Laurence B Lovat

Laurence B Lovat
University College London | UCL · Research Department of Tissue and Energy

BSc MBBS PhD FRCP

About

414
Publications
29,524
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8,823
Citations
Citations since 2017
170 Research Items
4990 Citations
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Introduction
Interest in GI cancer prevention using artificial intelligence to detect pre-cancerous lesions at endoscopy; big data to analyse endoscopic imaging trends and epigenetic analysis to detect cancer biomarkers in saliva. Also working on COVID: UK chief investigator for the CROWN CORONATION trial to prevent COVID in healthcare workers and the CONFESS study to explore the impact of face masks on transmission of droplets.

Publications

Publications (414)
Article
Full-text available
Colonoscopy remains the gold standard investigation for colorectal cancer screening as it offers the opportunity to both detect and resect pre-cancerous polyps. Computer-aided polyp characterisation can determine which polyps need polypectomy and recent deep learning-based approaches have shown promising results as clinical decision support tools....
Article
Full-text available
Oesophageal adenocarcinoma (OAC) provides an ideal case study to characterize large-scale rearrangements. Using whole genome short-read sequencing of 383 cases, for which 214 had matched whole transcriptomes, we observed structural variations (SV) with a predominance of deletions, tandem duplications and inter-chromosome junctions that could be ide...
Article
Full-text available
Colonoscopy is the gold standard for early diagnosis and pre-emptive treatment of colorectal cancer by detecting and removing colonic polyps. Deep learning approaches to polyp detection have shown potential for enhancing polyp detection rates. However, the majority of these systems are developed and evaluated on static images from colonoscopies, wh...
Conference Paper
Introduction Machine learning methods have been used to develop predictive models in gastroenterology.¹ Previously we identified features including age, history of psychological disorders and severity of dysphagia symptoms which were correlated with upper gastrointestinal (UGI) cancers.² We sought to create a machine learning based model which coul...
Conference Paper
Introduction Gastroesophageal reflux disease (GORD) is becoming increasingly prevalent in the western world. Lifestyle modification and medical therapy remain first line interventions, although anti-reflux surgery remains a choice in select individuals. Advances in endoscopic anti-reflux procedures have shown promise as an additional treatment opti...
Conference Paper
Introduction Previously our group had identified 20 features which were associated with the development of upper gastrointestinal (UGI) cancers using a machine learning approach.[1] We sought to refine this model and to validate this in an independent dataset to assess its generalisability in an interim analysis. Methods We selected patients who w...
Conference Paper
Introduction Gastrointestinal bleeding (GIB) secondary to pancreaticobiliary (PB) pathologies can carry significant morbidity and present difficult management decisions due to limited endoscopic access. Hemospray is a topical hemostatic powder used endoscopically for the management of upper GIB, and may be an option for these patients.Here we evalu...
Conference Paper
Introduction At the onset of the COVID-19 pandemic, based on BSG guidelines, all patients undergoing endoscopic surveillance for Barrett’s Oesophagus (BE) were indefinitely postponed. As well as the potential for missed progression to dysplasia, the negative impact on patients’ quality of life is immeasurable.The Cytosponge® is a minimally invasive...
Conference Paper
Introduction Endoscopic suturing offers a novel technique for deploying full thickness sutures in the gastrointestinal (GI) tract. Indications range from defect closure, stent fixation and tissue plication for obesity. Here we report our experience of endoscopic suturing in the upper gastrointestinal tract using the Apollo OverStitchTM device (Apol...
Conference Paper
Introduction We aimed to develop a computer aided detection system that can support the diagnosis of BE dysplasia on magnification endoscopy. Methods Videos were collected in high-definition magnification white light and virtual chromoendoscopy with i-scan (Pentax Hoya, Japan) imaging in patients with dysplastic/non-dysplastic BE (NDBE) from 4 cen...
Conference Paper
Introduction Invasive oesophageal adenocarcinoma arising in Barrett’s oesophagus (BE) can occur in up to 25% of patients one year after index endoscopic examination. Computer assisted diagnosis may reduce the incidence of overlooked early neoplasia in BE patients. Our group has previously trained a convolutional neural network (CNN) that achieves d...
Article
Full-text available
Oesophageal adenocarcinoma (OAC) provides an ideal case study to characterize large-scale rearrangements. Using whole genome short-read sequencing of 383 cases, for which 214 had matched whole transcriptomes, we observed structural variations (SV) with a predominance of deletions, tandem duplications and inter-chromosome junctions that could be ide...
Article
Full-text available
The use of artificial intelligence (AI) in clinical support systems is increasing. In this article, we focus on AI support for continuous interaction scenarios. A thorough understanding of end-user behaviour during these continuous human-AI interactions, in which user input is sustained over time and during which AI suggestions can appear at any ti...
Article
Full-text available
Background Radio-frequency ablation (RFA) for Barrett’s oesophagus (BE)-related neoplasia is currently used after endoscopic resection of visible neoplasia. The HALO 360 balloon has been used to ablate long segment BE. The Barrx™ 360 Express RFA self-sizing catheter (‘RFA Express’) may potentially allow quicker ablation times and improved treatment...
Conference Paper
Full-text available
Introduction The SPIT study (ISRCTN11921553) aims to investigate the methylation changes in saliva that result from Crohn’s disease with the ultimate aim of developing a diagnostic biomarker. Aims and Methods We selected 192 volunteers, 96 with Crohn’s Disease and 96 controls. These were drawn from participants in the SPIT study and were carefully...
Conference Paper
Full-text available
Introduction The SPIT study aims to investigate the methylation changes in saliva that result from oesophagael cancer with the ultimate aim of developing a diagnostic biomarker. Methods We recruited volunteers with adenocarcinoma, intramucosal carcinoma, Barrett’s Oesophagus and High-Grade Dysplasia. We also recruited two distinct classes of contr...
Conference Paper
Introduction Endoscopic surveillance for Barrett’s Oesophagus (BE) has been indefinitely postponed due to the COVID-19 pandemic (Rees Clin Med 2020). As well as the potential for missed progression to dysplasia, the negative impact on patients’ quality of life is immeasurable.The Cytosponge® is a minimally invasive cell sampling device which to dat...
Conference Paper
Introduction There have been significant advances in magnification endoscopic imaging of Barrett’s oesophagus (BE). Magnification endoscopy of mucosal and vascular patterns arising in BE can help predict non-dysplastic from dysplastic mucosa. This can inform sampling and guide endoscopic eradication therapy. We aimed to develop a computer aided det...
Conference Paper
Introduction Waiting times for endoscopy are rising rapidly following the COVID-19 pandemic. In addition, cancers may be missed as patients are placed on routine waiting lists but not monitored. Some hospitals use the Edinburgh Dysphagia Score to assess and prioritise patients for investigation. This offers a sensitivity of 98.4% and specificity of...
Conference Paper
Full-text available
Introduction Dual endoscopic therapy has been considered the standard of care for endoscopic management of GI bleeding. We aimed to look at the outcomes of Hemospray as a monotherapy treatment for GI bleeds. Methods Data was collected on patients with GI bleeds treated with Hemospray monotherapy in 18 centres. Haemostasis was defined as cessation...
Article
Full-text available
In colorectal surgery an anastomosis performed using poorly-perfused, ischaemic bowel segments may result in a leak and consequent morbidity. Traditional measures of perfusion assessment rely on clinical judgement and are mainly subjective, based on tissue appearance, leading to variability between clinicians. This paper describes a multispectral i...
Preprint
Full-text available
Background: COVID-19 has restricted singing in communal worship. We sought to understand variations in droplet transmission and the impact of wearing face masks. Methods: Using rapid laser planar imaging, we measured droplets while participants exhaled, said "hello" or "snake", sang a note or "Happy Birthday", with and without surgical face masks....
Article
Saliva and buccal samples are popular for epigenome wide association studies (EWAS) due to their ease of collection compared and their ability to sample a different cell lineage compared to blood. As these samples contain a mix of white blood cells and buccal epithelial cells that can vary within a population, this cellular heterogeneity may confou...
Preprint
Background & Aims: Barrett esophagus (BE) is a risk factor for the development of esophageal adenocarcinoma, however our understanding of how Barrett esophagus evolves is still poorly understood. We demonstrate that dynamic clonal phenotypic changes occur at the gland level, the mechanism by which these changes evolve, and how diversity may play a...
Article
Oesophageal cancer is the sixth commonest cause of overall cancer mortality. Clinical staging utilizes multiple imaging modalities to guide treatment and prognostication. T2N0 oesophageal cancer is a treatment threshold for neoadjuvant therapy. Data on accuracy of current clinical staging tests for this disease subgroup are conflicting. We performe...
Preprint
Purpose. Early squamous cell neoplasia (ESCN) in the oesophagus is a highly treatable condition. Lesions confined to the mucosal layer can be curatively treated endoscopically. We build a computer-assisted detection (CADe) system that can classify still images or video frames as normal or abnormal with high diagnostic accuracy. Methods. We present...
Article
Background and Aims Intrapapillary capillary loops (IPCLs) are microvascular structures that correlate with invasion depth of early squamous cell neoplasia (ESCN) and allow accurate prediction of histology. Artificial intelligence may improve human recognition of IPCL patterns and prediction of histology to allow prompt access to endoscopic therapy...
Article
Background & Aims A non-endoscopic approach to Barrett’s esophagus (BE) surveillance after radiofrequency ablation (RFA) would offer a less invasive method for monitoring. We assessed the test characteristics and cost-effectiveness of the Cytosponge® in post-RFA patients. Methods We performed a multicenter study of dysplastic BE patients after at...
Conference Paper
Full-text available
Introduction Missed oesophageal adenocarcinoma occurs within one year of index endoscopy in a quarter of patients undergoing surveillance for Barrett’s oesophagus (BE). Increased efforts are necessary to improve early neoplasia detection in BE so that early curative endotherapy can be offered. The aim of this study was to develop a deep Neural netw...
Conference Paper
Background and Aims Oesophageal cancer is the 7th most common cause of cancer worldwide and is the 6th most common cause of overall cancer mortality. Clinical staging utilises multiple imaging modalities and is the most appropriate guide for treatment and prognostication. T2N0 oesophageal cancer is a treatment threshold for neo-adjuvant therapy, bu...
Conference Paper
Full-text available
Introduction Recent advances in artificial intelligence (AI) have resulted in new AI applications for endoscopy. The aim of this study is to provide insight into the opinions of key leaders in Gastroenterology in the UK of these technologies. Methods An anonymous quantitative questionnaire was administered to 22 UK Gastroenterology consultants at...
Conference Paper
Introduction Endoscopic ablation therapy is recommended in patients with flat dysplastic Barrett’s oesophagus (BE). A proportion will be refractory to treatment. This is associated with neoplasia recurrence. The EndoRotor® device (Interscope Medical Inc, Whitinsville, MA, USA) is a non-thermal resection device. The aim was to compare the safety and...
Conference Paper
Full-text available
Introduction Endoscopic resection (ER) and radiofrequency ablation (RFA) have become the standard of care worldwide for treatment of early Barrett’s neoplasia. Procedural outcomes are highly dependent on the operator skill and training. Validated tools for assessment of competency in these 2 procedures are currently lacking. We aimed to develop and...
Conference Paper
Full-text available
Introduction Upper gastrointestinal bleeding (UGIB) is a leading cause of morbidity. The aim was to look at outcomes in patients with non-variceal UGIBs of all causes treated with Hemospray. Methods Data was collected prospectively (Jan’ 16- Nov’19) from 16 centres in the USA, UK, Germany, France and Spain. Hemospray was used during endoscopy as a...
Conference Paper
Full-text available
Introduction Lower Gastrointestinal bleeding (LGIB) accounts for 20% of GI bleeds, with significant mortality in the elderly and those with comorbidities. There is limited data on the use of Hemospray in LGIB’s. The primary aim was to look at its safety and efficacy in the treatment of LGIB’s. Methods Data was prospectively collected on the use of...
Conference Paper
Introduction Artificial intelligence may augment human recognition of early squamous cell neoplasia (ESCN) using intrapapillary capillary loop (IPCL) patterns, a validated endoscopic marker. We have developed a convolutional neural network (CNN), using the largest reported image dataset for this purpose, capable of classifying endoscopically imaged...
Conference Paper
Background Radiofrequency ablation (RFA) and endoscopic mucosal resection (EMR) are first line therapy for patients with dysplastic Barrett’s oesophagus (BE) or intramucosal carcinoma (IMC) to prevent oesophageal adenocarcinoma (OAC). We analysed patient outcome using 10 year data from the UK RFA registry. Methods Prospective data was collected fr...
Conference Paper
Introduction Oesophageal cancer is the 7th commonest cause of cancer death worldwide. Radiological staging of local oesophageal cancer is inaccurate. CT currently relies on attenuation of x-rays to generate contrast. Soft tissues have very similar attenuation properties so minimal contrast is generated.X-ray phase contrast imaging (XPCI) uses refra...
Conference Paper
Full-text available
Introduction BSG guidelines recommend endoscopic surveillance for patients with Barrett’s oesophagus (BE), due to the 0.5% annual risk of developing oesophageal adenocarcinoma.¹ Approximately 10% of GP 2-week wait (2WW) referrals result in a cancer diagnosis, and patients on a 2WW pathway should be told of a theoretical risk of cancer.² We therefor...
Article
Full-text available
Colonoscopy, the visual inspection of the large bowel using an endoscope, offers protection against colorectal cancer by allowing for the detection and removal of pre-cancerous polyps. The literature on polyp detection shows widely varying miss rates among clinicians, with averages ranging around 22%--27%. While recent work has considered the use o...
Article
Full-text available
Background Artificial intelligence (AI) research in colonoscopy is progressing rapidly but widespread clinical implementation is not yet a reality. We aimed to identify the top implementation research priorities. Methods An established modified Delphi approach for research priority setting was used. Fifteen international experts, including endoscop...
Preprint
Endoscopic examinations are used to inspect the throat, stomach and bowel for polyps which could develop into cancer. Machine learning systems can be trained to process colonoscopy images and detect polyps. However, these systems tend to perform poorly on objects which appear visually small in the images. It is shown here that combining the single-...
Article
Full-text available
INTRODUCTION: Esophagogastric junction outflow obstruction (EGJOO) defined on high-resolution esophageal manometry (HRM) poses a management dilemma given marked variability in clinical manifestations. We hypothesized that findings from provocative testing (rapid drink challenge and solid swallows) could determine the clinical relevance of EGJOO. ME...
Poster
Full-text available
Colonoscopy is the best tool for to screen for colorectal cancer. Adenoma detection rate (ADR) is the main quality control indicator for colonoscopy. An improvement in ADR translates into a reduction in the number of index and interval colorectal cancers. Computer-aided polyp detection (CAD) can improve ADR but the impact of real-time CAD on colono...
Article
Full-text available
The past decade has seen significant advances in endoscopic imaging and optical enhancements to aid early diagnosis. There is still a treatment gap due to the underdiagnosis of lesions of the oesophagus. Computer aided diagnosis may play an important role in the coming years in providing an adjunct to endoscopists in the early detection and diagnos...
Article
Colonoscopy is the gold standard for early diagnosis and pre-emptive treatment of colorectal cancer by detecting and removing colonic polyps. Deep learning approaches to polyp detection have shown potential for enhancing polyp detection rates. However, the majority of these systems are developed and evaluated on static images from colonoscopies, wh...
Conference Paper
Full-text available
Colonoscopy is the gold standard for early diagnosis and pre-emptive treatment of colorectal cancer by detecting and removing colonic polyps. Deep learning approaches to polyp detection have shown potential for enhancing polyp detection rates. However, the majority of these systems are developed and evaluated on static images from colonoscopies, wh...
Article
Colonoscopy is the gold standard for early diagnosis and pre-emptive treatment of colorectal cancer by detecting and removing colonic polyps. Deep learning approaches to polyp detection have shown potential for enhancing polyp detection rates. However, the majority of these systems are developed and evaluated on static images from colonoscopies, wh...
Conference Paper
Falls are one of the leading causes of unintentional injury related deaths in older adults. Although, falls among elderly is a well documented phenomena; falls of care homes’ residents was under-researched, mainly due to the lack of documented data. In this study, we use data from over 1,769 care homes and 68,200 residents across the UK, which is b...
Article
Introduction: COVID-19 has had a profound effect on the NHS. Little information has been published as to how the unselected medical take has been affected. Methods: We retrospectively reviewed patients who were referred to general medicine during March 2020. We compared clinical outcomes of patients with and without COVID-19. Results: 814 pati...
Chapter
Falls are one of the leading causes of unintentional injury related deaths in older adults. Although, falls among elderly is a well documented phenomena; falls of care homes’ residents was under-researched, mainly due to the lack of documented data. In this study, we use data from over 1,769 care homes and 68,200 residents across the UK, which is b...
Article
Full-text available
Background and study aims Cryoablation with the Cryoballoon device is a novel ablative therapy that uses cycles of freezing and thawing to induce cell death. This single-center prospective study evaluated the feasibility of the focal cryoablation device for the treatment of areas of refractory esophageal neoplasia in patients who had undergone firs...
Article
Background Prognostication in oesophageal cancer on the basis of preoperative variables is challenging. Many of the accepted predictors of survival are only derived after surgical treatment and may be influenced by neoadjuvant therapy. This study aims to explore the relationship between pre-treatment endoscopic tumour morphology and postoperative s...
Article
Full-text available
PURPOSE: Upper gastrointestinal (GI) endoscopic image documentation has provided an efficient, low-cost solution to address quality control for endoscopic reporting. The problem is, however, challenging for computer-assisted techniques, because different sites have similar appearances. Additionally, across different patients, site appearance variat...
Article
Full-text available
Introduction: With increasing advances in minimally invasive endoscopic therapies and endoscopic resection techniques for luminal disease, there is an increased risk of post-procedure bleeding. This can contribute to significant burden on patient's quality of life and health resources when reintervention is required. Hemospray (Cook Medical, North...
Article
Full-text available
Background Upper gastrointestinal bleeding (UGIB) is a leading cause of morbidity and is associated with a 2 % – 17 % mortality rate in the UK and USA. Bleeding peptic ulcers account for 50 % of UGIB cases. Endoscopic intervention in a timely manner can improve outcomes. Hemostatic spray is an endoscopic hemostatic powder for GI bleeding. This mult...
Article
Full-text available
OBJECTIVE: This economic evaluation aims to provide a preliminary assessment of the cost-effectiveness of radiofrequency ablation (RFA) compared with argon plasma coagulation (APC), when used to treat APC-refractory gastric antral vascular ectasia (GAVE) in symptomatic patients. METHODS: A Markov model was constructed to undertake a cost-utility an...
Article
Full-text available
PurposeEarly squamous cell neoplasia (ESCN) in the oesophagus is a highly treatable condition. Lesions confined to the mucosal layer can be curatively treated endoscopically. We build a computer-assisted detection system that can classify still images or video frames as normal or abnormal with high diagnostic accuracy.Methods We present a new bench...
Article
Full-text available
Saliva represents an ideal matrix for diagnostic biomarker development as it is readily available and requires no invasive collection procedures. However, salivary RNA is labile and rapidly degrades. Previous attempts to isolate RNA from saliva have yielded poor quality and low concentrations. Here we compare collection and processing methods and p...
Article
Background and aims: Endoscopic resections (ER) and radiofrequency ablation (RFA) are the established treatments for Barrett's-associated dysplasia and early esophageal neoplasia. The UK RFA Registry collects patient outcomes from 24 centers in the United Kingdom and Ireland treating patients. Learning curves for treatment of Barrett's dysplasia a...
Article
Full-text available
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1,2,3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG...