Radiation Dosimetry

There is theoretical and epidemiological evidence that the ICRP model is unsafe when applied to internal radiation exposure. A recent review by me  includes an overview of the main supporting evidence of the failure of the ICRP model as applied to internal radionuclide exposures, including criticism of the extensive studies of those individuals exposed to Radium-226 and Radium-228. The results of a study of the German Ra-224 patients have been presented in the literature [Nekolla et al 1999, 2010]. The paper was presented by Dr Elke Nekolla of the German Radiological Protection Agency BfS. This provides a useful set of data with which to follow up the assertion that these retrospective Radium studies are not safe for examining the health effects on Radium because of confounding causes of death. In addition these results demonstrate that a number of other cancers apart from bone cancer and head cancers are caused by exposure to Radium.

We propose a novel protocol for electron capture–mediated transmutation using synergistic external fields. Our approach combines magnetic polarization, pulsed electromagnetic excitation, and mechanical stimuli to indirectly mediate nuclear processes via electron-nucleus interactions (e.g., NEET, DNP). A key innovation is a two-phase reactor design that initiates a neutron-driven chain reaction under dynamic conditions before switching to a static state for stable operation and efficient heat management. This framework targets the precise conversion of long-lived fission products and on-demand energy release from nuclear isomers. Despite significant challenges in energy scaling and coherence, this work outlines a viable path toward compact, inherently safer systems for nuclear waste reduction.

Today, proton therapy is considered one of the most effective and advance methods in radiotherapy. In this method, the highest dose delivered to the tissue is at the end of the proton range, which is a unique feature that causes the most damage to the target tissue and the least damage to the adjacent tissues. The aim of this study is to provide an appropriate energy range and evaluate the dose received by the primary and secondary particles in the proton therapy simulation of a brain tumor using the Monte Carlo method. By obtaining an appropriate energy range of 102 to 120 MeV for the incident proton beams, and creating a spread Bragg peak (SOBP) to cover the target area, the MIRD phantom with a 2 cm radius brain tumor made of soft tissue was irradiated. The results obtained indicate the highest deposit energy for the tumor and brain regions with absorbed doses of 4.4940×10-11 (Gy) and 8.2584×10-12 (Gy) respectively, and for secondary particles (NDE) equal to 3.5917×10-13 (Sv) and 1.3258×10-13 (Sv). Other notable results obtained include the absence of proton absorbed dose for the thyroid and a neutron equivalent dose of 1.3889×10-15 (Sv).

Objective: To investigate the effect of surgical procedure, mastectomy versus breast conservation surgery (BCS) on radiotherapy dose to the lung, in patients of breast cancer treated with adjuvant radiotherapy (RT). Study Design: Retrospective longitudinal study. Place and Duration of Study: Combined Military Hospital Rawalpindi, Pakistan over a period of 8 months, on patients treated between Jan 2023-Aug 2023. Methodology: A total of 103 female breast cancer patients receiving an equivalent of 50 Gray in 25 fractions or more (upto 16 gray in 8 fractions or equivalent) of adjuvant radiotherapy to breast after breast conservation surgery (BCS) or chest wall (after mastectomy) were studied. All received field in field intensity modulated radiotherapy (IMRT) with tangential beams. Their lung doses were estimated by measuring the central lung distance (CLD), as a surrogate to volumetric lung dose. Data was analyzed by SPSS version 22. Pearson correlation was checked. Mean CLD between the two surgical groups was compared. Results: Of total 103 patients, 72(69.9%) had modified radical mastectomy (MRM) and 31(30.1%) had breast conservation surgery (BCS). Surgical procedure mastectomy versus breast conservation surgery has a significant correlation with CLD (r=-0.27, p-value 0.005). Mean CLD after MRM was 2.71±0.63 cm and after BCS was 2.34±0.49 cm with a statistically significant difference (p-value-0.005). Conclusion: Breast conservation surgery (BCS) not only spares the organ but also reduces the radiation toxicity due to lower effective doses to the underlying lung, leading to decreased side effects. All cases where BCS is possible, mastectomy should be avoided.

La estimación precisa del enriquecimiento del uranio-235 (235U) es un aspecto
fundamental en el monitoreo, control y verificación de materiales nucleares. Aquí se
presenta un estudio experimental y teórico enfocado en la utilización de
espectrometría gamma de alta resolución, empleando un detector HpGe, para la
determinación no destructiva del contenido de 235U en muestras de uranio.
El método se basa en la identificación y cuantificación de la línea gamma
característica de 185.7 keV emitida por el 235U, junto con otras líneas relevantes del
uranio-238 (238U) y sus productos de decaimiento. Gracias a la alta resolución del
sistema HpGe, fue posible discriminar con precisión las señales gamma
superpuestas, lo cual representa una mejora significativa frente a detectores
convencionales.
Se analizaron varias muestras de dióxido de uranio (UO2) Y octaóxido de triuranio
(U3O8) con enriquecimientos conocidos, aplicando la calibración energética y
normalización respecto al tiempo de conteo y a la masa de la muestra. Los
resultados mostraron una tendencia lineal sólida entre la intensidad neta de la línea
de 185.7 keV y el porcentaje de enriquecimiento, con coeficientes de correlación
superiores a R2 = 0.99.
El estudio demuestra que la espectrometría gamma con detectores HpGe permite
realizar estimaciones rápidas, precisas y no destructivas del enriquecimiento de
uranio, con una diferencia máxima del 15% entre lo declarado comparado con lo
experimental. Se identificaron variables críticas que afectan la exactitud de la
medición, como la geometría de la muestra y el blindaje por las condiciones de fondo
radiactivo. 
En conclusión, el método propuesto presenta una herramienta que puede ser
utilizada en aplicaciones de salvaguardias nucleares, inspecciones radiológicas,
control estratégico de materiales fisibles, etc.
Palabras clave: Uranio, Espectrometría gamma, HpGe, Radiación, Enriquecimiento,
No destructivo.

Background: Radiation exposure is the main hazard in medical X-ray investigations. The aim of this study was to evaluate the radiation dose received in chest x-rays for trauma patients in the Majmaah area. The results were compared with other national and international findings. Furthermore, the reference radiation dose level was measured for different examinations by conventional x-rays. Thus, conventional X-ray examination of trauma patients was investigated. Materials and Methods: Seven hundred patients were evaluated at King Khalid Hospital, Majmaah. The average and range of exposure parameters were 73.5 ± 9.1 (65.9-124.9) and 2.7 ± 0.71 (0.2-9.6) for X-ray tube potential (kVp) and current multiplied by the exposure time (s) (mAs), respectively. Results: The entrance surface air kerma dose measured for chest (PA), skull (AP and LAT), lumbosacral (AP and LAT), and knee joint (AP and LAT) were 0.20+0.07 with a range of 0.13-0.37, 0.86 ± 0.01 with a range of 0.09-2.92 and 0.09 ± 0.02 with a range of 0.04-0.17, 0.10 ± 0.02 with a range of (0.04-0.17 and 0.1 ± 0.02 with a range of 0.03-0.16, and 0.86 ± 0.01 with a range of 0.09-2.92, respectively. The measured doses for pediatric patients were 0.20 ± 0.07 (0.13-0.37) and 0.18 ± 0.03 (0.06-0.23) for female and male patients, respectively. Conclusion: It was concluded that 90% of the procedures had normal findings. However, a precise justification is required, especially for young patients. For dose measurement techniques, the machine-and patient-related factors must be fixed in order to obtain accurate results.

Radiation Exposure is the main hazard in medical x-rays investigations. The objective of this work was to study the attended radiation dose measured in the Majmaah area. Furthermore, to measure the radiation dose level for different examinations in conventional x-rays. Thus, conventional x-rays examination of traumatic patients. A sample of 700 patients was evaluated using at King Khaled Hospital-Majmaah. The average and range of exposure parameters were 73.5 ± 9.1 (65.9-124.9) KVp and 2.7 ± 0.71 (0.2-9.6) mAs for X-ray exposure factors, respectively. The measured Entrance Surface Air Kerma (ESAK) dose for chest (PA), skull ((AP) and (LAT.)), Lumbosacral ((AP) and (LAT.)) In addition, knee joints ((AP) and (LAT.)) were 0.20 + 0.07 with range of (0.13-0.37) mGy, (0.86 ± 0.01) with range of (0.09-2.92) mGy and 0.09 + 0.02 with range of (0.04-0.17) mGy, (0.10 ± 0.02 with range of (0.04-0.17) mGy and 0.1 + 0.02 with range of (0.03-0.16) mGy and 0.86 ± 0.01 with range of (0.09-2.92) mGy respectively. The study was concluded that most of the procedures were done in King Khalid Hospital-Majmaah were in the permissible limits. In dose measurement techniques, the machine and patient-related factors must be fixed for accurate results.

Introduction: Progress in both the development of Tyrosine Kinase Inhibitors (TKIs) and modern radiation therapy (RT) have opened new horizons for the safe and effective treatments of cancer. Combination therapies of TKIs and radiation therapy have been evaluated with variable sequencing and dosing of both agents. Radiation therapy induces cellular damage to cancer and normal tissue DNA by the production of direct and indirect ionization leading to a cascade of biological events. These ultimately lead to potential loss of cellular reproductive capacity, cell death or impotency. Repair mechanisms of RT-induced cell damage require repair pathways dependent on TK. TKIs are key regulators of cellular function and signaling proteins that catalyze phosphorylation reactions of tyrosine molecules. The purpose of this study was to briefly review the basic biology of RT and TKIs and to review the modern literature pertaining to the toxic and therapeutic effects of their combination in the tre...

The thermoluminescence kinetic parameters of Ge-doped flat fibre have been investigated comprehensively using the computerized glow curve deconvolution analysis. The Ge-doped flat fibre was irradiated to 6 MV and 10 MV photon beam with dose ranging from 100 cGy to 300 cGy. Analysis was done using WinGCF software on the dependence of the glow curve intensity on dose delivered and the determination of the trap parameters. Ge-doped flat fibre was found to be linear over the entire dose range explored for both 6 MV and 10 MV irradiations with r 2 value of 0.9955 and 0.9933 respectively. The glow curve consists of five individual glow peaks. The peak height increases with increasing irradiation dose. The first peak (P1) is a dominant individual peak for low temperature peak (LTP) with the maximum temperature ranging from 167.4°C to 179.0°C for both beams studied. Meanwhile, peak (P4) is a dominant individual glow curve for high temperature peak (HTP) with maximum temperature for 6 MV and 10 MV and is observed between 264.5°C to 279.4°C. Peak 1 has the lowest activation energy which is less than 0.72 eV while peak 2 shows the highest activation energy (1.3 eV < Ea < 2.1 eV) which indicates the deepest electrons trap. The results showed that the peak integral will increases as the dose increases. The Ge-doped flat fibre demonstrated the second-order kinetic peak behavior by exhibiting the symmetric shape of the glow curve with high temperature half of the curve slightly broader than the low temperature half, which suggests the possibility of electron retrapping.

I believed that the powers of place and the community you live in can provide a deep learning context.
Learning for the students and an opportunity to share the knowledge, information and dialogue with local residents.
The class has been studying the seemingly overnight come back of nuclear power, capturing headlines & people’s attention in the past year. We delved into the publicly available information (research papers,
Government documents, breaking news, PR and propaganda). We spoke with a wide many people; scientists, health professionals and engineers across a wide spectrum of professional disciplines. Students also spoke with and interviewed folks from Industry and government. Our inquiries included
understanding the proposed possible technologies, learning about what the social, environmental and ecological risks are, timelines, siting criteria, cost implications, & economic benefits. We also understood the need to inform the public about the potential of a nuclear plant in St. Lawrence
county. After our research was well underway we planned and conducted a survey to learn what local residents knew about nuclear energy and to inquire as to their current beliefs, attitudes and feelings about this controversial issue. To further engage with the community we held a Public Town Hall to provide an opportunity for people to hear about what we learned and to listen to townspeople's questions and opinions. This was accomplished with the help of local partners beyond the university. Kathy Stein, President of the St. Lawrence County League of Women Voters and Donna Seymour of the civic media series called “North Country Matters, " were instrumental in connecting with local residents. They worked closely with the students to arrange and publicize our public meeting. Additionally we wish to thank the
Village of Potsdam for allowing us the use of the Village Community Room for our Town Hall session.

The widespread adoption of wireless earbuds has raised concerns regarding potential health risks associated with electromagnetic field (EMF) exposure. This study evaluated EMF emissions from nine commercially available wireless earbud models across three operational modes: Idle, Music, and Calling. Using a calibrated EM Field Meter under controlled environmental conditions, measurements were conducted at a standardized distance of 5 cm to assess electric field strength (E-field), magnetic field strength (H-field), and specific absorption rate (SAR). Results showed significant variations across device models and operational modes. Calling Mode consistently produced the highest emissions, with mean values of 8.39 V/m (E-field), 1.92 µT (H-field), and 0.007 W/kg (SAR), while Music Mode exhibited the lowest levels. The P-Series model recorded peak values of 12.0 V/m, 4.4 µT, and 0.017 W/kg during Calling Mode. A strong positive correlation between E-field and SAR (R² = 99.1%) was observed. Comparison with international public exposure limits established by the International Commission on Non-Ionizing Radiation Protection-ICNIRP (61 V/m; 2.0 W/kg) and the Federal Communications Commission-FCC (1.6 W/kg) indicates that maximum recorded values represent less than 20% of the E-field limit and approximately 1% of the SAR limit. Based on margin-of-exposure analysis, EMF exposure from the tested wireless earbuds is classified as low risk, even under Calling Mode. These findings suggest compliance with international safety standards under normal operating conditions.
Keywords: Electromagnetic field, wireless earbuds, specific absorption rate, EMF exposure, wireless communication devices

Abstract- This study investigates the accumulation
of radiation dose over time in the presence of
radioactive decay, analyzing the impact of half-life,
initial dose rate, and decay constant on exposure
levels. Using an analytical modeling approach, the
research explores both short-term and long-term
dose accumulation, highlighting key differences in
radiation risk profiles. The findings indicate that
sources with shorter half-lives cause rapid initial
dose accumulation but stabilize quickly, whereas
longer half-life sources contribute to prolonged
radiation exposure. Sensitivity analysis reveals that
variations in the initial dose rate significantly affect
long-term exposure levels, while decay constants
influence the rate at which radiation stabilizes. The
study underscores the importance of managing
these factors to minimize radiation risks posesand
improve safety protocols in occupational and
environmental settings. These insights are crucial
for optimizing radiation protection strategies,
ensuring controlled exposure, and mitigating long-
term health effects.
Indexed Terms- Decay constant, Half-life,
Radiation dose accumulation, Radiation protection,
Sensitivity analysis

The aim of this study; was to developed and designs an indigenous quality control phantom QCP to be used for gamma camera resolution QC test which installed at Royal Care hospital (RCH) and Radiation & Isotopes Center of Khartoum (RICK), as well to compare its performance relative to the standard QC phantom recommended by National Electronic Manufacture Association NEMA. The phantom has been designed based on the parameters and specifications recommended by NEMA with specific indigenous designing in view of utilizing local cheep material such as Perspex and wires lead and geometrical engineering. The comparative QC assessment for RCH and RICK revealed that: for RCH and RICK the resolution was 94.0% and 89.5% respectively which was dependant on the minimum object size resolved in the designed phantom (0.5 mm), while the resolution obtained by NEMA standard phantom showed 95.5% and 91.8% respectively. Quite similar resolution% has been obtained by the designed phantom depending on the object frequency (number of object/cm) i.e. number of lead wires resolved per cm 2 , in this view the resolution was resolution was 94% and 90.3% respectively and in comparison with that obtained by NEMA phantom which was 95.5% and 91.8% respectively, the average deviation factor of the designed phantom from the standard was 1.5% -1.9. Also the general trend of correlation between object size versus resolution showed a linear proportional equation in a form of y = 6.59x + 47.87 and y = 6.64x + 43.1 for RCH and RICK respectively with significant correlation as R 2 = 0.98. And for object frequency versus resolution, the equation trend was inversely according to: for RCH and for RICK, where x refers to object frequency and y refers to resolution%, with significant correlation as R 2 = 1.

Se presentan los resultados en la aplicación de la simulación matemática para el estudio de la efi ciencia cuántica de un detector de silicio cristalino del tipo microbandas, destinado a imagenología médica y al desarrollo de otras aplicaciones como la autenticación y fechado de obras de arte. Se evaluó el efecto de la geometría fuente-detector, de la energía de los rayos X y del grosor de la zona muerta del detector en la efi ciencia cuántica de este dispositivo. Los resultados de la simulación se compararon con el pronóstico teórico y con los datos experimentales disponibles, verifi cándose una adecuada correspondencia. Se concluyó que la confi guración frontal es más efi ciente para energías incidentes menores a los 17 keV, y que la confi guración de borde es la recomendada para aplicaciones que requieran la detección de energías superiores a este valor. También se determinó que la disminución de la zona muerta del detector conduce a un considerable aumento de la efi ciencia para cualquier valor de energía en el intervalo de 5 a 100 keV.

An initial assessment of absorbed gamma dose rates was conducted at around 30 monitoring locations situated within specific residential structures in Shaqlawa, Iraq. This represents the first instance of conducting such measures within this particular environment. A Geiger-Müller digital survey meter was used to quantify the gamma exposure at each monitoring station, 1 meter above ground. Additionally, a GPS device was employed to correctly capture the coordinates. The average absorbed gamma dose rates observed were 0.123 μSv. h-1 and 0.117 μSv. h-1 for indoor and outdoor environments, respectively, while the average annual effective doses for these areas were found to be 0.864 mSv.y-1 and 0.205 mSv.y-1 , respectively. The findings indicate that both the indoor and outdoor gamma dose rates in Shaqlawa are approximately twice the global average values reported by UNSCEAR, suggesting elevated natural background radiation exposure in the area. Additionally, the excess lifetime cancer risk was estimated at 3.74×10-3 , which is considerably higher than the global average of 0.29×10-3. These results highlight a potential radiological health concern for residents and emphasize the need for continuous environmental radiation monitoring and further investigation of radionuclide sources in building materials and soils.

Mental health problems affect nearly half of university students worldwide, with around 20% reporting depressive symptoms and over 40% showing signs of anxiety. This burden is particularly acute in low-resource universities, where limited infrastructure and minimal investment in mental health restrict access to effective care. To address this gap, this study applies a projective research approach, defined as the design of evidence-based solutions without immediate empirical implementation. A systematic review of 402 scientific articles was carried out across major databases, from which 15 met strict inclusion criteria. The analysis identified recurrent barriers such as unstable internet connectivity, devices with less than 2 GB RAM, and the absence of regulatory frameworks governing AI in education. Based on these findings, an adaptive intervention model was proposed, integrating artificial intelligence (AI), machine learning (ML), and deep learning (DL) to deliver personalized psychological support directly on local devices, without requiring permanent connectivity. The proposed system demonstrated potential to reduce anxiety and depression scores by 15-25% in controlled studies and achieved prediction accuracies above 80% for stress and loneliness detection. This framework provides a scalable foundation for universities in developing contexts, contributing to equity in access to digital mental health services.

L-[Methyl-11 C]-methionine ( 11 C-methionine) is proposed as a useful radiotracer for tumour diagnosis. Human biodistribution data of cumulated activities and absorbed doses estimated by the MIRD (medical internal radiation dosimetry) method for 11 C-methionine are not available in the literature. In this study we measured the organ activity for 11 C-methionine by using whole-body positron emission tomography (PET) and estimated the absorbed doses to 25 organs by the MIRD method. Whole-body dynamic PET scans were performed on five normal volunteers to measure the time course of the organ activity concentration (activity/volume) after intravenous administration of 11 C-methionine. Cumulated activities of the ten source organs were calculated from the time-activity curves, obtained from the dynamic PET data. Absorbed dose estimates were performed by the MIRD method for the Caucasian reference man and for the Japanese reference man. The organs which received the highest absorbed doses for the Caucasian reference man were found to be the bladder wall (2.7×10 -2 mGy/MBq), the pancreas (1.9×10 -2 mGy/ MBq), the liver (1.8× 10 -2 mGy/MBq) and the kidney (1.1×10 -2 mGy/MBq). The effective doses for the Caucasian reference man and the Japanese reference man were calculated as 5.2×10 -3 and 5.0×10 -3 mSv/MBq, respectively.

Introduction-[ 11 C](R)-Rolipram is a selective radioligand for PET (positron emission tomography) imaging of phosphodiesterase 4, an enzyme that metabolizes cAMP. The aim of this study was to estimate the human radiation absorbed dose of the radioligand based on its biodistribution in both monkeys and humans. Methods-Whole-body PET images were acquired for 2 h after injecting [ 11 C](R)-rolipram in eight healthy humans and three monkeys. The simple method of using a single 2-dimensional (2D) planar image was compared to more time consuming methods that used two (bisected) or four (quadrasected) tomographic images in the anteroposterior direction. Results-Effective dose was 4.8 µGy/MBq based on 2D planar images. The effective dose was only slightly lower by 1% and 5% using the bisected and quadrasected images, respectively. Nevertheless, the two tomographic methods may have more accurately estimated the exposure of some organs (e.g., kidneys) that are asymmetrically located in the body or have radioactivity that appears to overlap on 2D planar images. Monkeys had a different biodistribution pattern compared to humans (e.g., greater urinary excretion) such that their data overestimated the effective dose in humans by 40%. Conclusions-The effective dose of [ 11 C](R)-rolipram was modest and comparable to that of other 11 C-labeled radioligands. The simple, and far less time consuming, 2D planar method provided accurate and somewhat more conservative estimates of effective dose than the two tomographic methods. Although monkeys are commonly used to estimate human radiation exposures, their data gave a considerable overestimation for this radioligand.

This report summarizes work after 1 year of a renewed 3-year project. The project has focused on applying basic and applied science methodology to improve the following: (1) characterization of Pu/americium (Am) intake by inhalation; (2) subsequent organ radiation doses; and (3) the associated health risks. To achieve these improvements, more appropriate distributions relating to uncertainty/variability have replaced traditional but inappropriate point estimates.

The Red Palm Weevil (RPW), Rhynchophorus ferrugineus Olivier is considered one of the most dangerous pests that destroy palm trees. The extensive use of chemical agents to control it has led to environmental pollution. Consequently, this study aimed to shed insight into the practice of alternate approaches to eliminate this pest. The experiments were conducted using a home microwave, as well as a modified microwave device consisting of 2 or 4 magnetron units. The microwave was used to study the effectiveness against eggs, larvae, pupae, and adults in the laboratory and semi-field to calculate mortality percentages and to determine the efficiency of the lowest energy level, and the suitable exposure time that highly reduced all weevil stages. The results showed that there was no hatching process of eggs exposed for 15, 20, and 30 seconds at different power levels, but hatching occurred in eggs exposed for 10 seconds. It was also noted that the higher the energy level, the lower the egghatching rate. In the case of larvae, it was observed that there was a direct relationship between the size of larvae, energy levels, & exposure time, and mortality percentages. Also, concerning pupae and adult stages, the same relationship was found between the reduction percentages, energy levels, and exposure durations. Respectable control results for insect stages were recorded with modified microwaves in semifield experiments. The longer the exposure time, the greater the reduction percentages of weevil stages without differences between devices having 2 or 4 magnetron units.