Cosmic rays are the primary source of the daily exposure of aircrew and passengers to ionising radiation. This study aims to estimate the effective doses of ionising radiation for aircraft crews in Bosnia and Herzegovina by taking into consideration factors such as flight duration and altitude, as well as the geographical position of airports. The CARI-7 algorithm and neural network method were used in the analysis of data obtained from the Sarajevo International Airport. The results show that the estimated annual effective doses in 2021 range from 0.06 to 10 mSv for flights to and from Belgrade and Dubai, respectively. Both linear regression and neural network models were developed to predict the effective dose based on flight duration, average altitude, latitude and maximum altitude. The findings reveal that flight duration is the most statistically significant factor, followed by average altitude, latitude and maximum altitude.

Occupational exposure in Bosnia and Herzegovina is regulated by the national regulation on radiation protection for occupational and public exposure. All radiation workers are required to be monitored using whole body passive thermoluminescent dosemeters and, in case of non-uniform external exposures, by dosemeters that would indicate dose to the most affected body parts. Exposed workers are almost exclusively employed in the medical field, and some of them work in nuclear medicine departments where they handle unsealed radioactive sources. Introduction of the positron emission tomography-computed tomography (PET-CT) in two largest clinical centers in the country was expected to cause the increase of equivalent doses to hands received by staff handling the positron emitting radionuclides. Hence, routine monitoring of finger doses became a necessity. The purpose of this study was to evaluate the available data on monitoring with ring dosemeters during PET-CT procedure in two hospitals in Bosnia and Herzegovina and compare them with other practices in the nuclear medicine department, as well as with the results of monitoring in other countries. In general, results confirm that effective doses, as well as equivalent doses to hands, are well below annual dose limits. Finger dosemeters have been proven to be an invaluable asset in the incidental situations that sometimes occur in nuclear medicine departments. Different number of patients and differences in injection methodologies are identified as a possible source of differences between doses in two hospitals. Overall, routine evaluation of doses to hands provides a sound basis for possible optimization processes, as well as confirmation of good practices.

Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.

Contouring, planning and dose calculation in treatment planning systems (TPS) are based on computedtomography (CT) images. Therefore, it is important to have developed, optimized and adapted scanning protocolsfor specific anatomic regions and special radiotherapy modalities such as stereotactic radiosurgery (SRS). The aimof this study was to determine influence of tube voltage, field of view size (FOV) and reconstruction kernels on CTnumbers and the resulting radiotherapy (RT) dose calculation.This study was performed at Clinic of Oncology, Clinical Center University of Sarajevo. Verification electrondensity and CT number values was performed using CIRS Thorax 002LFC phantom, while anthropomorphic CIRS038 phantom for stereotactic end-to-end verification was used for the purpose of dose plan calculation analysis withlarge bore CT simulator Canon Aquillion LB.The significant correlation between the tube voltage and the measuredvalues of CT numbers is significant for all materials (p < 0.05), except for water (p = 0.310). No significantcorrelation between FOV and obtained values of CT numbers was found in any of the evaluated tissue equivalentmaterials. Evaluating the impact of reconstruction kernels on Hounsfield units (HU), significant deviations werefound for the FC62, FC68 and FC07 reconstruction kernels. Also, analyzing the influence of reconstruction kernelson the RT dose calculation, the extreme values are associated with Dmin/D in PTV for kernels FC41 and FC68, wheredeviations from the values obtained using the baseline scanning parameters were -1.3% and -1.9%. For deviation of1 HU in muscle tissue of CIRS 002LFC, the calculated Dmin/D in PTV of CIRS STEEV phantom will reduce by0.79%. Similarly, the reduction of D₉₈ and D₂ would be 6.8 cGy and 3.03 cGy for 1 HU, respectively. Change of thereconstruction kernels caused differences of 0.4% in Dmin/D calculation in clinical target volume (CTV).CT scanning and reconstruction parameters may affect Hounsfield units, which could have an impact on dosecalculations in RT plan. Hence, it is recommended to standardize the scanning protocol used in calibration curvegeneration for TPS. One should avoid use of different tube voltages and kernels, while according to this study, thechange of FOV will have no impact on dose calculations

For more than two years, coronavirus disease 19 (COVID-19) has represented a threat to global health and lifestyles. Computed tomography (CT) imaging provides useful information in patients with COVID-19 pneumonia. However, this diagnostic modality is based on exposure to ionizing radiation, which is associated with an increased risk of radiation-induced cancer. In this study, we evaluated the common dose descriptors, CTDIvol and DLP, for 1180 adult patients. This data was used to estimate the effective dose, and risk of exposure-induced death (REID). Awareness of the extensive use of CT as a diagnostic tool in the management of COVID-19 during the pandemic is vital for the evaluation of radiation exposure parameters, dose reduction methods development and radiation protection.

Introduction: Axial-loaded magnetic resonance imaging (MRI), which can simulate an upright position of the patient may cause a significant reduction of the dural sac cross-sectional area (DCSA) compared with standard MRI, thus providing valuable information in the assessment of the lumbar spinal canal. The purpose of this study was to investigate excessiveness of the change in DCSA and depth of lateral recesses (DLRs) before and after axial-loaded imaging in relation to body mass index (BMI) of the subjects.Methods: Twenty patients were scanned to evaluate DCSA and DLR at three consecutive lumbar spine intervertebral disc levels (L3/4, L4/5, and L5/S1) on conventional-recumbent MRI, and after axial loading were applied.Results: Axial-loaded MRI demonstrates a significant difference of DSCA in comparison to conventional MRI. Furthermore, results show a significant correlation between the DCSA and BMI on level L3/L4, both before and after axial loading MRI. With axial loading, there is a reduction of DSCA of 12.2%, 12.1%, and 2.1% at the levels L3/L4, L4/L5, and L5/S1, respectively. After axial loading has been applied, the depth of the neural foramen has been reduced by an average of 10.1%.Conclusion: Axial-loaded MRI reduces DCSA and DLRs in comparison to standard MRI. Information obtained in this way may be useful to explain the patient’s symptomatology and may provide an additional insight that can influence the treatment decision plan accordingly.

Introduction: Today film-based technologies are largely abandoned in dental radiology. New technologies based on digital detectors are being adopted. This change is part of the global digitalization of radiological procedures. A person operating the radiological device needs to be educated and well informed about radiological procedures and technologies, as well as to know how the system operates and to be sure about the dose required for the adequate image quality. The awareness of radiation doses received by patients is necessary for the estimation of risk from ionizing radiation. Material and methods: The aim of this study was to evaluate whether patient doses in intraoral dental radiology affect image quality. The study included subjective analysis of radiological image quality for an intraoral x-ray device with possibility to use both digital and film detector. Subjective assessment of image quality is performed according to criteria taken from the literature and is expressed using the Likert scale, grade 1–5. In order to improve the quality of inferential statistics related ratings to detector quality and image quality were collected, thus introducing two variables: the detector quality index and the technique quality index. Results: Z-test proportions column shows that the number of grades four given as a contrast score is significantly higher in the RVG detector (65%) compared to the film (40%). There is also a significant difference in the number of given grades five as a rating of the apex preview. The share of grades five in film is 19%, while in RVG it is 42%. It is similar in the evaluation of the preview of the dental canal, where there is also a significant difference in the number of given grades five, so that the share in the film is 11% and in RVG 35%. Conclusion: Analysis of the subjective quality of the radiological image in devices for intraoral radiography with the possibility of recording using digital and film detectors indicates that the digital detector is superior to film in low contrast resolution, apex and dental canal preview.

Introduction: Radiation therapy has long played an integral role in the manage¬ment of locally advanced head and neck cancer (HNC), both for organ preservation and to improve tumor control in the postoperative setting. The aim of this research is to investigate the effects of adaptive radiotherapy on dosimetric, clinical, and toxicity outcomes for patients with head and neck cancer undergoing radiation therapy treatment. Many sources have reported volume reductions in the primary target, nodal volumes, and parotid glands over treatment, which may result in unintended dosimetric changes affecting the side effect profile and even efficacy of the treatment. Adaptive radiotherapy (ART) is an interesting treatment paradigm that has been developed to directly adjust to these changes.Material and methods: This research contains the results of 15 studies, including clinical trials, randomized prospective and retrospective studies. The researches analyze the impact of radiation therapy on changes in tumor volume and the relationship with planned radiation dose delivery, as well as the possibility of using adaptive radiotherapy in response to identified changes. Also, medical articles and abstracts that are closely related to the title of adaptive radiotherapy were researched.Results: The application of ART significantly improved the quality of life of patients with head and neck cancer, as well as two-year locoregional control of the disease. The average time to apply ART is the middle of the treatment course approximately 17 to 20 fractions of the treatment.Conclusion: Based on systematic review of the literature, evidence based changes in target volumes and dose reduction at OAR, adaptive radiotherapy is recommended treatment for most of the patients with head and neck cancer with the support of image-guided radiotherapy.

Introduction: Intervertebral disc (IVD) degeneration (IDD) is one of the main causes of low back pain (LBP). Standardized diagnostic algorithms for adequate estimation and classification of changes of lumbar discs are mandatory before starting with therapy.Methods: One hundred patients who were indicated for lumbar magnetic resonance imaging (MRI) were included in the study. Pfirrmann grading system was used for the determination of IDD, while the visual analog scale (VAS) is used for evaluation of the intensity of LBP. To quantification of disability for LBP, we used the Oswestry Disability Index (ODI).Result: Results showed higher Pfirrmann grades II and III for L2/L3 and L3/L4 lumbar levels and lower scores at L4/L5 and L5/S1. The analysis also showed low scores at the L2/3 and L3/4 lumbar level for Pfirrmann grades IV and V, and there was an increased at more inferior lumbosacral levels L4/5 and L5/S1. There was a significant correlation between Pfirrmann grades and ODI (p = 0.24) as well as VAS (p = 0.16).Conclusion: Higher Pfirrmann grades correlated with increased ODI and VAS. Therefore, MRI can be used as a strong indicator of clinical appearance, but it is important to take into consideration that LBP should be correlated with clinical features. By summing Pfirrmann grades of all lumbar intervertebral levels in each patient, we can get more accurate insight for the status of the lumbar spine.

This paper presents the study that would allow a revision of the currently valid diagnostic reference level in intraoral dental X-ray radiography in Bosnia and Herzegovina. The study was conducted for six procedures that are used to capture incisor, premolar and molar teeth, of both maxilla and mandible, in adults. Measurements were performed on 41 intraoral X-ray devices, 20 of which were systems with digital image receptor and 21 film-based X-ray systems. In this study, incident air kerma (Ki) and air kerma-area product (PKA) were used as patient dose descriptors. The third quartile (Q3) of the measured incident air-kerma values was used to compare with the current national diagnostic reference level (DRL) for intraoral dental procedures. The obtained results of Q3 for both types of devices, with film-based and digital image receptors, have shown that the third quartile values are lower (3.5 and 1.2 mGy, respectively) than the current national DRL (7.0 mGy). Hence, new data can be used to re-establish the diagnostic reference levels in intraoral dental X-ray examinations in Bosnia and Herzegovina.