Endoscopy December 01, 2023

Texture and color enhancement imaging versus high definition white-light endoscopy for detection of colorectal neoplasia: a randomized trial

Giulio Antonelli, Gianluca Bevivino, Silvia Pecere, et al.

Bottom Line

In an international, multicenter randomized trial, the use of Texture and Color Enhancement Imaging (TXI) during colonoscopy significantly increased the adenoma detection rate compared to standard high-definition white-light imaging.

Key Findings

1. The adenoma detection rate (ADR) was significantly higher in the TXI group at 58.9% (221 of 375 patients) compared to 42.7% (159 of 372 patients) in the standard white-light imaging (WLI) group (adjusted RR 1.38, 95% CI 1.20-1.59).

2. The mean number of adenomas detected per colonoscopy (APC) was significantly increased with TXI (1.36 ± 1.79) versus WLI (0.89 ± 1.35), yielding an incidence rate ratio of 1.53 (95% CI 1.25-1.88).

3. TXI improved the detection of both small (≤5 mm, RR 1.42) and medium-sized (6-9 mm, RR 1.36) adenomas, as well as lesions located in both the proximal (RR 1.28) and distal (RR 1.46) colon.

4. Mean withdrawal times were similar between the TXI and WLI groups (approximately 8 minutes), indicating that the enhanced imaging modality did not prolong the procedure.

Study Design

Design

Randomized Controlled Trial

Single-Blind

Sample

747

Patients

Duration

N/A

Median

Setting

Multicenter, International

Population Consecutive patients aged ≥40 years undergoing screening, surveillance, or diagnostic colonoscopy

Intervention Colonoscopy utilizing Texture and Color Enhancement Imaging (TXI)

Comparator Colonoscopy utilizing high-definition white-light imaging (WLI)

Outcome Adenoma detection rate (ADR)

Study Limitations

• As with most endoscopic imaging trials, the endoscopists could not be blinded to the imaging modality, which introduces potential performance bias.

• The trial was conducted by experienced endoscopists at specialized centers, all of whom already possessed high baseline ADRs; thus, the magnitude of the benefit might differ for community endoscopists with lower baseline detection rates.

• The study was not adequately powered to detect differences in the detection of advanced adenomas or actual colorectal cancer.

• Long-term outcomes, such as the reduction in interval colorectal cancer rates, were not evaluated.

Clinical Significance

The study demonstrates that integrating TXI—an image-enhancement tool that computationally optimizes color, brightness, and texture—into routine colonoscopy significantly increases the detection of precancerous adenomas without increasing procedural time. Because higher ADRs are strongly inversely correlated with risks of interval colorectal cancer and mortality, the routine use of TXI represents a viable, low-friction strategy to optimize colorectal cancer screening efficacy.

Historical Context

For decades, high-definition white-light imaging (HD-WLI) has been the gold standard for screening colonoscopy, but it misses roughly 20-25% of adenomas, particularly flat and subtle lesions. While dye-based chromoendoscopy improves detection, it is cumbersome. This led to the development of equipment-based image-enhanced endoscopy (IEE), such as Narrow Band Imaging (NBI) and Linked Color Imaging (LCI). TXI (Texture and Color Enhancement Imaging), introduced in the EVIS X1 system by Olympus, takes a different approach by computationally enhancing texture, brightness, and color gradients (specifically expanding the red and white color spaces) in real-time, producing an image that remains close to natural white light but sharply highlights mucosal irregularities. The Antonelli 2023 trial was a landmark as the first large, international, multicenter randomized controlled trial to robustly demonstrate TXI's superiority over standard WLI in detecting colorectal neoplasia.

Guided Discussion

High-yield insights from every perspective

Med Student

Medical Student

What is the Adenoma Detection Rate (ADR), and why is it considered the most important quality metric in screening colonoscopies?

Key Response

ADR is the percentage of screening colonoscopies in which at least one adenoma is found. It directly correlates with the risk of interval colorectal cancers; for every 1 percent increase in ADR, there is an estimated 3 percent decrease in the risk of interval CRC, making it a foundational concept for learning about colon cancer prevention.

Resident

Given the improved ADR with TXI, should image-enhanced endoscopy techniques be routinely activated during withdrawal for all average-risk screening colonoscopies, or should they be reserved for specific situations?

Key Response

Currently, HDWL is the standard, but routine use of Image Enhanced Endoscopy (IEE) during withdrawal is becoming more common as evidence shows ADR improvement, particularly for flat or subtle serrated lesions. Residents must learn to balance time, equipment availability, and diagnostic yield when establishing their standard withdrawal practices.

Fellow

How does TXI mechanically differ from Narrow Band Imaging (NBI) or Blue Light Imaging (BLI) in enhancing mucosal visualization, and how might this impact the detection of right-sided sessile serrated lesions (SSLs) versus conventional adenomas?

Key Response

NBI and BLI use specific light wavelengths to highlight hemoglobin and vascularity, whereas TXI computationally enhances color contrast, texture, and brightness of white-light images. Fellows must understand that this broader enhancement might theoretically improve detection of pale, flat SSLs in the right colon, which often lack the prominent vascular patterns targeted by NBI.

Attending

If implementing TXI broadly increases ADR by predominantly finding diminutive hyperplastic or benign polyps rather than advanced adenomas, how do we address the downstream consequences of increased pathology costs and prolonged procedure times?

Key Response

A common critique of IEE technologies is the risk of over-detection. While raising ADR is beneficial, finding clinically insignificant diminutive polyps increases healthcare burdens. Attendings must weigh whether the ADR bump translates to a meaningful reduction in CRC morbidity and consider adopting optical diagnosis strategies to offset pathology costs.

Scholarly Review

Critical appraisal through the lens of expert reviewers and guideline development

PhD

In a multicenter randomized trial comparing endoscopic imaging modalities, what are the primary threats to blinding and standardization, and how should endoscopist-level baseline ADR variations be accounted for in the statistical model?

Key Response

Endoscopists cannot be blinded to the imaging modality they are using, introducing performance bias. A robust methodology must use stratified randomization by endoscopist or mixed-effects models adjusting for baseline ADR to ensure the observed effect is due to TXI rather than operator skill or differential withdrawal times.

Journal Editor

When reviewing a trial reporting a significant increase in ADR with a proprietary imaging technology, how heavily should the editorial board scrutinize industry funding, and what objective secondary endpoints are required to prevent publication bias favoring marginal tweaks?

Key Response

Editors must be vigilant about industry-sponsored device trials that might show a statistically significant but clinically marginal ADR increase. Requiring metrics like Adenomas Per Colonoscopy (APC), Advanced Adenoma Detection Rate, and strict documentation of withdrawal times ensures the finding represents a true clinical advancement.

Guideline Committee

Does the addition of TXI data provide sufficient Level 1 evidence to upgrade current ESGE and USMSTF guidelines to universally recommend image-enhanced withdrawal over standard high-definition white-light for average-risk screening?

Key Response

While current guidelines acknowledge various image-enhancing techniques, they do not universally mandate their use over HDWL for average risk. The committee must evaluate if the pooled evidence across modalities like TXI and NBI now warrants a strong recommendation for routine use, balancing the ADR benefits against the lack of long-term interval CRC reduction data.

Clinical Landscape

Noteworthy Related Trials

2011

Narrow-Band Imaging vs High-Definition White-Light Endoscopy Trial

n = 1,256 · Gastroenterology

Tested

Narrow-Band Imaging (NBI)

Population

Adults undergoing screening or surveillance colonoscopy

Comparator

High-Definition White-Light Endoscopy (HD-WLE)

Endpoint

Adenoma Detection Rate (ADR)

Key result: NBI did not significantly improve the overall adenoma detection rate compared to high-definition white-light endoscopy during routine screening.

2019

LCI-FIND Trial

n = 1,414 · Ann Intern Med

Tested

Linked Color Imaging (LCI) colonoscopy

Population

Patients undergoing screening, surveillance, or diagnostic colonoscopy

Comparator

White-light endoscopy (WLE)

Endpoint

Proportion of patients with at least 1 neoplastic lesion detected

Key result: LCI significantly increased the detection of neoplastic lesions compared to WLE, finding more adenomas per patient without increasing withdrawal time.

2020

GI-Genius CADe Trial

n = 685 · Gastroenterology

Tested

Real-time computer-aided detection (CADe) integrated with HD-WLE

Population

Patients undergoing screening or surveillance colonoscopy

Comparator

HD-WLE alone

Endpoint

Adenoma Detection Rate (ADR)

Key result: The use of an AI-based CADe system significantly increased the ADR to 54.8% compared to 40.4% with standard HD-WLE.

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