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Biomedical subjects

K Faulkner

Publications and source records attributed to K Faulkner.

At least 19 recordsLinked to original sources
PubMed2006

A descriptive study of the decline in cervical screening coverage rates in the North East and Yorkshire and the Humber regions of the UK from 1995 to 2005.

Since the mid-1990s, there has been a steady decline in coverage rates for cervical screening in the target age group (25-64 years) across England. This article describes the rate of decline from 1995 to 2005 in the old health authority areas of the North East and the Yorkshire and the Humber (NEYH) regions in relation to age group, deprivation, ethnicity and religion. The results show that the rate of decline is faster in these northern regions than that in England as a whole, with a very strong correlation between age and rate of change of coverage rates. Younger age groups experience the fastest rate of decline, and those over 55 years show an increase in coverage rates. There is an association between the deprivation of the old health authority areas and the rate of change of coverage rates, with weaker evidence that areas with high proportions of Black or Mixed ethnicity may have a faster decline. However, the rate of decline is not associated with other ethnic groups or religions. Therefore, interventions could be targeted at younger women and those who live in deprived areas to prevent the widening of inequalities.

Adult↗
PubMed2006

Risk factors for induction of breast cancer by X-rays and their implications for breast screening.

In order to discuss the balance of benefit and radiation risk in a breast screening programme, it is necessary to have numerical values for the probability of breast cancer induction by X-rays, stratified by age. Various sets of such values have been used hitherto, mainly in relation to breast screening in the UK, both within the NHS Screening Programme and more generally for younger age groups. Further sets have recently been reported. These different sets of values are described and discussed, together with the effects of using additive or relative risk models, and the effect of using a dose and dose rate modifying factor (DDREF). Possible new radiation risk factors for breast cancer induction by X-rays, drawn from these sets, are identified. These are used to calculate fresh values of cancer detection/induction ratios, as an index of benefit/risk, for screening age women and for younger women with and without a family history of breast cancer.

Adult↗
PubMed2006

Relevant training issues for introduction of digital radiology: results of a survey.

Council Directive 97/43/Euratom establishes the need for adequate training of radiology staff. The transition to digital radiology implies changes in various imaging aspects, which are not sufficiently covered by current institutional training programmes. This work aimed to assess how professionals, experienced in digital imaging, acquired their expertise and hence, what form institutional training should take. Within DIMOND III, a survey on training and resources was performed among radiology professionals. A lack of institutional education for digital radiology was found. In the transition to digital radiology, 30-35% train on the job and another 23-28% receive training from digital equipment vendors. A general agreement exists on the need for new quality criteria and strategies for dose management. Issues relevant for conventional/digital transition are only sparsely covered in EC training programmes. Based on these results, a set of training issues was produced, to be included in future European guidelines.

Education, Medical, Continuing↗
PubMed2006

Mammographic screening: is the benefit worth the risk?

Justification of medical exposures is a fundamental principle of radiation protection. This principle applies to mammographic screening, both for the screened population and at an individual level. The benefit of mammographic screening may be considered to be the number of cancers detected or lives saved by breast screening. The risk is the hypothetical number of fatal cancers induced by the use of ionising radiation in screening mammography. Benefit can be deduced from the cancer detection rate in the NHS Breast Screening Programme. The number of additional lives saved by the intervention of a screening programme may be deduced from knowledge of the change in tumour size, stage and nodal status (and hence prognosis) in women with screening detected breast cancers compared with symptomatic women before screening. Calculations of benefit risk ratios to the UK population have been performed. It is concluded that breast screening is justified in radiation protection terms.

Breast Neoplasms↗
PubMed2006

The DIMOND project and its impact on radiation protection.

The DIMOND III project comprised work packages and subprojects to research digital imaging, interventional radiology and interventional cardiology, i.e. areas where there has been rapid technological change, not matched by radiation protection research. Whilst new practices have great potential benefit, there are risks to patients and staff if the technology is implemented inappropriately. DIMOND aimed to develop generic technology assessment and optimisation tools. Clinical quality criteria and technical parameters were included so that digital imaging procedures can be introduced appropriately. Frequency and dimensions of acceptance and constancy testing for digital imaging systems were studied, along with differences between objective measures of image quality and subjective indices. Patient dosimetry was performed to propose and to establish reference values. Clinical evaluation projects included cardiology, interventional radiology and digital mammography. As a result of the DIMOND project, quality criteria for several procedures were developed. Example results are presented in this paper.

Cardiology↗
PubMed2006

ICRP special radiation protection issues in interventional radiology, digital and cardiac imaging.

The International Commission on Radiological Protection (ICRP) has published two reports giving recommendations dealing with the avoidance of deterministic injuries in interventional radiology and the management of patient dose in digital radiology in 2001 and 2004, respectively. Another document, on radiation protection for cardiologists performing fluoroscopically guided procedures, will be produced during 2005. This paper highlights some of the topics of the published reports, their relevance to European legislation on medical exposures and the importance of radiation protection research in underpinning the ICRP task groups' work in to producing these documents. It is also anticipated that the results, obtained in the cardiology work package of the European research project, will be used in the new document on radiation protection for cardiologists.

Heart↗
PubMed2006

Personnel and patient doses: are there ethical consequences to the use of X-rays?

Interventional cardiology has witnessed a period of great technological change. The introduction of new dedicated cardiology X-ray equipment, as well as advances in catheter and stent design, has revolutionised clinical practice in cardiology. As a consequence, the number, range and complexity of procedures have increased. This has meant that patients can be treated as outpatients without requiring hospitalisation for surgery. The public are aware of these benefits and demand greater access. However, these changes have had an impact on patient and staff doses and these are reviewed. Simple approaches to dose reduction for patients and staff are illustrated. There are a number of ethical issues concerning both patients and staff. For patients, these are related to informed consent. For staff, the ethical issues are associated with dose control. These issues will be discussed.

Angioplasty, Balloon, Coronary↗
PubMed2006

Protocols for dosimetry and patient reference levels.

Doses in radiology should be as low as reasonably achievable. In order to compare practice in different centres it is necessary to compare patient doses. This can only be undertaken if dosimetry studies are similar. In order to facilitate comparisons, the DIMOND consortium developed a patient dosimetry protocol. Reference doses have been proposed to identify centres where optimisation studies would be of benefit. Whilst reference doses have been established for common radiographic and fluoroscopic examinations, little research has been undertaken in the area of digital radiology, partly owing to the rapid technological changes occurring in digital and interventional radiology. Dosimetry data obtained by the DIMOND research project were compared with data from published literature. Data for various digital and interventional radiology procedures were reviewed. Proposals are made for reference doses. There is obviously a need for standardised approaches to patient dosimetry, which should be recorded in the hospital's information system.

Angioplasty↗
PubMed2006

Image quality and dose management in digital radiography: a new paradigm for optimisation.

The advent of digital imaging in radiology, combined with the explosive growth of technology, has dramatically improved imaging techniques. This has led to the expansion of diagnostic capabilities, both in terms of the number of procedures and their scope. Throughout the world, film/screen radiography systems are being rapidly replaced with digital systems. Many progressive medical institutions have acquired, or are considering the purchase of computed radiography systems with storage phosphor plates or direct digital radiography systems with flat panel detectors. However, unknown to some users, these devices offer a new paradigm of opportunity and challenges. Images can be obtained at a lower dose owing to the higher detective quantum efficiency (DQE). These fundamental differences in comparison to conventional film/screens necessitate the development of new strategies for dose and quality optimizations. A set of referral criteria based upon three dose levels is proposed.

Humans↗
PubMed2006

On the use of DICOM cine header information for optimisation: results from the 2002 European DIMOND cardiology survey.

The paper explores the level of information contained within the DICOM header in images from various cardiology systems. Data were obtained in the European DIMOND survey on image quality (Italy, Ireland, Belgium, Greece and Spain). Images from five standard diagnostic cardiology procedures carried out in six European hospitals have been analysed. DICOM header information was extracted to a database in order to analyse how it could help in the optimisation of the procedures. The level of data contained in the headers differs widely between cardiology systems. None of the X-ray systems in the 2002 survey archives the dosimetric data in the DICOM header. The mean number of runs per procedure ranges between 7.5 and 15.4 and the mean number of frames per procedure between 575 and 1417. Differences in kVp, mA, pulse time, distances and C-arm angulations are substantial and suggest that there exists a wide range for optimisation.

Cardiology↗
PubMed2006

Patient dosimetry in diagnostic and interventional radiology: a practical approach using trigger levels.

Patient dosimetry is performed in radiology and interventional radiology to assess whether deterministic injuries may occur and to establish the risk of stochastic effects. A fundamental problem for patient dosimetry is that no single quantity can be used to accurately assess both the risk of stochastic effects and whether deterministic injuries will occur following a specific examination or procedure. In cardiology and interventional radiology, two different approaches to patient dosimetry are commonly used. Effective dose is a quantity which correlates reasonably well with the risk of stochastic effects. Effective dose may be deduced from the dose-area product (DAP) for the procedure if sufficient information is known. DAP does not correlate with maximum skin dose, which may be used to predict whether deterministic injuries may occur. DAP meter readings may be used as a trigger level for the investigation of maximum skin entrance dose. Trigger levels for different procedures are proposed.

Humans↗
PubMed2006

An assessment of digital stereotaxis in the National Health Service Breast Screening Programme.

A woman may be invited back for further assessment if an abnormality is found on her mammogram. A stereotactic attachment is used to determine where to place the biopsy device. Digital equipment has the advantage of providing images almost instantaneously and utilising software to determine the location of the sampling device. These devices should make the procedure quicker and hence less traumatic for the women. However, digital devices have poorer spatial and contrast resolution, which could adversely affect the accuracy of sampling device placement. Although the dose received during a normal screening mammogram is well known, the dose for the stereo procedure is unknown, partly because only a small part of the breast is directly irradiated. However, the lady may undergo multiple exposures. For a prospective survey of doses and technique arm of the study a proforma was completed for 134 women. The dose women received during a stereotactic procedure was estimated.

Aged↗
PubMed2006

Mammographic breast cancer screening for women previously treated with high breast doses for diseases such as Hodgkin's.

In screening of a general population for breast cancer, benefit/risk ratios are of the order of 100/1. For the very small subgroup of women treated by radiotherapy for Hodgkin's disease below age 35, calculations of this type require different considerations, an overview of which is given in this text. It is concluded that although such previous exposures will increase their radiation risk, their increased risk of carrying an undetected breast cancer means that the potential benefit for them of screening is increased even more. In the United Kingdom, the Department of Health has recommended annual screening for these women.

Adult↗
PubMed2006

Radiation benefit and risk at the assessment stage of the UK Breast Screening Programme.

The balance between benefit and radiation risk in a breast cancer screening programme has received much attention at the initial screening stage. This paper extends that attention to first stage assessment, i.e. the first stage at which women are recalled for further investigation because of suspected lesions or other suspect film features, and prior to any biopsy. Numbers of films, including magnification films, taken at this stage, have been established in two UK regions by different methods. Average total mean glandular dose has been calculated using published data of dose per film from initial screening and a multiplying factor to allow for magnification film dose. It is concluded that the benefit/risk ratio is considerably higher at first stage assessment than at initial screening by a factor of between 4 and 9, because of the very much higher cancer detection rate in this well-defined sub-group of women. Qualitatively, this conclusion is unaffected by the quite wide variation between screening centres in the numbers of films taken at first stage assessment.

Aged↗
PubMed2006

Influence of menopausal status and use of hormone replacement therapy on radiation dose from mammography in routine breast screening.

Menopausal status and hormone replacement therapy (HRT) cause alterations in breast structure which can affect mammographic image quality. Here we present the results of a study to discover the effect of menopausal status and HRT use on breast dose. Women attending routine screening completed questionnaires which included questions regarding menopausal status and HRT use. Details of the radiographic technique factors were recorded, from which the mean glandular dose (MGD) per film for each woman was calculated. MGD values were analysed with regard to the woman's menopausal status and HRT use. The data from 516 women were analysed. Among the women who had never used HRT, women who had not undergone the menopause had a mean MGD of 2.94 mGy per film, whereas post-menopausal women had a lower mean MGD of 2.52 mGy per film: a difference which was found to be highly significant (p = 0.0045). Post-menopausal women who had never used HRT and those who had previously used HRT, but had ceased using it, had identical mean MGDs (2.54 mGy per film), whereas current HRT users had a significantly greater mean MGD (2.89 mGy per film, p = 0.003). Women currently using HRT receive a statistically significantly larger radiation dose from routine breast screening than other women. However, this effect is small and only occurs during the period of HRT use. Women who have ceased using HRT show no difference in MGD compared with women who have never taken HRT.

Adult↗
PubMed2005

Ocular findings in patients with solid tumours treated with the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib ('Iressa', ZD1839) in Phase I and II clinical trials.

PURPOSE: To describe the strategy used for large-scale ophthalmological monitoring in the clinical development of the novel anticancer agent gefitinib ('Iressa', ZD1839), an epidermal growth factor receptor tyrosine kinase inhibitor, which had demonstrated ocular effects in preclinical animal models. METHODS: In this extensive clinical trial programme, patients in Phase I and II trials underwent frequent and intensive ophthalmological monitoring at baseline and during the trials. Data were reviewed by an external independent Ophthalmology Advisory Board. RESULTS: Ophthalmological data for 221 patients in Phase I trials of gefitinib and 425 patients in Phase II trials revealed no evidence of any consistent or drug-related ophthalmological toxicity. Interestingly, the baseline data revealed that, in an asymptomatic population, transient ophthalmological events are identified during monitoring. CONCLUSIONS: This study reports the methodology and normative data in an ophthalmological screening programme that should prove useful for future studies.

Adult↗
PubMed2003

Preliminary reference levels in interventional cardiology.

This article describes the European DIMOND approach to defining reference levels (RLs) for radiation doses delivered to patients during two types of invasive cardiology procedures, namely coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA). Representative centres of six European countries recorded patients' doses in terms of dose-area product (DAP), fluoroscopy time and number of radiographic exposures, using X-ray equipment that has been subject to constancy testing. In addition, a DAP trigger level for cardiac procedures which should alert the operator to possible skin injury, was set to 300 Gyxcm2. The estimation of maximum skin dose was recommended in the event that a DAP trigger level was likely to be exceeded. The proposed RLs for CA and PTCA were for DAP 45 Gyxcm2 and 75 Gyxcm2, for fluoroscopy time 7.5 min and 17 min and for number of frames 1250 and 1300, respectively. The proposed RLs should be considered as a first approach to help in the optimisation of these procedures. More studies are required to establish certain "tolerances" from the proposed levels taking into account the complexity of the procedure and the patient's size.

Angioplasty, Balloon, Coronary↗