Introduction

Computer-aided detection (CADe) systems have gained attention for their use in colonoscopy, with growing evidence of increased adenoma detection rates (ADR). However, results remain inconsistent, and debate regarding their usefulness continues, including their impact on serrated lesion (SL) detection and performance across varying levels of endoscopist expertise. Given that CADe is used as a real-time assistive tool, it is crucial to confirm its efficacy in lesion detection before considering long-term outcomes.

Aims & Methods

We conducted a multinational, multicenter randomized controlled trial in the Asia-Pacific (Project CAD/NCCH2217; jRCT1032230396) to assess the efficacy of CADe in improving lesion detection during colonoscopy performed as part of colorectal cancer (CRC) screening [1]. We enrolled asymptomatic individuals aged 50–79 years undergoing either primary screening colonoscopy or colonoscopy following a positive fecal immunochemical test (FIT), who had not received colonoscopy in the past 5 years. Participants were randomly assigned (1:1) to the CADe group (colonoscopy with CADe assistance) or the standard group (colonoscopy without CADe) using a minimization method to balance age, sex, colonoscopy indication, endoscopist experience, and country/region. In the CADe group, approved CADe devices were used in accordance with each country's regulations, including EndoBRAIN-EYE, ENDO-AID, CAD EYE, and WISE VISION. All procedures were performed by endoscopists with experience of ≥500 colonoscopies. The primary endpoint was adenoma detection rate (ADR). Secondary endpoints included adenomas per colonoscopy (APC), advanced ADR (AADR), sessile serrated lesion detection rate (SSLDR), sessile serrated lesions per colonoscopy (SSLPC), scope withdrawal time, and the resection rate of non-neoplastic lesions. Planned sample size was 1400 cases (one-sided α = 0.05, 80% power).

Results

Of the 1,399 participants enrolled between December 28, 2023, and March 6, 2025, 1,373 were included in the full analysis set (688 and 685 in the CADe and standard groups, respectively). In both groups, the proportions of primary screening and post-FIT colonoscopies were 75% and 25%, respectively. No differences were observed between the CADe and standard groups in ADR (54.7% vs. 53.9%; odds ratio [OR] 1.04; 95% confidence interval [CI], 0.83–1.30, one-sided p=0.38), APC (1.17 vs. 1.24; risk ratio [RR], 0.94; 95% CI, 0.81–1.09), or AADR (5.5% vs. 7.6%; OR, 0.71; 95% CI, 0.46–1.10). The CADe group showed higher SSLDR (9.0% vs. 6.0%; OR, 1.55; 95% CI, 1.03–2.33) and SSLPC (0.11 vs. 0.07; RR, 1.65; 95% CI, 1.09–2.50). Subgroup analysis based on endoscopist experience demonstrated a higher SSLDR in the CADe group among those with 500–4,999 (10.1% vs. 5.4%) and 5,000–9,999 (11.9% vs. 3.6%) prior colonoscopies, but not among those with experience of ≥10,000 procedures (7.0% vs. 7.5%). There was no difference between groups in the non-neoplastic lesion resection rate (14.7% vs. 13.4%; OR, 1.11; 95% CI, 0.82–1.50), and the median scope withdrawal time in cases without polypectomy was 9 minutes in both groups.

Conclusion

CADe assistance did not improve adenoma detection where high ADR was already achieved with standard colonoscopy. Nevertheless, it enhanced SSL detection, except among highly experienced endoscopists, without prolonging withdrawal time or increasing unnecessary polypectomies. While our findings do not overstate the efficacy of CADe, they support a reasonable and practical role for its use in improving colonoscopy quality in CRC screening.

References

1. Sekiguchi M, et al. Protocol for a multicenter randomized controlled trial to assess the usefulness of computer-aided detection systems for colonoscopy in colorectal cancer screening in the Asia-Pacific region (project CAD/NCCH2217). Jpn J Clin Oncol. 2025; 55: 837-40.

Disclosure

The authors have no conflict of interest related with this study.

Introduction

Accurate endoscopic diagnosis of colorectal polyps is essential for determining appropriate treatment strategies. The Japan NBI Expert Team (JNET) classification and pit pattern diagnosis are used for diagnosis, but their comparative diagnostic performance in real-world clinical settings remains unclear, particularly between experts and non-experts.

Aims & Methods

This post-hoc analysis aimed to evaluate the diagnostic accuracy of both classification across different levels of expertise using data from a prospective multicenter trial. We conducted a post-hoc analysis of the deTXIon trial¹ , a randomized controlled trial conducted at eight Japanese institutions between March and October 2023. From the per-protocol set, we analyzed colorectal lesions that had both JNET classification and pit pattern diagnosis with confirmed histopathology. JNET classification categorizes lesions into Type 1 (corresponding to hyperplastic polyps [HPs] and sessile serrated lesions [SSLs]), Type 2A (low-grade adenomas), Type 2B (high-grade adenomas or superficial submucosal invasive cancer), and Type 3 (deep submucosal invasive cancer). Pit pattern classification included Type II ( HPs/SSLs ), Type III_S/III_L/IV (low-grade adenomas), Type V_I low-grade (high-grade adenoma), and Type V_I high-grade/V_N (submucosal invasive cancer). We calculated sensitivity (Sen), specificity (Spe), positive predictive value (PPV), and negative predictive value (NPV) for each classification stratified by endoscopist expertise and lesion size.

Results

A total of 1,617 colorectal lesions with a median size (IQR) of 2(1-4) mm were included in this analysis. Histopathological examination revealed that 71.5% (1,156/1,617) were low-grade adenomas, 1.0% (16/1,617) were high-grade adenomas or cancer, 19.3% were HPs (312/1,617), and 8.2% (133/1,617) were SSLs. For JNET Type 1 lesions, diagnostic accuracy was comparable between experts (Sen: 82.8%, Spe: 95.9%, PPV: 88.3%, NPV: 93.7%) and non-experts (Sen: 81.7%, Spe: 93.4%, PPV: 83.1%, NPV: 92.8%). Similarly, for JNET Type 2A, both groups showed high diagnostic performance (experts: Sen 93.8%, Spe 81.0%, PPV: 92.6%, NPV: 83.8%; non-experts: Sen 91.5%, Spe 78.3%, PPV: 90.3%, NPV: 80.6%).
In contrast, pit pattern diagnosis experts showed higher performances, particularly for Type II (experts: Sen 80.9%, Spe 96.3%, PPV: 89.0%, NPV: 93.1%; non-experts: Sen 57.9%, Spe 92.8%, PPV: 76.0%, NPV: 84.8%). The diagnostic performance for small lesions (≤5mm) was consistently high with JNET classification (Type 1: Sen 79.5%, Spe 94.3%; Type 2A: Sen 93.7%, Spe 79.2%), while pit pattern diagnosis showed lower performance (Type II: Sen 70.8%, Spe 94.5%; Type III_S/III_L/IV: Sen 93.6%, Spe 79.5%), for these lesions among non-experts.

Conclusion

JNET classification demonstrates comparable diagnostic performance between expert and non-expert endoscopists, likely due to its standardized and intuitive visual criteria. Pit pattern diagnosis shows experience-dependent performance differences, suggesting that NBI-based assessment may be more suitable for routine clinical practice, especially for diminutive lesions.

References

1. Toyoshima N, Mizuguchi Y, Takamaru H,et al. The Efficacy of Texture and Color Enhancement Imaging Observation in the Detection of Colorectal Lesions: A Multicenter, Randomized Controlled Trial (deTXIon Study). Gastroenterology. 2025 in press

Disclosure

These authors disclose the following: Yutaka Saito, Masashi Misawa, Shin-ei Kudo, and Toshio Uraoka have received lecture fees from Olympus
Corporation. The remaining authors disclose no conflicts.

Introduction

Capsule colonoscopy and Pan-intestinal Capsule Endoscopy (PCE) are well-established diagnostic procedures. However, the optimal bowel preparation regimen remains undefined, with pooled adequate cleansing rates reaching only 72.5%¹. While ultra-low volume preparations (≤1L) have demonstrated efficacy in conventional colonoscopy², their effectiveness in capsule-based modalities has yet to be determined.

Aims & Methods

In this prospective, randomized, researcher-blind, single center trial, we compared the efficacy of two ultra-low volume bowel preparation regimens, 1L Polyethylene Glycol Plus Ascorbic Acid (PEG-Asc) and 1L Sodium Picossulfate with Magnesium Citrate (SPMC). Patients referred for capsule-based procedures were randomized in a 1:1 ratio to receive either PEG-Asc or SPMC. The primary endpoints were the rates of complete examinations, adequate bowel preparation, and excellent right colon cleansing.

Results

A total of 117 patients were included, referred for capsule colonoscopy due to incomplete colonoscopy (76.1%) or for PCE to assess luminal inflammation (17.9%) or anemia (6%). Overall, 61.5% were female, with a mean age of 61.3 ± 16 years. The complete examination rate was 71.8%, with no significant difference between groups (PEG-Asc 72.9% vs. SPMC 70.7%; p = 0.792). Adequate bowel preparation was achieved in 62.4% of cases, which was significantly more frequent in the PEG-Asc group (72.9%) compared to SPMC (51.7%; p = 0.018). Among complete procedures, excellent right colon cleansing was observed more often with PEG-Asc (34.1%) than with SPMC (7.3%; p = 0.003).

Conclusion

The completion and adequate preparation rates remain suboptimal in the capsule colonoscopy and PCE procedures. In this study, both ultra-low volume purgative solutions demonstrated comparable efficacy in achieving complete examinations, but the PEG-Asc resulted in significantly better overall preparation quality and superior right colon cleansing compared to SPMC. These findings suggest that PEG-Asc may be the preferred ultra-low volume regimen for optimizing bowel visualization in capsule-based examinations.

References

1. Rosa, B., Donato, H., Cúrdia Gonçalves, T., Sousa-Pinto, B. & Cotter, J. What Is the Optimal Bowel Preparation for Capsule Colonoscopy and Pan-intestinal Capsule Endoscopy? A Systematic Review and Meta-Analysis. Dig. Dis. Sci. 68, 4418–4431 (2023).
2. Arieira, C. et al. Bowel cleansing efficacy for colonoscopy: prospective, randomized comparative study of same-day dosing with 1-L and 2-L PEG + ascorbate. Endosc. Int. Open 09, E1602–E1610 (2021).