Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020

A Review on Emerging Techniques for Diagnosis of Colorectal Cancer

Common detection methods in practice for diagnosing colorectal cancer (CRC) are painful and invasive leading to less participation of individuals for CRC diagnosis. Whereas, improved or enhanced imaging systems and other minimally invasive techniques with shorter detection times deliver greater detail and less discomfort in individuals. Thus, this review is a summary of the diagnostic tests, ranging from the simple potential use in developing a flexible CRC treatment to the patient's potential benefits in receiving less invasive procedures and the advanced treatments that might provide a better assessment for the diagnosis of CRC and reduce the mortality related to CRC.

Deep Learning-Based Reconstruction Improves the Image Quality of Low-Dose CT Colonography

RATIONALE AND OBJECTIVES

To evaluate the image quality of low-dose CT colonography (CTC) using deep learning-based reconstruction (DLR) compared to iterative reconstruction (IR).

MATERIALS AND METHODS

Adults included in the study were divided into four groups according to body mass index (BMI). Routine-dose (RD: 120 kVp) CTC images were reconstructed with IR (RD-IR); low-dose (LD: 100kVp) images were reconstructed with IR (LD-IR) and DLR (LD-DLR). The subjective image quality was rated on a 5-point scale by two radiologists independently. The parameters for objective image quality included noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The Friedman test was used to compare the image quality among RD-IR, LD-IR and LD-DLR. The KruskalWallis test was used to compare the results among different BMI groups.

RESULTS

A total of 270 volunteers (mean age: 47.94 years ± 11.57; 115 men) were included. The effective dose of low-dose CTC was decreased by approximately 83.18% (5.18mSv ± 0.86 vs. 0.86mSv ± 0.05, P < 0.001). The subjective image quality score of LD-DLR was superior to that of LD-IR (3.61 ± 0.56 vs. 2.70 ± 0.51, P < 0.001) and on par with the RD- IR's (3.61 ± 0.56 vs. 3.74 ± 0.52, P = 0.486). LD-DLR exhibited the lowest noise, and the maximum SNR and CNR compared to RD-IR and LD-IR (all P < 0.001). No statistical difference was found in the noise of LD-DLR images between different BMI groups (all P > 0.05).

CONCLUSION

Compared to IR, DLR provided low-dose CTC with superior image quality at an average radiation dose of 0.86mSv, which may be promising in future colorectal cancer screening.

Is flexible sigmoidoscopy screening associated with reducing colorectal cancer incidence and mortality? a meta-analysis and systematic review

Background

The question of whether flexible sigmoidoscopy (FS) for colorectal cancer (CRC) affects incidence or mortality remains unclear. In this study, we conducted a meta-analysis and systematic review to explore this issue.

Methods

A systematic search of PubMed, EMBASE, and ClinicalTrials.gov was performed for cohort studies (CS), case-control studies, and randomized controlled trials (RCTs) of people who underwent FS and reported mortality or incidence of CRC until 11 December 2022. Relative risk (RR) was applied as an estimate of the effect of interest. To combine the RRs and 95% confidence intervals, a random-effects model was used. The quality of the included studies and evidence was assessed by the Newcastle-Ottawa quality assessment scale, the Jadad scale, and the "Grading of Recommendations Assessment, Development and Evaluation System."

Results

There were a total of six RCTs and one CS, comprising 702,275 individuals. FS was found to be associated with a 26% RR reduction in CRC incidence (RR, 0.74; 95% CI, 0.66-0.84) and a 30% RR reduction in CRC mortality (RR, 0.70; 95% CI, 0.58-0.85). In the incidence subgroup analysis, FS significantly reduced the incidence of CRC compared with non-screening, usual care, and fecal immunochemical testing. Significance was also shown in men, women, distal site, stages III-IV, ages 55-59, and age over 60. In terms of the mortality subgroup analysis, the results were roughly the same as those of incidence.

Conclusion

According to this study, FS might reduce the incidence and mortality of CRC. To confirm this finding, further prospective clinical studies should be conducted based on a larger-scale population.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023388925.

SEOM-GEMCAD-TTD clinical guidelines for the systemic treatment of metastatic colorectal cancer (2022)

Colorectal cancer (CRC) is the second leading cause of cancer deaths in Spain. Metastatic disease is present in 15-30% of patients at diagnosis and up to 20-50% of those with initially localized disease eventually develop metastases. Recent scientific knowledge acknowledges that this is a clinically and biologically heterogeneous disease. As treatment options increase, prognosis for individuals with metastatic disease has steadily improved over recent decades. Disease management should be discussed among experienced, multidisciplinary teams to select the most appropriate systemic treatment (chemotherapy and targeted agents) and to integrate surgical or ablative procedures, when indicated. Clinical presentation, tumor sidedness, molecular profile, disease extension, comorbidities, and patient preferences are key factors when designing a customized treatment plan. These guidelines seek to provide succinct recommendations for managing metastatic CRC.

Robotic Colonoscopy and Beyond: Insights into Modern Lower Gastrointestinal Endoscopy

Lower gastrointestinal endoscopy is considered the gold standard for the diagnosis and removal of colonic polyps. Delays in colonoscopy following a positive fecal immunochemical test increase the likelihood of advanced adenomas and colorectal cancer (CRC) occurrence. However, patients may refuse to undergo conventional colonoscopy (CC) due to fear of possible risks and pain or discomfort. In this regard, patients undergoing CC frequently require sedation to better tolerate the procedure, increasing the risk of deep sedation or other complications related to sedation. Accordingly, the use of CC as a first-line screening strategy for CRC is hampered by patients' reluctance due to its invasiveness and anxiety about possible discomfort. To overcome the limitations of CC and improve patients' compliance, several studies have investigated the use of robotic colonoscopy (RC) both in experimental models and in vivo. Self-propelling robotic colonoscopes have proven to be promising thanks to their peculiar dexterity and adaptability to the shape of the lower gastrointestinal tract, allowing a virtually painless examination of the colon. In some instances, when alternatives to CC and RC are required, barium enema (BE), computed tomographic colonography (CTC), and colon capsule endoscopy (CCE) may be options. However, BE and CTC are limited by the need for subsequent investigations whenever suspicious lesions are found. In this narrative review, we discussed the current clinical applications of RC, CTC, and CCE, as well as the advantages and disadvantages of different endoscopic procedures, with a particular focus on RC.

CT colonography: can we achieve an adequate bowel preparation without diet restriction?

OBJECTIVE

To evaluate if an adequate bowel preparation for CT colonography, can be achieved without diet restriction, using a reduced amount of cathartic agent and fecal tagging. To investigate the influence of patients' characteristics on bowel preparation and the impact on patients' compliance.

METHODS

In total, 1446 outpatients scheduled for elective CT colonography were prospectively enrolled. All patients had the same bowel preparation based on a reduced amount of cathartic agent (120 g of macrogol in 1.5 l of water) the day before the exam and a fecal tagging agent (60 ml of hyperosmolar oral iodinated agent) the day of the exam. No dietary restrictions were imposed before the exam. The bowel preparation was evaluated using a qualitative and quantitative score. Patients were grouped by age, gender, and presence of diverticula in both scores. Patients' compliance has been evaluated with a questionnaire after the end of the exam and with a phone-calling interview the day after the exam.

RESULTS

According to the qualitative score, adequate bowel preparation was achieved in 1349 patients (93.29%) and no statistical differences were observed among the subgroups of patients. Quantitative scores demonstrated that colon distension was significantly better in younger patients and without diverticula. A good patients' compliance was observed and most patients (96.5%) were willing to repeat it.

CONCLUSIONS

The lack of diet restriction does not affect the quality of CTC preparation and good patient's compliance could potentially increase the participation rate in CRC screening programs.

KEY POINTS

• An adequate quality bowel preparation for CT colonography can be achieved without diet restriction, using a reduced amount of cathartic agent (120 g of macrogol in 1.5 l of water) and fecal tagging (60 ml of hyperosmolar oral iodinated agent). • A bowel preparation based on the combination of a reduced amount of cathartic agent and fecal tagging, without diet restriction, allows obtaining good quality in more than 90% of patients. • The bowel preparation scheme proposed reduces the distress and discomfort experienced by the patients improving adherence to CTC.

Impact of colorectal cancer screening on incidence, mortality and surgery rates: Evidences from programs based on the fecal immunochemical test in Italy

Fecal immunochemical tests (FIT) are among the most commonly used tests for colorectal cancer (CRC) screening programs worldwide. However, no randomised controlled trials have been carried out evaluating the impact of FIT-based screening programs (FIT-progr) on CRC incidence and mortality rates. Italian FIT-progr represent one of the most widespread and established experience worldwide. This paper reviews the evidence on the impact of FIT-progr on CRC incidence, tumor stage at diagnosis, mortality and surgery rates, deriving from Italian routine programs, i.e., outside the research setting. Unfortunately, the application of FIT-progr in Italy can be considered as an unplanned experimental model, due to the differences between Regions, both in health system management and adherence of the target population to the screening programs. The analysis of the manuscripts considered in the review, confirms that FIT-progr are effective in reducing CRC incidence and mortality rates and in improving the rate of endoscopic treatment of early invasive lesions. The review also highlights that FIT-progr are less performing for proximal colon than for distal colon and rectum.

Green endoscopy: British Society of Gastroenterology (BSG), Joint Accreditation Group (JAG) and Centre for Sustainable Health (CSH) joint consensus on practical measures for environmental sustainability in endoscopy

GI endoscopy is highly resource-intensive with a significant contribution to greenhouse gas (GHG) emissions and waste generation. Sustainable endoscopy in the context of climate change is now the focus of mainstream discussions between endoscopy providers, units and professional societies. In addition to broader global challenges, there are some specific measures relevant to endoscopy units and their practices, which could significantly reduce environmental impact. Awareness of these issues and guidance on practical interventions to mitigate the carbon footprint of GI endoscopy are lacking. In this consensus, we discuss practical measures to reduce the impact of endoscopy on the environment applicable to endoscopy units and practitioners. Adoption of these measures will facilitate and promote new practices and the evolution of a more sustainable specialty.

Low Colon Capsule Endoscopy (CCE) False Negative Rate for Polyps Excluding Reader Error

BACKGROUND

CCE is a diagnostic tool lacking clinical data on false negative rates. We aimed to assess this rate and the reader/technical error breakdown.

METHODS

False negative CCEs were identified after comparing to a colonoscopy database. Missed pathology characteristics and study indications/quality were collated. Cases were re-read by experts and newly identified lesions/pathologies were verified by an expert panel and categorised as reader/technical errors.

RESULTS

Of 532 CCEs, 203 had an adequately reported comparative colonoscopy, 45 (22.2%) had missed polyps, and 26/45 (57.8%) reached the colonic section with missed pathology. Of the cases, 22 (84.6%) had adequate bowel preparation. Indications included 13 (50%) polyp surveillance, 12 (46%) GI symptoms, 1 (4%) polyp screening. CCE missed 18 (69.2%) diminutive polyps and 8 (30.8%) polyps ≥ 6 mm, 18/26 (69.2%) of these were adenomas. Excluding incomplete CCE correlates, colonoscopy total and significant polyp yield were 97/184 (52.7%) and 50/97 (51.5%), respectively. CCE total polyp and significant polyp false negative rate was 26.8% (26/97) and 16% (8/50), respectively. Following re-reading, reader and technical error was 20/26 (76.9%) and 6/26 (23.1%). Total and significant missed polyp rates were 20.6% (20/97) and 14% (7/50) for reader error, 6.2% (6/97) and 2% (1/50) for technical error.

CONCLUSIONS

False negative CCE rate is not insubstantial and should be factored into clinical decision making.

Colon capsule endoscopy following incomplete colonoscopy in routine clinical settings

BACKGROUND

Colon capsule endoscopy (CCE) was introduced in our department on two indications; following incomplete colonoscopy as an alternative to CT colonography, and in patients with a history of incomplete colonoscopy as an alternative to anesthesia-assisted (AA) colonoscopy. We aimed to compare the quality of CCE, defined by completion rate and polyp detection rate (PDR), with that of CT colonography and AA colonoscopy, respectively.

METHODS

Patients referred for CCE from May 2020 until November 2021 were consecutively included in this prospective cohort study. Demographics, indication and CCE outcomes were registered from the electronic patient record. Completion rate and PDR in CCE as an alternative to CT colonography were compared with those of a historical cohort undergoing CT colonography following incomplete colonoscopy. Completion rate and PDR in CCE as an alternative to AA colonoscopy were compared with those of a time true parallel cohort undergoing AA colonoscopy.

RESULTS

In 65 patients undergoing CCE, 36 (57%) were referred as an alternative to CT colonography. The completion rate in this group was 44% compared to 96% in CT colonography (p < 0.001). The PDR in complete CCE in this group was 75% in CCE compared to 20% in CT colonography (p < 0.001). The remaining 27 (43%) of the sample were referred for CCE as an alternative to AA colonoscopy. The completion rate in this group was 33% compared to 100% in AA colonoscopy (p < 0.001). The PDR in complete CCE in this group was 78% in CCE compared to 35% in AA colonoscopy (p = 0.013).

CONCLUSIONS

The completion rate of CCE following incomplete colonoscopy is inferior to that of CT colonography and AA colonoscopy. The PDR of CCE was high, indicating an acceptable sensitivity in complete investigations, but in our settings the completion rate of CCE on this indication is unacceptably low.

CLINICAL TRIAL REGISTRATION

NCT04307901 (ClinicalTrials.gov, March 13, 2020).

The optimal use of colon capsule endoscopes in clinical practice

Colon capsule endoscopy (CCE) has been available for nearly two decades but has grappled with being an equal diagnostic alternative to optical colonoscopy (OC). Due to the COVID-19 pandemic, CCE has gained more foothold in clinical practice. In this cutting-edge review, we aim to present the existing knowledge on the pros and cons of CCE and discuss whether the modality is ready for a larger roll-out in clinical settings. We have included clinical trials and reviews with the most significant impact on the current position of CCE in clinical practice and discuss the challenges that persist and how they could be addressed to make CCE a more sustainable imaging modality with an adenoma detection rate equal to OC and a low re-investigation rate by a proper preselection of suitable populations. CCE is embedded with a very low risk of severe complications and can be performed in the patient's home as a pain-free procedure. The diagnostic accuracy is found to be equal to OC. However, a significant drawback is low completion rates eliciting a high re-investigation rate. Furthermore, the bowel preparation before CCE is extensive due to the high demand for clean mucosa. CCE is currently not suitable for large-scale implementation in clinical practice mainly due to high re-investigation rates. By a better preselection before CCE and the implantation of artificial intelligence for picture and video analysis, CCE could be the alternative to OC needed to move away from in-hospital services and relieve long-waiting lists for OC.

Inter/Intra-Observer Agreement in Video-Capsule Endoscopy: Are We Getting It All Wrong? A Systematic Review and Meta-Analysis

Video-capsule endoscopy (VCE) reading is a time- and energy-consuming task. Agreement on findings between readers (either different or the same) is a crucial point for increasing performance and providing valid reports. The aim of this systematic review with meta-analysis is to provide an evaluation of inter/intra-observer agreement in VCE reading. A systematic literature search in PubMed, Embase and Web of Science was performed throughout September 2022. The degree of observer agreement, expressed with different test statistics, was extracted. As different statistics are not directly comparable, our analyses were stratified by type of test statistics, dividing them in groups of “None/Poor/Minimal”, “Moderate/Weak/Fair”, “Good/Excellent/Strong” and “Perfect/Almost perfect” to report the proportions of each. In total, 60 studies were included in the analysis, with a total of 579 comparisons. The quality of included studies, assessed with the MINORS score, was sufficient in 52/60 studies. The most common test statistics were the Kappa statistics for categorical outcomes (424 comparisons) and the intra-class correlation coefficient (ICC) for continuous outcomes (73 comparisons). In the overall comparison of inter-observer agreement, only 23% were evaluated as “good” or “perfect”; for intra-observer agreement, this was the case in 36%. Sources of heterogeneity (high, I² 81.8–98.1%) were investigated with meta-regressions, showing a possible role of country, capsule type and year of publication in Kappa inter-observer agreement. VCE reading suffers from substantial heterogeneity and sub-optimal agreement in both inter- and intra-observer evaluation. Artificial-intelligence-based tools and the adoption of a unified terminology may progressively enhance levels of agreement in VCE reading.

Colon Capsule Endoscopy in the Diagnosis of Colon Polyps: Who Needs a Colonoscopy?

Colon screening programs have reduced colon cancer mortality. Population screening should be minimally invasive, safe, acceptably sensitive, cost-effective, and scalable. The range of screening modalities include guaiac or immunochemical fecal occult blood testing and CT colonography and colonoscopy. A number of carefully controlled studies concur that second-generation capsule endoscopy has excellent sensitivity for polyp detection and a high negative predictive value. Colon capsules fulfill the screening expectation of safety, high sensitivity for polyp detection, and patient acceptance, and appear to straddle the divide between occult blood testing and colonoscopy. While meeting these criteria, there remains the challenges of scaling, capsule practitioner training, resource allocation, and implementing change of practice. Like CT colonography, capsule screening presents the clinician with a decision on the threshold for colonoscopy referral. Overall, colon capsules are an invaluable tool in polyp detection and colon screening and offer a filter that determines “who needs a colonoscopy?”.

Effect of dose splitting of a low-volume bowel preparation macrogol-based solution on CT colonography tagging quality

Purpose

To compare examination quality and acceptability of three different low-volume bowel preparation regimens differing in scheduling of the oral administration of a Macrogol-based solution, in patients undergoing computed tomographic colonography (CTC). The secondary aim was to compare CTC quality according to anatomical and patient variables (dolichocolon, colonic diverticulosis, functional and secondary constipation).

Methods

One-hundred-eighty patients were randomized into one of three regimens where PEG was administered, respectively: in a single dose the day prior to (A), or in a fractionated dose 2 (B) and 3 days (C) before the examination. Two experienced radiologists evaluated fecal tagging (FT) density and homogeneity both qualitatively and quantitatively by assessing mean segment density (MSD) and relative standard deviation (RSD). Tolerance to the regimens and patient variables were also recorded.

Results

Compared to B and C, regimen A showed a lower percentage of segments with inadequate FT and a significantly higher median FT density and/or homogeneity scores as well as significantly higher MSD values in some colonic segments. No statistically significant differences were found in tolerance of the preparations. A higher number of inadequate segments were observed in patients with dolichocolon (p < 0.01) and secondary constipation (p < 0.01). Interobserver agreement was high for the assessment of both FT density (k = 0.887) and homogeneity (k = 0.852).

Conclusion

The best examination quality was obtained when PEG was administered the day before CTC in a single session. The presence of dolichocolon and secondary constipation represent a risk factor for the presence of inadequately tagged colonic segments.

Faecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer (CRC): a joint guideline from the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG)

Faecal immunochemical testing (FIT) has a high sensitivity for the detection of colorectal cancer (CRC). In a symptomatic population FIT may identify those patients who require colorectal investigation with the highest priority. FIT offers considerable advantages over the use of symptoms alone, as an objective measure of risk with a vastly superior positive predictive value for CRC, while conversely identifying a truly low risk cohort of patients. The aim of this guideline was to provide a clear strategy for the use of FIT in the diagnostic pathway of people with signs or symptoms of a suspected diagnosis of CRC. The guideline was jointly developed by the Association of Coloproctology of Great Britain and Ireland/British Society of Gastroenterology, specifically by a 21-member multidisciplinary guideline development group (GDG). A systematic review of 13 535 publications was undertaken to develop 23 evidence and expert opinion-based recommendations for the triage of people with symptoms of a suspected CRC diagnosis in primary care. In order to achieve consensus among a broad group of key stakeholders, we completed an extended Delphi of the GDG, and also 61 other individuals across the UK and Ireland, including by members of the public, charities and primary and secondary care. Seventeen research recommendations were also prioritised to inform clinical management.

Performance of a Deep Learning System for Automatic Diagnosis of Protruding Lesions in Colon Capsule Endoscopy

Background: Colon capsule endoscopy (CCE) is an alternative for patients unwilling or with contraindications for conventional colonoscopy. Colorectal cancer screening may benefit greatly from widespread acceptance of a non-invasive tool such as CCE. However, reviewing CCE exams is a time-consuming process, with risk of overlooking important lesions. We aimed to develop an artificial intelligence (AI) algorithm using a convolutional neural network (CNN) architecture for automatic detection of colonic protruding lesions in CCE images. An anonymized database of CCE images collected from a total of 124 patients was used. This database included images of patients with colonic protruding lesions or patients with normal colonic mucosa or with other pathologic findings. A total of 5715 images were extracted for CNN development. Two image datasets were created and used for training and validation of the CNN. The AUROC for detection of protruding lesions was 0.99. The sensitivity, specificity, PPV and NPV were 90.0%, 99.1%, 98.6% and 93.2%, respectively. The overall accuracy of the network was 95.3%. The developed deep learning algorithm accurately detected protruding lesions in CCE images. The introduction of AI technology to CCE may increase its diagnostic accuracy and acceptance for screening of colorectal neoplasia.

Detection methods of synchronous colorectal lesions in proximal colon for patients with obstructive colorectal cancer: a literature review

INTRODUCTION

Colorectal cancer holds a high morbidity and mortality rate. As a common method for colorectal cancer detection, colonoscopy has difficulty in passing through the malignant stenosis in patients with obstructive colorectal cancer, which results in incomplete detection and missed diagnosis. The missed synchronous lesions increase the risk of metachronous cancer. Therefore, detecting proximal synchronous lesions in patients with obstructive colorectal cancer should be appreciated before operation.

AREA COVERED

This review evaluates related literature, aiming at providing clinicians with more ideas and attention for detecting proximal synchronous lesions in patients with obstructive colorectal cancer.

EXPERT OPINION

In patients with obstructive colorectal cancer, missed diagnosis of lesions proximal to the obstruction may lead to metachronous colorectal cancer. Except for preoperative colonoscopy which is difficult to pass through malignant stenosis, other methods that can evaluate proximal colon segment are critical. This article introduced several preoperative, intraoperative and postoperative measures for synchronous lesions detection. The choice of methods should base on patients' conditions, aiming at a high diagnostic yield and low risk. Early detection and resection of synchronous lesions in the proximal section of malignant obstruction are expected to minimize the risk of metachronous colorectal cancer and even effect follow-up treatment strategy, which deserves the attention of clinicians.

Transverse Colorectal Carcinoma Imaging: A Case Report

Colorectal cancer (CRC) is a type of malignancy in the digestive system. Colorectal cancer can be found anywhere along the large intestine from the cecum to the rectum. However, transverse colorectal cancer is a rare case and is only found in 6.8% of total colorectal cancers. A 64-year-old male patient with complaints of weakness, changes in the pattern of defecation, namely dark brown bowel movements for approximately +/- 8 months, anemia, and an increase in serum CEA. The results of the initial examination with plain abdominal radiographs did not reveal any abnormalities, only normal gas shadows mixed with fecal material were found that were prominent in the right to left hypochondrium region. After further examination, the patient was found to have stage 4 transverse colorectal cancer. The diagnosis of transverse colorectal carcinoma (CRC) was established based on fluoroscopy findings which showed filling abnormalities and colonic lumen irregularities in the medial 1/3 of the transverse colon forming an apple core image with the narrowest diameter + /- 3 mm along +/- 6 cm, shouldering sign (+), and on CT abdomen with contrast, an intraluminal malignant mass was found (Staging AJCC 8th ed 2018 T4aN2aM0). The diagnosis of CRC was confirmed by the results of resection and histopathological examination which found well-differentiated adenocarcinoma of the colon.

State-of-the-Art Review on Immersive Virtual Reality Interventions for Colonoscopy-Induced Anxiety and Pain

BACKGROUND

Colonoscopy related fear impairs the current gold standard screening of colorectal cancer. Compared to other minimally invasive procedures for cancer screening, colonoscopy-induced anxiety exceeds the procedure through bowel preparation. Immersive virtual reality's (iVR) role in alleviating the complex stress-pain relationship encountered during medical procedures is directly proportional to the rising affordability of state-of-the-art Head-Mounted-Displays (HMDs).

OBJECTIVE

to assess the effect of iVR on patients' colonoscopy-induced anxiety and pain.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, Cochrane Central Register of Controlled Trials, Web of Science, Embase and Scopus databases up to January 2022. Clinical trials evaluating anxiety as an outcome were included without language restriction.

RESULTS

Four clinical trials were included: three on the patients' intraprocedural anxiety and one on patient education. Intraprocedural iVR interventions for colonoscopy-induced anxiety and pain revealed a similar effect as conventional sedation, while a statistically significant reduction was reported for non-sedated patients. iVR patient education improved the quality of bowel preparation and reduced patient anxiety before colonoscopy.

CONCLUSIONS

The current research highlights the need to use high-end HMDs and appropriate interactive iVR software content for colonoscopy-induced anxiety. Methodological frameworks regarding the eligibility of participants, double-blinding and randomization of iVR studies can facilitate the development of iVR implementation for anxiety and pain management.

Comparing Colon Capsule Endoscopy to colonoscopy; a symptomatic patient’s perspective

Background

Colon Capsule Endoscopy (CCE) has proven efficacy in a variety of gastrointestinal diseases. Few studies have assessed patient-reported outcomes and preference between colonoscopy and CCE.

Methods

Patients from our centre who had both a CCE and colonoscopy within a 12-month period were identified. We performed over-the-phone interviews focused on satisfaction, comfort, and overall preference with a 10-point Likert scale. Electronic records were reviewed; reported Modified-Gloucester-Comfort-Scale (GCS) score, sedation, bowel preparation and endoscopist grade were documented. Data was compared between procedures. A Fishers exact test was used to compare proportions and a Student t-test was used to compare means, a p < 0.05 was considered significant.

Results

In all, 40 patients were identified, 57.5% (23/40) were female and the mean age was 48 years (24–78). All patients were referred for investigation of lower gastrointestinal symptoms as part of an ongoing study [Endosc Int Open. 2021;09(06):E965–70]. There was a significance difference in mean comfort (9.2 vs 6.7, p < 0.0001, 95% CI − 3.51 to − 1.44) but not satisfaction (8.3 vs 7.7, p = 0.2, 95% CI − 1.48 to 0.33) between CCE and colonoscopy. Main cause of dissatisfaction with CCE was bowel preparation and for colonoscopy was discomfort. Age and gender were not found to be variables. The correlation between GCS and patient reported values was weak (R = − 0.28). Overall, 77.5% (31/40) of patients would prefer a CCE if they required further bowel investigation. Of these, 77.4% (24/31) preferred a CCE despite the potential need for follow-up colonoscopy.

Conclusions

CCE has a high satisfaction rating (8.3 vs 7.7) and has a higher patient reported comfort rating (9.2 vs 6.7) than colonoscopy. Studies have confirmed CCE and colonoscopy have equivalent diagnostic yields. The majority of patients in our cohort prefer CCE to colonoscopy. CCE should be considered as an alternative to colonoscopy in selected individuals.

Systematic review and meta-analysis of colon capsule endoscopy accuracy for colorectal cancer screening. An alternative during the Covid-19 pandemic?

Aim

To determine the diagnostic accuracy of colon capsule endoscopy for colorectal cancer screening.

Methods

Studies that compared the diagnostic performance of colonoscopy and second-generation colon capsule endoscopy (CCE-2) for screening of asymptomatic patients aged 50–75 years were included. The primary outcomes were sensitivity, specificity, and positive and negative likelihood ratios for polyps and adenomas measuring at least 6 mm or 10 mm.

Results

Eight full-text studies that evaluated 1602 patients were included for systematic review. Of these, 840 (52.43%) patients participated in an opportunistic screening program. The pooled outcomes of CCE-2 for polyps at least 6 mm / 10 mm were (CI = confidence interval): sensitivity: 88% (95% CI: 0.84–0.91) / 88% (95% CI: 0.82–0.93), specificity: 94% (95% CI: 0.92–0.95) / 95.5% (95% CI: 0.94–0.97); positive likelihood ratio: 11.86 (95% CI: 5.53–25.46) / 23.07 (95% CI: 6.163–86.36); negative likelihood ratio: 0.14 (95% CI: 0.1–0.21) / 0.14 (95% CI: 0.09–0.21). The area under the summary receiver operating characteristic curve for polyps at least 6 and 10 mm was 96.3% and 96.7%, respectively. The only cancer missed by complete CCE-2 was shown at multiple frames in the unblinded review. In total, 125 (7.8%) patients presented mild adverse events mostly related to bowel preparation.

Conclusion

CCE-2 is demonstrated to be an effective and safe alternative method for colorectal cancer screening. Diagnostic performance of CCE-2 for polyps of at least 6 and 10 mm was similar. Completion rates still need to be improved.

Applicability of colon capsule endoscopy as pan-endoscopy: From bowel preparation, transit, and rating times to completion rate and patient acceptance

Background and study aims  Colon capsule endoscopy (CCE) has the potential to explore the entire gastrointestinal tract. The aim of this study was to assess the applicability of CCE as pan-endoscopy. Patients and methods  Healthy participants received CCE with bowel preparation (bisacodyl, polyethylene electrolyte glycol (PEG) + ascorbic acid) and booster regimen (metoclopramide, oral sulfate solution (OSS)). For each segment of the gastrointestinal tract, the following quality parameters were assessed: cleanliness, transit times, reading times, patient acceptance and safety of the procedure. When all gastrointestinal segments had cleansing score good or excellent, cleanliness of the whole gastrointestinal tract was assessed as good. Participants' expected and perceived burden was assessed by questionnaires and participants were asked to grade the procedure (scale 0-10). All serious adverse events (SAEs) were documented. Results  A total of 451 CCE procedures were analyzed. A good cleansing score was achieved in the stomach in 69.6%, in the SB in 99.1 % and in the colon in 76.6 %. Cleanliness of the whole gastrointestinal tract was good in 52.8 % of the participants. CCE median transit time of the whole gastrointestinal tract was 583 minutes IQR 303-659). The capsule reached the descending colon in 94.7 %. Median reading time per procedure was 70 minutes (IQR 57-83). Participants graded the procedure with a 7.8. There were no procedure-related SAEs. Conclusions  CCE as pan-endoscopy has shown to be a safe procedure with good patient acceptance. When cleanliness of all gastrointestinal segments per patient, completion rate and reading time will be improved, CCE can be applied as a good non-invasive alternative to evaluate the gastrointestinal tract.

Efficacy of bowel preparation regimens for colon capsule endoscopy: a systematic review and meta-analysis

Background and study aims  Colon capsule endoscopy (CCE) is an alternative to conventional colonoscopy (CC) in specific clinical settings. High completion rates (CRs) and adequate cleanliness rates (ACRs) are fundamental quality parameters if CCE is to be widely implemented as a CC equivalent diagnostic modality. We conducted a systematic review and meta-analysis to investigate the efficacy of different bowel preparations regimens on CR and ACR in CCE. Patients and methods  We performed a systematic literature search in PubMed, Embase, CINAHL, Web of Science, and the Cochrane Library. Data were independently extracted per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The primary outcome measures (CR, ACR) were retrieved from the individual studies and pooled event rates were calculated. Results  Thirty-four observational (OBS) studies (n = 3,789) and 12 randomized clinical trials (RCTs) (n = 1,214) comprising a total 5,003 patients were included. The overall CR was 0.798 (95 % CI, 0.764-0.828); the highest CRs were observed with sodium phosphate (NaP) + gastrografin booster (n = 2, CR = 0.931, 95 % CI, 0.820-0.976). The overall ACR was 0.768 (95 % CI, 0.735-0.797); the highest ACRs were observed with polyethylene glycol (PEG) + magnesium citrate (n = 4, ER = 0.953, 95 % CI, 0.896-0.979). Conclusions  In the largest meta-analysis on CCE bowel preparation regimens, we found that both CRs and ACRs are suboptimal compared to the minimum recommended standards for CC. PEG laxative and NaP booster were the most commonly used but were not associated with higher CRs or ACRs. Well-designed studies on CCE should be performed to find the optimal preparation regimen.

Artificial intelligence and colon capsule endoscopy: development of an automated diagnostic system of protruding lesions in colon capsule endoscopy

BACKGROUND

Colon capsule endoscopy (CCE) is a minimally invasive alternative for patients unwilling to undergo conventional colonoscopy, or for whom the latter exam is contraindicated. This is particularly important in the setting of colorectal cancer screening. Nevertheless, these exams produce large numbers of images, and reading them is a monotonous and time-consuming task, with the risk of overlooking important lesions. The development of automated tools based on artificial intelligence (AI) technology may improve some of the drawbacks of this diagnostic instrument.

METHODS

A database of CCE images was used for development of a Convolutional Neural Network (CNN) model. This database included anonymized images of patients with protruding lesions in the colon or patients with normal colonic mucosa or with other pathologic findings. A total of 3,387,259 frames from 24 CCE exams were retrospectively reviewed. For CNN development, 3640 images (860 protruding lesions and 2780 with normal mucosa or other findings) were ultimately extracted. Training and validation datasets were constructed for the development and testing of the CNN.

RESULTS

The CNN detected protruding lesions with a sensitivity, specificity, positive and negative predictive values of 90.7, 92.6, 79.2 and 96.9%, respectively. The area under the receiver operating characteristic curve for detection of protruding lesions was 0.97.

CONCLUSIONS

The deep learning algorithm we developed is capable of accurately detecting protruding lesions. The application of AI technology to CCE may increase its diagnostic accuracy and acceptance for screening of colorectal neoplasia.

Colorectal Cancer Screening with Computed Tomography Colonography: Single Region Experience in Kazakhstan

Background/Aims

The aim of our study was to determine the efficacy of computed tomography colonography (CTC) in screening for colorectal cancer (CRC).

Methods

A total of 612 females and 588 males aged 45 to 75 years were enrolled in CTC screening. CTC was performed following standard bowel preparation and colonic insufflation with carbon dioxide. The main outcomes were the detection rate of CRC and advanced adenoma (AA), prevalence of colorectal lesions in relation to socio-demographic and health factors, and overall diagnostic performance of CTC.

Results

Overall, 56.5% of the 1,200 invited subjects underwent CTC screening. The sensitivity for CRC and AA was 0.89 and 0.97, respectively, while the specificity was 0.71 and 0.99, respectively. The prevalence of CRC and AA was 3.0% (18/593) and 7.1% (42/593), respectively, with the highest CRC prevalence in the 66-75 age group (≥12 times; odds ratio [OR], 12.11; 95% confidence interval [CI], 4.45-32.92). CRC and AA prevalence were inversely correlated with Asian descent, physical activity, and negative fecal immunochemical test results (OR=0.43; 95% CI, 0.22-0.83; OR=0.16; 95% CI, 0.04-0.68; OR=0.5; 95% CI, 0.07-3.85, respectively).

Conclusions

Our study revealed high accuracy of CTC in diagnosing colonic neoplasms, good compliance with CTC screening, and high detection rate of CRC.

Scoring Systems for Clinical Colon Capsule Endoscopy-All You Need to Know

In the constantly developing era of minimal diagnostic invasiveness, the role of colon capsule endoscopy in colonic examination is being increasingly recognised, especially in the context of curtailed endoscopy services due to the COVID-19 pandemic. It is a safe diagnostic tool with low adverse event rates. As with other endoscopic modalities, various colon capsule endoscopy scores allow the standardisation of reporting and reproducibility. As bowel cleanliness affects CCE’s diagnostic yield, a few operator-dependent scores (Leighton–Rex and CC-CLEAR scores) and a computer-dependent score (CAC score) have been developed to grade bowel cleanliness objectively. CCE can be used to monitor IBD mucosal disease activity through the UCEIS and the panenteric CECDAIic score for UC and CD, respectively. CCE may also have a role in CRC screening, given similar sensitivity and specificity rates to conventional colonoscopy to detect colonic polyps ≥ 10 mm and CRC. Given CCE’s diagnostic yield and reproducible clinical scores with high inter-observer agreements, CCE is fast becoming a suitable alternative to conventional colonoscopy in specific patient populations.

A Review of Colorectal Cancer in Terms of Epidemiology, Risk Factors, Development, Symptoms and Diagnosis

This review article contains a concise consideration of genetic and environmental risk factors for colorectal cancer. Known risk factors associated with colorectal cancer include familial and hereditary factors and lifestyle-related and ecological factors. Lifestyle factors are significant because of the potential for improving our understanding of the disease. Physical inactivity, obesity, smoking and alcohol consumption can also be addressed through therapeutic interventions. We also made efforts to systematize available literature and data on epidemiology, diagnosis, type and nature of symptoms and disease stages. Further study of colorectal cancer and progress made globally is crucial to inform future strategies in controlling the disease's burden through population-based preventative initiatives.

How should we do colon capsule endoscopy reading: a practical guide

In this article, we aim to provide general principles as well as personal views for colonic capsule endoscopy. To allow an in-depth understanding of the recommendations, we also present basic technological characteristics and specifications, with emphasis on the current as well as the previous version of colonic capsule endoscopy and relevant software. To date, there is no scientific proof to support the optimal way of reading a colonic capsule endoscopy video, or any standards or guidelines exist. Hence, any advice is a mixture of recommendations by the capsule manufacturer and experts’ opinion. Furthermore, there is a paucity of data regarding the use of term(s) (pre-reader/reader-validator) in colonic capsule endoscopy. We also include a couple of handy tables in order to get info at a glance.

Computed tomography colonography and radiation risk: How low can we go?

Computed tomography colonography (CTC) has become a key examination in detecting colonic polyps and colorectal carcinoma (CRC). It is particularly useful after incomplete optical colonoscopy (OC) for patients with sedation risks and patients anxious about the risks or potential discomfort associated with OC. CTC's main advantages compared with OC are its non-invasive nature, better patient compliance, and the ability to assess the extracolonic disease. Despite these advantages, ionizing radiation remains the most significant burden of CTC. This opinion review comprehensively addresses the radiation risk of CTC, incorporating imaging technology refinements such as automatic tube current modulation, filtered back projections, lowering the tube voltage, and iterative reconstructions as tools for optimizing low and ultra-low dose protocols of CTC. Future perspectives arise from integrating artificial intelligence in computed tomography machines for the screening of CRC.

The Roadmap of Colorectal Cancer Screening

Colorectal cancer (CRC) is the third most common form of cancer in terms of incidence and the second in terms of mortality worldwide. CRC develops over several years, thus highlighting the importance of early diagnosis. National screening programs based on fecal occult blood tests and subsequent colonoscopy have reduced the incidence and mortality, however improvements are needed since the participation rate remains low and the tests present a high number of false positive results. This review provides an overview of the CRC screening globally and the state of the art in approaches aimed at improving accuracy and participation in CRC screening, also considering the need for gender and age differentiation. New fecal tests and biomarkers such as DNA methylation, mutation or integrity, proteins and microRNAs are explored, including recent investigations into fecal microbiota. Liquid biopsy approaches, involving novel biomarkers and panels, such as circulating mRNA, micro- and long-non-coding RNA, DNA, proteins and extracellular vesicles are discussed. The approaches reported are based on quantitative PCR methods that could be easily applied to routine screening, or arrays and sequencing assays that should be better exploited to describe and identify candidate biomarkers in blood samples.