RSS 1.0Medical Physics and Clinical Engineering
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Determining the risk of developing symptomatic COVID-19 infection after attending hospital for radiological examinations: Controlled cohort studyOBJECTIVE To determine whether brief attendance for outpatient radiological investigations is associated with increased risk of clinically significant coronavirus disease 2019 (covid-19) infection.DESIGN Observational cohort study with a historical control.SETTING 2 large UK University Hospitals located in Nottingham and Cardiff.PARTICIPANTS All 47,340 patients who attended an outpatient radiology appointment at Nottingham University Hospitals and University Hospital of Wales during the first wave of the pandemic in 2020, and 70,655 patients that comprised the control cohort who attended for outpatient radiology the same period in 2019.MAIN OUTCOME MEASURES The risk of developing clinically significant covid-19 infection within 28-days of attending a radiological examination. Covid-19 infection rates for the 2020 cohort were compared against a control group who attended in 2019.RESULTS 84 positive SARS-CoV-2 tests were temporally associated with 47,340 radiological examinations across two hospitals in 2020. This low infection rate was higher than the 2019 control cohort; OR 2.507 (1.766 – 3.559) and equates to an approximate 1 positive covid-19 infection per 1000 radiology investigations.CONCLUSIONS Our data suggests that attending hospitals for outpatient radiological investigations during the pandemic is associated with a very small absolute risk of acquiring clinically significant covid-19 infection. It is unlikely that this risk is directly attributable to radiology attendance, considering the reasons leading individuals to attend hospitals during the pandemic, the true attributable risk will likely be even lower.TRIAL REGISTRATION ClinicalTrials.gov NCT04544176Competing Interest StatementThe authors have declared no competing interest.Clinical TrialNCT04544176Funding StatementNo specific funding was provided for this study.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:This study was approved by the Health Research Authority (20/HRA/4783) and was not reviewed by a research ethics committee as the research was limited to using previously collected, non-identifiable information.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData sharing: A summary of the data may be provided by application to the corresponding author at nikos.evangelou{at}nottingham.ac.uk subject to the necessary ethical and regulatory approvals by the applicant, and subject to data availability.
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Limited value of radiomics compared to quantitative MRI measures for predicting 10-year disability in newly diagnosed multiple sclerosis: A real-world data exploratory study (P11-6.018)Objective: To compare the predictive value of radiomic features versus quantitative MRI for long-term disability in newly-diagnosed people with Multiple Sclerosis (MS). Background(s): MRI measures (lesions, linear-atrophy) correlate with MS severity, however their predictive value for long-term prognosis is limited. Machine learning (ML) classifiers perform well for cross-sectional disability prediction, but their value for longterm EDSS-prediction is unclear. Design/Methods: 158 MRI (sagittal T2-FLAIR and T1-weighted spin-echo sequences) and clinical data-sets of eighty-one patients with MS from the Nottingham MS Clinic 52 women;35.4(+/-10.3)y; diagnosis, five- and ten-years data] were used. We measured the T2-FLAIR-lesion( 3mm)number/volumes, and linear-atrophy (third-ventricular width, medullary width, corpus callosum index and inter-caudate diameter) using 3DSlicer4.13.0. 107 radiomics features were extracted from the T2-FLAIR images using Pyradiomics package. A Multilayer-Perceptron (MLP) model was trained on clinical data, with/without the radiomic features, to forecast the likelihood of EDSS score 6 at 10y. Due to the limited amount of data, a feature-ranking strategy was executed using Random Forest. With a fine-tuning on a small validation set, the number of features was reduced to <10 to reduce noise and prevent overfitting. esults: The MLP classifiers were tested on the whole dataset using 5-fold cross-validation approach. The accuracy for predicting 10y EDSS 6 before/after feature selection was 0.56/0.77 for the set of features including clinical/demographic and quantitative MRI data. Baseline(diagnosis) clinical/demographic features alone had a comparable accuracy (0.74). Adding radiomic features obtained from the clinical scans at diagnosis did not significantly improve accuracy (0.56/0.79). Adding 5y-followup data slightly improved accuracy (0.62/0.85). Conclusion(s): Within the limitation of the small sample-size, the use of radiomic features from first (diagnostic) MS clinical scan does not significantly improve the prediction of long-term disability accumulation compared to quantitative MRI. Mechanisms underlying disability progression in MS are complex, and predictive models should account for the relative weight of various factors beyond routine brain imaging.
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Hookworm treatment for relapsing multiple sclerosis: A randomized double-blinded placebo-controlled trialImportance: Studies suggest gut worms induce immune responses that can protect against multiple sclerosis (MS). To our knowledge, there are no controlled treatment trials with helminth in MS. Objective(s): To determine whether hookworm treatment has effects on magnetic resonance imaging (MRI) activity and T regulatory cells in relapsing MS. Design, Setting, and Participant(s): This 9-month double-blind, randomized, placebo-controlled trial was conducted between September 2012 and March 2016 in a modified intention-To-Treat population (the data were analyzed June 2018) at the University of Nottingham, Queen's Medical Centre, a single tertiary referral center. Patients aged 18 to 61 years with relapsing MS without disease-modifying treatment were recruited from the MS clinic. Seventy-Three patients were screened; of these, 71 were recruited (2 ineligible/declined). Intervention(s): Patients were randomized (1:1) to receive either 25 Necator americanus larvae transcutaneously or placebo. The MRI scans were performed monthly during months 3 to 9 and 3 months posttreatment. Main Outcomes and Measures: The primary end point was the cumulative number of new/enlarging T2/new enhancing T1 lesions at month 9. The secondary end point was the percentage of cluster of differentiation (CD) 4+CD25highCD127negT regulatory cells in peripheral blood. Result(s): Patients (mean SD] age, 45 9.5] years; 50 women 71%]) were randomized to receive hookworm (35 49.3%]) or placebo (36 50.7%]). Sixty-six patients (93.0%) completed the trial. The median cumulative numbers of new/enlarging/enhancing lesions were not significantly different between the groups by preplanned Mann-Whitney U tests, which lose power with tied data (high number of zeroactivity MRIs in the hookworm group, 18/35 51.4%] vs 10/36 27.8%] in the placebo group). The percentage of CD4+CD25highCD127negT cells increased at month 9 in the hookworm group (hookworm, 32 4.4%]; placebo, 34 3.9%]; P =.01). No patients withdrew because of adverse effects. There were no differences in adverse events between groups except more application-site skin discomfort in the hookworm group (82% vs 28%). There were 5 relapses (14.3%) in the hookworm group vs 11 (30.6%) receiving placebo. Conclusions and Relevance: Treatment with hookworm was safe and well tolerated. The primary outcome did not reach significance, likely because of a low level of disease activity. Hookworm infection increased T regulatory cells, suggesting an immunobiological effect of hookworm. It appears that a living organism can precipitate immunoregulatory changes that may affect MS disease activity. Trial Registration: ClinicalTrials.gov Identifier: NCT01470521.Copyright © 2020 American Medical Association. All rights reserved.
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Noncontrast computed tomography signs as predictors of hematoma expansion, clinical outcome, and response to tranexamic acid in acute intracerebral hemorrhageBackground and Purpose - Blend, black hole, island signs, and hypodensities are reported to predict hematoma expansion in acute intracerebral hemorrhage. We explored the value of these noncontrast computed tomography signs in predicting hematoma expansion and functional outcome in our cohort of intracerebral hemorrhage. Methods - The TICH-2 (Tranexamic acid for IntraCerebral Hemorrhage-2) was a prospective randomized controlled trial exploring the efficacy and safety of tranexamic acid in acute intracerebral hemorrhage. Baseline and 24-hour computed tomography scans of trial participants were analyzed. Hematoma expansion was defined as an increase in hematoma volume of >33% or >6 mL on 24-hour computed tomography. Poor functional outcome was defined as modified Rankin Scale of 4 to 6 at day 90. Multivariable logistic regression was performed to identify predictors of hematoma expansion and poor functional outcome. Results - Of 2325 patients recruited, 2077 (89.3%) had valid baseline and 24-hour scans. Five hundred seventy patients (27.4%) had hematoma expansion while 1259 patients (54.6%) had poor functional outcome. The prevalence of noncontrast computed tomography signs was blend sign, 366 (16.1%); black hole sign, 414 (18.2%); island sign, 200 (8.8%); and hypodensities, 701 (30.2%). Blend sign (adjusted odds ratio aOR] 1.53 95% CI, 1.16-2.03]; P=0.003), black hole (aOR, 2.03 1.34-3.08]; P=0.001), and hypodensities (aOR, 2.06 1.48-2.89]; P0.05). Conclusions - Blend sign, black hole sign, and hypodensities predict hematoma expansion while black hole sign, hypodensities, and island signs predict poor functional outcome. Noncontrast computed tomography signs did not predict a better response to tranexamic acid.Copyright © 2019 The Authors.
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COLOFIT: Development and internal-external validation of models using age, sex, faecal immunochemical and blood tests to optimise diagnosis of colorectal cancer in symptomatic patientsBackground: Colorectal cancer (CRC) is the third most common cancer in the United Kingdom and the second largest cause of cancer death. Aim(s): To develop and validate a model using available information at the time of faecal immunochemical testing (FIT) in primary care to improve selection of symptomatic patients for CRC investigations. Method(s): We included all adults (>= 18 years) referred to Nottingham University Hospitals NHS Trust between 2018 and 2022 with symptoms of suspected CRC who had a FIT. Predicted 1-year CRC diagnosis were calculated, and externally validated, using Cox proportional hazards modelling with selected multiple fractional polynomial transformations for age, faecal haemoglobin concentration (f-Hb) value, mean corpuscular volume (MCV), platelet count and sex. Result(s): At a CRC risk threshold of 0.6% (equivalent to f-Hb = 10 mug Hb/g (mug/g)) overall performance of the validated model across age strata using Harrell's C index was >= 0.91% (overall C-statistic 93%, 95% CI 92%-95%) with acceptable calibration. Using this model yields similar numbers of detected and missed cancers, but requires ~20% fewer investigations than a f-Hb >= 10 mug/g strategy. For approximately 100,000 people per year with symptoms of suspected CRC, we predict it might save > 4500 colonoscopies with no evidence that more cancers would be missed if we used our model compared to using FIT f-Hb >= 10 mug/g. Conclusion(s): Including age, sex, MCV, platelets and f-Hb in a survival analysis model to predict the risk of CRC yields greater diagnostic utility than a simple binary cut off f-Hb >= 10 mug/g.Copyright © 2025 The Author(s). Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.
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Systematic review: Mortality associated with raised faecal immunochemical test and positive faecal occult blood resultsBackground: Faecal haemoglobin (f-Hb) testing is used in colorectal cancer (CRC) screening and increasingly to guide the investigation in patients with symptoms suggestive of CRC. Studies have demonstrated increased mortality with raised f-Hb. Aim(s): To assess the association of raised f-Hb with all-cause, non-CRC (any cause excluding CRC) and cause-specific mortality. Method(s): We searched Medline and Embase on 9 February 2024 to identify papers reporting mortality after faecal immunochemical (FIT) or guaiac faecal occult blood tests (gFOBT). The primary outcome was all-cause mortality following a positive compared to a negative test. Result(s): The search identified 3155 papers. Ten met the inclusion criteria: three reported gFOBT and seven reported FIT results, as screening tests. These reported a total of 14,687,625 f-Hb results. Elevated f-Hb was associated with an increased risk of all-cause, non-CRC and cause-specific mortality including death from cardiovascular, digestive and respiratory diseases. Crude risk ratios for all-cause mortality with a positive versus negative test were derived from six papers (three reporting gFOBT, three FIT). An increased risk was demonstrated in five, with RRs ranging from 1.11 (95% CI: 1.06-1.16) to 2.95 (95% CI: 2.85-3.05). For non-CRC mortality risk, RRs ranged from 1.09 (95% CI: 1.04-1.15) to 2.79 (95% CI: 2.70-2.89). We did not perform meta-analysis due to a limited number of papers reporting suitable results for each type of f-Hb test. Conclusion(s): All-cause, non-CRC and cause-specific mortality appear higher in those with raised f-Hb. Population-based studies are warranted to elicit whether this association occurs in symptomatic patients.Copyright © 2024 The Author(s). Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.
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'Low' faecal immunochemical test (FIT) colorectal cancer: A 4-year comparison of the Nottingham '4F' protocol with FIT10 in symptomatic patientsAim: The aim of this work was to evaluate colorectal cancer (CRC) outcomes after 'low' (sub-threshold) faecal immunochemical test (FIT) results in symptomatic patients tested in primary care. Method(s): This work comprised a retrospective audit of 35 289 patients with FIT results who had consulted their general practitioner with lower gastrointestinal symptoms and had subsequent CRC diagnoses. The Rapid Colorectal Cancer Diagnosis pathway was introduced in November 2017 to allow incorporation of FIT into clinical practice. The local '4F' protocol combined FIT results with blood tests and digital rectal examination (DRE): FIT, full blood count, ferritin and finger DRE]. The outcome used was detection rates of CRC, missed CRC and time to diagnosis in local 4F protocols for patients with a subthreshold faecal haemoglobin (fHb) result compared with thresholds of 10 and 20 mug Hb/g faeces. Result(s): A single threshold of 10 mug Hb/g faeces identifies a population in whom the risk of CRC is 0.2%, but this would have missed 63 (10.5%) of 599 CRCs in this population. The Nottingham 4F protocol would have missed fewer CRCs 42 of 599 (7%)] despite using a threshold of 20 mug Hb/g faeces for patients with normal blood tests. Subthreshold FIT results in patients subsequently diagnosed with a palpable rectal tumour yielded the longest delays in diagnosis. Conclusion(s): A combination of FIT with blood results and DRE (the 4F protocol) reduced the risk of missed or delayed diagnosis. Further studies on the impact of such protocols on the diagnostic accuracy of FIT are expected. The value of adding blood tests to FIT may be restricted to specific parts of the fHb results spectrum.Copyright © 2024 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.
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Quantifying white matter lesions in multiple sclerosis: A multiple technique comparisonBackground: Measurement of total white matter (WM) lesion volume is important for the treatment and diagnosis of multiple sclerosis (MS). Manual delineation is time consuming and susceptible to operator dependent variability. Semi and fully automated methods have been developed and widely used in research, but direct comparisons are limited. Objective(s): To quantify variability across WM lesion volumes from two semi-automated software packages JIM 7.0 (Xinapse Systems, Northants, UK) and 3D Slicer, and one fully-automated FDA-cleared and CE-marked method QyScore Methods: Total lesion volume was calculated for 44 MS research patients (mean age=53 (range 36-65), 16M/28F, 16 Primary Progressive/28 Secondary Progressive) using JIM, 3D Slicer, and QyScore Comparisons were performed by calculating linear regression with the agreement between the different software packages assessed using the Bland-Altman method. Visual assessment of the results from a subset of the cases was conducted by experienced image analysts to identify sources of discrepancy with neuroradiologist review pending. Result(s): Mean (sd) lesion volumes were 11.38 (8.00), 18.39 (12.65), and 26.38 (18.06) ml for 3D Slicer, QyScore and JIM respectively. Correlation coefficients were calculated with greater similarity found between 3D Slicer and QyScore in determining relative lesion volume compared to JIM. Bland-Altman analysis indicated significant discrepancy between all three methods with a percentage bias of +38% (167% CI) between JIM and QyScore, -46% (78% CI) between 3D Slicer and QyScore, and +79% (155% CI) between JIM and 3D Slicer. The difference between regression and bias results highlights the challenges in delineating WM lesions across a typical pathological range. Visual assessment suggests this is largely driven by erroneous grey matter inclusion using JIM and under sampling of lesions with 3D Slicer. In the most discrepant cases QyScore produced the most representative WM segmentations. An additional consideration with semi-automated software is user dependency. Average user-input time (minutes) was 30 for both JIM and 3D Slicer. Conclusion(s): The method used for the quantification of WM lesions significantly impacts lesion volumes and ongoing work to better characterize this variability is key for precision and efficacy in MS clinical decision making. Metrics evaluated by QyScore are fast, accurate and reproducible.
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Quantitative BOLD (qBOLD) imaging of oxygen metabolism and blood oxygenation in the human body: A scoping reviewPurpose: There are many approaches to the quantitative BOLD (qBOLD) technique described in the literature, differing in pulse sequences, MRI parameters and data processing. Thus, in this review, we summarized the acquisition methods, approaches used for oxygenation quantification and clinical populations investigated. Method(s): Three databases were systematically searched (Medline, Embase, and Web of Science) for published research that used qBOLD methods for quantification of oxygen metabolism. Data extraction and synthesis were performed by one author and reviewed by a second author. Result(s): A total of 93 relevant papers were identified. Acquisition strategies were summarized, and oxygenation parameters were found to have been investigated in many pathologies such as steno-occlusive diseases, stroke, glioma, and multiple sclerosis disease. Conclusion(s): A summary of qBOLD approaches for oxygenation measurements and applications could help researchers to identify good practice and provide objective information to inform the development of future consensus recommendations.Copyright © 2024 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.
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Oxygen-enhanced MRI assessment of tumour hypoxia in head and neck cancer is feasible and well tolerated in the clinical settingBackground: Tumour hypoxia is a recognised cause of radiotherapy treatment resistance in head and neck squamous cell carcinoma (HNSCC). Current positron emission tomography-based hypoxia imaging techniques are not routinely available in many centres. We investigated if an alternative technique called oxygen-enhanced magnetic resonance imaging (OE-MRI) could be performed in HNSCC. Method(s): A volumetric OE-MRI protocol for dynamic T1 relaxation time mapping was implemented on 1.5-T clinical scanners. Participants were scanned breathing room air and during high-flow oxygen administration. Oxygen-induced changes in T1 times (DELTAT1) and R2* rates (DELTAR2*) were measured in malignant tissue and healthy organs. Unequal variance t-test was used. Patients were surveyed on their experience of the OE-MRI protocol. Result(s): Fifteen patients with HNSCC (median age 59 years, range 38 to 76) and 10 non-HNSCC subjects (median age 46.5 years, range 32 to 62) were scanned; the OE-MRI acquisition took less than 10 min and was well tolerated. Fifteen histologically confirmed primary tumours and 41 malignant nodal masses were identified. Median (range) of DELTAT1 times and hypoxic fraction estimates for primary tumours were -3.5% (-7.0 to -0.3%) and 30.7% (6.5 to 78.6%) respectively. Radiotherapy-responsive and radiotherapy-resistant primary tumours had mean estimated hypoxic fractions of 36.8% (95% confidence interval CI] 17.4 to 56.2%) and 59.0% (95% CI 44.6 to 73.3%), respectively (p = 0.111). Conclusion(s): We present a well-tolerated implementation of dynamic, volumetric OE-MRI of the head and neck region allowing discernment of differing oxygen responses within biopsy-confirmed HNSCC. Trial registration: ClinicalTrials.gov, NCT04724096. Registered on 26 January 2021. Relevance statement: MRI of tumour hypoxia in head and neck cancer using routine clinical equipment is feasible and well tolerated and allows estimates of tumour hypoxic fractions in less than ten minutes. Key points: * Oxygen-enhanced MRI (OE-MRI) can estimate tumour hypoxic fractions in ten-minute scanning. * OE-MRI may be incorporable into routine clinical tumour imaging. * OE-MRI has the potential to predict outcomes after radiotherapy treatment. Graphical Abstract: (Figure presented.)Copyright © The Author(s) 2024.
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T1 based oxygen-enhanced MRI in tumours; A scoping review of current researchOBJECTIVE: Oxygen-enhanced MRI (OE-MRI) or tissue oxygen-level dependent (TOLD) MRI is an imaging technique under investigation for its ability to quantify and map oxygen distributions within tumours. The aim of this study was to identify and characterise the research into OE-MRI for characterising hypoxia in solid tumours., METHODS: A scoping review of published literature was performed on the PubMed and Web of Science databases for articles published before 27 May 2022. Studies imaging solid tumours using proton-MRI to measure oxygen-induced T1/R1 relaxation time/rate changes were included. Grey literature was searched from conference abstracts and active clinical trials., RESULTS: 49 unique records met the inclusion criteria consisting of 34 journal articles and 15 conference abstracts. The majority of articles were pre-clinical studies (31 articles) with 15 human only studies. Pre-clinical studies in a range of tumour types demonstrated consistent correlation of OE-MRI with alternative hypoxia measurements. No clear consensus on optimal acquisition technique or analysis methodology was found. No prospective, adequately powered, multicentre clinical studies relating OE-MRI hypoxia markers to patient outcomes were identified., CONCLUSION: There is good pre-clinical evidence of the utility of OE-MRI in tumour hypoxia assessment; however, there are significant gaps in clinical research that need to be addressed to develop OE-MRI into a clinically applicable tumour hypoxia imaging technique., ADVANCES IN KNOWLEDGE: The evidence base of OE-MRI in tumour hypoxia assessment is presented along with a summary of the research gaps to be addressed to transform OE-MRI derived parameters into tumour hypoxia biomarkers.
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Synthesis of the European ALARA network 20th workshop 'ALARA for interventional radiology and nuclear medicine'The European as low as reasonably achievable(ALARA) network regularly organises workshops on topical issues in radiation protection (RP). The topic of the 20th workshop was: 'ALARA for interventional radiology (IR) and nuclear medicine (NM)'. The objective was to examine the challenges faced when applying the optimisation principle (ALARA) in IR and NM and to consider how ALARA could be better implemented for patient and staff exposures. This memorandum provides a synthesis of the workshop sessions, and recommendations coming from the working groups discussion. Parallels are drawn with the recommendations arising from the 13th EAN workshop on 'ALARA and the medical sector (2011)' to consider how the optimisation challenges in IR and NM have evolved over the past decade. Current levels of exposure are presented along with operational practice and the challenges and opportunities for improvement, both in monitoring and practice. Whilst RP challenges remain, the application of ALARA appears more established in IR compared with experiences reported in 2011. The application of ALARA to emerging technologies in the NM setting is in need of further development to ensure that RP is considered at all stages in the development process of new radiopharmaceuticals. Besides the obvious technical and operational aspects, the importance of education and training, human factors and broadly the RP 'culture' were deemed fundamental to the success of the application of ALARA and where further emphasis is needed. All concerned parties, medical physics experts (MPEs), radiation protection experts, clinical staff, manufacturers and regulators have a role to play in the application of ALARA and this is discussed in the memorandum. Many of the recommendations from the 13th EAN workshop remain applicable today and overlap with the recommendations arising from the 20th workshop. This should prompt attention given that the use of IR and the development of novel radiopharmaceuticals for NM is only anticipated to increase with time.Copyright © 2024 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.
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Assessing empirical thresholds for investigation in people referred on a symptomatic colorectal cancer pathway: A cohort study utilising faecal immunochemical and blood tests in EnglandObjective To quantify risk of colorectal cancer (CRC) at empirical FIT cut offs, across age, haemoglobin and platelet strata in current diagnostic pathways. Design Cohort study of all people who were referred on a symptomatic CRC diagnosis pathway from primary care with a FIT test in Nottingham, UK between November 2017 and 2021 with 1-year follow-up for cancer and death. Heat maps showed the cumulative 1-year CRC risk using Kaplan-Meier estimates. We estimated the number of investigations that could potentially be re-purposed if a threshold of >=3% 1-year risk of CRC was instigated. Results During the study period 514 (1.5%) colorectal cancers were diagnosed following 33694 index FIT tests with available blood tests. Individuals with a FIT >=10 microg Hb/g faeces had a greater than 3% risk of CRC, except patients under the age of 40 years (CRC risk 1.45% (95% CI 0.03-2.86%)). Non-anaemic patients with a FIT =3% CRC threshold in patients < 55 years calculated using FIT, age and anaemia would allow 160-220 colonoscopies per 10000 FIT tests to be used for other pathways, at the cost of missing 1-2 CRCs. Conclusions CRC risk varies by FIT, age and anaemia status when fHb levels are below 100 microg Hb/g faeces. Tailored cut offs for investigation on a CRC pathway could reduce the number of investigations needed at a 3% CRC risk threshold.Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.
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National UK survey of radiation doses during endovascular aortic interventionsPurpose: Endovascular aortic repair (EAR) interventions, endovascular abdominal aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR), are associated with significant radiation exposures. We aimed to investigate the radiation doses from real-world practice and propose diagnostic reference level (DRL) for the UK. Material(s) and Method(s): Radiation data and essential demographics were retrospectively collected from 24 vascular and interventional radiology centres in the UK for all patients undergoing EAR-standard EVAR or complex, branched/fenestrated (BEVAR/FEVAR), and TEVAR-between 2018 and 2021. The data set was further categorised according to X-ray unit type, either fixed or mobile. The proposed national DRL is the 75th percentile of the collective medians for procedure KAP (kerma area product), cumulative air kerma (CAK), fluoroscopy KAP and CAK. Result(s): Data from 3712 endovascular aortic procedures were collected, including 2062 cases were standard EVAR, 906 cases of BEVAR/FEVAR and 509 cases of TEVAR. The majority of endovascular procedures (3477/3712) were performed on fixed X-ray units. The proposed DRL for KAP was 162 Gy cm2, 175 Gy cm2 and 266 Gy cm2 for standard EVAR, TEVAR and BEVAR/FEVAR, respectively. Conclusion(s): The development of DRLs is pertinent to EAR procedures as the first step to optimise the radiation risks to patients and staff while maintaining the highest patient care and paving the way for steps to reduce radiation exposures.Copyright © 2023, The Author(s).
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A comparison of two peak skin dose metrics calculated by patient dose management systems: Implications for clinical managementObjective: The patient dose monitoring systems DoseWatch and DoseWise were compared to evaluate their reported patient Peak Skin Dose. Method(s): 20 patients with the highest Peak Skin Dose on DoseWise were obtained; the values were converted to a Reference Point Air Kerma (RPAK) value and used for comparison. These patients were accessed in DoseWatch to obtain the recorded Worst Case RPAK. The co-ordinates for the position were obtained for each patient to find a primary and secondary angular position for the peak skin dose. The two positions produced by the two softwares were compared. Result(s): There is a mean deviation of over 0.5 Gy between the two software packages when comparing the calculated maximum skin air kerma Peak skin dose from DoseWise and the Worst Case RPAK from DoseWatch. Conclusion(s): We have shown mean deviations between these two systems. This difference is enough, for higher peak skin absorbed dose patients, to change the management of patients, so local services must understand their models to properly implement patient management. Advances in knowledge: Neither system is incorrect, but these differences show that a deeper understanding of the analysis limitations is required to properly inform post-procedural high-skin dose follow-up procedures.Copyright © 2021 The Authors. Published by the British Institute of Radiology
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Expression of Cathepsin D in early-stage breast cancer and its prognostic and predictive valuePurpose: Cathepsin D is a proteolytic enzyme that is normally localized in the lysosomes and is involved in the malignant progression of breast cancer. There are conflicting results regarding Cathepsin D significance as prognostic and predictor marker in breast cancer. This study aimed to evaluate the expression and prognostic significance of Cathepsin D in early-stage breast cancer. Method(s): Expression of Cathepsin D was assessed by immunohistochemical staining of tissue microarrays, in a large well-characterized series of early-stage operable breast cancer (n = 954) from Nottingham Primary Breast Carcinoma Series between the period of 1988 and 1998 who underwent primary surgery. Correlation of Cathepsin D expression with clinicopathological parameters and prognosis was evaluated. Result(s): Cathepsin D expression was positive in 71.2% (679/954) of breast cancer tumours. Positive expression of Cathepsin D was significantly associated with high histological grade (p = 0.007), pleomorphism (p = 0.002), poor Nottingham Prognostic Index (NPI) score (p < 0.002), recurrence (p = 0.005) and distant metastasis (p < 0.0001). Kaplan-Meier analysis showed that Cathepsin D expression was significantly associated with shorter breast cancer-specific survival (p = 0.001), higher risk of recurrence (p = 0.001) and distant metastasis (p < 0.0001). ER-positive tumours expressing Cathepsin D and treated with tamoxifen demonstrated a significantly higher risk of distant metastasis. Conclusion(s): Cathepsin D expression significantly predicts poor prognosis in breast cancer and is associated with variables of poor prognosis and shorter outcome. The strong association of Cathepsin D with aggressive tumour characteristics and poor outcomes warrants further research of its potential as a therapeutic target The results also suggest a possible interaction between Cathepsin D and tamoxifen therapy in ER-positive breast cancer which needs further investigation to elucidate the underlying mechanisms.Copyright © The Author(s) 2024.
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The use of cerebral computed tomographic angiography as an ancillary investigation to support a clinical diagnosis of death using neurological criteria: A consensus guidelineThis multidisciplinary consensus statement was produced following a recommendation by the Faculty of Intensive Care Medicine to develop a UK guideline for ancillary investigation, when one is required, to support the diagnosis of death using neurological criteria. A multidisciplinary panel reviewed the literature and UK practice in the diagnosis of death using neurological criteria and recommended cerebral CT angiography as the ancillary investigation of choice when death cannot be confirmed by clinical criteria alone. Cerebral CT angiography has been shown to have 100% specificity in supporting a diagnosis of death using neurological criteria and is an investigation available in all acute hospitals in the UK. A standardised technique for performing the investigation is described alongside a reporting template. The panel were unable to make recommendations for ancillary testing in children or patients receiving extracorporeal membrane oxygenation. Copyright © 2023 Association of Anaesthetists.
