Amount Of Dose Research Articles

Uncertainty quantification of TMS simulations considering MRI segmentation errors

Objective. Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation method that is used to study brain function and conduct neuropsychiatric therapy. Computational methods that are commonly used for electric field (E-field) dosimetry of TMS are limited in accuracy and precision because of possible geometric errors introduced in the generation of head models by segmenting medical images into tissue types. This paper studies E-field prediction fidelity as a function of segmentation accuracy. Approach.The errors in the segmentation of medical images into tissue types are modeled as geometric uncertainty in the shape of the boundary between tissue types. For each tissue boundary realization, we then use an in-house boundary element method to perform a forward propagation analysis and quantify the impact of tissue boundary uncertainties on the induced cortical E-field. Main results. Our results indicate that predictions of E-field induced in the brain are negligibly sensitive to segmentation errors in scalp, skull and white matter (WM), compartments. In contrast, E-field predictions are highly sensitive to possible cerebrospinal fluid (CSF) segmentation errors. Specifically, the segmentation errors on the CSF and gray matter interface lead to higher E-field uncertainties in the gyral crowns, and the segmentation errors on CSF and WM interface lead to higher uncertainties in the sulci. Furthermore, the uncertainty of the average cortical E-fields over a region exhibits lower uncertainty relative to point-wise estimates. Significance. The accuracy of current cortical E-field simulations is limited by the accuracy of CSF segmentation accuracy. Other quantities of interest like the average of the E-field over a cortical region could provide a dose quantity that is robust to possible segmentation errors.

Establishment of national diagnostic reference levels for percutaneous coronary interventions (PCIs) in Thailand

PurposeTo establish national diagnostic reference levels (DRLs) for percutaneous coronary intervention (PCI) in Thailand for lesions of different complexity. MethodsRadiation dose quantity as kerma-area-product (KAP) and cumulative air-kerma at reference point (CAK) from 76 catheterization labs in 38 hospitals in PCI registry of Thailand was transferred online to central data management. Sixteen months data (May 2018 to August 2019) was analyzed. We also investigated role of different factors that influence radiation dose the most. ResultsAnalysis of 22,737 PCIs resulted in national DRLs for PCI of 91.3 Gy.cm2 (KAP) and 1360 mGy (CAK). The NDRLs for KAP for type C, B2, B1 and A lesions were 106.8, 82.6, 67.9, and 45.3 Gy.cm2 respectively and for CAK, 1705, 1247, 962, and 790 mGy respectively. Thus, as compared to lesion A, lesion C had more than double the dose and B2 had nearly 1.6 times and B1 had 1.2 times CAK. Our DRL values are lower than other Asian countries like Japan and Korea and are in the middle range of Western countries. University hospital had significantly higher dose than private or public hospital possibly because of higher load of complex procedures in university hospitals and trainees performing the procedures. Transradial approach showed lower doses than transfemoral approach. ConclusionsThis large multi-centric study established DRLs for PCIs which can act as reference for future studies. A hallmark of our study is establishment of reference levels for coronary lesions classified as per ACC/AHA and thus for different complexities.

Degradation Characteristics and Mechanism of Ibuprofen by Ozone Catalyzed by Nitrogen-Doped Biochar

This study used a novel nitrogen-doped biochar (N-C) to catalyze the oxidative degradation of IBP in water by ozone and studied the catalytic ozone oxidation degradation of ibuprofen (IBP) efficiency and mechanism. Furthermore, it explored the influence of pH, ozone dosing quantity, catalyst dosing quantity, different anions, and background of water quality conditions on the IBP degradation efficiency. The results showed that, compared with that of some common carbon-based catalysts (g-C3N4, biochar, and granular-activated carbon) and metal catalysts (MnO2 and Fe3O4), the N-C catalytic ozone system had a very outstanding oxidation degradation performance of organic pollutants; the removal rate of IBP reached 100% in 5 min, and the utilization rate of ozone was increased from 10% to 46%. The treatment efficiency of the system was enhanced with the increase in pH. Compared with that by increasing the ozone dosage, the treatment capacity of the system was significantly improved by increasing the concentration of catalyst. The quenching experiment and EPR further confirmed that N-C could effectively catalyze ozone to produce more reactive oxygen species, such as superoxide radicals (·O2-) and H2O2. It was also found that·O2- was the main active substance in the reaction system and played a leading role in the degradation of IBP.

Uncertainty quantification of TMS simulations considering MRI segmentation errors.

Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation method that is used to study brain function and conduct neuropsychiatric therapy. Computational methods that are commonly used for electric field (E-field) dosimetry of TMS are limited in accuracy and precision because of possible geometric errors introduced in the generation of head models by segmenting medical images into tissue types. This paper studies E-field prediction fidelity as a function of segmentation accuracy. The errors in the segmentation of medical images into tissue types are modeled as geometric uncertainty in the shape of the boundary between tissue types. For each tissue boundary realization, we then use an in-house boundary element method to perform a forward propagation analysis and quantify the impact of tissue boundary uncertainties on the induced cortical E-field. Our results indicate that predictions of E-field induced in the brain are negligibly sensitive to segmentation errors in scalp, skull and white matter, compartments. In contrast, E-field predictions are highly sensitive to possible CSF segmentation errors. Specifically, the segmentation errors on the CSF and gray matter interface lead to higher E-field uncertainties in the gyral crowns, and the segmentation errors on CSF and white matter interface lead to higher uncertainties in the sulci. Furthermore, the uncertainty of the average cortical E-fields over a region exhibits lower uncertainty relative to point-wise estimates. The accuracy of current cortical E-field simulations is limited by the accuracy of CSF segmentation accuracy. Other quantities of interest like the average of the E-field over a cortical region could provide a dose quantity that is robust to possible segmentation errors.

A patient-specific hybrid phantom for calculating radiation dose and equivalent dose to the whole body

Objective. As cancer survivorship increases, there is growing interest in minimizing the late effects of radiation therapy such as radiogenic second cancer, which may occur anywhere in the body. Assessing the risk of late effects requires knowledge of the dose distribution throughout the whole body, including regions far from the treatment field, beyond the typical anatomical extent of clinical computed tomography (CT) scans. Approach. A hybrid phantom was developed which consists of in-field patient CT images extracted from ground truth whole-body CT scans, out-of-field mesh phantoms scaled to basic patient measurements, and a blended transition region. Four of these hybrid phantoms were created, representing male and female patients receiving proton therapy treatment in pelvic and cranial sites. To assess the performance of the hybrid approach, we simulated treatments using the hybrid phantoms, the scaled and unscaled mesh phantoms, and the ground truth whole-body CTs. We calculated absorbed dose and equivalent dose in and outside of the treatment field, with a focus on neutrons induced in the patient by proton therapy. Proton and neutron dose was calculated using a general purpose Monte Carlo code. Main results. The hybrid phantom provided equal or superior accuracy in calculated organ dose and equivalent dose values relative to those obtained using the mesh phantoms in 78% in all selected organs and calculated dose quantities. Comparatively the default mesh and scaled mesh were equal or superior to the other phantoms in 21% and 28% of cases respectively. Significance. The proposed methodology for hybrid synthesis provides a tool for whole-body organ dose estimation for individual patients without requiring CT scans of their entire body. Such a capability would be useful for personalized assessment of late effects and risk-optimization of treatment plans.

Radiation dose and image quality in abdominal CT: Phantom Study

The purpose of this study was to evaluate and compare the effect of acquisition parameters of the abdominal computed tomography protocol on image quality and dose quantities, including contrast-to-noise ratio (CNR), noise, spatial resolution (SR) as well as volumetric computed tomography dose index (CTDIv).
 The measurements have been done on a HITACHI 16-slice scanner using two phantoms (PMMA and Catphan 500), two tube voltages of 120KVp and 100KVp have been analyzed while varying the tube current settings from 155 to 300 (mAs) in order to measure the abdominal image quality quantities and dose (CTDIv).
 The scanning at 100KVp compared to 120KVp has resulted in a dose reduction up to 38% at mAs ranging from 100 to 300, a decrease in CNR of 28%, a slight decrease in spatial resolution accompanied with an increase in noise.
 This study has shown that despite the increase in noise at low tube voltages, it is possible to reduce the dose without affecting the quantities of spatial resolution and the contrast/noise ratio by lowering the tube voltage from 120KVp to 100KVp.
 Keywords: Abdominal CT; CTDIv; Image Quality; Phantom.

Microstructure Study for Effect of Local Admixture in Concrete Durability

Concrete permeability plays the main role in concrete durability because of the entry of harmful substances such as chlorides, sulfates, carbon dioxide (CO2), oxygen (O2). Concrete permeability is affected by factors such as size and proportion of aggregate, type, and quantity of cement, water-cement ratio, type and dose of admixture used, which help concrete have a high life. This research aims to investigate the effect of local admixture prepared to improve concrete properties, especially reducing the permeability of concrete using its proven effectiveness in salt attack. This research studies the effect of this admixture on concrete microstructure for several concrete specimens. This chemical admixture, which contains calcium oxide (CaO), chloride (Cl), and others, helps obtain a good performance of concrete. Adding calcium oxide (CaO) plays an important role in improving the physicochemical properties of concrete. An increase in the compressive strength was observed for all specimens. Incorporating additives without CaO to concrete has been shown to decrease its strength. In the present study, concrete showed higher compressive strength than other concrete, which has not contain this admixture which may be explained by the larger quantity of CaO in the cement.

Occupational eye dose correlation with neck dose and patient-related quantities in interventional cardiology procedures.

Occupational eye dose monitoring during interventional radiology and interventional cardiology is important to avoid radiation-induced cataracts. The aim of this study was to assess the eye dose correlation with neck dose and patient-related quantities for interventional cardiology physicians and nurses. The originality of this study lies in obtaining correlations between the location of the dosimeter and eye dose radiation readings among different procedures and practitioners. The doses were measured for each procedure (18 procedures of coronary angiography and 16 procedures of percutaneous coronary intervention) using an active personal dosimeter. The eye dose for physicians was not correlated with the neck dose. The eye dose for nurses had a good correlation with the neck dose during both coronary angiography (R2 = 0.91) and percutaneous coronary intervention (R2 = 0.93). Kerma-area product values may be used for a rough estimation of the eye dose for physicians during routine coronary angiography procedures (R2 = 0.76). For nurses, the neck dose is a good proxy for the eye dose during coronary angiography and percutaneous coronary intervention procedures.

Skin dose contamination conversion coefficients. Benchmark with three simulation codes

Handling of radioactive material by operators can lead to contamination at the surface of the skin in case of an accident. The quantification of the dose received by the skin due to a contamination scenario is performed by means of dedicated dose coefficients as it is the case for other radiation protection dose quantities described in the literature. However, most available coefficients do not match realistic scenarios according to state-of-the-art of science and technology. Therefore, this work deals with dedicated dose conversion factors for skin contamination. Since there is an increasing demand on dose coefficients in general, these specific coefficients can be used for various calculations in radiation protection. In this work a method to evaluate such coefficients for the skin contamination dose related to photons, electrons, positrons, alpha and neutron particles is proposed. The coefficients are generated using Monte-Carlo simulations with three well established calculation codes (FLUKA, MCNP, and GEANT4). The results of the various codes are compared against each other for benchmarking purposes. The new dose coefficients allow the computation of the skin received dose, in the case of skin contamination scenario of an individual, taking into account the decay radiation of the radionuclides of interest. To benchmark the quantity derived here, comparisons of radionuclide contamination doses to the skin using the VARSKIN code available in the literature are performed with the results of this work.

Technical note: Relationship between peak skin dose and fluoroscopic Ka,r : Clinical variations and application in establishing substantial radiation dose levels.

The reference point cumulative air kerma (Ka,r ) is a commonly used dose quantity for establishing substantial radiation dose levels (SRDLs) that can provide guidance for patient dose management actions following fluoroscopically guided procedures. However, the Ka,r may not correlate well with the patient peak skin dose (Dskin,max ) because the relationship between Ka,r and Dskin,max may vary widely due to clinical variations. Therefore, it may be prudent for institutions to establish different Ka,r -based SRDL values based on the clinical procedure type. The present study investigates the relationship between Ka,r and Dskin,max for different clinical services and how that variation may overestimate or underestimate the need for patient follow-up. Additionally, the study suggests a possible framework for establishing Ka,r SRDLs based on the clinical data analysis. A retrospective analysis was performed for fluoroscopically guided interventions exceeding 5Gy Ka,r . For each procedure, the patient Dskin,max was estimated and the ratio of Dskin,max to Ka,r (DKR) was calculated. Results were pooled into one of three clinical service categories: body interventions (n=33), cardiac interventions (n=81), or neurological (neuro) interventions (n=44). The distributions in Ka,r , Dskin,max , and DKR were analyzed in aggregate and by the clinical service category. The median Ka,r values for procedures exceeding 5Gy were 6.0Gy (95% CI [5.6, 6.4]) for body interventions, 5.8Gy (95% CI [5.5, 6.0]) for cardiac interventions, and 6.3Gy (95% CI [5.9, 6.6]) for neuro interventions. Dskin,max for the same procedure data sets were 5.0Gy (95% CI [4.4, 5.6]) for body interventions, 5.5Gy (95% CI [5.2, 5.8]) for cardiac interventions, and 3.7Gy (95% CI [3.4, 4.0]) for neuro interventions. This resulted in median DKR values of 0.81 for body interventions, 0.91 for cardiac interventions, and 0.59 for neuro interventions. This study illustrates the need to understand the relationship between the reported Ka,r and the patient Dskin,max for different types of interventional procedures. This is especially important when an institution uses Ka,r as the parameter for establishing an SRDL threshold to identify patients who may require clinical follow-up. The implications of this research and a guide for how to implement these findings are elaborated on in the Discussion.

Impact of the dose quantity used in MV photon optimization on dose distribution, robustness, and complexity

Convolution/superposition algorithms used in megavoltage (MV) photon radiotherapy model radiation transport in water, yielding dose to water-in-water (Dw,w ). Advanced algorithms constitute a step forward, but their dose distributions in terms of dose to medium-in-medium (Dm,m ) or dose to water-in-medium (Dw,m ) can be problematic when used in plan optimization due to their different dose responses to some atomic composition heterogeneities. Failure to take this into account can lead to undesired overcorrections and thus to unnoticed suboptimal and unrobust plans. Dose to reference-like medium (Dref,m* ) was recently introduced to overcome these limitations while ensuring accurate transport. This work evaluates and compares the performance of these four dose quantities in planning target volume (PTV)-based optimization. We considered three cases with heterogeneities inside the PTV: virtual phantom with water surrounded by bone; head and neck; and lung. These cases were planned with volumetric modulated arc therapy (VMAT) technique, optimizing with the same setup and objectives for each dose quantity. We used different algorithms of the Varian Eclipse treatment planning system (TPS): Acuros XB (AXB) for Dm,m and Dw,m , and Analytical Anisotropic Algorithm (AAA) for Dw,w . Dref,m* was obtained from Dm,m distributions using an in-house software considering water as the reference medium (Dw,m* ). The optimization process consisted of: (1) common first optimization, (2) dose distribution computed for each quantity, (3) re-optimization, and (4) final calculation for each dose quantity. The dose distribution, robustness to patient setup errors, and complexity of the plans were analyzed and compared. The quantities showed similar dose distributions after the optimization but differed in terms of plan robustness. The cases with soft tissue and high-density heterogeneities followed the same pattern. For AXB Dm,m , cold regions appeared in the heterogeneities after the first optimization. They were compensated in the second optimization through local fluence increases, but any positional mismatch impacted robustness, with clinical target volume (CTV) variations from the nominal scenario around +3% for bone and up to +7% for metal. For AXB Dw,m the pattern was inverse (hot regions compensated by fluence decreases) and more pronounced, with CTV dose variations around -7% for bone and up to -17% for metal. Neither AXB Dw,m* nor AAA Dw,w presented these dose inhomogeneities, which resulted in more robust plans. However, Dw,w differed markedly from the other quantities in the lung case because of its lower radiation transport accuracy. AXB Dm,m was the most complex of the four dose quantities and AXB Dw,m* the least complex, though we observed no major differences in this regard. The dose quantity used in MV photon optimization can affect plan robustness. Dw,w distributions from convolution/superposition algorithms are robust but may not provide sufficient radiation transport accuracy in some cases. Dm,m and Dw,m from advanced algorithms can compromise robustness because their different responses to some composition heterogeneities introduce additional fluence compensations. Dref,m* offers advantages in plan optimization and evaluation, producing accurate and robust plans without increasing complexity. Dref,m* can be easily implemented as a built-in feature of the TPS and can facilitate and simplify the treatment planning process when using advanced algorithms. Final reporting can be kept in Dm,m or Dw,m for clinical correlations.

Reflection on the proposed changes to dose quantities—an industrial perspective

In 2021, the ICRP initiated the revision of the general recommendations of the system of radiation protection, and part of it will focus on dose quantities. The recently published ICRP Publication 147 and ICRU Report 95 have described the extent of the proposed modifications and paved the way for the strategy to be adopted. These revisions would seek to simplify, improve the accuracy and extend the field of use of dose quantities. While the Radiological Protection Working Group of the World Nuclear Association recognises the notable improvement in the estimation of the protection quantities and the usefulness of such changes for the medical and research sector, the benefits of the proposed new system seem very limited for the nuclear industry and industries involving naturally occurring radioactive materials. The complexity associated with changing a long-standing and robust system and the risk incurred by the human factor seem unjustified, bearing in mind the likely cost.

Designing a Smart Drug Box

It is evident that punctuality in taking medicine can be an issue and failure to take appropriate medication as prescribed by the physician on the proper time may lead to health complications. Management of medication is very important for acute illness and long-term health conditions. Smart Drug Box (SDB) connected through a mobile application installed on the patient smartphone can be used to remind the patient as per the prescription by the physician. The construction of the SDB is divided into three phases. The first phase is the box design using Computer Aided-Design (CAD), the second phase is the software design, and the last phase is printing the box. The prototype of our SDB is designed with a miniaturized size and a user friendly-interface. The SDB prototype weighs 350 grams when empty without any medication. This SDB meets the needs of the market in terms of integrating electronic technology and network functionality and can be used by patients at their homes or by nursing facilities. Using the SDB will not only significantly reduce the chances of errors but also enhance and speed up the caretaker follow-up by letting the SDB to take care of medicine management. The proposed SDB is simple to use, affordable and, has high accuracy. The main purpose of this is to improve health care and patient’s overall health condition by giving scheduled reminders, therefore, ensuring patient adherence to the treatment plan in terms of dose time and quantity.

Impact of new operational dosimetric quantities on individual monitoring services

The new operational dosimetric quantities framework, proposed in the ICRU95 report, has stimulated the scientific community to start investigations that aim to assess its impact on radiation protection practices. As part of this effort, the present study describes an inter-comparison exercise among individual monitoring services (IMSs) on passive whole-body dosimetry. The inter-comparison is performed in terms of both the existing operational dose quantity and its proposed replacement , to allow an evaluation of the actions that may be necessary to adapt dosimetry systems to the proposed quantity. For two of the tested IMSs, simple modifications to the detector response function, or the dose calculation algorithm, were sufficient to obtain results within acceptable limits. However, these approaches are not sufficient to give a level of performance comparable to that achieved in terms of . This may require a modification to dosemeter design.

Topical Nasal Decongestant Oxymetazoline: Safety Considerations for Perioperative Pediatric Use.

The over-the-counter nasal decongestant oxymetazoline (eg, Afrin) is used in the pediatric population for a variety of conditions in the operating room setting. Given its vasoconstrictive properties, it can have cardiovascular adverse effects when systemically absorbed. There have been several reports of cardiac and respiratory complications related to use of oxymetazoline in the pediatric population. Current US Food and Drug Administration approval for oxymetazoline is for patients ≥6 years of age, but medical professionals may elect to use it short-term and off label for younger children in particular clinical scenarios in which the potential benefit may outweigh risks (eg, active bleeding, acute respiratory distress from nasal obstruction, acute complicated sinusitis, improved surgical visualization, nasal decongestion for scope examination, other conditions, etc). To date, there have not been adequate pediatric pharmacokinetic studies of oxymetazoline, so caution should be exercised with both the quantity of dosing and the technique of administration. In the urgent care setting, emergency department, or inpatient setting, to avoid excessive administration of the medication, medical professionals should use the spray bottle in an upright position with the child upright. In addition, in the operating room setting, both monitoring the quantity used and effective communication between the surgeon and anesthesia team are important. Further studies are needed to understand the systemic absorption and effects in children in both nonsurgical and surgical nasal use of oxymetazoline.

Dose quantities for measurement and comparison of doses to individual patients in computed tomography (CT)

The dose quantities displayed routinely on CT scanners, the volume averaged CT dose index (CTDIvol) and dose length product, provide measures of doses calculated for standard phantoms. The American Association of Medical Physics has published conversion factors for the adjustment of CTDIvol to take account of variations in patient size, the results being termed size-specific dose estimate (SSDE). However, CTDIvol and SSDE, while useful in comparing and optimising doses from a set procedure, do not provide risk-related information that takes account of the organs and tissues irradiated and associated cancer risks. A derivative of effective dose that takes account of differences in body and organ sizes and masses, referred to here as size-specific effective dose (SED), can provide such information. Data on organ doses from NCICT software that is based on Monte Carlo simulations of CT scans for 193 adult phantoms have been used to compute values of SED for CT examinations of the trunk and results compared with corresponding values of SSDE. Relationships within ±8% were observed between SED and SSDE for scans extending over similar regions for phantoms with a wide range of sizes. Coefficients have been derived from fits of the data to estimate SED values from SSDEs for different regions of the body for scans of standard lengths based on patient height. A method developed to take account of differences in scan length gave SED results within ±5% of values calculated using the NCI phantom library. This approach could potentially be used to estimate SED from SSDE values, allowing their display at the time a CT scan is performed.

STUDY THE HARMFUL EFFECTS OF DIETHYL PHTHALATE ON LIVER AND TESTES OF MALE MICE, (Mus musculus)

The current study was designed in order to evaluate the harmful effects of Diethyl Phthalate (DEP) on testes and liver of 8 weeks-old mouse Mus musculus, which were grouped as Control group and Experimental groups. Control group was given corn oil and experimental groups were given dose of DEP I 1.2 mg/g B.W and DEP II 1.60 mg/g B.W in super refined corn oil with the help of syringe for 21 days. Dose quantity was 0.1 ml. Glutathione Peroxidase 5(GPx5) and Malondialdehyde (MDA) hormones were used. Morphological examination was done on both experimental group and control group. Methods In Dose group, DEP I (1.2 mg/g B W) various deformities were observed i.e. wrinkled surface, shrinkage and reduced size of testes, while in dose group, DEP II (1.60 mg/g BW) showed abnormalities in their size, appearance , shape, their surface become wrinkled and shrinkage of cell also observed. In Morphometric analysis the control and experimental group showed significant results regarding length, width and weight. In control group there is no certain change in the weight, length and width of testes of male mice, whereas in dose group, DEP 1 (1.2 mg/g B.W) and DEP II (1.60 mg/g B.W) shows the significant effects on decreasing length, width and weight of testes in both groups. In the current experiment, the glutathione level has decreased after the intake of dose in male mice. Experimental group show decreased level of glutathione while control group show the normal level. In the recent experiment the level of Malondialdehyde (MDA) significantly increased after administration of certain doses. In control group, MDA level remains normal while in the experimental group, MDA level increases and the antioxidant enzyme of testicles, glutathione peroxidase (GPx) and a hormone testosterone significantly decreased. Liver histological examination in control group show normal deposition of glycogen, normal and intact association of sinusoid, portal vein, with complete lobular boundary, and appear

Intraoperative Fluoroscopic Radiation Exposure During Hip Fracture Fixation: A Study Combining Surgical Experience and Fracture Complexity.

AimHip fracture fixation surgeries are one of the most common surgeries that every trauma unit does regularly. Surgical training and expertise to fix these fractures properly are quite crucial for every orthopaedic surgeon. Therefore, orthopaedic training programmes all over the world consider significant focus on this and teach trainee surgeons expectantly to manage these fractures independently. Surgical fixation of hip fractures often requires fluoroscopy assistance in the operating theatre with associated hazards from ionising radiation. Moreover, hip fractures can be sometimes quite complex and may require relatively more fluoroscopy usage even with the higher grade of the operating surgeons. Therefore, training need for hip fracture fixation surgery is imperative and there is also a need for intraoperative radiation safety. This study has tried to find a balance between intraoperative fluoroscopic radiation exposure, surgical training requirement, and hip fracture complexity.MethodologyThis single centre study has collected retrospective peri-operative data over a period of two years including hip fractures that required fluoroscopy-guided surgical fixation. Femoral head fractures, subtrochanteric fractures, diaphyseal fractures, and trochanteric fractures with associated pelvic fractures were excluded from the study. We collected data on demographic parameters, fracture complexity and grading (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association [AO/OTA] Classification), intraoperative ionising radiation exposure (centi-Gray/cm2), and grade of the operating surgeon in order to find any relation between these factors.ResultsTotal 268 patients were included in the study with a mean age of 81.8 years (SD 9.3) comprising of 83 (31%) male patients and 185 (69%) female patients. The study population was further stratified into three groups depending upon the operating grade of the surgeon: ‘Junior Trainee’ (<five years of experience; 77 cases [29%]); ‘Senior Trainee’ (>five years of experience; 148 cases [55%]); and ‘Consultant’ (fully trained to practice independently; 43 cases [16%]). There was no statistically significant difference among these three sub-groups with regards to the age (p = 0.79), gender (p = 0.73), body mass index (p = 0.46), and fracture pattern (p = 0.96) of the patients. However, consultants tend to operate more on the higher American Society of Anesthesiologists (ASA) grade patients (p = 0.049) with more comorbidities. There was statistically significant higher fluoroscopic radiation exposure while junior trainee surgeons (p = 0.005) were operating and during the higher complex grade of hip fracture (p = <0.001) fixation.ConclusionIn conclusion, the quantity of intra-operative radiation dose utilised in the surgical fixation of hip fractures is significantly associated with the grade and level of training of the operating surgeon and fracture complexity type. The results of this study emphasise and support the importance of comprehensive, supervised, and structured orthopaedic training for in-theatre radiation safety. It is recommended to have a safe balance between teaching, learning, and prevention of ionising radiation hazards in order to optimally achieve trainee’s professional development with successful patient outcomes.

Referring physician perspective on how to handle frequent use of CT imaging

The increasing use of computed tomography (CT) and other relatively high radiation dose exams in a recurrent manner result in radiation risks to individual patients. Recent studies have provided alarming information not only to the radiological community but also to referring physicians. We, as referring physicians, are often implicated in the overuse of imaging. However, a recent paper rightfully summarized the situation that despite the best use of available clinical decision support system for prescribing an imaging exam at a major hospital in the USA, many patients were found to have high cumulative doses. Motivated by the cue provided by the paper in this very journal, we decided to come forward with a possible solution taking the example of the drug prescription system that we routinely use. We provide a template to translate prescription drug monitoring program to ionising radiation imaging. We suggest that all body CT exams should be monitored at an individual, prescriber, and institution level for frequency of use. Furthermore, there should be radiation risk stratification of an individual patient based on the cumulative radiation burden in recent years. Further, an individual’s radiation risk-stratified in different risk levels should be available for use by the referring/ordering clinicians at the point of care. Finally, we feel distanced by the use of multiple scary radiation dose quantities in different imaging modalities and would prefer as simple a metric as ‘milligram.’

The use of dose quantities in radiological protection: ICRP publication 147 Ann ICRP 50(1) 2021

The International Commission on Radiological Protection has recently published a report (ICRP Publication 147; Ann. ICRP 50, 2021) on the use of dose quantities in radiological protection, under the same authorship as this Memorandum. Here, we present a brief summary of the main elements of the report. ICRP Publication 147 consolidates and clarifies the explanations provided in the 2007 ICRP Recommendations (Publication 103) but reaches conclusions that go beyond those presented in Publication 103. Further guidance is provided on the scientific basis for the control of radiation risks using dose quantities in occupational, public and medical applications. It is emphasised that best estimates of risk to individuals will use organ/tissue absorbed doses, appropriate relative biological effectiveness factors and dose–risk models for specific health effects. However, bearing in mind uncertainties including those associated with risk projection to low doses or low dose rates, it is concluded that in the context of radiological protection, effective dose may be considered as an approximate indicator of possible risk of stochastic health effects following low-level exposure to ionising radiation. In this respect, it should also be recognised that lifetime cancer risks vary with age at exposure, sex and population group. The ICRP report also concludes that equivalent dose is not needed as a protection quantity. Dose limits for the avoidance of tissue reactions for the skin, hands and feet, and lens of the eye will be more appropriately set in terms of absorbed dose rather than equivalent dose.