Polyp Size Measurement Research Articles

Colorectal polyp size measurement: can we trust our own eyes?

Colorectal polyp size measurement: can we trust our own eyes?

Comparison of the Size Measurement of Gallbladder Polyps by Three Different Radiologists in Abdominal Ultrasonography.

There is little information regarding the size measurement differences in gallbladder (GB) polyps performed by different radiologists on abdominal ultrasonography (US). To reveal the differences in GB polyp size measurements performed by different radiologists on abdominal US. From June to September 2022, the maximum diameter of 228 GB polyps was measured twice on abdominal US by one of three radiologists (a third-year radiology resident [reader A], a radiologist with 7 years of experience in abdominal US [reader B], and an abdominal radiologist with 8 years of experience in abdominal US [reader C]). Intra-reader agreements for polyp size measurements were assessed by intraclass correlation coefficient (ICC). A Bland-Altman plot was used to visualize the differences between the first and second size measurements in each reader. Reader A, reader B, and reader C evaluated 65, 77, and 86 polyps, respectively. The mean size of measured 228 GB polyps was 5.0 ± 1.9 mm. Except for the case where reader A showed moderate intra-reader agreement (0.726) for polyps with size ≤ 5 mm, all readers showed an overall high intra-reader reliability (reader A, ICC = 0.859; reader B, ICC = 0.947, reader C, ICC = 0.948), indicative of good and excellent intra-reader agreements. The 95% limit of agreement of reader A, B, and C was 1.9 mm of the mean in all three readers. GB polyp size measurement on abdominal US showed good or excellent intra-reader agreements. However, size changes of approximately less than 1.9 mm should be interpreted carefully because these may be within the measurement error.

CT colonography has advantages over colonoscopy for size measurement of colorectal polyps

PurposeThe aim of this study was to compare the accuracy of colonoscopy (CS) and CT colonography (CTC) in the measurement of colorectal polyps using pathological size as a reference.Materials and methodsThe analysis included 61 colorectal polyps in 28 patients who underwent preoperative CTC at our institution. All polyps were endoscopically resected. Polyp sizes were measured by CS and CTC. Endoscopic polyp size was extracted from endoscopy records written by one of two endoscopists (A with 11 and B with 6 years of endoscopic experience, respectively), who estimated the size visually/categorically without any measuring devices. After matching the location, the polyp size was measured on CTC using manual three-dimensional (3D) measurement on a workstation. The sizes of resected polyps were also measured after pathological inspection. Differences of the polyp size between CTC and histology, and between CS and histology were compared using paired t tests. Differences in measurement between the two endoscopists were also analyzed.ResultsThe mean diameters of polyps measured using CS, CTC, and pathology were 10.5 mm, 9.2 mm, and 8.4 mm, respectively. There was a significant correlation between CS and pathology, as well as between CTC and pathology (both P < 0.0001). The correlation coefficient for CS (r = 0.86) was lower than that for CTC (r = 0.96). The correlations between CS and pathology for endoscopists A and B were 0.90 and 0.89, respectively.ConclusionMeasurements of polyp size using CTC were closer to the pathological measurements compared to those by CS, which exhibited greater variability. This suggests that CTC may be more suitable for polyp size measurements in the clinical setting if patients undergo CTC concurrently with colonoscopy.

A Preclinical Blinded Randomized-Controlled Trial Evaluating the Clinical Relevance of Polyp Size Measurement Using a Virtual Scale Endoscope.

The virtual scale endoscope (VSE) helps endoscopists measure colorectal polyp size more accurately compared to visual assessment (VA). However, previous studies were not adequately powered to evaluate the sizing of polyps at clinically relevant size thresholds and relative accuracy for size subgroups. We created 64 artificial polyps of varied sizes and Paris class morphology, randomly assigned 1:1 to be measured (383 total measurement datapoints with VSE and VA by 6 endoscopists blinded to true size) in a colon model. We added data from two previous trials (480 measurement datapoints). We evaluated for correct classification of polyps into size groups at 3 mm, 5 mm, 10 mm, and 20 mm size thresholds and the relative size measurement accuracy for diminutive polyps (≤5 mm), small polyps (5-9 mm), large polyps at 10-19 mm, and polyps (≥20). VSE had significantly less size group misclassifications at the 5 mm, and 10 mm thresholds (28 percent vs. 45 percent, P = 0.0159 and 26 percent vs. 44 percent, P = 0.0135, respectively). For the 3 mm and 20 mm thresholds, VSE had lower misclassifications; however, this was not statistically significant (36 percent vs. 46 percent, P = 0.3853 and 38 percent vs. 41 percent, P = 0.2705, respectively). The relative size measurement accuracy was significantly higher for VSE compared to VA for all size subgroups (diminutive (P < 0.01), small polyps (P < 0.01), 10-19 mm (P < 0.01), and ≥20 mm (P < 0.01)). VSE outperforms VA in categorizing polyps into size groups at the clinically relevant size thresholds of 5 mm and 10 mm. Using VSE resulted in significantly higher relative measurement accuracy for all size subgroups.

Measuring Size of Colorectal Polyps Using a Virtual Scale Endoscope or Visual Assessment: A Randomized Controlled Trial.

This study aimed to compare the accuracy of polyp size measurements using a virtual scale endoscope (VSE) with an integrated laser-based adaptive scale function and visual assessment (VA) during colonoscopies. We conducted a single-blinded, prospective randomized controlled trial. Eligible patients (aged 45-80 years) undergoing screening, surveillance, or diagnostic colonoscopies were randomly assigned (1:1) into 2 groups. In the intervention group, all detected polyps were measured for size using VSE; in the control group, all polyps were measured using VA. Size measurements were compared with a reference standard of digital caliper measurement immediately post polypectomy. The primary outcome was the relative accuracy of real-time VSE measurement compared with VA. Secondary outcomes included the mean differences and the correlations between VSE or VA sizes and the reference standard of measurement. Overall, 230 patients were enrolled and randomized. The relative size measurement accuracy of VSE was 84% in 118 polyps, which was significantly higher than that of VA (105 polyps; 68.4%, P < 0.001). VSE resulted in a significantly higher percentage of size measurements within 25% of true size compared with VA (81.4% vs 41%, P < 0.001). VSE had a significantly lower percentage for >5-mm polyps incorrectly sized as 1-5 mm compared with VA (13.5% vs 57.1%; P < 0.001) and a significantly lower percentage for >3-mm polyps incorrectly sized as 1-3 mm compared with VA (11.3% vs 56.5%; P < 0.001). VSE significantly improves the size measurement accuracy of colorectal polyps during colonoscopies compared with VA and results in fewer misclassifications at relevant decision-making size thresholds.

Accuracy in Polyp Size Measurement Among Surgeons, Gastroenterologists, Trainees, and Experts: A Prospective Video-Based Study.

Polyp size determination plays an important role in endoscopic decision making and follow-up determination. However, there is a lack of knowledge of endoscopist accuracy for polyp sizing and efficacy of available tools for size measurement. Our aim was to compare the accuracy of visual assessment, snare, forceps, and virtual scale endoscope (VSE) in estimating polyp size among a diverse group of endoscopists. We conducted a prospective video-based study. One hundred twenty polyps measured and recorded along with all available measurement tools were randomized to visual assessment, snare, forceps, or VSE group. Eleven endoscopists conducted video-based measurement using the randomized measurement tool. Primary outcome was relative accuracy in polyp size measurement compared with caliper measurement immediately postresection. One thousand three hundred twenty measurements were performed. VSE had statistically significantly higher relative accuracy when compared to forceps (79.3 vs 71.3%; P < 0.0001). Forceps had statistically significantly higher relative accuracy when compared to visual assessment (71.3 vs 63.6%; P = 0.0036). There was no statistically significant difference when comparing visual assessment and snare-based measurements (63.6 vs 62.8%; P = 0.797). Overall, 21.5% of polyps >5 mm were misclassified as ≤5 mm and 17.3% of polyps ≥10 mm were misclassified as <10 mm. VSE had the lowest percentage of polyps >5 mm misclassified as ≤5 mm (2.6%), polyps ≤5 mm misclassified as >5 mm (5.1%), and polyps <10 mm misclassified as ≥10 mm (1.7%). Visual size estimation of polyps is inaccurate independently of training level, sex, and specialty. Size measurement accuracy can be improved using forceps and yields the highest relative accuracy when an adaptive scale technology is used.

Endoscopic measurement of the size of gastrointestinal polyps using an electromagnetic tracking system and computer vision-based algorithm

PurposePolyp size is an important factor that may influence diagnosis and clinical management decision, but estimation by visual inspection during endoscopy is often difficult and subject to error. The purpose of this study is to develop a quantitative approach that enables an accurate and objective measurement of polyp size and to study the feasibility of the method.MethodsWe attempted to estimate polyp size and location relative to the gastro-oesophageal junction by integrating data from an electromagnetic tracking sensor and endoscopic images. This method is based on estimation of the three-dimensional coordinates of the borders of the polyp by combining the endoscope camera position and the corresponding points along the polyp border in endoscopic images using a computer vision-based algorithm. We evaluated the proposed method using a simulated upper gastrointestinal endoscopy model.ResultsThe difference between the mean of ten measurements of one artificial polyp and its actual size (10 mm in diameter) was 0.86 mm. Similarly, the difference between the mean of ten measurements of the polyp distance from the gastroesophageal junction and its actual distance (~ 22 cm) was 1.28 mm. Our results show that the changes in camera positions in which the images were taken and the quality of the polyp segmentation have the most impact on the accuracy of polyp size estimation.ConclusionThis study demonstrated an innovative approach to endoscopic measurements using motion tracking technologies and computer vision and demonstrated its accuracy in determining the size and location of the polyp. The observed magnitude of error is clinically acceptable, and the measurements are available immediately after the images captured. To enhance accuracy, it is recommended to avoid identical images and instead utilise control wheels on the endoscope for capturing different views. Future work should further evaluate this innovative method during clinical endoscopic procedures.

Artificial intelligence-based polyp size measurement in gastrointestinal endoscopy using the auxiliary waterjet as a reference.

Measurement of colorectal polyp size during endoscopy is mainly performed visually. In this work, we propose a novel polyp size measurement system (Poseidon) based on artificial intelligence (AI) using the auxiliary waterjet as a measurement reference. Visual estimation, biopsy forceps-based estimation, and Poseidon were compared using a computed tomography colonography-based silicone model with 28 polyps of defined sizes. Four experienced gastroenterologists estimated polyp sizes visually and with biopsy forceps. Furthermore, the gastroenterologists recorded images of each polyp with the waterjet in proximity for the application of Poseidon. Additionally, Poseidon's measurements of 29 colorectal polyps during routine clinical practice were compared with visual estimates. In the silicone model, visual estimation had the largest median percentage error of 25.1 % (95 %CI 19.1 %-30.4 %), followed by biopsy forceps-based estimation: median 20.0 % (95 %CI 14.4 %-25.6 %). Poseidon gave a significantly lower median percentage error of 7.4 % (95 %CI 5.0 %-9.4 %) compared with other methods. During routine colonoscopies, Poseidon presented a significantly lower median percentage error (7.7 %, 95 %CI 6.1 %-9.3 %) than visual estimation (22.1 %, 95 %CI 15.1 %-26.9 %). In this work, we present a novel AI-based method for measuring colorectal polyp size with significantly higher accuracy than other common sizing methods.

Evaluation of the competence of an artificial intelligence-assisted colonoscopy system in clinical practice: A post hoc analysis.

Artificial intelligence-assisted colonoscopy (AIAC) has been proposed and validated in recent years, but the effectiveness of clinic application remains unclear since it was only validated in some clinical trials rather than normal conditions. In addition, previous clinical trials were mostly concerned with colorectal polyp identification, while fewer studies are focusing on adenoma identification and polyps size measurement. In this study, we validated the effectiveness of AIAC in the clinical environment and further investigated its capacity for adenoma identification and polyps size measurement. The information of 174 continued patients who went for coloscopy in Chongqing Rongchang District People's hospital with detected colon polyps was retrospectively collected, and their coloscopy images were divided into three validation datasets, polyps dataset, polyps/adenomas dataset (all containing narrow band image, NBI images), and polyp size measurement dataset (images with biopsy forceps and polyps) to assess the competence of the artificial intelligence system, and compare its diagnostic ability with endoscopists with different experiences. A total of 174 patients were included, and the sensitivity of the colorectal polyp recognition model was 99.40%, the accuracy of the colorectal adenoma diagnostic model was 93.06%, which was higher than that of endoscopists, and the mean absolute error of the polyp size measurement model was 0.62 mm and the mean relative error was 10.89%, which was lower than that of endoscopists. Artificial intelligence-assisted model demonstrated higher competence compared with endoscopists and stable diagnosis ability in clinical use.

Measurement of colorectal polyp size: End of a long-running story?

Although colonoscopy is effective at detecting and removing polyps, which can prevent colorectal cancer (CCR), there is room for improvement. Accurate characterization is necessary to predict histology and to select the most appropriate treatment method; these range from cold-snare polypectomy to surgery through mucosal resection techniques or submucosal dissection. Improvements in CCD captors, optical and numerical zoom functions of colonoscopes, together with virtual chromoendoscopy, can enhance analysis of morphology, pit pattern, and vascular pattern. However, polyp size measurement is problematic, despite it being the basis of all recommendations on polyp resection and monitoring [1] [2] [3].

A112 MEASURING COLORECTAL POLYP SIZE USING A NOVEL VIRTUAL SCALE FUNCTION DURING ENDOSCOPIES: A CLINICAL PILOT STUDY

Abstract Background Although accurate polyp size measurement is essential for adequately managing patients, we still rely on the endoscopists' subjective visual estimation of polyp size in routine practice. Purpose We therefore conducted a clinical pilot study to evaluate relative accuracy of measuring colorectal polyp size during live colonoscopies using a novel virtual scale endoscope (VSE) that superimposes a virtual linear or circular ruler onto objects in the endoscopist's field of view. Method We conducted a pilot phase 1 study to evaluate the relative accuracy of VSE for polyp size measurement. We measured polyp size from fresh polypectomy specimens before formalin fixation using a digital vernier caliper. These reference measurements were compared to visual size estimations and VSE measurements obtained during live colonoscopies. The primary outcome was the relative accuracy of visual size estimation versus size estimation using VSE. The secondary outcome was the percentage of measurements that fall within 25% of true polyp size. Result(s) 43 patients (mean age: 63.3 years; 44.2% male) undergoing screening, surveillance, or diagnostic colonoscopies were included in the pilot study. Colonoscopies were performed by two endoscopists, including one trainee and one staff gastroenterologist. Visual, VSE, and reference size measurements was performed for 17 polyps. VSE during live colonoscopies had a higher relative accuracy of polyp size measurements when compared with visual polyp size estimation 84.3% (95% confidence interval (CI) 77.22% to 91.41%) vs 69.3% (95%CI 61.13% to 77.39%) (p=0.005). The percentage of size measurements that were within 25% of sizes as measured by caliper were 41.2% for visual polyp size estimation and 88.2% for VSE (p=0.02). Conclusion(s) We found that a novel endoscope equipped with a virtual scale allowed for significantly higher accuracy in polyp size measurement. A prospective randomized controlled trial is currently underway to validate these results. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding below: Fujifilm Disclosure of Interest R. Djinbachian: None Declared, M. Zarandi-Nowroozi: None Declared, M. Taghiakbari: None Declared, D. von Renteln Grant / Research support from: Daniel von Renteln is supported by a “Fonds de Recherche du Québec Santé” (FRQS) career development award and has received research funding from ERBE, Ventage, Pendopharm, Fujifilm, and Pentax., Consultant of: Boston Scientific and Pendopharm,

A123 COMPARING SIZE MEASUREMENT OF SIMULATED COLORECTAL POLYPS WHEN USING A NOVEL VIRTUAL SCALE ENDOSCOPE, ENDOSCOPIC RULER OR FORCEPS: A BLINDED RANDOMIZED TRIAL

Abstract Background Accurate polyp size measurement is important for guideline conforming choice of polypectomy techniques and subsequent surveillance interval assignments. Some endoscopic tools (forceps or endoscopic rulers [ER]) exist to help with visual size estimation. A virtual scale endoscope (VSE) has been developed that allows superimposing a virtual measurement scale during live endoscopies. Purpose Our aim was to evaluate the performance of VSE when compared to ER and forceps-based measurement. Method We conducted a randomized trial to evaluate the relative accuracy of size measurement of simulated colorectal polyps when using: VSE, ER, and forceps. Six endoscopists performed 60 measurements randomized at a 1:1:1 ratio using each method. Primary outcome was relative accuracy in polyp size measurement. Secondary outcomes included misclassification of sizes at the 5, 10, and 20mm thresholds. Result(s) A total of 360 measurements were performed. The relative accuracy of biopsy forceps, ER, and VSE was 78.9% (95%CI=76.2-81.5), 78.4% (95%CI=76.0-80.8), and 82.7% (95%CI=80.8-84.8). VSE had significantly higher accuracy compared to biopsy forceps (p=0.02) and ER (p=0.006). VSE misclassified a lower percentage of polyps &amp;gt;5mm as ≤5mm (9.4%) compared to forceps (15.7%) and ER (20.9%). VSE misclassified a lower percentage of ≥20mm polyps as &amp;lt;20mm (8.3%) compared with forceps (66.7%) and ER (75.0%). 25.6%, 25.5%, and 22.5% of polyps ≥10mm were misclassified as &amp;lt;10mm with ER, forceps, and VSE, respectively. Conclusion(s) VSE had significantly higher relative accuracy in measuring polyps compared to ER or forceps assisted measurement. VSE improves correct classification of polyps at clinically important size thresholds. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest R. Djinbachian: None Declared, M. Taghiakbari: None Declared, C. Haumesser: None Declared, M. Zarandi-Nowroozi: None Declared, M. Abou-Khalil: None Declared, S. Sidani: None Declared, J. Liu: None Declared, B. Panzini: None Declared, D. von Renteln Grant / Research support from: Daniel von Renteln is supported by a “Fonds de Recherche du Québec Santé” (FRQS) career development award and has received research funding from ERBE, Ventage, Pendopharm, Fujifilm, and Pentax., Consultant of: Boston Scientific and Pendopharm,

Comparing size measurement of colorectal polyps using a novel virtual scale endoscope, endoscopic ruler or forceps: A preclinical randomized trial.

Background and study aims Accurate polyp size measurement is important for guideline conforming choice of polypectomy techniques and subsequent surveillance interval assignments. Some endoscopic tools (biopsy forceps [BF] or endoscopic rulers [ER]) exist to help with visual size estimation. A virtual scale endoscope (VSE) has been developed that allows superimposing a virtual measurement scale during live endoscopies. Our aim was to evaluate the performance of VSE when compared to ER and BF-based measurement. Methods We conducted a preclinical randomized trial to evaluate the relative accuracy of size measurement of simulated colorectal polyps when using: VSE, ER, and BF. Six endoscopists performed 60 measurements randomized at a 1:1:1 ratio using each method. Primary outcome was relative accuracy in polyp size measurement. Secondary outcomes included misclassification of sizes at the 5-, 10-, and 20-mm thresholds. Results A total of 360 measurements were performed. The relative accuracy of BF, ER, and VSE was 78.9 % (95 %CI = 76.2-81.5), 78.4 % (95 %CI = 76.0-80.8), and 82.7 % (95 %CI = 80.8-84.8). VSE had significantly higher accuracy compared to BF ( P = 0.02) and ER ( P = 0.006). VSE misclassified a lower percentage of polyps > 5 mm as ≤ 5 mm (9.4 %) compared to BF (15.7 %) and ER (20.9 %). VSE misclassified a lower percentage of ≥ 20 mm polyps as < 20 mm (8.3 %) compared with BF (66.7 %) and ER (75.0 %). Of polyps ≥10mm, 25.6 %, 25.5 %, and 22.5 % were misclassified as <10 mm with ER, BF, and VSE, respectively. Conclusions VSE had significantly higher relative accuracy in measuring polyps compared to ER or BF assisted measurement. VSE improves correct classification of polyps at clinically important size thresholds.

Virtual scale endoscope-assisted wide-field resection of large sessile serrated lesions.

Large sessile serrated lesions (SSLs) are associated with a very high risk of incomplete resection. The CARE study found almost 50 % incomplete resections among 10 to 20-mm SSLs [1]. Wide-field cold snare resection with submucosal injection (cap-assisted endoscopic mucosal resection, C-EMR) has been proposed as an effective method to prevent incomplete resection since distinguishing SSL margins during resection is difficult [2] [3] [4]. In contrast to a hot snare, a more extended resection field is recommended for a cold snare [5]. However, quantification of the resection field extent in comparison to polyp size has been challenging in the past. The novel virtual scale endoscope (VSE; SCALE EYE, Fujifilm, Tokyo, Japan) can be used as dedicated technology to measure polyp size before resection and to ensure adequate post-resection defect size. The VSE allows polyp size measurement during live colonoscopies by emitting a laser beam onto the mucosa to measure distance. This permits superimposition of a linear/circular ruler that changes in size depending on distance of the endoscope to the laser point ([Fig. 1]).

Computer-Aided Size Estimation of Colorectal Polyps

The presence of colorectal adenomas sized 10 mm or larger is related to the future risk of colorectal cancer; thus, it plays a crucial role in determining surveillance intervals with colonoscopy1,2. To provide an appropriate surveillance interval, objective and accurate polyp size measurements are mandatory. However, there are many hurdles to achieving this goal: size measurement after polyp removal is influenced by natural shrinkage of polyps; measurement after fixation of formalin is likely to underestimate the polyp size; and interobserver agreement and accuracy in measurement of size during colonoscopy is also suboptimal due to overestimation3 and terminal digit preference bias4.

Artificial intelligence-based measurement outperforms current methods for colorectal polyp size measurement.

An accurate polyp size estimation during colonoscopy is crucial to determine the surveillance interval and predict the risk of malignant progression. However, there is a high degree of subjectivity in estimating polyp size among endoscopists in clinical practice. We aimed to assess the efficacy of a novel method that uses artificial intelligence (AI) to measure the size of colon polyps and compare it with current approaches. Using the W-Net model for vessel segmentation and based on retinal image datasets (DRIVE, STARE, CHASE-DB, and HRF) and colonoscopy images, we developed the bifurcation-to-bifurcation (BtoB) distance measuring method and applied it to endoscopic images. Measurements were compared with those obtained by eight endoscopists (four expert and four trainees). Diagnostic ability and reliability were evaluated using Lin's concordance correlation coefficients (CCCs) and Bland-Altman analyses. For both experts and trainees, visually estimated sizes of the same polyp were significantly inconsistent depending on the camera view used (P < 0.001). Bland-Altman analyses showed that there was a trend toward underestimation of the sizes of the polyps in both groups, especially for polyps larger than 10 mm. The new technique was highly accurate and reliable in measuring the size of colon polyp (CCC, 0.961; confidence interval 0.926-0.979), clearly outperforming the visual estimation and open biopsy forceps methods. The new AI measurement method improved the accuracy and reliability of polyp size measurements in colonoscopy images. Incorporating AI might be particularly important to improve the efficiency of trainees at estimating polyp size during colonoscopy.

The clinical importance of polyp size measurement through two-dimensional saline infusion sonohysterography prior to hysteroscopic resection in predicting premalignant and malignant endometrial lesions.

To evaluate the clinical importance of endometrial polyp size measured using saline infusion sonohysterography (SIS) before performing a hysteroscopic resection in predicting premalignant/malignant lesions. A retrospective observational study analysis was conducted of 365 patients, who underwent SIS, in a reference hospital. The longest plane of the polyp size was taken as base. Polyps were classified as benign, premalignant, or malignant. The rates of premalignant and malignant lesions were 7.4% and 0.9%, respectively. The mean polyp size was 17.7±0.5mm in benign patients and 23.7±1.8mm in premalignant/malignant individuals (P<0.001). In the group of polyps that were 0-10, 10-20, 20-30, and >30mm, premalignancy/malignancy rates were 0.0%, 4.8%, 13.3%, and 18.8%, respectively. The cut-off value for polyp size to be able to predict lesions was calculated as 22.5mm (sensitivity: 63%, specificity: 80%) on receiver operating characteristics curve analysis (P=0.001, area under the curve 0.732). The power of the study was calculated as 90.86%. During the female reproductive years, endometrial polyps smaller than 10mm, as measured in SIS, can be followed. However, when the polyp size is 22.5mm or more, especially in postmenopausal women, treatment should be planned.

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.

Proper window width of polyp size measurement in CT colonography

Proper window width of polyp size measurement in CT colonography

550 Discordance in Colorectal Polyp Size Determination Between Colonoscopy and Pathology Reporting

INTRODUCTION: National guidelines recommend that patients with colorectal adenomas ≥1cm undergo surveillance colonoscopy to prevent colorectal cancer. Polyp size is often assessed twice, once during colonoscopy and again during pathology examination. It remains unclear whether these measurements vary and which should govern surveillance intervals. METHODS: We retrospectively analyzed a random sample of primary care patients who underwent polypectomy between January 1, 2013 and January 1, 2016 in a large academic healthcare center. Chart abstractors reviewed electronic health record data for colonoscopic polyp descriptors and measurements, corresponding pathology measurements, and histology. We excluded cases with normal histology, missing pathology, fragments, unreliable polyp matches between reports, and &gt;5 polypectomies. We performed a paired t-test to assess polyp size discordance between reports and calculated Cohen's kappa coefficient to assess agreement whether the size was ≥1 cm. RESULTS: We reviewed 1,528 patient charts, and 831 (54.4%) met inclusion criteria, representing 1,532 polyps. Sizes ranged from 0.1-3.0cm on colonoscopy and 0.1-2.7cm on pathology reports. On colonoscopy report, the majority (881, 57.5%) used only a descriptive term rather than a numeric value to describe size (Table 1). Descriptive size terms were diminutive (513), tiny (39), small (328), and large (1). Only 2.8% of polyps described as diminutive, small, or tiny on the colonoscopy report were ≥1cm on the corresponding pathology report. Among the 367 (24.0%) polyps with discrete numeric sizes on both reports, size discordance varied by &gt;0.2 cm for 50% of polyps (Figure 1). More of these polyps were ≥1 cm on colonoscopy (70) than on pathology (51) report, and there was remarkable clustering at 1 cm by colonoscopy report estimation (Figure 2). There was moderate agreement (kappa = 0.52) on size ≥1 cm. Among tubular adenomas (TA) ≥1 cm on colonoscopy or pathology report (36), 10 (27.8%) were ≥1 cm on both, 18 (50.0%) were ≥1 cm on colonoscopy only, and 8 (22.2%) were ≥1 cm on pathology only. CONCLUSION: There is considerable discordance between colonoscopic and pathology polyp size measurements, with more polyps sized as ≥1 cm by colonoscopic estimation compared to pathology, which has implications for surveillance frequency. Future studies should investigate the implications of discordant measurements on clinical outcomes and inform guidelines on surveillance intervals.