Abstract Introduction Radiation damage to the central nervous system (CNS) has been a persistent problem for decades, owing to difficulties such as brain radiotherapy and astronaut radiation protection during space flight. Hippocampus is the most radiation-sensitive structure of the central nervous system. The present study aims to investigate damage induced by 12 C ions and proton radiation in pyramidal neurons of cornu ammonis regions and dentate granule neurons using Geant4 toolkit. Materials and Methods The Geant4/Geant4-DNA Monte Carlo toolkits were used to simulate the neuron shape and particle track structures. The computations were done for various energy proton beams and 12 C particles with different linear energy transfers from a few to hundreds of keV/µm. Damage to pyramidal and dentate granule neurons of hippocampus as well as length reduction of the dendrites were studied by the dose absorbed in dendrite and D TH (dendrites threshold dose). Also, in the present study, using Spearman’s correlation test, we examined the correlation between the morphological characteristics of neurons and the reduction in the length of their dendrites. Results According to the results obtained in this study, the apical dendrites of CA3 and the basal dendrites of CA1 were more vulnerable following proton irradiation and carbon ions with different energies under proton and carbon radiation. But, the pyramidal neurons of CA2 were more resistant to radiation than those of CA1and CA3 regions. Furthermore, the dentate granule neurons were more resistant to radiation than the pyramidal neurons. According to the results of Spearman’s correlation test, there was a statistical significance correlation (p-value< 0.05) between some of the morphological characteristics of neurons and the reduction in the length of their dendrites. Conclusion The results indicate that the neuron morphology is an important factor determining the accumulation of absorbed dose and length reduction of neurons. By evaluating the neurons with different morphology from the hippocampus, it was found that the dentate granule and pyramidal neurons had different vulnerabilities to radiation. The pyramidal neurons with less densely packed are more resistant to radiation.

Abstract This systematic review examines the establishment of Diagnostic Reference Levels (DRLs) in digital mammography across 18 European countries, based on studies from 2005-2025. A total of 353 articles were identified through the comprehensive search of academic networks: Google Scholar, PubMed, Research Gate, Academia. Only 18 peer-reviewed studies met inclusion criteria – reporting Mean Glandular Dose (MGD)-based DRLs from Finland to Malta. Eight studies used patient data, four used phantom measurements, and six used both. To overcome the challenging comparison of the variety of reported parameters, we undertook some data harmonisation procedures, focusing on a common Compressed Breast Thickness (CBT) range of 50-59 mm. The DRLs varied notably by country, with 75 th percentile MGDs ranging from 1.1 to 2.6 mGy and 95 th percentile from 1.6 to 2.9 mGy, averaging to 1.44 mGy, which is lower than the achievable European level (2 mGy). The harmonisation approach enabled the derivation of a comparable dataset of average MGDs, facilitating cross-country comparisons and insights into radiation dose optimisation in digital mammography across Europe.

Abstract Introduction Among biological macromolecules, proteins are increasingly recognised as key radiation targets. Conformational modifications of proteins and their stability after exposure to ionising radiation are fundamental issues in radiobiology and radiotherapy. This study aimed to qualitatively assess the accelerated ageing of human serum proteins after in vitro exposure to neutron radiation using differential scanning calorimetry (DSC). Material and methods Human serum samples from healthy volunteers were exposed to a 5 Gy dose of neutron radiation. The Californ-252 was utilised as the radiation source, with activity ranging from 65 to 58 MBq and an average neutron energy of 2.35 MeV. DSC profiles were acquired for fresh, control, and irradiated serum samples immediately after exposure. Subsequent DSC measurements were conducted weekly for one month. Results A qualitative analysis of DSC profiles made it possible to assess alterations in the serum proteins’ denaturation processes over time. The appearance of a low-temperature exothermic transition before the endothermic transition appears to be a characteristic feature of ageing-altered DSC serum profiles. All the changes visible on the DSC profiles of the irradiated samples are much more advanced than on the profiles of the control samples. In addition, the DSC method made it possible to observe the effect of individual variability on the shape of the DSC serum profiles of particular volunteers. Conclusions The study revealed that neutron irradiation most likely accelerates serum protein ageing processes. The results indicate a considerable variation in individual radiosensitivity of proteins taken from individuals to the effect of neutron radiation. In the future, the DSC measurement could be a simple test that provides information on the magnitude of personal radiosensitivity, an interesting aspect in the context of personalised radiotherapy.

Abstract Introduction Accurate electron beam dosimetry is crucial for effective radiotherapy treatment. This study aimed to validate modified electron beam calibration methods through a comprehensive cross-calibration analysis against the established IAEA TRS-398 and AAPM TG-51 protocols. Materials and methods A Varian Trilogy linac with electron beam energy of 6, 9, 12, 15, and 18 MeV was used to perform dosimetric assessments using cylindrical (FC65-G and CC13) and parallel-plate (PPC40) ion chambers. The sequential method was employed for cross-calibration at 18 MeV, with each chamber alternatively serving as the reference and field chambers according to TRS-398 (yielding calibration correction factor N TRS –398 ) and TG-51 (yielding calibration correction factor N TG –51 ) protocols. The ratios of N TRS –398 and N TG –51 compared to the calibration correction factors from country SSDL ( N Co ) it ranged from 0.990 to 1.020. Absorbed doses to water per monitor unit (cGy/MU) were calculated at maximum absorption depths. Results For modified calibration methods, the values of N TRS –398 and N TG –51 yielded absorbed dose values between 0.977-1.005 cGy/MU and 0.980-1.009 cGy/MU, respectively. Dose ratios of the modified methods compared to TRS-398 ranged from 0.982 to 1.010, while ratios compared to TG-51 varied between 0.985 and 1.021. The average absorbed dose to water using N TRS –398 and N TG –51 ranged from 0.984-0.996 cGy/MU and 0.986-0.997 cGy/MU, respectively. The results were also compared with previous studies to demonstrate that the modified calibration methods closely align with the established protocols, with discrepancies within the IAEA’s ±2% tolerance threshold. Conclusions The study highlights the importance of cross-calibration in ensuring the accuracy and reliability of modified electron beam calibration methods. These findings suggest that the modified approaches can serve as effective alternatives to traditional protocols, potentially enhancing dosimetric precision and flexibility in clinical radiotherapy settings.

Abstract Introduction Given its rapid transmission and heightened fatality rate, early detection of viral pneumonia is imperative. The virus mainly affects the lung, leading to pneumonia alongside symptoms like fatigue, dry cough, and fever, which can sometimes be misdiagnosed as other respiratory conditions such as lung cancer or pneumonia. Chest X-rays are widely used in the healthcare sector to provide both swift and accurate diagnoses. Deep learning algorithms have demonstrated significant efficiency in detecting and classifying lung diseases, which enhanced the diagnostic process and saving valuable time for medical applications and therapy.The objective of this study is to develop and evaluate a deep learning-based architecture for the accurate multi-class classification of respiratory diseases, including pneumonia, lung opacity, and COVID-19, using chest X-ray images to enhance diagnostic efficiency in healthcare settings. Material and methods A substantial dataset comprising X-ray images was crated, including 1026 pneumonia cases, 1256 COVID-19 cases, 2305 lung opacity cases and 3224 normal X-ray images. For classification purposes, we employed a pre-trained VGG19 model combined with an SVM classifier. To validate the model’s accuracy, we utilized cross-validation techniques and performance metrics, including precision, recall, F1-score, and the area under the curve (AUC). This approach ensures robust evaluation of the proposed framework. Results The experimental results demonstrated the superiority of our proposed VGG16+SVM model over existing approaches, achieving an accuracy of 93.50%, recall of 94.16%, precision of 94.45%, F1 score of 93.28%, and area under the curve (AUC) of 90.16%. Conclusions This enhanced performance equips healthcare practitioners with the tools to diagnose and treat patients more expeditiously and effectively.

Abstract Introduction. A school backpack, as an off-axis external load, induces changes in the spinal alignment within the compensatory mechanism. Objective. Considering the above, the aim of this study was to examine how the angular parameters of the sagittal plane, the thoracic kyphosis angle, and the lumbar lordosis angle change under normative school backpack load. Additionally, the study aimed to assess how carrying a backpack affects the symmetry of foot load distribution in children. Materials and Methods. The study included 75 children (45 girls and 30 boys) aged 7-9 years (Mean = 8.48; SD = 0.89). A backpack model closely resembling those currently available on the Polish market was developed. The backpack’s weight was standardized, and sagittal plane measurements were taken using a digital inclinometer. The symmetry of load distribution was assessed using a stabilometric platform, and the endurance of postural muscles was evaluated with the Matthias test. The study only included backpacks that met the standard weight range of 10–15% of the child’s body weight. Results. Three previously undescribed types of compensation were identified: flexion type, extension type, and balanced type. Only in the balanced type did the endurance of postural muscles not significantly decrease after wearing the school backpack. Conclusions. It is necessary to modify the design of school backpacks to prevent spinal alignment changes in the sagittal plane, even within normative or excessive load values. Proper spinal curvatures are crucial for maintaining an upright body posture. Non-invasive, modern technologies based on thermal imaging should be considered as potential solutions.

Abstract Introduction Radiopharmaceutical therapy (RPT) uses radiopharmaceuticals that target cancer cells and is increasingly used as an oncological treatment. Estimating the absorbed dose of ionizing radiation in the patient’s organs is the basis for personalized RPT. This article presents a technique for assessing the performance of a quantitative reconstruction using NEMA phantom. The goal of this work was to compare the accuracy of quantitative SPECT images using the same reconstruction algorithm but acquired with two different SPECT/CT systems from two different manufacturers. Materials and Methods We performed a series of SPECT/CT acquisitions of a NEMA IEC Body Phantom filled with 177Lu using two gamma cameras. The images were reconstructed and quantified using Hermes software. Results There was no statistically significant difference in the results of recovered activities between the Symbia Intevo Bold and the NM/CT 850 gamma cameras. For a sphere with a diameter of 37 mm, the Rc values ranged from 0.69 to 0.75 for the Symbia Intevo Bold and 0.70 to 0.73 for the NM/CT 850. For a sphere with a diameter of 28 mm, the Rc values ranged from 0.61 to 0.71 for the Symbia Intevo Bold and 0.61 to 0.70 for the NM/CT 850. For a sphere with a diameter of 22 mm, the Rc values fell within the range of 0.56 to 0.63 for the Symbia Intevo Bold and 0.51 to 0.59 for the NM/CT 850. Conclusions Quantitative SPECT images are necessary to perform dosimetry calculations and before using them in the clinical settings it is important to perform validation. This validation can be simply performed by acquiring images of the phantom filled with known activity using the same acquisition and reconstruction parameters as those employed for patients studies. In our study we observed comparable performance between images acquired by the systems from two different manufacturers.

Abstract Introduction: FLASH radiotherapy is based on delivering an ultra-high dose of ionizing radiation in a very short time, which allows for the enhanced protection of healthy tissues and the effective destruction of tumour tissues. The paper presents experimental verification of the applicability of the intraoperative electron radiotherapy (IOERT) accelerator to obtain electron beams with ultra-high dose rates. The results of electron beam dosimetric measurements were compared with simulations to verify the parameters of the electron beams obtained in FLASH mode. Material and Methods: The IOERT AQURE accelerator is designed and manufactured at the National Centre for Nuclear Research. The device provides electron beams with energies in the energy range of 4-12 MeV. The accelerator was recently upgraded to deliver ultra-high-dose rates (FLASH). The emitted electron beams were verified by percentage dose depth (PDD) and beam profile measurements using Gafchromic EBT-XD films. The measurement results were compared with Monte Carlo simulations performed using the Geant4 application. Results: Conventional and FLASH electron beam parameters, i.e. depths of doses, most probable beam energies at the phantom surface, and average beam energies at the phantom surface were determined experimentally for the upgraded IOERT accelerator for 6 MeV and 9 MeV. The results of dose measurements showed that the accelerator can provide electron beams with homogeneous and symmetrical fields with dose rates up to 300 Gy/s ± 6 Gy/s, for an electron beam at a nominal energy of 6 MeV, and up to 440 Gy/s ± 9 Gy/s at a nominal energy of 9 MeV. A comparison of measured and simulated PDDs and dose profiles for FLASH beams showed good agreement (no worse than 90%) under the gamma index of 3%/3 mm. Conclusions: The results obtained confirm that the upgraded intraoperative accelerator can be used in planned, pre-clinical radiobiology experiments in both conventional and ultra-high dose rate (FLASH-RT) modes.

Abstract Introduction: An analysis of Heart Rate Variability (HRV) is widely used in clinical and research. To properly calculate HRV parameters, the RR intervals series must be properly preprocessed. There are already automated tools for correcting these artifacts; however, they are not fully transparent and fully customizable. To address these limitations, we introduce CoRRection, a semi-automatic tool for RR interval correction, which integrates both automatic and manual approaches providing greater control over which intervals are corrected. Material and Methods: The application offers detection and correction methods. Additionally, it allows to manually remove an artifact before applying a correction method. It also allows to clean artifacts in shorter segments which enables applying different detection methods in one example, e.g., gathered during intense exercise. The application provides a test to assess signal stationarity (Augmented Dickey-Fuller test). After signal processing the report is created, containing the number of probes deleted and modified. Results: The proposed CoRRection application allows both technical and non-technical users to preprocess RR signals with a better control over the process by enabling the use of semi-automatic approach. A few examples of studies which required Correction’s unique approach of semi-automatic correction were presented. The need for different methods and not only considering different examinations, but also different segments within one recording was emphasized. Conclusions: We have presented a new application designed to preprocess RR intervals signal with a few popular detection and correction methods. This approach enables a good compromise between a precise manual approach and a less time-consuming automatic approach. The semi-automatic method of artifact correction empowers users to explore multiple identification and correction methods (and to choose the one best fitted to the data or measurement conditions), and offers a better understanding of the examination preprocessing tools. This may also result in a better trust in the automatic approach among the users.

Abstract Introduction: In some clinical cases a full therapeutic dose needs to be delivered in the area close to the skin surface where a high dose gradient and there no charged-particle equilibrium (CPE) exists. The accuracy of dose distribution calculations performed in this region with the treatment planning system is limited. In this work we investigated the usefulness of small pieces of Gafchromic EBT3 film for measurements of the absolute dose value in the area close to the skin surface. Material and methods: The Gafchromic EBT3 film detectors of size 1.0 cm x 1.5 cm were prepared. The film samples were calibrated in 6 MV photon beam (Elekta Versa HD). Calibration was performed in a dose range of 0 – 250 cGy. Films were scanned using the EPSON EXPRESSION 10000 XL flatbed scanner in 48-bit RGB mode, with a resolution of 72 dpi. ImageJ software was used to calculate the dose. Triple-channel film dosimetry was applied. The uncertainty of the dose measurement method was estimated. Film measurements were compared with the dose measurements using ionization chamber. The conformity of measurements was assessed using the metrological compliance test. Results: The relative differences between dose measurements using Gafchromic EBT3 film detectors and ionization chamber for a single square photon beam were -0.8% and 0.3% for a depth of 0.5 cm and 5.0 cm (CPE) respectively. The values of the metrological compatibility test factor ζ were 0.3 and 0.1 respectively. The maximum relative differences for dynamic beams were 0.9% and −1.0% for a depth of 0.5 cm and 5.0 cm respectively. Metrological compatibility test showed also good agreement (ζ=0.3). Conclusions: Small film detectors made of Gafchromic EBT3 film allow for the accurate dose measurements in the high dose gradient region and without CPE. They can be used to validate the calculation of the treatment planning systems also for VMAT techniques.