min/0 cm was 414 µSv/h, at 30 min/30 cm was 99.7 µSv/h, and 60 min/100 cm was 18.3 µSv/h. The radiation doses at different distances (0, 30, 100, 150, and 200 cm) were 160.9 µSv/h, 70.9 µSv/h, 12.4 µSv/h, 7 µSv/h, and 3.7 µSv/h, respectively. Conclusion In conclusion, the patient can be safely released after 2 h of injection in (18F-FDG) PET/CT and the radiation dose can be limited by increasing distance from the radiation source and also instructing them to drink much more water to enhance the process of excretions. The dose rates are low in this study; if the staff interact with multiple patients, they will not approach exposure limits. Similarly, dose rates are so low at patient release that family will not receive doses above regulatory limits.

Background: FLASH proton therapy has the potential to reduce side effects of conventional proton therapy by delivering a high dose of radiation in a very short period of time. However, significant progress is needed in the development of FLASH proton therapy. Increasing the dose rate while maintaining dose conformality may involve the use of advanced beam‐shaping technologies and specialized equipment such as 3D patient‐specific range modulators, to take advantage of the higher transmission efficiency at the highest energy available. The dose rate is an important factor in FLASH proton therapy, but its definition can vary because of the uneven distribution of the dose over time in pencil‐beam scanning (PBS). Purpose: Highlight the distinctions, both in terms of concept and numerical values, of the various definitions that can be established for the dose rate in PBS proton therapy. Methods: In an in silico study, five definitions of the dose rate, namely the PBS dose rate, the percentile dose rate, the maximum percentile dose rate, the average dose rate, and the dose averaged dose rate (DADR) were analyzed first through theoretical comparison, and then applied to a head and neck case. To carry out this study, a treatment plan utilizing a single energy level and requiring the use of a patient‐specific range modulator was employed. The dose rate values were compared both locally and by means of dose rate volume histograms (DRVHs). Results: The PBS dose rate, the percentile dose rate, and the maximum percentile dose are definitions that are specifically designed to take into account the time structure of the delivery of a PBS treatment plan. Although they may appear similar, our study shows that they can vary locally by up to 10%. On the other hand, the DADR values were approximately twice as high as those of the PBS, percentile, and maximum percentile dose rates, since the DADR disregards the periods when a voxel does not receive any dose. Finally, the average dose rate can be defined in various ways, as discussed in this paper. The average dose rate is found to be lower by a factor of approximately 1/2 than the PBS, percentile, and maximum percentile dose rates. Conclusions: We have shown that using different definitions for the dose rate in FLASH proton therapy can lead to variations in calculated values ranging from a few percent to a factor of two. Since the dose rate is a critical parameter in FLASH radiation therapy, it is essential to carefully consider the choice of definition. However, to make an informed decision, additional biological data and models are needed. [ABSTRACT FROM AUTHOR]

X-ray/gamma, neutron, electromagnetic and Bremsstrahlung shielding parameters were studied for the different aluminium alloys such as Al–Li, Duralumin, Hiduminium, Hydronalium, Italma, Magnalium, Ni–Ti–Al and Y-alloy. X-ray/gamma shielding properties such as mass attenuation coefficient, Half Value layer (HVL), Tenth Value layer (TVL), effective atomic number ( Z e f f ), electron density ( n e ), build-up factors (BF), KERMA coefficient (KE), and radiation protection efficiency (RPE) of Al alloys of various compositions were studied. Shielding effectiveness for electromagnetic radiation at different frequency ranges from radio waves to infrared radiations is studied in the above-mentioned aluminium alloys. Further, we investigated neutron scattering lengths and cross sections for the above alloys. Bremsstrahlung shielding parameters such as Bremsstrahlung dose rate, probability of bremsstrahlung and bremstrahlung production efficiency were also studied. Bremsstrahlung's dose rate for the distinct β emitters corresponding to maximum energy are investigated for the different aluminium alloys. Thorough investigations reveal that Ni–Ti–Al aluminium alloy is found to be a good absorber of X-ray/γ radiation, neutron, electromagnetic and Bremsstrahlung radiations. As a consequence, we recommend Ni–Ti–Al as a good radiation shielding material among the aluminium alloys. [ABSTRACT FROM AUTHOR]

Recent discovery and investigation of the flow of glasses under the electron beams of transmission electron microscopes raised the question of eventual occurrence of such type effects in the vitrified highly radioactive nuclear waste (HLW). In connection to this, we analyse here the flow of glasses and glass–liquid transition in conditions of continuous electron irradiation such as under the e-beam of transmission electron microscopes (TEM) utilising the configuron (broken chemical bond) concept and configuron percolation theory (CPT) methods. It is shown that in such conditions, the fluidity of glasses always increases with a substantial decrease in activation energy of flow at low temperatures and that the main parameter that controls this behaviour is the dose rate of absorbed radiation in the glass. It is revealed that at high dose rates, the temperature of glass–liquid transition sharply drops, and the glass is fully fluidised. Numerical estimations show that the dose rates of TEM e-beams where the silicate glasses were fluidised are many orders of magnitude higher compared to the dose rates characteristic for currently vitrified HLW. [ABSTRACT FROM AUTHOR]

The "passive" sorption detectors based on the activated charcoal together with scintillation spectrometry were utilized to measure radon flux density from the soil surface as well as volumetric activity of indoor radon at the dwellings of rural areas of Uzbekistan. Additionally, gamma dose rates as well as concentrations of natural radionuclides in soil and building materials samples were determined. Based on the values of natural radionuclides, common radiological indices have been calculated. It was found that varying greatly, 94% radon flux density values did not exceed 80 mBq/(m2·s), while volumetric activities of radon were in the range of 35–564 Bq/m3. The radium equivalent activity for studied soil and building materials samples were below the allowed limit of 370 Bq/kg. Computed gamma dose rates were in the range of 55.50–73.89 ƞGyh−1 below the limit of 80 ƞGyh−1 and annual effective dose rate 0.068–0.091 mSvy−1, the average value of which was higher than the standard limit > 0.47 mSvy−1. The gamma representative index range was 0.89–1.19 with an average of 1.002 which was higher than the standard limit of 1.0. The range of activity utilization index was equal to 0.70–0.86 with an average value 0.77 which was lower than the recommended level ≤ 2.0. And lastly, excess lifetime cancer risk index values were from 1.9 × 10−4 to 2.5 × 10−4 and were lower than the recommended value 2.9 × 10−4 indicating low radiological risk. The results are consistent with the research conducted by other authors earlier, implying suitability of employing the method for the assessment of residential areas. [ABSTRACT FROM AUTHOR]

Radiotherapy (RT) is performed in approximately 75% of patients with cancer, and its efficacy is often hampered by the low tolerance of the surrounding normal tissues. Recent advancements have demonstrated the potential to widen the therapeutic window using “very short” radiation treatment delivery (from a conventional dose rate between 0.5 Gy/min and 2 Gy/min to more than 40 Gy/s) causing a significant increase of normal tissue tolerance without varying the tumor effect. This phenomenon is called “FLASH Effect (FE)” and has been discovered by using electrons. Although several physical, dosimetric, and radiobiological aspects need to be clarified, current preclinical “in vivo” studies have reported a significant protective effect of FLASH RT on neurocognitive function, skin toxicity, lung fibrosis, and bowel injury. Therefore, the current radiobiological premises lay the foundation for groundbreaking potentials in clinical translation, which could be addressed to an initial application of Low Energy Electron FLASH (LEE) for the treatment of superficial tumors to a subsequent Very High Energy Electron FLASH (VHEE) for the treatment of deep tumors. Herein, we report a clinical investigational scenario that, if supported by preclinical studies, could be drawn in the near future.

Radon (Rn) mitigation techniques and radioactivity control in house are well-established. Majority of these techniques apply to detached and semi-detached houses, where the earth beneath the structures serves as the primary source of Rn. For the place of Bangalore city, indoor Rn and Tn (thoron) concentrations have been measured using solid state nuclear track detector-based dosimeters. Observations were recorded with and without formica laminated material (a composite material) on the room walls. After a month, the measured concentrations of Rn (222Rn) and Tn (220Rn) were 43.5 and 28.6 Bq m-3 without any coatings and 12.9 and 9.7 Bq m-3 with a thin sheet of formica laminated material. For the same measurements the dose rates of Rn and Tn were 0.5 and 0.2 mSv y-1, respectively. According to the preliminary study, formica laminated material on the walls caused a concentration drop more than 50 %. [ABSTRACT FROM AUTHOR]