Patient Effective Dose Research Articles

Evaluation of radiation dose to Korean population by general radiography

General radiography has the highest usage among diagnostic radiology in Korea, resulting in high radiation dose by general radiography. For the medical radiation safety of patients, it is necessary to evaluate Korean population dose by general radiography. In this study, collective dose and per capita effective dose from general radiography in the Korean population were calculated. To this end, the raw data on the usage of general radiography in Korea as of 2017 was analyzed. Moreover, information on radiation dose from domestic general radiography was collected and PCXMC was used to evaluate the effective dose for patients during general radiography. As of 2017, the usage rate for lower extremity and chest examinations was high, accounting for more than 20 % of the total general radiography examinations. The effective dose depending on the examination type was the highest for whole-spine AP (1.06 mSv), followed by whole-spine LAT (0.61 mSv), and lumbar spine AP (0.51 mSv). As a result of evaluating Korean population dose by general radiography, the collective dose was 22,066 man∙Sv and the per capita effective dose was 0.43 mSv. The evaluation results of the Korea population dose obtained from this study can contribute to patient dose management in general radiography.

Patients’ effective doses assessment during low-dose computed tomography

Computed tomography has become increasingly common for diagnosing socially significant diseases in recent years. In foreign practice, screening schemes for lung cancer in people belonging to risk categories have been developed and implemented. These schemes have been successfully used over the past 10 years. In this case, “low-dose” scanning protocols are used, which make it possible to perform examination with patient effective dose several times lower compared to standard protocols. Lung cancer screening methods using low-dose computed tomography are beginning to be introduced in the Russian Federation. To ensure the radiation safety of those individuals eligible for inclusion in screening programs or participating in biomedical research testing lung cancer screening, it is necessary to evaluate effective doses from low-dose computed tomography and compare these doses to established radiation dose limits. This study assessed the patients’ effective doses who underwent different types of low-dose computed tomography of chest at two medical organizations. The results of the study show that it is possible to achieve non-exceedance of the current annual effective dose limit of 1 mSv only for patients weighing less than 90 kg. For patients with higher body weight, the minimum effective dose will be in the range of 1.2 – 1.4 mSv. The results of the study indicate the need to make changes to the current regulatory and methodological documents of Rospotrebnadzor to ensure the possibility of using low-dose computed tomography as part of screening for all categories of people.

Comparison between the intraoperative CT O-arm and C-arm related to radiation dose and accuracy in scoliosis surgery: A review study

Pedicle screw placement is a vital scoliosis therapy operation that aims to address spinal abnormalities while avoiding consequences including neurological damage caused by misplaced screws. Accurate imaging is required for precise screw insertion, with intraoperative CT (O-arm) and fluoroscopy (C-arm) being the principal modalities used. This review assesses various modalities based on their radiation dosages and accuracy. It comprises research published between 2012 and 2020 that evaluates both effective dose and accuracy for pediatric and adult patients. According to the review, the O-arm outperforms the C-arm in terms of accuracy, resulting in shorter procedure times for both pediatric and adult patients. The O-arm's sophisticated 3-D imaging capacity enhances screw insertion accuracy, reducing the likelihood of problems and the need for additional procedures. Furthermore, using pediatric low-dose protocols and techniques like the Detachable Pedicle Marker and Probe (DPMPs) with pulsed fluoroscopy can reduce radiation exposure while still ensuring precise screw placement. The review suggests that the O-arm has considerable advantages over the C-arm, such as improved image quality and lower radiation risk. This leads to enhanced patient safety and procedural outcomes. Overall, the O-arm's capacity to produce high-quality 3-D pictures makes it an invaluable tool in pedicle screw insertion, resulting in more accurate surgical outcomes and reducing the risk of problems associated with spinal deformity repairs.

Assessment of occupational radiation exposure during a specific endoscopic retrograde cholangiopancreatography procedure.

The aim of this study was to evaluate the occupational radiation exposure of staff during endoscopic retrograde cholangiopancreatography (ERCP), with a focus on individuals closest to the radiation source, and to identify potential increases in exposure to hands and eye lenses. Patient radiation exposure during ERCP was also assessed. Staff organ doses were monitored using a Philips Allura Xper FD 20 fluoroscopy system, during 24 ERCP procedures for a period of 7months. Staff doses were measured using thermoluminescence dosemeters and electronic personal dosemeters, and patient effective doses were simulated and calculated. Physicians' annual organ doses ranged from 0.2 to 1.6mSv for shoulders, 0.1 to 0.4mSv for eye lenses, and 0.3 to 1.6mSv for fingers. The annual organ dose of the nursing staff ranged from 0.08 to 2.4mSv for shoulders, 0.02 to 2.3mSv for eye lenses, and 1.2 to 5.3mSv for fingers. The effective dose to patients ranged from 0.009 to 0.46mSv. Staff doses were within safe limits, but patient doses were high, emphasizing the need for improved radiation protection.

Evaluation of the detector linearity response of the DR system in different x-ray bean filters

In the recent past, at Brazilian radiology services, direct digital radiography (DR) systems are replacing Computed Radiography (CR). This situation provides several significant advantages such as improving digital image quality, patient effective dose reduction, and improved speed of examinations performed. To evaluate DR systems, various organizations have published protocols with guidelines concerning quality assurance and acceptance tests for DRs. In these protocols, there are methodologies for evaluating several parameters, such as the detector linearity response (DLR). To test the DLR, different methodologies are proposed by the organizations, such as the application of different additional filters on the X-ray beams spectrum to promote the X-ray doses suitable to produce the latent image in the DR. The objective of this work was to evaluate the results of different protocol methodologies for carrying out the DLR test of a DR flat panel. An analogic radiology equipment, a primary ionization chamber, a DR system and images unprocessed were used in this study. As indicated by the protocols, the spectra of the X-rays were modified by additional filters of copper (Cu) with aluminum (Al); Al; Cu; and polymethylmethacrylate (PMMA). The spectra of the X-rays were modified to achieve the exposure range of 0.1 to 7 mR. The results showed that the DLR curves adjustment were R²>0.99, for a logarithmic equation, type y=a.ln(x)+b. For the filters of 0.5 mmCu with 1.0 mmAl; 11.5 mmAl; 1.0 mmCu; 21 mmAl the mean pixel values showed 0.9% of the coefficient of variation (COV), while for 10 cm PMMA filters, the COV increased to 2.7%. The study showed that methodologies using Al, Cu and Al with Cu filters DLR have similar responses while using PMMA, the response was slightly different.

The determination of coefficients for size specific effective dose for adult and pediatric patients undergoing routine computed tomography examinations.

The effective dose resulting from computed tomography (CT) scans provides an assessment of the risk associated with stochastic effects but does not account for the patient's size. Advances in Monte Carlo simulations offer the potential to obtain organ dose data from phantoms of varying stature, enabling derivation of a size-specific effective doses (SEDs) representing doses to individual patients. This study aimed to compute size-specific k-conversion factors for SED in routine CT examinations for adult and pediatric patients of different sizes. Radiation interactions were simulated for adult and pediatric phantom models of various sizes using National Cancer Institute CT version 3.0.20211123. Subsequent calculations of SED were performed, and coefficients for SED were derived, considering the variations in body sizes. The results revealed a strong correlation between effective diameter and weight, observed with size-specific k-conversion factors for adult and pediatric phantoms, respectively. While size-specific k-conversion factors for CT brain remained constant in adults, values for pediatric cases varied. When using the tube current modulation (TCM) system, size-specific k-conversion factors increased in larger phantoms and decreased in smaller ones. The extent of this increase or decrease correlated with the set TCM strength. This study provides coefficients for estimating SEDs in routine CT exams. Software utilizing look-up tables of coefficients can be used to provide dose information for CT scanners at local hospitals, offering guidance to practitioners on doses to individual patients and improving radiation risk awareness in clinical practice.

Effect of palliative radiation dose on symptom response in metastatic sarcomas

PurposePalliative radiotherapy (RT) plays a crucial role in alleviating symptoms associated with metastatic sarcoma. However, there is a lack of consensus on the optimal palliative radiation dose and fractionation for metastatic sarcomas. We analyzed the association between biologically effective radiation dose and symptom response for patients who underwent palliative RT for metastatic sarcomas Methods and materialsWe retrospectively identified patients with metastatic sarcoma treated with palliative RT between 1999 and 2021 at our institution. We assessed the association between equivalent dose in 2 Gy fractions (EQD2) with an α/β of three and symptom relief or overall survival (OS) using univariable and multivariable analyses. ResultsOf the 198 metastatic sites treated, the most common indications for palliative radiation were pain (n = 181, 91 %) and compression of adjacent structures (n = 16, 8 %). In our analysis, an EQD2 of > 20 Gy was associated with greater rates of short-term symptom relief (n = 143, 85 %) at the RT site compared to an EQD2 of ≤ 20 Gy (n = 14, 54 %, P = 0.001) with no reports of grade 3 or higher toxicity. However, there was no significant improvement in short-term symptom relief for higher radiation doses. Patients treated with an EQD2 of ≤ 20 Gy had a significantly worse performance status, but there was no significant difference in overall survival based on EQD2 on multivariable analysis. ConclusionsAn EQD2 ≤ 20 Gy (e.g., 8 Gy in 1 fraction) provided inadequate palliative benefit in this series. An EQD2 > 20 Gy resulted in greater rates of symptom palliation in metastatic sarcomas, but further dose escalation did not improve symptom response or durability. These findings suggest standard palliative regimens such as 20 Gy in 5 fractions (EQD2 of 28 Gy) are effective for patients with metastatic sarcomas.

How Much Radiation Are Women in Saudi Arabia Receiving from Mammography? A Review

This review compiles and assesses data from recent studies on mammographic radiation doses in Saudi Arabia, aiming to evaluate mean glandular dose (MGD) exposure during mammography and its implications in breast cancer risk. The reviewed studies spanned from 2019 to 2023 and included a range of sample sizes and institutional settings, with patients’ ages from 27 to 85 years. Considerations such as the number of mammographic views and compressed breast thickness were examined. The studies reported average MGDs below the National Diagnostic Reference Level set by the Saudi Food and Drug Authority. However, limitations were noted regarding sample size selection and incomplete data on all mammographic projections. Despite these limitations, the findings highlight the need for continued assessment of patient doses to optimize mammography practices and address the absence of quality standardization acts in Saudi Arabia. These insights are critical for governing authorities to ensure that effective patient dose monitoring occurs regularly and that the establishment of minimum quality standards for breast cancer screening is intact.

Contribution of CT scan to patient's radiation exposure in parathyroid SPECT/CT scintigraphy

IntroductionDual phase technetium-99mTc-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography with computed tomography (SPECT/CT) may be the most accurate conventional imaging approach for localization of enlarged parathyroid gland (EPG). The imaging is based on the radiopharmaceutical (RP) retention in EPG compared to washout from normal thyroid and normal parathyroid glands. This study aimed to estimate and optimize the contribution of computed tomography (CT) scan and scan range to effective dose (ED) in dual-phase MIBI SPECT/CT parathyroid scintigraphy. MethodsThe study included seventy-four patients; thirty-seven with reduced and thirty-seven with extended CT scan range. The ED caused by the CT scan was calculated using Dose Length Product (DLP) data and estimated using the Imaging Performance Assessment of CT scanners (ImPACT) calculator. ResultsFor all patients, the contribution of CT to the ED in a combined SPECT/CT examination was 2.62 ± 0.29 mSv (48%). The contribution of CT to the total ED was 1.8 ± 0.18 mSv (33%) when using reduced and 3.44 ± 0.23 mSv (64%) when using extended scan range. The DLP and ED were statistically significantly different between the reduced and extended CT scan range (p < 0.001) in the first and second phases. The individual organ dose was reduced from 8% to 94%. ConclusionThe hybrid SPECT/CT improves the interpretation of nuclear medicine images and also increases the radiation dose to the patient. An adequately defined CT scan range on SPECT/CT imaging, can significantly reduce a patient's ED. Implications for practiceThe research findings showed that knowledge of anatomy, pathology and technology can provide optimising diagnostic procedures and reduce patient ED after SPECT/CT scans.

Navigated pedicle screw insertion with the Surgivisio system: Malposition rate and risk factors – about 648 screws

PurposePedicle screw malposition rates vary greatly in scientific literature depending on the chosen criteria. Different techniques have been developed to lower the risk of screw malposition. Our primary objective is to evaluate the malposition rate associated with the use of the Surgivisio navigation system and to identify risk factors for screw malposition. The secondary objectives are to assess operating time and radiation data. Materials and methodsWe performed a monocentric retrospective consecutive case series. All patients operated for pedicle screw implantation using the Surgivisio system between September 2017 and June 2020 were included. Screw positioning was evaluated on postoperative CT scans using Heary and Gertzbein classifications. Thirteen potential risk factors for screw malposition were hypothesized and tested with a univariate and multivariate analysis. ResultsSix hundred and forty-eight screws could be evaluated in 97 patients. Our study reported a 92.4% satisfactory screw implantation rate with a mean operative time per screw of 14.5±6.7minutes and a patient effective dose of 0.47±0.31 mSv per screw. One screw was neurotoxic and required an early revision (0.15%). Three risk factors for screw malposition have been identified in a multivariate analysis: female gender (OR=2.13 [1.11; 4], p=0.0219), an implantation level above D10 (OR=2.17 [1.13; 4.16], p=0.0197), and an “open” surgery (as opposed to percutaneous) (OR=3.47 [1.83; 6.56], p=0.0002). ConclusionPedicle screw malposition rate and operative time with the Surgivisio navigation system are comparable with those reported in scientific literature. We theorized that intraoperative patient reference displacement could be a major cause of navigation failure. Level of evidenceIV.

Abstract 7161: Preclinical pharmacology modeling (pharmacokinetics/efficacy) of narazaciclib (HX301 or ON123300) to predict its clinical effective dose

Abstract Background: Acute myeloid leukemia (AML) is an aggressive leukemia of myeloid lineage. CSF1R (colony-stimulating factor 1 receptor) regulates the proliferation, differentiation and polarization of cells of myeloid lineages, e.g. monocytes/macrophages. CSF1R expression is aberrantly upregulated in many AML, leading to a hypothesis that CSF1R is a putative leukemogenic driver in a subset of AML and thus could be a potential target for treating AML. Previous studies demonstrated that Narazaciclib (HX301 or ON123300), an investigational kinase inhibitor (TKi), exhibited high potency activity against CSF1R (IC50 0.285 nM) and inhibition of macrophage proliferation and AML tumor growth both in vitro/in vivo, implicating its potential use as an AML therapeutic1 (An et al., 2023 AACR Annual Meeting). In addition, narazaciclib has recently completed the dose escalation phase 1 study in advanced solid tumors. However, the therapeutic window of narazaciclib as a CSF1Ri for treating AML remains to be determined. The present study attempted to utilize both preclinical PK and in vivo efficacy models to predict the effective clinical dose of narazaciclib for guiding the future AML clinical trials. Methods: A single dose of narazaciclib at various of dose levels was orally administrated in NOD/Scid mice, and plasma samples were collected at designated timepoints. The concentrations of narazaciclib in plasma were analyzed by LC-MS. In a Ba/F3-ETV6-CSF1R in vivo xenograft tumor model in Nod/Scid mice, narazaciclib at various dose levels was orally administrated daily. Tumor volumes were measured twice weekly. Results: The mouse PK study showed that narazaciclib displayed overall similar absorption pattern as seen in unpublished human clinical data. Narazaciclib was absorbed rapidly after oral dosing with a mean Tmax ranging from 1 to 2 hours in mouse. However, narazaciclib was cleared faster in mouse, with a mean T1/2 ranging from 1.9 to 2.8 hours, than in human. In addition, the exposures of narazaciclib, as measured by Cmax and AUC in plasma, increased in a relatively dose-proportional manner, as seen in human patients. In the Ba/F3-ETV6-CSF1R xenograft model where the tumor cell growth is solely dependent on the CSF1R kinase activity, narazaciclib at 10 mg/kg did not induce any anti-tumor effects with a TGI of -14.61%. In contrast, narazaciclib at 50 mg/kg and 100 mg/kg exerted significant anti-tumor effects with a TGI of 85.49% and 94.55%, respectively. Based on the mouse PK results, narazaciclib at 50 mg/kg in mouse is estimated to have an AUC of approximate 2000 h*ng/mL, which is equivalent to the dose of 160 - 200 mg/d in human patients. Therefore, 160 mg dose level is predicted to be an effective dose for narazaciclib in AML patients. Conclusions: Narazaciclib at 160 mg/d is predicted to be an effective dose in AML patients. Citation Format: Tao Yang, Hang Ke, Jinping Liu, Kefeng Gong, Henry Qixiang Li. Preclinical pharmacology modeling (pharmacokinetics/efficacy) of narazaciclib (HX301 or ON123300) to predict its clinical effective dose [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7161.

Introducing fitting models for estimating age-specific dose and effective dose in paediatric patients undergoing head, chest and abdomen-pelvis imaging protocols: a patient study.

Concerns regarding the adverse consequences of radiation have increased due to the expanded application of computed tomography (CT) in medical practice. Certain studies have indicated that the radiation dosage depends on the anatomical region, the imaging technique employed and patient-specific variables. The aim of this study is to present fitting models for the estimation of age-specific dose estimates (ASDE), in the same direction of size-specific dose estimates, and effective doses based on patient age, gender and the type of CT examination used in paediatric head, chest and abdomen-pelvis imaging. A total of 583 paediatric patients were included in the study. Radiometric data were gathered from DICOM files. The patients were categorised into five distinct groups (under 15 years of age), and the effective dose, organ dose and ASDE were computed for the CT examinations involving the head, chest and abdomen-pelvis. Finally, the best fitting models were presented for estimation of ASDE and effective doses based on patient age, gender and the type of examination. The ASDE in head, chest, and abdomen-pelvis CT examinations increases with increasing age. As age increases, the effective dose in head and abdomen-pelvis CT scans decreased. However, for chest scans, the effective dose initially showed a decreasing trend until the first year of life; after that, it increases in correlation with age. Based on the presented fitting model for the ASDE, these CT scan quantities depend on factors such as patient age and the type of CT examination. For the effective dose, the gender was also included in the fitting model. By utilising the information about the scan type, region and age, it becomes feasible to estimate the ASDE and effective dose using the models provided in this study.

Investigating the Effect of Patient-Related Factors on Computed Tomography Radiation Dose Using Regression and Correlation Analysis

Computed tomography (CT) is a widely utilized diagnostic imaging modality in medicine. However, the potential risks associated with radiation exposure necessitate investigating CT exams to minimize unnecessary radiation. The objective of this study is to evaluate how patient-related parameters impact the CT dose indices for different CT exams. In this study, a dataset containing CT dose information for a cohort of 333 patients categorized into four CT exams, chest, cardiac angiogram, cardiac calcium score and abdomen/pelvis, was collected and retrospectively analyzed. Regression analysis and Pearson correlation were applied to estimate the relationships between patient-related factors, namely body mass index (BMI), weight and age as input variables, and CT dose indices, namely the volume CT dose index (CTDIvol), dose length product (DLP), patient effective dose (ED) and size-specific dose estimate (SSDE), as output variables. Moreover, the study investigated the correlation between the different CT dose indices. Using linear regression models and Pearson correlation, the study found that all CT dose indices correlate with BMI and weight in all CT exams with varying degrees as opposed to age, which did not demonstrate any significant correlation with any of the CT dose indices across all CT exams. Moreover, it was found that using multiple regression models where multiple input variables are considered resulted in a higher correlation with the output variables than when simple regression was used. Investigating the relationships between the different dose indices, statistically significant relationships were found between all dose indices. A stronger linear relationship was noticed between CTDIvol and DLP compared to the relationships between each pair of the other dose indices. The findings of this study contribute to understanding the relationships between patient-related parameters and CT dose indices, aiding in the development of optimized CT exams that ensure patient safety while maintaining the diagnostic efficacy of CT imaging.

Radiation exposure in augmented fluoroscopic bronchoscopy procedures: a comprehensive analysis for patients and physicians

Cancer is a major health challenge and causes millions of deaths worldwide each year, and the incidence of lung cancer has increased. Augmented fluoroscopic bronchoscopy (AFB) procedures, which combine bronchoscopy and fluoroscopy, are crucial for diagnosing and treating lung cancer. However, fluoroscopy exposes patients and physicians to radiation, and therefore, the procedure requires careful monitoring. The National Council on Radiation Protection and Measurement and the International Commission on Radiological Protection have emphasised the importance of monitoring patient doses and ensuring occupational radiation safety. The present study evaluated radiation doses during AFB procedures, focusing on patient skin doses, the effective dose, and the personal dose equivalent to the eye lens for physicians. Skin doses were measured using thermoluminescent dosimeters. Peak skin doses were observed on the sides of the patients’ arms, particularly on the side closest to the x-ray tube. Differences in the procedures and experience of physicians between the two hospitals involved in this study were investigated. AFB procedures were conducted more efficiently at Hospital A than at Hospital B, resulting in lower effective doses. Cone-beam computed tomography (CT) contributes significantly to patient effective doses because it has higher radiographic parameters. Despite their higher radiographic parameters, AFB procedures resulted in smaller skin doses than did image-guided interventional and CT fluoroscopy procedures. The effective doses differed between the two hospitals of this study due to workflow differences, with cone-beam CT playing a dominant role. No significant differences in left and right eye Hp (3) values were observed between the hospitals. For both hospitals, the Hp (3) values were below the recommended limits, indicating that radiation monitoring may not be required for AFB procedures. This study provides insights into radiation exposure during AFB procedures, concerning radiation dosimetry, and safety for patients and physicians.

O USO DO O-ARM® OU DA RADIOSCOPIA EM CIRURGIAS DA COLUNA: REVISÃO SISTEMÁTICA COM META-ANÁLISE

ABSTRACT The great advances in using new devices and imaging systems in surgeries aim to reproduce an ideal and safe scenario for the surgeon, the team, and the patient. New systems and devices are constantly available to demonstrate and facilitate intraoperative navigation, thereby reducing errors and avoiding complications for the patient and staff. This study evaluates and compares using the O-arm® system and radioscopy in the freehand technique in spine surgeries. For this, searches were conducted in PubMed and Embase for randomized and non-randomized studies using the O-arm® system and radioscopy in spine surgery. Twenty-four studies were included and compared regarding procedure time, accuracy of implant positioning, effective radiation dose, safety, and efficacy. In one study, the O-arm® group showed a shorter surgical time when compared to the freehand technique (222.5 min. [SD=38.0] vs. 255.2 min. [SD=40.3], p=0.011, respectively). In two studies, the freehand technique resulted in a lower effective radiation dose for patients. In 12 studies, a higher incidence of complications was observed among patients undergoing surgery with the freehand technique. It was concluded that using the O-arm® is associated with a reduction in malposition of implants and more safety for instrumented procedures. Still, no evidence exists that its use can result in less surgical time. Level of Evidence I; Diagnostic Analysis and Studies, Investigation of a Diagnostic Test.

Study the variations in radiation doses in different multi-slice CT scan machines

Objectives: This study aimed to measure variations in dose output and patient’s effective dose across the different computed tomography scanners during standard CT examinations of head, chest and abdomen, so as to determine patient, and machine settings that contribute to variations in radiation dose to optimize patient effective dose. Methods: Retrospective, study performed in different hospitals, in Najran province (K.S.A) from October 2022 to June 2023. The study comprise 360 adults CT examinations. The mean values of CT dose index volume (CTDIvol) and dose length product (DLP) were measured. The patient effective dose (ED) were calculated for each protocol and compared among different CT scanners. Results: The mean values of CTDIvol , DLP, and ED, varied across the different CT scanners, Regarding abdomen CT, the CTDIvol mean values were (5.56 mGy to 18.655 mGy) , the DLP (289.78 to 968.241 mGy/cm), and mean effective doses were (4.34 to 14.5 mSv), in chest CTs the mean values of CTDIvol were (5.05 to 14.39mGy), the DLP were (202.84 to 499.098mGy/cm), and median effective doses were (2.85 to 6.97 mSv), in head CTs the mean values of CTDIvol were (42.4to 68.278mGy), the DLP were (781 to 1209.18mGy/cm), and effective doses were (1.636 to 2.528mSv). Conclusion: Regarding selected exams, CTDI, DLP and ED were found to be varied from low variations in head CT scan, to medium in chest CT scan and high variation in abdomen CTs among different CT scanners, The highest values of CTDI and DLP were noted in head CTs followed by abdomen, and the lowest were in chest CTs. The most factors affected the CT dose variations were the technical parameters settings, mainly the number of slices, however the scanner specifications reported some impact. Optimizing dose to a reliable standard for each anatomical part should be adjusting independently by each department according to the scanner characteristics, settings and patient factors.

Assessment of organ doses, peak skin doses and effective doses in patients undergoing anterior cervical discectomy and fusion utilising VirtualDose-IR software.

In this study, the effect of patient- and procedure-related parameters on organ doses (ODs), peak skin dose (PSD) and effective dose (E) during anterior cervical discectomy and fusion (ACDF) was evaluated. Patient- and procedure-related parameters, as well as fluoroscopy time, kerma-area product (KAP), cumulative air-kerma (Kair) and incident Kair, were analysed for 50 ACDF procedures performed with a mobile C-arm. These parameters were inserted in VirtualDose-IR software implementing sex-specific and body mass index (BMI)-adjustable anthropomorphic phantoms to calculate OD, PSD and E. The BMI, gender and type of implants did not significantly affect KAP, incident Kair, PSD and E. However, the type of fusion significantly affected the E. The single fusions in C5/C6 resulted in significantly higher KAP, incident Kair and E than C4/C5 levels, while those performed in C6/C7 resulted in significantly higher E and PSD than C4/C5 levels. The thyroid, oesophagus and salivary glands received the largest doses in all groups studied. The BMI did not significantly affect ODs. The salivary glands absorbed significantly higher doses in males than females, while the extrathoracic region's dose significantly increased for multi- than single-level fusions. The fusions in C6/C7 resulted in significantly higher oesophagus and thyroid doses than C3/C4 and C4/C5 levels, as well as fusions performed in C5/C6 compared with C4/C5 levels. The data presented here could be used by the neurosurgeons as a comparator for future studies in optimising radiation protection during ACDF procedures in the operating theatre by keeping the ODs, PSD and E as low as reasonably practicable.

Proton Pump Inhibitors Increases Longitudinal Risk of Mortality, Decompensation, and Infection in Cirrhosis: A Meta-Analysis.

Proton pump inhibitors (PPIs) are frequently prescribed to cirrhotic patients, but there is limited longitudinal evidence regarding their effects. This study aimed to assess the impact of PPIs on adverse events in cirrhotic patients. A comprehensive search was conducted using the Medline and Embase databases to identify relevant articles. Pooled hazard ratios (HRs) using DerSimonian and Laird random-effects model were calculated to evaluate the risk of adverse events such as long-term mortality, hepatic decompensation, hepatic encephalopathy (HE), spontaneous bacterial peritonitis (SBP), and overall infection in cirrhotic patients with PPI use. The analysis included 28 studies with 260,854 cirrhotic patients. The prevalence of PPI use among cirrhotic patients was 55.93%. The use of PPIs was not significantly associated with short-term mortality in cirrhotic patients. However, long-term mortality (HR 1.321, 95% CI 1.103-1.581, P = 0.002), decompensation (HR 1.646, 95% CI 1.477-1.835, P < 0.001), HE (HR 1.968, 95% CI 1.372-2.822, P < 0.001), SBP (HR 1.751, 95% CI 1.649-1.859, P < 0.001), and infection (HR 1.370, 95% CI 1.148-1.634, P < 0.001) were significantly associated with PPI use. Sensitivity analysis with prospective studies yielded similar results. PPIs should be reserved for appropriate indications at lowest effective dose for cirrhotic patients due to the potential harm.

Effect of tin spectral filtration on organ and effective dose in CT colonography and CT lung cancer screening.

Studies of tin spectral filtration have demonstrated potential in reducing radiation dose while maintaining image quality for unenhanced computed tomography (CT) scans. The extent of dose reduction, however, was commonly measured using the change in the scanner's reported CTDIvol . This method does not account for how tin filtration affects patient organ and effective dose. To investigate the effect of tin filtration on patient organ and effective dose for CT Lung Cancer Screening (LCS) and CT Colonography (CTC). A previously-developed Monte Carlo program was adapted to model a 96-row CT scanner (Somatom Force, Siemens Healthineers) with tin filtration capabilities at 100kV (100Sn) and 150kV (150Sn). The program was then validated using experimental CTDIvol measurements at all available kV (70-150kV) and tin-filtered kV options (100Sn and 150Sn). After validation, the program simulated LCS scans of the chest and CTC scan of the abdomen-pelvis for a population of 53 computational patient models from the extended cardiac-torso family. Each scan was performed using three different spectra: 120kV, 100Sn, and 150Sn. CTDIvol -normalized organ doses and DLP-normalized effective doses, commonly referred to as dose conversion factors, were compared between the different spectra. For all LCS and CTC scans, CTDIvol -normalized organ doses and DLP-normalized effective doses increased with increasing beam hardness (120kV, 100Sn, 150 Sn). For LCS, relative for 120kV, conversion factors for 100Sn produced a median increase in effective dose of 9%, with organ dose increases of 8% to lung, 5% to breast, 15% to thyroid, and 3% to skin. Conversion factors for 150Sn produced a median increase in effective dose of 20%, with organ dose increases of 16%, 18%, 26%, and 12% to these same organs, respectively. For CTC, relative for 120kV, conversion factors for 100Sn produced a median increase in effective dose of 12%, with organ dose increases of 9% to colon, 10% to liver, 11% to stomach, and 4% to skin. Conversion factors for 150Sn produced a median increase in effective dose of 21%, with organ dose increases of 16%, 17%, 19%, and 10% to these same organs, respectively. Results show that dose conversion factors are greater when using tin filtration and should be considered when evaluating tin's potential for dose reduction.

Breast radiation dose equivalent and cancer risk estimation during PET/CT examinations

Mammary glands or breasts are radiosensitive organs that makeup 12% of the body's overall radiation sensitivity. According to estimates, Saudi Arabia has a 27.3% overall cancer incidence rate for breast cancer. Recent studies reported that breasts get significant organ equivalent doses during diagnostic procedures with ionizing radiation, even though the breast is not the target organ. The objective of this work is to assess the effective and breast equivalent doses during positron emission tomography (PET)/Computed tomography (CT) imaging examinations. The effective and breast equivalent doses per PET/CT (GE PET/CT 710) examination were quantified using the amount of the injected radiopharmaceutical (MBq) (18F- fluorodeoxyglucose (FDG)), and external doses from CT examinations. The average, standard deviation (SD) and range of examined patients' age (years) and body mass index ((BMI), kg/m2) were 58 ± 11 (39–76) and 30 ± 5 (20.7–43.1), respectively. Constant administered activity (AA, 185 MBq) and tube potential (120 kVp) were used for all patients. The average, SD, and range of the patients effective dose (mSv) from PET/CT (18F- FDG) examination was 8.0 ± 0.93 (7.0–10.0) and 2.075 ± 0.11 (1.91–2.29) in that order. Breast doses are comparable with previous studies during the PET/CT and mammographic examination. Proper justification criteria and dose optimization are essential to lowering excessive exposure while preserving image quality, especially for young females because they have a higher risk of radiation-induced cancer.