Short educational video to improve the accuracy of colorectal polyp size estimation: Multicenter prospective study

Use of a short educational video to improve the accuracy of colorectal polyp morphology assessment: A multicenter randomized controlled study

Objectives

Although accurate assessment of polyp morphology helps endoscopists select the appropriate management for colorectal polyps, some studies have reported unsatisfactory accuracy in such assessment. This study aimed to clarify the usefulness of a short educational video available on the Internet for accurate polyp morphology assessment.

Methods

This was a multicenter randomized controlled trial. Participants were randomly assigned to the pre- or post-education groups after a pre-test comprising images of 42 polyps, including 12 laterally spreading tumors. Participants who scored ≥ 80% on the pre-test were excluded. Only the post-education group completed the diagnostic test after watching an online educational video. The primary outcome was the difference in diagnostic accuracy between the pre-test and diagnostic tests for each group.

Results

Of the 296 endoscopists enrolled from 48 institutions, 34 missed the test deadline, and 29 who scored ≥ 80% in the pre-test were excluded. The primary outcome analysis sets were 117 and 116 in the pre- and post-education groups, respectively. The mean pre-test accuracies in the pre-education and post-education groups were 60.6% and 60.7%, respectively. The difference in diagnostic accuracy between the pre-test and diagnostic test was significantly higher in the post-education than the pre-education group (12.0 points, 95% confidence interval [CI] 9.9-14.1 and 2.3 points, 95% CI 0.9-3.6; p < 0.001).

Conclusion

This multicenter randomized controlled trial demonstrated the usefulness of a short educational video for accurate polyp morphology assessment.

Short- and longer-term learning effects from virtual scale endoscopy videos: a useful tool for colorectal lesion size estimation (with videos)

BACKGROUND AND AIMS

Accurate assessment of colorectal polyp size is crucial for determining treatment and surveillance policies. However, visual estimation of lesion diameter is often inaccurate, making simple and effective educational tools essential. We aimed to evaluate the learning effects of virtual scale endoscopy (VSE).

METHODS

Thirty-three endoscopists first watched prelearning videos for SET1. They then estimated the diameters of 20 lesions and referred to instructional videos with VSE for self-study. Subsequently, they watched the postlearning videos for SET2 and estimated the lesion diameters. The error between the estimated and correct lesion sizes of both sets was compared. To evaluate longer-term learning effects, participants answered SET3 and SET4, which consisted of the same questions as SET2 and SET1, respectively, but 2 to 3 months later without watching the instructional video for SET2.

RESULTS

The error in the participants' estimation of the correct lesion diameter improved from SET1 to SET2 (34.7 ± 6.6 mm vs 30.7 ± 7.7 mm, P = .048), with a significant learning effect and error improvement specifically among nonexperts (35.2 ± 5.3 mm vs 30 ± 6.8 mm, P = .028). In SET3 and SET4, participants' errors indicated that the learning effect was well maintained (SET2 vs SET3: 30.7 ± 7.7 mm vs 28.6 ± 7.2 mm [P = .1]; SET1 vs SET4: 34.7 ± 6.6 mm vs 31.7 ± 7.1 mm [P = .025]).

CONCLUSIONS

VSE videos are a valuable learning tool for estimating lesion diameter, particularly for novice endoscopists, both in the short and longer term.

A real-time deep learning-based system for colorectal polyp size estimation by white-light endoscopy: development and multicenter prospective validation

BACKGROUND

The choice of polypectomy device and surveillance intervals for colorectal polyps are primarily decided by polyp size. We developed a deep learning-based system (ENDOANGEL-CPS) to estimate colorectal polyp size in real time.

METHODS

ENDOANGEL-CPS calculates polyp size by estimating the distance from the endoscope lens to the polyp using the parameters of the lens. The depth estimator network was developed on 7297 images from five virtually produced colon videos and tested on 730 images from seven virtual colon videos. The performance of the system was first evaluated in nine videos of a simulated colon with polyps attached, then tested in 157 real-world prospective videos from three hospitals, with the outcomes compared with that of nine endoscopists over 69 videos. Inappropriate surveillance recommendations caused by incorrect estimation of polyp size were also analyzed.

RESULTS

The relative error of depth estimation was 11.3% (SD 6.0%) in successive virtual colon images. The concordance correlation coefficients (CCCs) between system estimation and ground truth were 0.89 and 0.93 in images of a simulated colon and multicenter videos of 157 polyps. The mean CCC of ENDOANGEL-CPS surpassed all endoscopists (0.89 vs. 0.41 [SD 0.29]; P<0.001). The relative accuracy of ENDOANGEL-CPS was significantly higher than that of endoscopists (89.9% vs. 54.7%; P<0.001). Regarding inappropriate surveillance recommendations, the system's error rate is also lower than that of endoscopists (1.5% vs. 16.6%; P<0.001).

CONCLUSIONS

ENDOANGEL-CPS could potentially improve the accuracy of colorectal polyp size measurements and size-based surveillance intervals.

Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size

INTRODUCTION

The virtual scale endoscope (VSE) is a newly introduced endoscope that helps endoscopists in measuring colorectal polyp size (CPS) during colonoscopy by displaying a virtual scale. This study aimed to determine the usefulness of the VSE for CPS measurement and the educational benefit of using VSE images to improve CPS estimation accuracy.

METHODS

This study included 42 colorectal polyps in 26 patients treated at Hiroshima University Hospital. In study 1, CPS measured using a VSE before endoscopic mucosal resection was compared with CPS measured on resected specimens, and the agreement between the two measurement methods was evaluated via Bland-Altman analysis. In study 2, 14 endoscopists (5 beginners, 5 intermediates, and 4 experts) took a pre-test to determine the size of 42 polyps. After the pre-test, a lecture on CPS measurement using VSE images was given. One month later, the endoscopists took a post-test to compare CPS accuracy before and after the lecture.

RESULTS

In study 1, Bland-Altman analysis revealed no fixed or proportional errors. The mean bias ±95% limits of agreement (±1.96 standard deviations) of the measurement error was -0.05 ± 0.21 mm, indicating that the agreement between two measurement methods was sufficient. In study 2, the accuracy of CPS measurement was significantly higher among beginners (59.5% vs. 26.7%, p < 0.01) and intermediates (65.2% vs. 44.3%, p < 0.05) in the post-test than in the pre-test.

CONCLUSION

The VSE accurately measures CPS before resection, and its images are useful teaching tools for beginner and intermediate endoscopists.

Factors associated with inaccurate size estimation of colorectal polyps: A multicenter cross-sectional study

BACKGROUND AND AIM

Accurate polyp size estimation is essential in deciding the therapeutic strategy of colorectal polyps and endoscopic surveillance intervals. However, many endoscopists frequently make incorrect size estimations without being aware of their errors. This cross-sectional study aimed to clarify the characteristics of endoscopists associated with inaccurate estimation.

METHODS

We previously conducted a web trial involving 261 endoscopists in 51 institutions in Japan to assess their ability to estimate polyp size. Participants answered questions about polyp size using visual estimates in a test involving images of 30 polyps. Here, we investigated the relationships between inaccurate size estimation and the backgrounds of participants. The rates of overestimation and underestimation of polyp size were also compared to clarify any trends in the answers of participants with low accuracy (< 50%).

RESULTS

Multivariable logistic regression analysis revealed that the number of colonoscopic procedures in the past year was the only factor associated with a low accuracy of polyp size estimation (odds ratio 0.750, 95% confidence interval 0.609-0.925; P = 0.007). Endoscopists with low accuracy had a greater tendency to overestimate polyp size (42.3% overestimation and 21.2% underestimation, P < 0.001) compared with other endoscopists (16.6% overestimation and 17.9% underestimation, P = 0.951).

CONCLUSIONS

Endoscopists with limited experience of colonoscopy in the past year were more likely to make frequent errors in size estimation. Furthermore, endoscopists making inaccurate size estimations had a propensity to overestimate polyp size.

Usefulness of a Colonoscopy Cap with an External Grid for the Measurement of Small-Sized Colorectal Polyps: A Prospective Randomized Trial

Accurate measurement of polyp size during colonoscopy is crucial. The usefulness of cap-assisted colonoscopy and external grid application on monitor (gCAP) was evaluated for polyp size measurement in this 3-year, single-center, single-blind, randomized trial. Using the endoscopic forceps width as reference, the discrepancy percent (DP), error rate (ER), and measurement time were compared between gCAP and visual estimation (VE) after randomization. ER was calculated within a 20% and 33% limit. From the 111 patients, 280 polyps were measured. The mean polyp sizes were 4.0 ± 1.7 mm and 4.2 ± 1.8 mm with gCAP and VE, respectively (p = 0.368). Compared with that by the forceps method, DP was significantly lower in the gCAP group than in the VE group. Moreover, ER was significantly lower in the gCAP group within its preset limit. The measurement time was 4 s longer in the gCAP group than in the VE group (8.2 ± 4.8 s vs. 4.2 ± 1.5 s; p < 0.001). However, the forceps method lasted 28 s longer than the others. On subgroup analysis by size, gCAP was more accurate for polyp size ≥ 5 mm. The gCAP method was more accurate for polyp size measurement than VE, especially for polyps ≥ 5 mm, and was more convenient than the forceps method.