OBJECTIVE: To benchmark image quality and corresponding radiation doses for acute abdominal CT examination across different laboratories and CT manufacturers.
METHODS: An anthropomorphic phantom was scanned once with local abdominal CT protocols at 40 CT scanners, from four vendors, in thirty-three sites. Quantitative image quality was evaluated by CNR and SNR in the liver and kidney parenchyma. Qualitative image quality was assessed by visual grading analysis performed by three experienced radiologists using a five-point Likert scale to score thirteen image quality criteria. The CTDIvol was recorded for each scan. Pearson\'s correlation coefficient was calculated for the continuous variables, and the intraclass correlation coefficient was used to investigate interrater reliability between the radiologists.
RESULTS: CTDIvol ranged from 3.5 to 12 mGy (median 5.3 mGy, third quartile 6.7 mGy). SNR in liver parenchyma ranged from 4.4 to 14.4 (median 8.5), and CNR ranged from 2.7 to 11.2 (median 6.1). A weak correlation was found between CTDIvol and CNR (r = 0.270, p = 0.092). Variations in CNR across scanners at the same dose level CTDIvol were observed. No significant difference in CTDIvol or CNR was found based on scanner installation year. The oldest scanners had a 15 % higher median CTDIvol and a 12 % lower median CNR. The ICC showed acceptable agreement for all dose groups: low (ICC=0.889), medium (ICC=0.767), high (ICC=0.847), and in low (ICC=0.803) and medium (ICC=0.811) CNR groups.
CONCLUSIONS: There was large variation in radiation dose and image quality across the different CT scanners. Interestingly, the weak correlation between CTDIvol and CNR indicates that higher doses do not consistently improve CNR, indicating a need for systematic assessment and optimization of image quality and radiation doses for the abdominal CT examination.

OBJECTIVE: To identify swallowing-related structures (SRSs) predicting post-radiotherapy dysphagia in oropharyngeal carcinoma patients.
METHODS: Between September 2020 and October 2022, oropharyngeal cancer patients who had completed radiotherapy at least one year before without recurrence or residuals were selected. They underwent flexible endoscopic evaluation of swallowing (FEES) assessments and dysphagia grading. The mean radiation doses delivered to their SRSs were recalculated. The correlation between radiation doses to each SRS and FEES scores was analysed.
RESULTS: Twenty-nine participants, aged 51-73 years, were enrolled. Six patients had received two-dimensional radiotherapy, eight had undergone three-dimensional conformal radiotherapy, and fifteen had received intensity-modulated radiation therapy. Radiation doses to the inferior pharyngeal constrictor, cricopharyngeus and glottic larynx significantly predicted dysphagia for both semisolids (p = 0.023, 0.030 and 0.001) and liquid diets (p = 0.021, 0.013 and 0.002). The esophageal inlet significantly predicted swallowing outcomes for only the liquid diet (p = 0.007).
CONCLUSIONS: This study supports that SRS-sparing during radiotherapy for oropharyngeal cancers improves swallowing outcomes.

OBJECTIVE: identification of clinical and metabolic characteristics of osteogenesis and factors affecting bone mineral density (BMD) in children living in radioactively contaminated territories (RCT) after the ChNPP accident for the use of therapeutic and preventive measures aiming to reduce the incidence of disorders.
METHODS: Children aged 4 to 18 years old (n = 539) were involved in the study within 4 age groups, namely under 7 years old, 7-10 years old, 10-14 years old, older than 14 years old. Studied parameters in children with a reduced BMD (85-65 relative units and under 65 relative units) were estimated vs. the normative BMD (100-85 relative units) cases. Diagnosis of osteopenia and osteoporosis in children was established according to the BMD T-index. Family history of the relatives of children was studied. Body weight at birth, fractures of the long bones, complaints of osalgia, jaw anomalies, dental caries, presence of obesity, and hypermobility syndrome (HMS) were assessed. Peripheral blood biochemical tests were performed featuring the serum total protein, alkaline phosphatase (APh), calcium, vitamin D, creatinine, serum iron (SI), ferritin, cortisol, pituitary thyroid-stimulating hormone (TSH), and free thyroxine (FT4) assay. BMD was measured and radiation doses in children were reconstructed.
RESULTS: BMD depended on the age of children. A direct correlation was established between the cholelithiasis and urolithiasis incidence (р < 0.01), cancer and endocrine diseases (р < 0.05) in the relatives of children that had BMD under 65 relative units. Dental caries developed more often (р < 0.05), while obesity was less frequent (р < 0.05) in the subjects with BMD < 65 relative units. A direct correlation was established between the level of serum creatinine and BMD (р < 0.01), and there was an inverse correlation between the serum APh level and BMD (р < 0.001).Every third child had a vitamin D deficiency. Fractures of long bones and increased content of SI and TSH were characteristic for the children having got osteopenia (BMD within 85-65 relative units), while besides a predisposition to bone fractures the higher levels of SI, APh, cortisol both with calcium deficiency were found in children with osteoporosis (BMD < 65 relative units) compared to the general group with a similar BMD. An increased incidence of HMS was characteristic too. Radiation doses in children with osteopenia were higher than in those with osteoporosis: (1.17 ± 0.09) mSv and (0.92 ± 0.06) mSv respectively (р < 0.05). No correlation was found between the radiation doses and clinical signs, blood biochemistry or BMD.
CONCLUSIONS: Study of the functional mechanisms of bone structures in children, depending on their metabolism, had made it possible to reveal the factors that affect bone formation in children living in RCT after the ChNPP accident, and to form the population groups for the timely application of therapeutic and preventive measures aiming to reduce the incidence of disorders of musculoskeletal system.
Мета: встановити клініко-метаболічні особливості процесів остеоутворення та фактори, що впливають на щільність кісткової тканини (ЩКТ), у дітей, жителів радіоактивно забруднених територій (РЗТ), після аварії на ЧАЕС.Матеріали і методи. Обстежено 539 дітей віком від 4 до 18 років. Сформовано 4 вікові групи: діти до 7 років, 7–10 років, 10–14 років, старші 14 років. Показники у дітей зі зниженою ЩКТ (85–65 ум. од. та нижче 65 ум. од.) оцінювали відносно нормативної ЩКТ (100–85 ум. од.). Діагноз остеопенії та остеопорозу у дітей визначали за Т-показником мінеральної ЩКТ. Вивчали сімейний анамнез родичів дітей. У дітей оцінювали масу тіла при народженні, переломи довгих кісток, скарги на осалгії, аномалії щелепи, карієс зубів, наявність ожиріння, гіпермобільний синдром (ГМС). Вивчали показники периферичної крові та біохімічні тести (загальний білок, лужна фосфатаза (ЛФ), кальцій, вітамін D, креатинін, сироваткове залізо (СЗ), феритин), а також рівні кортизолу, тиреотропного гормону гіпофізу (ТТГ), вільного тироксину (FT4), в сироватці крові та ЩКТ. Розраховували дози опромінення дітей.Результати. ЩКТ залежала від віку дітей. У родичів дітей зі ЩКТ нижче 65 ум. од. встановлено прямий кореляційний зв’язок між частотою сечокам’яної (СКХ) та жовчнокам’яної (ЖКХ) хвороб (р < 0,01), онкологічними й ендокринними хворобами (р < 0,05). У пацієнтів зі ЩКТ нижче 65 ум. од. частіше розвивався карієс зубів (р < 0,05, та рідше зустрічалось ожиріння (р < 0,05). Встановлено прямий кореляційний зв’язок між рівнем креатиніну в сироватці крові та ЩКТ (р < 0,01); зворотний кореляційний зв’язок між рівнем ЛФ в сироватці крові та ЩКТ (р < 0,001). У третини дітей був дефіцит вітаміну D. Для дітей з остеопенією (ЩКТ 85–65 ум. од.) характерними є переломи довгих кісток, підвищений рівень СЗ та ТТГ в сироватці крові; у дітей з остеопорозом (ЩКТ нижче 65 ум. од.) крім переломів, наявні більш високі рівні СЗ, ЛФ, кортизолу та дефіцит кальцію в сироватці крові, ніж у осіб загальної групи з аналогічною ЩКТ, та підвищена частота ГМС. Дози опромінення дітей з остеопенією були вищими, ніж при остеопорозі, і складали (1,17 ± 0,09) мЗв, при остеопорозі – (0,92 ± 0,06) мЗв (р < 0,05).Дози опромінення дітей не корелювали з клінічними ознаками, біохімічними параметрами крові та ЩКТ.Висновки. Вивчення механізмів функціонування кісткових структур у дітей залежно від їхнього метаболізму дозволило визначити фактори, котрі впливають на процеси остеоутворення у дітей, жителів радіоактивно забруднених територій після аварії на ЧАЕС, та сформувати групи пріоритетного нагляду.

BACKGROUND: The study was conducted on patients who received diagnostic X-rays in King Khalid Hospital (KKH), Majmaah.
BACKGROUND: The study included the seven most frequently performed investigations, which were carried out on over 1504 patients using digital radiography equipment.
METHODS: The X-ray tube\'s output and exposure parameters were used to calculate the effective dose (ED) and patient entry surface air kerma (ESAK). Additionally, based on these results, conversion coefficients were determined. This study also examined the 75th percentile distributions of ESAK and KAP. The findings of this research were compared with the findings of other researchers throughout the country and the world. The study presents the uncertainty U values, as well as the mean ESAK, KAP, and ED values.
RESULTS: The results of the ESAK, KAP, and ED values were 0.12-5.74 mGy, 0.9-1.84 Gy cm2, and 0.01-0.23 mSv, respectively. As a result, the dosages were much lower than those previously published for the European DRL, national standards, and other studies.
CONCLUSIONS: The study concludes that during dose surveys, the importance of detecting and comprehending radiation doses, as well as the proper technique for taking the finest photos possible, can be emphasized to patients in order to assist them in avoiding radioactive particles and radiation exposure.

Deep-inspiration breath-hold (DIBH) reduces the radiation dose to the heart and lungs during breast radiotherapy in cancer. However, there is not enough discussion about suitable breathing methods for DIBH. Therefore, we investigated the radiation doses and organ and body surface displacement in abdominal DIBH (A-DIBH) and thoracic DIBH (T-DIBH). Free-breathing, A-DIBH, and T-DIBH computed tomography images of 100 patients were used. After contouring the targets, heart, and lungs, radiotherapy plans were created. We investigated the heart and lung doses, the associations between the heart and left lung displacements, and the thorax and abdominal surface displacements. No significant differences were observed in the target dose indices. However, the heart and lung doses were significantly lower in A-DIBH than in T-DIBH for all the indices; the mean heart and lung doses were 1.69 and 3.48 Gy, and 1.91 and 3.55 Gy in A-DIBH and T-DIBH, respectively. The inferior displacement of the heart and the left lung was more significant in A-DIBH. Therefore, inferior expansion of the heart and lungs may be responsible for the respective dose reductions. The abdominal surface displaced more than the thoracic surface in both A-DIBH and T-DIBH, and thoracic surface displacement was greater in T-DIBH than in A-DIBH. Moreover, A-DIBH can be identified because abdominal surface displacement was greater in A-DIBH than in T-DIBH. In conclusion, A-DIBH and T-DIBH could be distinguished by comparing the abdominal and thoracic surfaces of A-DIBH and T-DIBH, thereby ensuring the implementation of A-DIBH and reducing the heart and lung doses.

UNASSIGNED: The embryo/fetus may be accidentally exposed to ionizing radiation. The aim of this study is to calculate embryo/fetus doses in pregnant women who underwent F-18 fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan.
UNASSIGNED: Between June 2015 and June 2021, 15 pregnant women underwent F-18 FDG PET/CT applied to the Genetic Research Center (GETAM). The OLINDA/EXM package program was used for internal radiation dosimetry according to the Medical Internal Radiation Dose scheme. FetDose V4 computer software was used to compute the embryo/fetus absorbed dose from CT scan.
UNASSIGNED: The amount of the injected F-18 FDG activity to patients varied between 333 and 555 MBq. The mean embryo/fetal dose from F-18 FDG was 7.2 ± 2.8 mGy. In addition, the CT component dose to the embryo/fetus dose ranged from 8.5 to 16 mGy with a mean of 12.14 ± 2.05.
UNASSIGNED: The embryo/fetus dose from F-18 FDG PET/CT was <15 mGy, however, questioning the women\'s childbearing prior to scintigraphy is the first-line strategy to avoid accidental radiation exposure and stochastic risks.

Intensity-modulated radiotherapy (IMRT) is a treatment method that is used in the treatment of head and neck cancers. Impairment of chewing and swallowing functions in the early and late periods of radiotherapy is frequent. Therefore, revealing the dose-effect relationship is important. The main purpose of this study is to investigate the dose-effect relationship between chewing and swallowing structures objectively via a standardized videofluoroscopy protocol. The study included 35 participants treated with chemo-IMRT. A videofluoroscopic swallowing study (VFSS) was performed before IMRT, and 3 and 6 months after IMRT. VFSS results were scored according to the Modified Barium Swallow Impairment Profile (MBSImP) and the Penetration-Aspiration Scale (PAS). Maximum interincisor mouth opening, body mass index (BMI), and Functional Oral Intake Scale levels were determined in these cases. The quality of life of participants was evaluated. There was a significant increase in PAS and MBSImP scores and a significant decrease in BMI scores of the patients after treatment. Xerotomy and sticky saliva complaints increased after treatment. The dose to the mastication muscles (> 40 Gy) and the temporomandibular joint (> 46 Gy) were found to be associated with a decrease in BMI; the dose to the superior pharyngeal constructor muscle (> 58 Gy) was found to be associated with pharyngeal stripping wave. The presence of aspiration was associated with the inferior pharyngeal constructor muscle, glottic larynx, supraglottic larynx, and upper esophageal sphincter. Important findings to emerge from this study include detected toxic dose limits. These findings may guide physicians to minimize the side effects of IMRT.

BACKGROUND: Radiation accidents at the Chornobyl Nuclear Power Plant (USSR, 1986) and Fukushima-1 (Japan,2011) have shown that global environmental contamination is an intervention in normal human life making nega-tive effect on population health. These accidents highlighted a number of statutory and regulatory both with me-dical and social problems for individuals, who returned voluntarily for permanent residence in the ChornobylExclusion Zone i.e. a radiation-hazardous area (they are named the «self-settlers»).
OBJECTIVE: generalization of experience in the settlement of normative-legal, ecological-dosimetric and medico-social life issues of population living in the Chornobyl NPP (ChNPP) Exclusion Zone («self-settlers»).
OBJECTIVE: The chosen problem is complex, necessitating the generalization of radiation-hygienic, med-ical-biological, socio-economic, demographic and sociological research results obtained by the national and foreignauthors. A set of theoretical research and analysis of empirical data methods on the principles of interdisciplinaryinteraction was used; the systematic, legal, economic, medical-biological, demographic and retrospective-dosimet-ric approaches of research were applied.
RESULTS: It was shown that a part of population refused to evacuate or had returned for permanent residence to theradiation-hazardous lands after the ChNPP accident. In 1986-2009 the number of «self-settlers» ranged from 150to 2,000 in different years. In 2021 - the 101 people. Those were mainly people of working age, mostly females, single people or widows/widowers. Рrevious medical and dosimetric studies have shown that long-term residence inthe Exclusion Zone affects physical and mental health of «self-settlers» and causes atypical aging, includinginvolvement of the central nervous system. According to calculations, the average effective total radiation doseaccumulated by «self-settlers» for the first 3 years was 30 % of dose for the entire post-accident period, and thedose accumulated over 20 years was 54 % of the dose accumulated over 35 years. But the effective radiation dosesaccumulated in different periods after the accident differ significantly in residents of different Exclusion Zone settlements. This information needs further study in terms of the «radiation dose - health status» dependence.
CONCLUSIONS: The effective radiation doses accumulated in different periods after the accident differ significantlyin the residents of different Exclusion Zone settlements. Тhe average effective total radiation dose accumulated by«self-settlers» for the first 3 years was 30 % of the dose for the entire post-accident period, and the dose accumulated over 20 years was 54 % of the dose accumulated over 35 years.
Peredumovy. Radiatsiĭni avariï na Chornobyl\'s\'kiĭ AES (SRSR, 1986 r.) ta Fukusima-1 (Iaponiia, 2011 r.) zasvidchy-ly, shcho global\'ne zabrudnennia dovkillia ie vtruchanniam v normal\'nu zhyttiediial\'nist\' liudeĭ ta negatyvno vplyvaiena populiatsiĭne zdorov’ia naselennia. Zaznacheni avariï vysvitlyly nyzku normatyvno-pravovykh i medyko-sotsial\'-nykh problem shchodo fizychnykh osib («samoseliv»), iaki povernulysia na nebezpechnu za radiatsiĭnym chynnykom tery-toriiu dlia postiĭnogo prozhyvannia.Meta doslidzhennia: uzagal\'nennia dosvidu vreguliuvannia normatyvno-pravovykh, ekologo-dozymetrychnykh ta me-dyko-sotsial\'nykh aspektiv zhyttiediial\'nosti naselennia, iake prozhyvaie v zoni vidchuzhennia Chornobyl\'s\'koï AES(ChAES) («samoseliv»).Ob’iekt ta metody doslidzhennia. Obrana problema maie kompleksnyĭ kharakter, shcho zumovylo neobkhidnist\' uza-gal\'nennia radiatsiĭno-gigiienichnykh, medyko-biologichnykh, sotsial\'no-ekonomichnykh, demografichnykh i sotsiologichnykhnaukovykh doslidzhen\' vitchyznianykh ta zarubizhnykh avtoriv. Vykorystano kompleks metodiv teoretychnogodoslidzhennia ĭ analizu empirychnykh danykh na pryntsypakh mizhdystsyplinarnoï vzaiemodiï, zastosovano systemnyĭ,pravovyĭ, ekonomichnyĭ, medyko-biologichnyĭ, demografichnyĭ ta retrospektyvno-dozymetrychnyĭ pidkhody do-slidzhennia.Rezul\'taty. Pokazano, shcho pislia avariï na ChAES chastyna naselennia vidmovylasia vid evakuatsiï abo povernulasiadlia postiĭnogo prozhyvannia do radiatsiĭno nebezpechnykh zemel\'. U 1986–2009 rr. kil\'kist\' «samoseliv» kolyva-lasia vid 150 do 2 000 osib u rizni roky, stanom na 2021 r. – 101 osoba. Tse perevazhno osoby pisliapratsezdatno-go viku, zhinky, odynoki abo vdovy/vdivtsi. Vstanovleno, shcho dovgotryvale prozhyvannia na terytoriï zony vidchu-zhennia vplyvaie na stan fizychnogo ta psykhichnogo zdorov’ia «samoseliv» i zumovliuie atypove starinnia, zokrematsentral\'noï nervovoï systemy. Zgidno z rozrakhunkamy serednia efektyvna doza sumarnogo oprominennia, nako-pychena «samoselamy» za pershi 3 roky skladaie 30 % vid dozy za ves\' pisliaavariĭnyĭ period, a doza, nakopyche-na za 20 rokiv – 54 % vid dozy, nakopychenoï za 35 rokiv. Prote efektyvni dozy oprominennia meshkantsiv-samo-seliv riznykh naselenykh punktiv zony vidchuzhennia, nakopycheni u rizni periody pislia avariï znachno rizniat\'sia. Tsiainformatsiia potrebuie podal\'shogo vyvchennia u rozrizi «doza oprominennia – stan zdorov’ia».Vysnovky. Pislia avariï na ChAES chastyna naselennia vidmovylasia vid evakuatsiï ta prodovzhyla prozhyvaty naradiatsiĭno nebezpechnykh zemliakh. Efektyvni dozy oprominennia meshkantsiv-samoseliv zony vidchuzhennia, nakopy-cheni u rizni periody pislia avariï znachno rizniat\'sia. Serednia efektyvna doza sumarnogo oprominennia, nakopyche-na «samoselamy» za pershi 3 roky skladaie 30 % vid dozy za ves\' pisliaavariĭnyĭ period, a doza, nakopychena za20 rokiv – 54 % vid dozy, nakopychenoï za 35 rokiv.

BACKGROUND: Immunotherapy (IO) provides a significant benefit for a subgroup of non-small cell lung cancer (NSCLC) patients. Radiotherapy (XRT) might enhance the efficacy of IO. We evaluated the impact of the specifics of XRT treatments on the OS of IO-treated NSCLC patients.
METHODS: Metastatic NSCLC patients treated with IO were retrospectively identified. Parameters included demographics, tumor characteristics, IO and XRT details. Correlation between the parameters and OS was tested with Cox regression.
RESULTS: 453 patients were included. No XRT was given to 167 (36.9%) patients, whereas XRT prior and after IO had 182 (40.2%) and 104 (22.9%) patients, respectively. XRT total doses between 30 and 40 Gy had better overall survival (OS) compared to non-irradiated patients (hazard ratio (HR) 0.5, 95% CI 0.25-1.0, p = 0.049). Worse outcome was seen with total doses ≤ 10 Gy (HR 1.67, 95% 1.13-2.5, p = 0.01), XRT fractions of 4.1-8 Gy (HR 1.48, 95% CI 1.05-2.1, p = 0.027) and XRT to the bone (HR 1.36, 95% CI 1.01-1.8, p = 0.04). Several clinical parameters correlated with OS in the univariate analysis of the IO-treated patients. While, in the multivariate analysis, only ECOG-PS, treatment line, type of IO, albumin and NLR remained statistically significant.
CONCLUSIONS: Specific doses, fractions and sites of XRT correlated with the OS of IO-treated NSCLC patients in the univariate analysis, although not in the multivariate analysis.

Assessing the radiation doses received by patients in computed tomography is still challenging. To overcome this, the American Association of Physicists in Medicine has introduced the concept of the size specific dose estimate (SSDE). However, the calculation of SSDE for head CT scans requires the knowledge of attenuation characteristics of the volume scanned, making its implementation in the daily clinical workflow cumbersome. In this study, we defined conversion coefficients from CTDIvol,16cmto SSDE for head CT scans based solely on the age of the patient. Using the head circumference-for-age from the child growth standards of the World Health Organization (WHO), the effective diameter-for-age was calculated for male and female individuals from 0 to 60 months-old. The effective diameter was converted into a water equivalent diameter-for-age, using a correlation established from the measurements of both quantities in 295 exams of male and female patients, from 0 to 18 years-old. WHO-estimated water equivalent diameter-for-age was validated against the measured water equivalent diameter-for-age. The head circumference-for-age from WHO was extrapolated for male and females individuals up to 18 years-old and their respective water equivalent diameter were estimated. Finally, the SSDE was calculated for all the CT head scans performed in a 9-years period in patients aged from 0 to 18 years old. Typical values of CTDIvol,16cmand DLP were also defined. SSDE varied from 0.80 up to 1.16 of the CTDIvol,16cm, depending on sex and age of the patient. WHO-estimated water equivalent diameter-for-age differed less than 20% from the measured water equivalent diameter-for-age. Typical values of SSDE varied from 28.5 up to 38.9 mGy, while typical values ranged from 30.9 up to 47.6 mGy for the CTDIvol,16cmand from 417.6 up to 861.1 mGy*cm for the DLP. SSDE can be directly calculated for head CT scans once the age of the patient is known.