Local Reference Research Articles

Diagnostic Value and Thyroid Hormone Variations in Pregnant Women During Pregnancy in Hui'an County in China.

To evaluate the diagnostic value of thyroid hormones in pregnancy-related thyroid conditions and ascertain the reference range of thyroid hormones in Hui'an pregnant women. We examined 760 pregnant women (406 early, 172 mid, and 182 late pregnancy) and 114 non-pregnant controls. A 95% medical reference range was computed based on measurements of thyroid hormone levels (FT3, FT4, and TSH). Group comparisons were conducted, and the diagnostic accuracy was assessed using ROC curves. There were significant differences in thyroid hormone levels between pregnant women at different stages and non-pregnant women (P < 0.05). In contrast to mid-pregnancy and controls, FT3 and FT4 were higher in the early and late stages of pregnancy (P < 0.05), although TSH was decreased during pregnancy. Compared to healthy or hypothyroid pregnant women, the diagnostic positive rate for hyperthyroidism was greater (P < 0.05). TSH, FT3, and FT4 had larger AUCs in ROC analysis for identifying hyperthyroidism than hypothyroidism (P < 0.05), and the combination of these markers improved diagnostic accuracy (P < 0.05). In Hui'an, thyroid hormone levels vary over the weeks of pregnancy and between pregnant and non-pregnant women. By establishing local reference ranges, thyroid problems in pregnancy can be diagnosed, and complications can be avoided.

Advanced Charge Control Dynamics Simulation for the LISA Gravitational Reference Sensor

Abstract A gravitational wave detector in space, the Laser Interferometer Space Antenna (LISA) will be able to detect gravitational waves in the frequency range of 0.1 mHz to 1 Hz, adding to humanity’s knowledge of the dark cosmos. The LISA gravitational reference sensor contains a test mass (TM) and is used to determine the local inertial reference frame and as endpoints for the interferometry. The TM is surrounded by an electrode housing to detect changes in TM position and orientation, which is fed back to the spacecraft thrusters for&amp;#xD;drag-free control. As seen on LISA Pathfinder, the TM builds up charge over time from the space environment and needs to be discharged in order to keep the resulting force noise as low as possible. The operation of intelligently discharging&amp;#xD;the TM is known as charge control, and is one area of improvement to be explored for LISA.&amp;#xD;&amp;#xD;To explore new methods of TM discharge, UV LEDs will be pulsed synchronized with an existing 100 kHz high frequency electric field to facilitate photoelectron current direction and to achieve lower UV light powers by duty cycling. This paper addresses new pulsed methods for the LISA Charge Management System, which require in-depth modeling, analysis, and testing because space environment validation will not be possible prior to LISA launch. Therefore, it is necessary to model the dynamics of charge movement to determine&amp;#xD;the force noise contribution of pulsed continuous charge control. The charge dynamics model is described, and simulation results featured for charge control efficacy in a deep space radiation environment. Experimental testing of the simulation results could be done in the University of Florida Torsion Pendulum, a key technology to testing GRS performance in a space-like environment.

Establishment of Local Diagnostic Reference Levels for Pediatric Neck CT at Nine University Hospitals in South Korea.

To establish local diagnostic reference levels (DRLs) for pediatric neck CT based on age, weight, and water-equivalent diameter (WED) across multiple university hospitals in South Korea. This retrospective study analyzed pediatric neck CT examinations from nine university hospitals, involving patients aged 0-18 years. Data were categorized by age, weight, and WED, and radiation dose metrics, including volume CT dose index (CTDIvol) and dose length product, were recorded. Data retrieval and analysis were conducted using a commercially available dose-management system (Radimetrics, Bayer Healthcare). Local DRLs were established following the International Commission on Radiological Protection guidelines, using the 75th percentile as the reference value. A total of 1159 CT examinations were analyzed, including 169 scans from Institution 1, 132 from Institution 2, 126 from Institution 3, 129 from Institution 4, 128 from Institution 5, 105 from Institution 6, 162 from Institution 7, 127 from Institution 8, and 81 from Institution 9. Radiation dose metrics increased with age, weight, and WED, showing significant variability both within and across institutions. For patients weighing less than 10 kg, the DRL for CTDIvol was 5.2 mGy. In the 10-19 kg group, the DRL was 5.8 mGy; in the 20-39 kg group, 7.6 mGy; in the 40-59 kg group, 11.0 mGy; and for patients weighing 60 kg or more, 16.2 mGy. DRLs for CTDIvol by age groups were as follows: 5.3 mGy for infants under 1 year, 5.7 mGy for children aged 1-4 years, 7.6 mGy for ages 5-9 years, 11.2 mGy for ages 10-14 years, and 15.6 mGy for patients 15 years or older. Local DRLs for pediatric neck CT were established based on age, weight, and WED across nine university hospitals in South Korea.

Establishing Local Diagnostic Reference Levels for Common X-ray Examinations at the Federal Neuro-Psychiatric Hospital Maiduguri, Nigeria

Establishing Local Diagnostic Reference Levels for Common X-ray Examinations at the Federal Neuro-Psychiatric Hospital Maiduguri, Nigeria

A klímaváltozás vízmérlegre gyakorolt hatásának előrejelzése egy gyepborítású tesztparcellán

The ongoing climate change in Europe is characterized by statistically significant warming in all seasons. Increasing temperatures also affect the precipitation intensity through the hydrological cycle, so that the assumed changes in the distribution and amount of precipitation and the continuously increasing temperatures may increase the rate of water use by plants, making the adaptability of vegetation to climate change a key issue. In the present paper, the hydrological effects of climate change were investigated under typical environmental conditions of a specific agricultural area in Austria. For this purpose, (1) a simple Thornthwaite-type monthly time-step water balance model was developed and (2) the model was used to project the water balance components for the 21st century for (a) a normal root depth (current condition) and (b) a (hypothetically) increased root depth representing the adaptation potential of vegetation to warming. To achieve the main objectives, the model was calibrated and validated with local reference data. The key parameter of the model is the soil moisture holding capacity (SOILMAX), expressed using root depth. The latter was calibrated using available evapotranspiration and soil physics properties. The calibrated model was used for projections using data from four bias-corrected regional climate models. Model runs with normal root depths resulted in increasing annual averages for evapotranspiration and soil moisture, but decreasing annual averages for soil moisture minimums by the end of the 21st century. However, the monthly values indicated that a decrease in soil moisture during the growing season is projected by the end of the 21st century. The vegetation of the selected agricultural area was shown in the model runs to be able to successfully adapt to increasing drought stress by increasing its root zone to its potential maximum.

Formulation of a New Finite Element with Drilling Rotation Based on Assumed Strains for Membrane Structures

A new membrane finite element with four nodes that is based on the strain approach using Airy’s function is developed for the resolution of plane linear elasticity problems in general. The adoption of linear variations for the normal components of the strain and constant shear strain improves the accuracy of the elements. However, any singularity is eliminated by the use of a local reference frame oriented in an optimal manner. From numerical examples of a beam subjected to bending and shearing, we conclude that exact solutions can be obtained and they demonstrate the accuracy of the proposed procedure.

The scalable variant call representation: enabling genetic analysis beyond one million genomes.

The Variant Call Format (VCF) is widely used in genome sequencing but scales poorly. For instance, we estimate a 150 000 genome VCF would occupy 900 TiB, making it costly and complicated to produce, analyze, and store. The issue stems from VCF's requirement to densely represent both reference-genotypes and allele-indexed arrays. These requirements lead to unnecessary data duplication and, ultimately, very large files. To address these challenges, we introduce the Scalable Variant Call Representation (SVCR). This representation reduces file sizes by ensuring they scale linearly with samples. SVCR's linear scaling relies on two techniques, both necessary for linearity: local allele indices and reference blocks, which were first introduced by the Genomic Variant Call Format. SVCR is also lossless and mergeable, allowing for N + 1 and N + K incremental joint-calling. We present two implementations of SVCR: SVCR-VCF, which encodes SVCR in VCF format, and VDS, which uses Hail's native format. Our experiments confirm the linear scalability of SVCR-VCF and VDS, in contrast to the super-linear growth seen with standard VCF files. We also discuss the VDS Combiner, a scalable, open-source tool for producing a VDS from GVCFs and unique features of VDS which enable rapid data analysis. SVCR, and VDS in particular, ensure the scientific community can generate, analyze, and disseminate genetics datasets with millions of samples. https://github.com/hail-is/hail/.

Establishment of Local Diagnostic Reference Levels for Head CT Imaging in the Madina Region, Saudi Arabia.

Background: Computed Tomography (CT) is crucial in medical diagnosis, particularly for head examinations. Diagnostic Reference Levels (DRLs) are pivotal in balancing diagnostic efficacy with radiation safety. International organizations such as the International Atomic Energy Agency (IAEA) and the International Commission on Radiological Protection (ICRP) provide guidelines for establishing DRLs, emphasizing their importance in optimizing radiation doses. Aim: This study aimed to establish and standardize DRLs for head CT imaging in institutional and regional settings, emphasizing the need for tailored reference levels specific to each region's practices and standards. Method: Data collection included patient demographics, imaging parameters, and radiation dose indices, namely volume-weighted CT dose index (CTDIvol) and dose-length product (DLP). Statistical analyses were conducted to determine the median and 3rd quartile values for establishing DRLs. The results were compared with national and international benchmarks to assess variations in radiation doses across regions. Results: Demographic profiles detailed gender distributions and ages across hospitals. Imaging parameters exhibited variability in tube voltage, milliampere-seconds (mAs), pitch, scan length, and field of view (FOV). For CTDIvol, the 3rd quartile value was 65.8 mGy (range: 24.8-85.9 mGy), and for DLP, it was 1230.95 mGy·cm (range: 382.3-1189.0 mGy·cm). These values were slightly higher than the national DRLs for Saudi Arabia in 2021 and other international benchmarks, underscoring the need for further optimization and alignment of protocols. Conclusion: Optimizing and standardizing DRLs for head CT imaging is crucial for effectively managing radiation doses while ensuring diagnostic accuracy. Comparison with national and international benchmarks highlighted the importance of tailoring reference levels to regional practices and standards, ensuring patient safety without compromising diagnostic efficacy.

An Analytical Study of the Cultural Content of English Language Textbooks for Secondary School in the Saudi Arabia in Light of the Challenges of Globalization

The present study aimed at identifying the extent of the inclusion of cultural contents in the English textbook "Flying High "in the light of globalization challenges. Thus, this analytical study intended to answer the following question: to what extent does the English textbook "Flying High" include the cultural contents in the light of globalization challenges? The researcher conducted the descriptive analytical approach to answer the research question. The sample of the study consisted of the English textbook of 1st Secondary Stage "Flying High", level (1) published in Saudi Arabia. A content analysis tool was prepared by the researcher for collecting data depending on theoretical framework. The results of the study can be summarized as follows:1) Local cultural content" received the lion's share of total cultural contents in (56.8%) for big "C" culture and (63.5 %) for Small "c" culture. 2) Target cultural content received (16,2%) for big "C" culture and (25,4%) for small "c" culture. 3) International cultural content received (27%) for big "C" culture and (11,1%) for small "c" culture. Therefore, the results revealed that there was an extensive use of local cultural references while there was an obvious absence of many other target and international cultural contents. It was also clear that cultural elements were presented in many positions, but in a superficial and narrow way. Based on the findings of the study, several suggestions for enhancing the cultural content of English textbooks have been offered.

Establishment of local diagnostic reference levels in terms of dose area product (DAP) in conventional radiology at the Regional Hospital Center of Souss Massa, Morocco

Introduction: The effectiveness of diagnostic reference levels (DRLs) in reducing the doses delivered to patients has been demonstrated. Establishing DRLs in terms of the dose surface product (DSP) is an essential step in the management of radiation doses in conventional radiology. Objective: This retrospective study aimed to assess local diagnostic reference levels (LDRLs) for four types of X-ray examinations in terms of DAP at the Regional Hospital Center of Souss Massa. Materials and methods: Data from 120 adult patients, 30 per location (thorax (PA), pelvis (AP), lumbar spine (AP) and abdomen (AP)) were collected. Patient parameters such as gender, age, BMI, clinical indications, and examination acquisition parameters such as kV, mAs, patient source distance (PSD), and exposure field dimensions were recorded for each patient. The calculation of DRLs is based on a statistical method known as the 75th percentile of the distribution of DAP. The data were statistically analysed by SPSS software V 21.0. Pearson’s parametric test was used to explore the relationship between the different quantitative variables. Results: The mean ESDs for the thorax (PA), lumbar spine (AP), abdomen (AP), and pelvis (AP) were 0.17, 2.55, 2.16, and 2.63 mGy, respectively. The mean DAP values for the thorax (PA), lumbar spine (AP), abdomen (AP), and pelvis (AP) were 16.53, 213.11, 230.55, and 265.19 cGy.cm2, respectively. The DRLs in terms of ESD for the thorax (PA), lumbar spine (AP), abdomen (AP), and pelvis (AP) were 0.17, 2.77, 2.64, 2.87 mGy, respectively. In terms of DAP, they were 16.58, 245, 291.83, and 300.45 cGy.cm², respectively. The results show a significant relationship between DAP and tension, charge, and ESD for all examinations. In addition, there was a significant relationship between DAP and BMI for abdomen X-ray, and no significant relationship for the three other X-ray examinations. Conclusion: It is possible to reduce the dose delivered to patients in the Regional Hospital Center of Souss Massa through the continuous training of radiology workers, implementation of a quality assurance program for equipment, and institutionalization of DRL as an approach to reducing patient doses and health service costs.

An approach to construct fast and robust local reference frames based on point cloud

An approach to construct fast and robust local reference frames based on point cloud

Netflix’s transnational identities: From Europeanness to cosmopolitanism in Sex Education

A British creation, Netflix’s original hit series Sex Education (2019–23) casually navigates local, national and global references. British and American protagonists appear from the first episode, joined by international characters from northern Europe and francophone Africa, although not much is made of these supposedly foreign identities. As much as the period in which the show is set cannot be easily pinpointed, since references to different temporal eras are screened in a vibrant mix of songs, patterns and colours, so does identity appear as fluid, constructed as a diffuse mix of accented languages, native idioms and cultural backgrounds. Aiming to unpack this apparently harmonious mix, this article focuses on Episode 5 of the third season, in which Eric travels to Nigeria with his family, while the remaining students go on a study trip to France. It asks what visions of hyphenated identities emerge, as well as what representations of Europe are put forward. From First World War trenches to romance, from toilet humour to rude French characters, the episode disparages ‘Europeanness’ and instead foregrounds the value of cosmopolitanism. It thus contributes to our understanding of the idea of Europe and its future, as framed by global audio-visual cultures.

DNA barcode reference database and gap analysis for biomonitoring Hong Kong’s marine animals

DNA-based taxonomic identification relies on comprehensive DNA reference libraries, but uneven barcode coverage poses a global challenge. Here we determined the gaps in BOLD and GenBank for marine animals in Hong Kong’s subtropical waters. We compiled 170,529 sequences from four marker genes [cytochrome c oxidase subunit I (COI), 12S ribosomal RNA (rRNA), 16S rRNA, and 18S rRNA] representing 4074 marine animal species spanning 17 phyla. Gap analysis highlighted variations in COI barcode coverage across phyla, ranging from 0 % in Ctenophora, Gnathostomulida, Hemichordata, Phoronida and Platyhelminthes to 90.44 % in Chordata. The average coverage of COI (53.24 % in BOLD and 58.47 % in GenBank) was substantially higher than that of the other three rRNA genes (19.46–32.25 %). In total, 4392 Barcode Index Numbers (BINs) were assigned to 2169 species, of which 41.13 % were taxonomically concordant and 50.71 % were displayed multiple BINs, indicating the presence of cryptic species and the potential for undiscovered diversity. Overall, this study provided a valuable DNA barcode library for marine animals in Hong Kong, revealed that many marine animals lack a barcode, and many species may be undescribed, highlighting the need for enhanced reference libraries. We also outlined a strategy for filling the gaps in the database. Utilizing the local reference database can significantly enhance molecular-based biodiversity assessment and improve the identification of cryptic (morphologically similar) and invasive species, thereby providing more informed support for coastal management and conservation efforts in Hong Kong waters and the surrounding areas of China’s Hong Kong-Zhuhai-Macau Greater Bay Area.

Percentile Values of Specific Physical Performances in Tunisian Basketball Players Aged 9 to 21: Considering Maturity Status

Background: Success in basketball is influenced by various factors, including biological maturation. Peak height velocity (PHV) is a key indicator of maturation, playing an important role in assessing the performance of basketball players. This study aimed to analyze the effects of maturational status, chronological age, and gender on anthropometric characteristics and physical performance parameters in Tunisian basketball players and to establish local percentile reference values for physical performance. Methods: A total of 470 basketball players (240 males and 230 females) were categorized into three maturity status groups: pre-PHV (n = 111), circa-PHV (n = 170), and post-PHV (n = 189). Anthropometric and physical fitness parameters were assessed to provide percentile reference values. Results: Our findings revealed significantly higher anthropometric and physical performance values in the post-PHV athletes compared to those in the pre- and circa-PHV groups. Additionally, male athletes outperformed females in most measured variables. Basketball-specific skills appeared to be more dependent on chronological age than on pubertal status. Conclusions: Percentile values were established for both boys and girls, offering valuable references for trainers to quantify and individualize training programs. These findings may assist practitioners in identifying potentially talented basketball players based on their maturation status.

Coagulation assay results at birth in preterm infants: A cohort study highlighting the relevance of local reference values for interpretation.

Routine coagulation screens at birth are still standard in some European neonatal intensive care units (NICUs), although interpretation of these results is complex in preterm infants. It is unclear to what extent local coagulation assay results agree with published reference ranges when using different analysers and reagents. We aimed to assess coagulation assay results on day 1 of life in very preterm infants admitted to the NICU. We included all preterm infants born below 32 weeks gestational age (GA) admitted to the Leiden University Medical Center between 2004 and 2020 in whom coagulation assays (prothrombin time [PT] and activated partial thromboplastin time [APTT]) were obtained during the first 24 h of life. Infants either diagnosed with major intraventricular haemorrhage or who received plasma transfusion before coagulation assay were excluded. We assessed coagulation assay results and compared the results between <28 weeks (extremely preterm) and 28-32 weeks (very preterm) GA groups. Coagulation assays were obtained at birth in 144 infants (144/2577; 5.5%) of whom 104 fulfilled the inclusion criteria. We found similar median PT and APTT values for extremely and very preterm infants (PT: 18.1 vs. 18.7 s [p-value = 0.400]; APTT: 44.2 vs. 47.7 s [p-value = 0.252], respectively). We found similar coagulation assay results at birth for extremely and very preterm infants; however, results deviated considerably from some of the published reference ranges. This may be due to differences between analysers and reagents, underlining the need for reference ranges calibrated to the equipment used per NICU.

OPTIMIZATION OF RADIATION PROTECTION IN PATIENTS THROUGH IMPLEMENTATION OF LOCAL DIAGNOSTIC REFERENCE LEVEL (DRL) IN PANORAMIC DENTAL EXAMINATION IN RADIOLOGY INSTALLATION OF PROF. DR. MARGONO SOEKARJO HOSPITAL

One of the principles of radiation protection is optimization. Optimization is done to make the dose received as low as reasonably achievable (ALARA) by considering economic and social factors. Implementation of radiation protection optimization can be done with dose management through the Local Diagnostic Reference Level (DRL). In recent years, the Nuclear Energy Regulatory Agency (BAPETEN) has set the Indonesian DRL value for several X-ray modalities, including dental panoramic. This study was motivated by panoramic patient dose audit data using the auto mode exposure factor, which operators often use. The method for determining the manual mode exposure factor is carried out by comparing the image quality of the current variations of 6.3 mA, 8 mA, 10 mA, 13 mA, and 16 mA with a fixed voltage of 66 kV and a time of 14.1 seconds. The local DRL value was obtained by comparing the dental panoramic auto mode measurements with manual mode using certain exposure factors according to the recommendations in the initial study using a head phantom. This study used 100 patient data with adult human criteria aged over 15. The results obtained from the initial study and questionnaires in manual mode were the values that had the highest CNR and SNR at a current variation of 10 mA. The exposure factor was then used to collect patient data. The local DRL value obtained for auto mode was 83.35 mGy cm2; in manual mode, it was 57.7 mGy cm2. Manual mode exposure factors in dental panoramic examinations affected the implementation of local DRL values with a decrease of 30.77% from auto mode. The use of manual mode in dental panoramic examinations significantly reduces the radiation dose received by patients, so the use of manual mode is one of the steps to optimize radiation protection. Keywords: Diagnostic Reference Level (DRL), optimization of radiation protection in patients, dental panoramic.

REFERENCE AREAS SELECTION AFFECTS REGISTRATION OF AI-SEGMENTED MANDIBLES ACQUIRED WITH CBCT

Introduction Precise registration of sequential 3D datasets is crucial for accurate dimensional analysis. Utilizing the Local Best-Fit (LBF) algorithm and stable Registration Reference Areas (RRAs) facilitates the accurate alignment of 3D surface models. Currently, Cone-beam Computed Tomography (CBCT) and Deep Learning (DL) algorithms are at the forefront for segmenting CBCT scans to monitor morphological changes in the residual alveolar ridge. This study compares the effectiveness of different RRAs in registration sequential 3D surface models of partially edentulous mandibles. Methods DL-assisted software segmented two sequential CBCTs (T0 and T1) from 10 patients, producing sequential 3D mandibular models. These models were aligned using three distinct RRAs: (i) WHOLE, encompassing the entire surface model; (ii) MND_BODY, covering the mandibular body while excluding the unstable alveolar ridge; and (iii) SPIN_FOR, incorporating stable RRAs (mental foramina and mental spine). An innovative method assessed registration accuracy by generating centroids from cross-sectional outlines of the mandibular nerve canals at the anterior third (A), medial third (B), and posterior third (C) of the posterior edentulous areas. The distance between centroids at T0 and T1 quantified registration accuracy. Results The MND_BODY group exhibited superior accuracy, whereas the SPIN_FOR group showed the least, with accuracy decreasing from A to C, suggesting rotational misalignments. ConclusionsWhen selecting RRAs, both stability and spatial distribution must be taken into account. For optimal alignment, sequential 3D surface models should use RRAs that are both stable and widely distributed.

DETERMINATION OF DOSE REFERENCE LEVELS AT BENDAN PEKALONGAN REGIONAL HOSPITAL FOR INTERNAL DOSE AUDIT AS AN EFFORT TO OPTIMIZE RADIATION PROTECTION FOR PATIENTS

Unnecessary exposure is less of a concern because it is considered not to cause injury to patients. Radiation protection optimization is carried out for patients to reduce unnecessary exposure. Following BAPETEN Regulation No. 4 of 2020 Article 46, permit holders are required to implement radiation protection optimization [1]. This study aimed to obtain the local dose reference level (TPD) value through an internal dose audit to optimize patient radiation protection. This optimization is carried out in several steps, including conducting an internal dose audit, determining the local TPD, and evaluating the examination. This study is expected to motivate documentation of radiation parameters to obtain sufficient data for analysis. The method used in this study is a literature study through related references and X-ray radiation output data to calculate the dose in the form of incident air kerma (INAK) and entrance surface air kerma (ESAK). The results showed that the local INAK TPD value was 52% below the national TPD, and the local ESAK TPD value was 57% below the national TPD. The expected local TPD value is a TPD value that is lower than the national TPD value. This indicates that the imaging protocol at RSUD Bendan has been well-optimized. However, there are still several types of examinations where the local TPD value exceeds the national TPD, indicating the need to review further the imaging techniques and protocols used. The influence of body weight and radiological image diagnosis was analyzed as a basis for further optimization. Thus, the determination of this local TPD can be an essential reference in efforts to improve patient safety and optimize radiation protection in health facilities. Keywords: radiation protection optimization of patient, Dose Reference Level (DRL), patient dose.

DETERMINATION OF DIAGNOSTIC REFERENCE LEVEL (DRL) AND STUDY OF EXPOSURE PARAMETER SELECTION IN HEAD AND ABDOMEN CT SCAN AT BANGIL REGIONAL HOSPITAL

A study has been conducted to determine the local diagnostic reference level (DRL) value of CT scans at Bangil Regional Hospital. The determination and calculation of the DRL value are based on the measurement of the patient's dose, namely using the CT scan examination results in the form of CTDIVol values and DLP values. The DRL value is determined from the CTDIVol and DLP data distribution in quartile 3. Patient dose data uses a Toshiba 16-slice CT scan and a Canon 160-slice CT scan. Seven hundred twenty data were obtained, distinguished by 680 adults and 40 children. The local DRL value at Bangil Regional Hospital for CT scans of the Head without contrast for the adult group CTDIVol 47.5 mGy and DLP 1162 mGy.cm. CT scans of the Head with contrast for the adult group CTDIVol 47.22 mGy and DLP 2784.38 mGy.cm. DRL on CT scan Abdomen without contrast adult age group at Bangil Hospital CTDIVol 3.7 mGy and DLP 179.9 mGy.cm. CT scan of Abdomen with contrast CTDIVol 3.9 mGy and DLP 774.92 mGy.cm. When compared to the National DRL value, this value is still below the National DRL value. However, the nature of DRL is dynamic, so each period is expected to be lower. Efforts should focus on achieving lower DRL values by considering the selection of parameters and the skills of radiographers that influence the dose administered to patients. Values that exceed the DRL value are evaluated using the choice of parameters. Factors that affect the DRL value include kV, mAs, rotation time, pitch, iterative reconstruction, and number of phases. The parameters used in CT scans at Bangil Hospital must be adjusted to provide optimal doses to patients. Keywords: diagnostic reference level (DRL), dose length product (DLP), CT dose index (CTDI), CT Head, CT Abdomen, dose delivery parameters.

DETERMINATION OF LOCAL DIAGNOSTIC REFERENCE LEVEL (DRL) ON CONVENTIONAL RADIOTHERAPY SIMULATOR WITH BRAIN METASTASIS CASES AT DR. ADHYATMA, MPH HOSPITAL

Conventional simulators in 2-dimensional (2D) radiotherapy procedures can be done with fluoroscopy and single exposure features. The most significant percentage of 2D patients in the radiotherapy installation of Dr. Adhyatma MPH Hospital, are patients with brain metastasis cases, with a percentage of 65% of all 2D patients. Therefore, this study focuses on brain metastasis cases. The feature used in the Radiotherapy Installation of Dr. Adhyatma MPH Hospital is the single exposure feature, which is identical to conventional diagnostic radiology examinations. Radiation in diagnostic radiology requires a local Diagnostic Reference Level (DRL) on a conventional radiotherapy simulator as a guideline for optimizing radiation protection for medical exposure. This study aims to determine the local DRL value of a conventional radiotherapy simulator in cases of brain metastasis and compare it with the national DRL in lateral head examinations. The local DRL value obtained is then used as a guideline in improving services to increase the quality of service to patients. The data collection method is carried out in 2 (two) ways, namely calculating the local DRL value from the ESAK value and interviews related to the quality of the resulting image. The exposure factors used in this study followed the same routine exposure factors with a tube voltage of 72 kV and a tube current of 25 mAs. The local DRL value obtained was 0.586 mGy, with a percentage difference of 51% lower than the national DRL. With this value, the quality of the resulting image is classified as optimal and easy to assess. Thus, the exposure factors in the conventional radiotherapy simulation process in cases of brain metastasis can be used as a guideline for clinical practice at RSUD dr. Adhyatma, MPH. Keywords: conventional radiotherapy simulator, 2-dimensional radiotherapy, local DRL, diagnostic patients, radiation dose.