Radiation And Environmental Biophysics[JOURNAL]
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200 papers
Modulated Arc Therapy for hippocampal-avoidance whole brain radiation therapy: planning comparison with intensity modulated Radiation Therapy.
Martín-Tovar EA, Badillo-Alvarado AH, Cocom-Poot LE … +1 more , Gaxiola-Sosa JL
Radiat Environ Biophys · 2024 Aug · PMID 38809486 · Publisher ↗
This study aimed to evaluate the modulated arc therapy (mARC) technique as a planning and treatment option for hippocampal sparing whole brain radiotherapy (HS-WBRT) following the Radiation Therapy Oncology Group (RTOG)...
This study aimed to evaluate the modulated arc therapy (mARC) technique as a planning and treatment option for hippocampal sparing whole brain radiotherapy (HS-WBRT) following the Radiation Therapy Oncology Group (RTOG) 0933 dosimetric criteria. Computed tomography (CT) and magnetic resonance imaging (MRI) were selected retrospectively for 15 patients. Two types of plans were created for each patient, namely an intensity-modulated radiation therapy (IMRT) and a mARC plan. IMRT and mARC plans were compared in terms of plan quality indices, absorbed dose to organs at risk (OARs), number of monitor units (MUs), and treatment time. All plans in both techniques were considered clinically acceptable for treatment. However, IMRT plans presented a higher conformity (p = 0.01) as well as a higher homogeneity as compared to mARC plans, but this difference was not statistically significant (p > 0.05). In terms of the preservation of the hippocampus, it was observed that the IMRT plans achieved significantly lower doses for both 100% of its volume and for its maximum dose (p < 0.001). The evaluation of the remaining OARs showed that the IMRT technique resulted in lower doses, and significant differences were observed for the following organs: left cochlea (p < 0.001), left eye (p < 0.001), right eye (p = 0.03), both lenses of the eye (p < 0.001), and right optic nerve (p = 0.02). Despite these differences, the absolute differences in all dosimetric parameters were low enough to bear any clinical relevance. A drastic (close to 65%) and significant (p < 0.001) decrease was observed in the number of MUs for the mARC plans. This resulted in a substantial decrease in treatment time (60.45%, p < 0.001). It is concluded that the mARC technique is a feasible planning and treatment solution for HS-WBRT that meets the RTOG 0933 criteria. The main advantage of using mARC over IMRT for HS-WBRT is the considerable reduction in MUs and treatment time.
Impact of flattening filter-free beams on remaining volume at risk in lung cancer treatment.
Alfishawy MM, Kany AI, Elshahat KM
Radiat Environ Biophys · 2024 Aug · PMID 38762614 · Publisher ↗
Modern radiotherapy machines offer a new modality, like flattening filter-free beam (FFF), which is used especially in stereotactic body radiation therapy (SBRT) to reduce treatment time. The remaining volume at risk (RV...
Modern radiotherapy machines offer a new modality, like flattening filter-free beam (FFF), which is used especially in stereotactic body radiation therapy (SBRT) to reduce treatment time. The remaining volume at risk (RVR) is known as undefined normal tissue, and assists in evaluating late effects such as carcinogenesis. This study aimed to compare the effects of flattening and un-flattened beams on RVR in lung cancer treated by conventional doses using volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT). Twenty-three lung cancer patients with a prescribed dose of 60 Gy delivered in 30 fractions were selected retrospectively. Four treatment plans were generated for each case (VMAT FF, VMAT FFF, IMRT FF and IMRT FFF). Mean doses to RVR and volumes that received low doses (V15Gy, V10Gy and V5Gy) were introduced as RVR evaluation parameters. Variance percentage comparison between flattening filter (FF) and FFF for the RVR evaluation parameters gave 2.38, 1.10, 1.80 and 2.22 for VMAT, and 1.73, 1.18, 1.62 and 1.81 for IMRT. In contrast, VMAT and IMRT RVR evaluation parameters resulted in variance percentage differences of 10.29, 5.02, - 8.84 and - 4.82 for FF, and 11.18, 4.96, - 8.59 and - 4.48for FFF. It is concluded that in terms of RVR evaluation parameters, FFF is clinically beneficial compared to FF for RVR, due to the decrease in mean RVR dose and low-dose irradiated RVR volume. Furthermore, VMAT is preferred in the mean RVR dose and V15Gy, while IMRT is better in V10Gy and V5Gy for RVR.
Comparative analysis of simultaneous integrated boost and sequential boost radiotherapy in node-positive cervical cancer: dosimetric and radiobiological considerations.
Mishra R, Singh S, Patel G … +7 more , Mandal A, Mishra H, Pandey A, Bahadur B, Singh PK, Sachan S, Tewari M
Radiat Environ Biophys · 2024 May · PMID 38722389 · Publisher ↗
For locally advanced cervical cancer, the standard therapeutic approach involves concomitant chemoradiation therapy, supplemented by a brachytherapy boost. Moreover, an external beam radiotherapy (RT) boost should be con...
For locally advanced cervical cancer, the standard therapeutic approach involves concomitant chemoradiation therapy, supplemented by a brachytherapy boost. Moreover, an external beam radiotherapy (RT) boost should be considered for treating gross lymph node (LN) volumes. Two boost approaches exist with Volumetric Intensity Modulated Arc Therapy (VMAT): Sequential (SEQ) and Simultaneous Integrated Boost (SIB). This study undertakes a comprehensive dosimetric and radiobiological comparison between these two boost strategies. The study encompassed ten patients who underwent RT for cervical cancer with node-positive disease. Two sets of treatment plans were generated for each patient: SIB-VMAT and SEQ-VMAT. Dosimetric as well as radiobiological parameters including tumour control probability (TCP) and normal tissue complication probability (NTCP) were compared. Both techniques were analyzed for two different levels of LN involvement - only pelvic LNs and pelvic with para-aortic LNs. Statistical analysis was performed using SPSS software version 25.0. SIB-VMAT exhibited superior target coverage, yielding improved doses to the planning target volume (PTV) and gross tumour volume (GTV). Notably, SIB-VMAT plans displayed markedly superior dose conformity. While SEQ-VMAT displayed favorable organ sparing for femoral heads, SIB-VMAT appeared as the more efficient approach for mitigating bladder and bowel doses. TCP was significantly higher with SIB-VMAT, suggesting a higher likelihood of successful tumour control. Conversely, no statistically significant difference in NTCP was observed between the two techniques. This study's findings underscore the advantages of SIB-VMAT over SEQ-VMAT in terms of improved target coverage, dose conformity, and tumour control probability. In particular, SIB-VMAT demonstrated potential benefits for cases involving para-aortic nodes. It is concluded that SIB-VMAT should be the preferred approach in all cases of locally advanced cervical cancer.
Usability of sand samples in TL Radiation Dosimetry.
Madcour WE, Shahein AY, Hafez HS
Radiat Environ Biophys · 2024 May · PMID 38709277 · Publisher ↗
This study investigated natural sand thermoluminescence (TL) response as a possible option for retrospective high-dose gamma dosimetry. The natural sand under investigation was collected from six locations with selection...
This study investigated natural sand thermoluminescence (TL) response as a possible option for retrospective high-dose gamma dosimetry. The natural sand under investigation was collected from six locations with selection criteria for sampling sites covering the highest probability of exposure to unexpected radiation on the Egyptian coast. Dose-response, glow curve, chemical composition, linearity, and fading rate for different sand samples were studied. Energy Dispersive X-ray Spectroscopy (EDX) analysis revealed differences in chemical composition among the various geological sites, leading to variations in TL glow curve intensity. Sand samples collected from Ras Sedr, Taba, Suez, and Enshas showed similar TL patterns, although with different TL intensities. Beach sands of Matrouh and North Coastal with a high calcite content did not show a clear linear response to the TL technique, in the dose range of 10 Gy up to 30 kGy. The results show that most sand samples are suitable as a radiation dosimeter at accidental levels of exposure. It is proposed here that for high-dose gamma dosimetry with doses ranging from 3 to 10 kGy, a single calibration factor might be enough for TL measurements using sand samples. However, proper calibration might allow dose assessment for doses even up to 30 kGy. Most of the investigated sand samples had nearly stable fading rates after seven days of storage. The Ras Sedr sands sample was the most reliable for retrospective dose reconstruction.
Assessment of stereotactic high-resolution detectors for stereotactic body radiotherapy: comparative analysis between myQA® SRS and Gafchromic EBT-XD films.
Chinnaiya D, Mudhana G
Radiat Environ Biophys · 2024 May · PMID 38683360 · Publisher ↗
The study aimed to evaluate dosimetry systems used for stereotactic body radiotherapy (SBRT), specifically 2D array dosimetry and film dosimetry systems, for exploring their characteristics and clinical suitability. For...
The study aimed to evaluate dosimetry systems used for stereotactic body radiotherapy (SBRT), specifically 2D array dosimetry and film dosimetry systems, for exploring their characteristics and clinical suitability. For this, high-resolution myQA SRS detectors and Gafchromic EBT-XD films were employed. Film analysis included net optical density (OD) values depending on energy, dose rate, scanner orientation, scanning side, and post-exposure growth. For myQA SRS, signal values were evaluated in terms of dose rate (400-1400 MU/min) and angular dependence (0-180° at 30° intervals) along with couch angles of 0°, 45°, and 90°. Pre-treatment verification included 32 SBRT patients for whom myQA SRS results were compared with those obtained with Gafchromic EBT-XD films. Analysis revealed less than 1% deviation in net OD for energy and dose rate dependence. Scanner orientation caused 2.5% net OD variation, with minimal differences between film front and back scan orientations (variance < 1.0%). A rapid OD rise occurred within six hours post-exposure, followed by gradual increase. The myQA SRS detector showed - 3.7% dose rate dependence (400 MU/min), while the angular dependence at 90° was - 26.7%. A correction factor effectively reduced these differences to < 1%. For myQA SRS, gamma passing rates were-93.6% (2%/1 mm), while those for EBT-XD films were-92.8%. Improved rates were observed with 3%/1 mm: for myQA SRS-97.9%, and for EBT-XD film-98.16%. In contrast, for 2%/2 mm with 10% threshold, for myQA SRS-97.7% and for EBT-XD film-98.97% were obtained. It is concluded that both myQA SRS detectors and EBT-XD films are suitable for SBRT pre-treatment verification, ensuring accuracy and reliability. However, myQA SRS detectors are preferred over EBT-XD film due to the fact that they offer real-time measurements and user-friendly features.
Influence of rock type and geophysical properties on radon flux density.
Ryzhakova NK, Stavitskaya KO, Plastun SA
Radiat Environ Biophys · 2024 May · PMID 38668871 · Publisher ↗
The most significant source of human exposure to ionizing radiation is the radioactive gas radon (basically Rn) and its daughter decay products, creating more than half of the effective dose from all natural sources. Rad...
The most significant source of human exposure to ionizing radiation is the radioactive gas radon (basically Rn) and its daughter decay products, creating more than half of the effective dose from all natural sources. Radon enters buildings mainly from dense rocks, which are below building foundations at depths of 1 m and more. In this paper long-term measurements of radon flux density are analyzed, with radon exhalation from the surface of the most common rocks-loams, sandy loams, clays, clay shales, several types of sandy-gravel-pebble deposits, clay and rocky limestone. The influence of geophysical properties of rocks on radon flux density due to exhalation from surfaces of those rocks was studied. Based on the results obtained, a method of local assessment of the hazard from radon and its progeny in buildings is proposed, which is based on the geophysical properties of rocks below the foundations of those buildings.
Impact of flight route changes on cosmic ray exposure: consequences of the conflict between Ukraine and the Russian federation.
Hubert G
Radiat Environ Biophys · 2024 May · PMID 38668870 · Publisher ↗
This work investigates the impact on cosmic ray exposures to aircrew due to changing flight routes operated in the context of the recent conflict between Ukraine and the Russian Federation. All analyses were done based o...
This work investigates the impact on cosmic ray exposures to aircrew due to changing flight routes operated in the context of the recent conflict between Ukraine and the Russian Federation. All analyses were done based on Paris-Tokyo and Tokyo-Paris flights taken as examples, and differences in radiation exposures were quantified by comparing the situation before and after the beginning of the conflict. Regarding space weather scenarios, a quiet solar period and an extreme solar event (ground level enhancement (GLE) 5) were considered in the study. Analyses showed that the new Paris-Tokyo flight route established after the beginning of the conflict results in a smaller radiation dose to aircrew than that operated before the conflict, particularly during solar events. In contrast, for Tokyo-Paris flights the new high-latitude route crossing the Atlantic Ocean and North America increases the dose significantly (+ 50% in the worst case). Although this analysis is limited only to flights connecting Paris and Tokyo, it allowed for an evaluation of the consequences of new routes (particularly polar ones) on ambient dose equivalent values.
A Monte Carlo simulation-based decision support system for radiation oncologists in the treatment of glioblastoma multiforme.
Praveen Kumar C, Aggarwal LM, Bhasi S … +1 more , Sharma N
Radiat Environ Biophys · 2024 May · PMID 38664268 · Publisher ↗
In the present research, we have developed a model-based crisp logic function statistical classifier decision support system supplemented with treatment planning systems for radiation oncologists in the treatment of glio...
In the present research, we have developed a model-based crisp logic function statistical classifier decision support system supplemented with treatment planning systems for radiation oncologists in the treatment of glioblastoma multiforme (GBM). This system is based on Monte Carlo radiation transport simulation and it recreates visualization of treatment environments on mathematical anthropomorphic brain (MAB) phantoms. Energy deposition within tumour tissue and normal tissues are graded by quality audit factors which ensure planned dose delivery to tumour site thereby minimising damages to healthy tissues. The proposed novel methodology predicts tumour growth response to radiation therapy from a patient-specific medicine quality audit perspective. Validation of the study was achieved by recreating thirty-eight patient-specific mathematical anthropomorphic brain phantoms of treatment environments by taking into consideration density variation and composition of brain tissues. Dose computations accomplished through water phantom, tissue-equivalent head phantoms are neither cost-effective, nor patient-specific customized and is often less accurate. The above-highlighted drawbacks can be overcome by using open-source Electron Gamma Shower (EGSnrc) software and clinical case reports for MAB phantom synthesis which would result in accurate dosimetry with due consideration to the time factors. Considerable dose deviations occur at the tumour site for environments with intraventricular glioblastoma, haematoma, abscess, trapped air and cranial flaps leading to quality factors with a lower logic value of 0. Logic value of 1 depicts higher dose deposition within healthy tissues and also leptomeninges for majority of the environments which results in radiation-induced laceration.
The effects of re-irradiation on the chemical and morphological properties of permanent teeth.
Dos Santos TT, Mattos VS, Molena KF … +7 more , de Paula-Silva FWG, de Oliveira HF, Faraoni JJ, Nelson-Filho P, de Castro Neto JC, Palma-Dibb RG, de Queiroz AM
Radiat Environ Biophys · 2024 May · PMID 38625398 · Publisher ↗
This study aimed to assess the in vitro effects of re-irradiation on enamel and dentin properties, simulating head and neck cancer radiotherapy retreatment. Forty-five human permanent molars were classified into five gro...
This study aimed to assess the in vitro effects of re-irradiation on enamel and dentin properties, simulating head and neck cancer radiotherapy retreatment. Forty-five human permanent molars were classified into five groups: non-irradiated; irradiated 60 Gy, and re-irradiated with doses of 30, 40, and 50 Gy. Raman spectroscopy, scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were employed for analysis. Raman spectroscopy assessed intensity, spectral area, and specific peaks comparatively. Statistical analysis involved Kolmogorov-Smirnov and One-Way ANOVA tests, with Tukey's post-test (significance level set at 5%). Significant changes in irradiated, non-irradiated, and re-irradiated enamel peaks were observed, including phosphate (438 nm), hydroxyapatite (582 nm), phosphate (960 nm), and carbonate (1070 nm) (p < 0.05). Re-irradiation affected the entire tooth (p > 0.05), leading to interprismatic region degradation, enamel prism destruction, and hydroxyapatite crystal damage. Dentin exhibited tubule obliteration, crack formation, and progressive collagen fiber fragmentation. EDX revealed increased oxygen percentage and decreased phosphorus and calcium post-reirradiation. It is concluded that chemical and morphological changes in irradiated permanent teeth were dose-dependent, exacerbated by re-irradiation, causing substantial damage in enamel and dentin.
The role of nuclear fragmentations in high energy transfers to a micro-object exposed to primary space radiation.
Fedotov SN, Kushin VV
Radiat Environ Biophys · 2024 May · PMID 38565701 · Publisher ↗
This paper describes events of anomalously high energy transfer to a micro-object by fragments of nuclei generated in nuclear interactions in the environment on board a spacecraft in flight in low-Earth orbit. An algorit...
This paper describes events of anomalously high energy transfer to a micro-object by fragments of nuclei generated in nuclear interactions in the environment on board a spacecraft in flight in low-Earth orbit. An algorithm has been developed that allows for the calculation of the absorbed energy from one or more fragments - products of nuclear interaction. With this algorithm the energy distributions for a spherical micro-volume in an aqueous medium were calculated. And the resulting absorbed energy spectra from nuclear fragments and from primary cosmic rays were compared. The role of nuclear interactions in events of large energy transfers in micro-objects in the field of primary cosmic radiation has been evaluated. The calculations performed in this study showed that the energy in a micro-volume from nuclear events can be several times higher compared to the energy imparted by primary space radiation.
The European intercomparison of in-vivo monitoring laboratories: the EIVIC-2020 project.
Franck D, Meisenberg O, Beaumont T … +7 more , Buchholz W, López MA, Navarro JF, Pérez B, Hürkamp K, Breustedt B, Vanhavere F
Radiat Environ Biophys · 2024 Mar · PMID 38413426 · Full text
The EIVIC project was launched in 2020, and the main goal was the organisation of a European intercomparison of in-vivo monitoring laboratories dealing with direct measurements of gamma-emitting radionuclides incorporate...
The EIVIC project was launched in 2020, and the main goal was the organisation of a European intercomparison of in-vivo monitoring laboratories dealing with direct measurements of gamma-emitting radionuclides incorporated into the body of exposed workers. This project was organised jointly by members of EURADOS Working Group 7 on internal dosimetry (WG7), the Federal Office for Radiation Protection (BfS, Germany) and the Radioprotection and Nuclear Safety Institute (IRSN, France). The objective was to assess the implementation of individual-monitoring requirements in EU Member States on the basis of in-vivo measurements and to gain insight into the performance of in-vivo measurements using whole-body counters. In this context, a total of 41 in-vivo monitoring laboratories from 21 countries, together with JRC (EC) and IAEA participated. The results were submitted in terms of activity (Bq) of the radionuclides identified inside phantoms that were circulated to all participants. The measured data were compared with reference activity values to evaluate the corresponding bias according to the standards ISO 28218 and ISO 13528. In general, the results of the different exercises are good, and most facilities are in conformity with the criteria for the bias and z-scores in the ISO standards. Furthermore, information about technical and organisational characteristics of the participating laboratories was collected to test if they had a significant influence on the reported results.
Po and Pb radioactivity levels in local and imported tobacco used in Palestine and Jordan.
Mashal LA, Buss FM, Thabayneh KM
Radiat Environ Biophys · 2024 Mar · PMID 38411924 · Publisher ↗
This study aimed to assess the concentrations of Po and Pb in various tobacco samples from Palestine and Jordan. Cigarette smoking is recognized as a significant contributor to the radiation dose received by individuals,...
This study aimed to assess the concentrations of Po and Pb in various tobacco samples from Palestine and Jordan. Cigarette smoking is recognized as a significant contributor to the radiation dose received by individuals, primarily due to the elevated levels of Pb and Po found in tobacco. The analysis revealed that the average concentrations of Po in locally sourced tobacco and cigarette samples in Palestine are 16.8 ± 2.3 mBq/g and 18.5 ± 2.0 mBq/g, with a total average of 17.8 ± 7.4 mBq/g (15.5 mBq/cigarette). Similarly, the average concentrations of Pb in these samples are 18.5 ± 2.6 mBq/g and 20.3 ± 2.2 mBq/g, with a total average of 19.6 ± 8.1 mBq/g (17.0 mBq/cigarette). In Jordan, the average concentrations of Po in cigarette samples and narghile tobacco are 20.1 ± 2.4 mBq/g and 18.3 ± 4.1 mBq/g, with a total average value of 19.6 ± 9.9 mBq/g (18.0 mBq/cigarette), while the average concentrations of Pb are 22.2 ± 2.6 mBq/g and 20.2 ± 4.5 mBq/g, with a total average value of 21.6 ± 10.8 mBq/g (19.9 mBq/cigarette). The annual effective doses resulting from inhalation were calculated for smokers of these samples. The findings revealed that the levels of Po and Pb radioactivity in certain investigated samples exceeded the results of studies in many countries of the world. The associated effective doses per year from smoking for all brands products in Palestine range from 34.7 μSv/y to 186.5 μSv/y with an average of 109.5 μSv/y, while in Jordan 54.5 μSv/y to 289.1 μSv/y with an average of 130.9 μSv/y.
Minimum reporting standards about dosimetry of radiation sources used in radiation research studies.
Wojcik A, Thierry-Chef I, Friedl AA … +1 more , Rühm W
Radiat Environ Biophys · 2024 May · PMID 38376815 · Publisher ↗
The necessity of precise dosimetry and its documentation in research is less obvious than in medicine and in radiological protection. However, in radiation research, results can only be validated if experiments were carr...
The necessity of precise dosimetry and its documentation in research is less obvious than in medicine and in radiological protection. However, in radiation research, results can only be validated if experiments were carried out with sufficient precision and described with sufficient details, especially information regarding dosimetry. In order to ensure this, an initiative was launched to establish reproducible dosimetry reporting parameters in published studies. Minimum standards for reporting radiation dosimetry information were developed and published in parallel in the International Journal of Radiation Biology and Radiation Research. As editors of Radiation and Environmental Biophysics, we support this initiative and reproduce the agreed minimum irradiation parameters that should be reported in publications on radiation biology submitted to our journal.
Putting radioactive materials on the sustainability agenda: a report from a workshop on the sustainability of human-made radioactive materials held at the safeND Research Symposium 2023.
Böse F, Wimmers A, Neugebauer J … +7 more , Lösel T, Hermes T, Beppler J, Nickel MS, Morawe P, Weber M, von Hirschhausen C
Radiat Environ Biophys · 2024 Mar · PMID 38367061 · Full text
This report summarizes the findings of a workshop held at the safeND Research Symposium and hosted by the German Federal Office for the Safety of Radioactive Waste Management (BASE) in Berlin in September 2023. The works...
This report summarizes the findings of a workshop held at the safeND Research Symposium and hosted by the German Federal Office for the Safety of Radioactive Waste Management (BASE) in Berlin in September 2023. The workshop aimed to channel perspectives from various fields of expertise to discuss key sustainability concepts in terms of radioactive waste management. Therefore, the report highlights that current sustainability concepts, such as the United Nations' Sustainable Development Goals (SDG) as well as the concept of Planetary Boundaries, neglect challenges arising from the production and storage of human-made radioactive materials. The workshop consisted of three group tasks. The first attempted at identifying the interrelations between "sustainability" and radioactive waste management. The second was to map the global nature of the challenges. The third took first steps to determine a human-made radioactive material as a potential planetary sub-boundary for "novel entities". All three groups identified valuable knowledge gaps that should be addressed by future research and concluded that radioactive waste management is underrepresented in these sustainability concepts.
Influence of neutron cross-section resonances on organ/tissue equivalent and effective dose coefficients for the ICRP voxel phantoms.
Hiller MM, Veinot KG, Hertel NE
Radiat Environ Biophys · 2024 Mar · PMID 38310599 · Publisher ↗
The materials which compose the ICRP Voxel phantoms used in the computation of conversion coefficients involve neutron interaction cross-sections that have resonances at specific energies. Depending on the energy bin str...
The materials which compose the ICRP Voxel phantoms used in the computation of conversion coefficients involve neutron interaction cross-sections that have resonances at specific energies. Depending on the energy bin structure used in the computations, these cross-section resonances may occur at energies that fall between energies at which dose coefficients are computed, thus their effects may not be completely accounted for in the reported coefficients. In the present study, a highly refined energy grid that closely follows the resonance structure in the phantom material cross-sections was identified and used to calculate dose coefficients. Both the equivalent organ/tissue doses for male and female voxel phantoms were computed as well as their summation to obtain the effective dose coefficients. The used refined energy grid tracks very closely the cross-sections in the vicinity of the resonances. The resulting refined energy grid coefficients are compared to coefficients for the coarser energy grid used in ICRP Publication 116. Additionally, reference spectra have been folded with both the fine and coarse sets of conversion coefficients. The resulting total effective doses for these reference spectra are used to assess the adequacy of the dose coefficients calculated on the original ICRP 116 energy grid. The dose coefficients were similarly computed for the local skin dose on the trunk of the body using the ICRU Report 95 phantom. The overall impact of the resonances on the organ/tissue equivalent dose, the effective dose, and the local skin dose are presented and discussed. In general, it was found that resonances can impact neutron dose coefficients, but in most cases the wide range of neutron energies encountered minimized this effect. The impact of resonances was further limited when computing effective dose due to organ/tissue summing and sex-averaging. For the neutron fields studied here, the impact was below 5%.
Evaluation of conventional IMRT and VMAT strategies for postmastectomy radiation therapy after immediate implant-based reconstruction using the new ESTRO-ACROP contouring guidelines.
Araujo AS, Silva RMV, Souza DN
Radiat Environ Biophys · 2024 Mar · PMID 38300284 · Publisher ↗
This study evaluated the usability of conventional templates based on the new contour guidelines of the European Society of Radiation and Oncology and Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) for t...
This study evaluated the usability of conventional templates based on the new contour guidelines of the European Society of Radiation and Oncology and Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) for treatment plans of postmastectomy radiotherapy after immediate implant-based reconstruction. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans generated with two different treatment planning systems (TPSs, Eclipse and Monaco) were examined. Six computed tomography scans of patients aged 35-54 years were retrospectively analysed who had undergone mastectomy and breast reconstruction using silicone implants after being diagnosed with left breast cancer. Six radiation oncologists participated in this study, and each of them contoured the target volume of one left breast using conventional contour (CTV-CONV) and new contour (CTV-ESTRO) methods. This study showed that compared with CTV-CONV, using CTV-ESTRO with objectives and cost functions similar to those of TPSs worsened the target volume coverage and increased the total number of monitor units. Considering the organs at risk, CTV-ESTRO tended to increase the mean dose delivered to the contralateral lung. It is concluded that the approach used for the new ESTRO-ACROP contour method cannot be applied in a manner similar to that for the conventional breast contour method, implying that the new ESTRO-ACROP contour method may require more time for improving plans for a given treatment.
Forty-eight-year follow-up of a female worker exposed to highly enriched uranium via chronic and acute inhalation.
Avtandilashvili M, Tolmachev SY
Radiat Environ Biophys · 2024 Mar · PMID 38217567 · Publisher ↗
The United States Transuranium and Uranium Registries (USTUR) is a unique resource of data and materials for studying biokinetics of uranium in the human body. In this study, bioassay data and post-mortem organ activitie...
The United States Transuranium and Uranium Registries (USTUR) is a unique resource of data and materials for studying biokinetics of uranium in the human body. In this study, bioassay data and post-mortem organ activities from a female whole-body USTUR donor who was exposed to highly enriched uranium were analyzed using the IMBA Professional Plus® software to derive the best estimate of the total intake. The resulting radiation doses delivered to this individual's whole body and major target organs were calculated from estimated intake based on case-specific dose coefficients derived using the AIDE® software. Both intake and dose calculations were carried out using the biokinetic and dosimetric models recommended by the International Commission on Radiological Protection (ICRP) in its Occupational Intakes of Radionuclides publication series. Different exposure scenarios including chronic and acute inhalation intakes were tested. A combination of a chronic inhalation intake and two acute inhalation intakes appears to best describe the bioassay data. To fit this female individual's autopsy data, the transfer rate from the liver to the blood was increased by a factor of 8 and the transfer rate from the kidneys to the blood was decreased by a factor of 2.2. This resulted in the best fit to all data (p = 0.519). The total intake was estimated to be 44.1 kBq, and the committed effective dose was 211 mSv with 96.8% contributed by U. 96.6% of the committed effective dose was contributed by the lungs. The remaining 3.4% of the committed effective dose was contributed by all systemic tissues and organs with the highest contribution (0.40%) from the red bone marrow. It is concluded that the current ICRP models, with the adjustment for smoking status, adequately describe uranium biokinetics for this individual except retention in the liver and kidneys. However, this study was based on a single case and may not be sufficient to identify any apparent sex-specific differences in uranium biokinetics.
Risk of central nervous system tumour incidence in a cohort of workers chronically exposed to ionising radiation.
Moseeva MB, Azizova TV, Bannikova MV
Radiat Environ Biophys · 2024 Mar · PMID 38212569 · Publisher ↗
The aim of the present study was to assess the risk of primary central nervous system (CNS) tumour incidence in a cohort of 22,377 Mayak Production Association workers chronically exposed to ionising radiation. There wer...
The aim of the present study was to assess the risk of primary central nervous system (CNS) tumour incidence in a cohort of 22,377 Mayak Production Association workers chronically exposed to ionising radiation. There were 96 primary CNS tumours, including 42 cases of glioma and 44 cases of meningioma, registered during the whole follow-up period (1948-2018). The study demonstrated that the risk of primary CNS tumour incidence was associated with sex, attained age, calendar period, tall body height, age at the beginning of exposure, and facility type. There was no association found between risk of CNS tumour incidence and body mass index, smoking (males) and alcohol consumption status. The study did not find an effect of the total external gamma radiation dose absorbed in the brain on risk of CNS tumour incidence irrespective of whether an adjustment for the total external neutron dose absorbed in the brain was included or not. Excess relative risk per 1 Gy of external gamma brain dose was 0.05 (95% confidence interval (CI) -0.30; 0.70) for all CNS tumours, -0.18 (95% CI -; 0.44) for gliomas, and 0.38 (95% CI -0.32; 2.08) for meningiomas without adjustment for total neutron brain dose. There was no effect modification by sex, attained age, age at hire or facility.
Internal dose rate due to intake of uranium and thorium by fish from a dam reservoir associated with a uranium mine in Brazil.
de Souza Pereira W, Kelecom A, Lopes JM … +7 more , Charles-Pierre M, do Carmo AS, Paiva AK, Pelegrinelli SQ, Filho WSS, Silva LF, da Silva AX
Radiat Environ Biophys · 2024 Mar · PMID 38197922 · Publisher ↗
Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the e...
Uranium mining can cause environmental impacts on non-human biota around mine sites. Because of this, the reduction in non-human biota exposure becomes an important issue. Environmental radioprotection results from the evolution of human radioprotection; it is based on dose rate to non-human biota and uses, as a biological target, and has harmful effects on populations. In the present study, a flooded impoundment created following dam construction in a uranium mine plant undergoing decommissioning was investigated. Internal dose rates due to activity concentration of natural uranium (U) and Th in omnivorous, phytophagous, and carnivorous fish species were estimated. Radionuclide activity concentrations were obtained by spectrophotometry with arsenazo III in the visible range. The dose rate contribution of Th was lower than that of U. There were no differences between the internal dose rates to studied fish species due to Th, but there were differences for U. A dose rate of 2.30·10 µGy∙d was found due to the two studied radionuclides. Although this value falls below the benchmark for harmful effects, it is important to acknowledge that the assessment did not account for other critical radionuclides from uranium mining, which also contribute to the internal dose. Moreover, the study did not assess external doses. As a result, the possibility cannot be excluded that dose rates at the study area overcome the established benchmarks for harmful effects.
Long-term retention and distribution of highly enriched uranium in an occupationally exposed female.
Tolmachev SY, Avtandilashvili M
Radiat Environ Biophys · 2024 Mar · PMID 38197921 · Publisher ↗
The United States Transuranium and Uranium Registries' (USTUR) female whole body tissue donor studied here was occupationally exposed to highly enriched uranium for 17 years. One hundred and twenty-nine tissue samples we...
The United States Transuranium and Uranium Registries' (USTUR) female whole body tissue donor studied here was occupationally exposed to highly enriched uranium for 17 years. One hundred and twenty-nine tissue samples were collected at the time of death, 31 years post-exposure. These samples were radiochemically analyzed for uranium. The highest uranium concentration of 16.5 ± 2.0 µg kg was measured in the lungs, and the lowest concentration of 0.11 ± 0.01 µg kg in the liver. The thyroid had the highest concentration of 6.3 ± 2.9 µg kg among systemic tissues. Mass-weighted average concentration in the entire skeleton was estimated to be 1.60 ± 0.19 µg kg. In the skeleton, uranium was non-uniformly distributed among different bones. Thirty-one years after the intake, approximately 40% of occupational uranium was still retained in the skeleton, followed by the kidneys (~ 30%), and the brain and liver (~ 10%). Systemic uranium was equally distributed between the skeleton and soft tissues. Uranium content in systemic organs followed the pattern: skeleton > > brain ≈ kidneys > heart ≈ liver > thyroid ≈ spleen. Uranium distribution in this female was compared to previously published USTUR data for male tissue donors. It is concluded that no difference in uranium systemic distribution was observed between female and male individuals. It is demonstrated that dose assessment based on the current ICRP biokinetic model overestimated the dose to the brain by 20%.
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