Polyp malignancy classification with CNN features based on Blue Laser and Linked Color Imaging

In-vivo classification of benign and pre-malignant polyps is a laborious task that requires histophatology confirmation. In an effort to improve the quality of clinical diagnosis, medical experts have come up with visual models with only limited success. In this paper, a classification approach is proposed to differentiate between polypmalignancy, using features extracted from the Global Average Pooling (GAP) layer of a pre-trained Convolutional Neural Network (CNNs) . Two recently developed endoscopic modalities are used to improve the pipeline prediction: Blue Laser Imaging (BLI) and Linked Color Imaging (LCI). Furthermore, a new strategy of per-class data augmentation is adopted to tackle the differences of unbalanced class distribution. The results are compared with a more general approach, showing how artificial examples can improve results on highly unbalanced problems. For the same reason, the combined features for each patient are extracted and trained using several machine learning classifiers without CNNs. Moreover to speed up computation, a recent GPU based Support Vector Machine (SVM) scheme is employed to substantially decrease the overload during training time. The presented methodology shows the feasibility of using the LCI and BLI techniques for automatic polypmalignancy classification and facilitates future advances to limit the need for time-consuming and costly histopathological assessment

Triplet network for classification of benign and pre-malignant polyps

Colorectal polyps are critical indicators of colorectal cancer (CRC). Classification of polyps during colonoscopy is still a challenge for which many medical experts have come up with visual models, albeit with limited success. An early detection of CRC prevents further complications in the colon, which makes identification of abnormal tissue a crucial step during routinary colonoscopy. In this paper, a classification approach is proposed to differentiate between benign and pre-malignant polyps using features learned from a Triplet Network architecture. The study includes a total of 154 patients, with 203 different polyps. For each polyp an image is acquired with White Light (WL), and additionally with two recent endoscopic modalities:Blue Laser Imaging (BLI) and Linked Color Imaging (LCI). The network is trained with the associated triplet loss, allowing the learning of non-linear features, which prove to be a highly discriminative embedding, leading to excellent results with simple linear classifiers. Additionally, the acquisition of multiple polyps with WL, BLI and LCI, enables the combination of the posterior probabilities, yielding a more robust classification result. Threefold cross-validation is employed as validation method and accuracy, sensitivity, specificity and area under the curve (AUC) are computed as evaluation metrics. While our approach achieves a similar classification performance compared to state-of-the-art methods, it has a much lower inference time (from hours to seconds, on a single GPU). The increased robustness and much faster execution facilitates future advances towards patient safety and may avoid time-consuming and costly histhological assessment.</p

Novel cryoballoon 180° ablation system for treatment of Barrett's esophagus-related neoplasia:a first-in-human study

Background The novel 180 degrees cryoballoon (CbAS (180) ) enables semicircumferential treatment over a length of 3cm per application. This first-in-human study evaluates its feasibility, efficacy, and safety for the treatment of Barrett's esophagus (BE) neoplasia. Methods This multicenter study consisted of dose-finding and extension phases. Dose-finding started with the lowest dose possible (1.0mm/s). For each dose, six patients were treated circumferentially over a 3-cm length. The dose was increased until the median BE regression was >= 60% without serious adverse events (SAEs). In the extension phase, the dose was confirmed in 19 new patients. The outcomes were technical success, BE regression after one treatment, and SAEs. Results 25 patients (median Prague C0M3) were included (6 dose-finding/19 extension). In two patients, the CbAS (180) could not be applied because of unstable balloon positioning. The technical success rate was 96% (22/23). In the six dose-finding patients, the starting dose resulted in median BE regression of 94% (95% confidence interval [CI] 60%-97%) without SAEs and was thus considered effective. Overall median BE regression was 80% (95%CI 60%-90%). Conclusion Single-session CbAS (180) seems feasible, safe, and effective, and is a promising technique for the treatment of patients with BE neoplasia

A novel cryoballoon ablation system for eradication of dysplastic Barrett's esophagus:a first-in-human feasibility study

BACKGROUND:  Endoscopic cryoablation for Barrett's esophagus (BE) might offer advantages over heat-based ablation. Focal cryoballoon ablation has been promising for short-segment BE, whereas the novel 90°-swipe cryoballoon ablation system (CbSAS90) ablates larger areas in a single step (90° over 3 cm). The system allows for dose adjustment. CbSAS90 has been feasible and safe in animal and pre-esophagectomy studies. This is the first clinical study to assess feasibility, safety, and efficacy of CbSAS90 for eradication of dysplastic BE. METHODS:  In this prospective study in dysplastic BE patients, dose finding started with semi-circumferential treatment at 0.8 mm/s (dose 1). The dose was escalated by reducing speed by 0.1 mm/s in six patients until BE surface regression was ≥ 80 % without complications ("effective dose"). The effective dose was subsequently confirmed with circumferential treatment in 12 new patients. Post-procedural pain (0 - 10) and dysphagia (0 - 4) were evaluated. Outcomes were feasibility, safety, and BE surface regression. RESULTS:  25 patients were included, with technically successful treatment in 92 % (95 %CI 73 % - 99 %). Median (95 %CI) BE surface regression was 78 % (50 % - 85 %) for dose 1 and 85 % (55 % - 95 %) for dose 2 (0.7 mm/s), which was defined as the effective dose. Circumferential treatment resulted in 93 % (88 % - 96 %) regression. Two of 12 patients with circumferential treatment developed strictures that required dilation. Median pain and dysphagia scores were low (0 - 3 and 0, respectively). CONCLUSIONS: CbSAS90 was feasible and effective for ablating larger BE areas. The optimal dose for circumferential treatment that balances safety and efficacy requires further evaluation

Artificial intelligence for characterization of diminutive colorectal polyps::A feasibility study comparing two computer-aided diagnosis systems

BACKGROUNDArtificial intelligence (AI) has potential in the optical diagnosis of colorectal polyps.AIMTo evaluate the feasibility of the real-time use of the computer-aided diagnosis system (CADx) AI for ColoRectal Polyps (AI4CRP) for the optical diagnosis of diminutive colorectal polyps and to compare the performance with CAD EYETM (Fujifilm, Tokyo, Japan). CADx influence on the optical diagnosis of an expert endoscopist was also investigated.METHODSAI4CRP was developed in-house and CAD EYE was proprietary software provided by Fujifilm. Both CADx-systems exploit convolutional neural networks. Colorectal polyps were characterized as benign or premalignant and histopathology was used as gold standard. AI4CRP provided an objective assessment of its characterization by presenting a calibrated confidence characterization value (range 0.0-1.0). A predefined cut-off value of 0.6 was set with values &lt; 0.6 indicating benign and values ≥ 0.6 indicating premalignant colorectal polyps. Low confidence characterizations were defined as values 40% around the cut-off value of 0.6 (&lt; 0.36 and &gt; 0.76). Self-critical AI4CRP’s diagnostic performances excluded low confidence characterizations.RESULTSAI4CRP use was feasible and performed on 30 patients with 51 colorectal polyps. Self-critical AI4CRP, excluding 14 low confidence characterizations [27.5% (14/51)], had a diagnostic accuracy of 89.2%, sensitivity of 89.7%, and specificity of 87.5%, which was higher compared to AI4CRP. CAD EYE had a 83.7% diagnostic accuracy, 74.2% sensitivity, and 100.0% specificity. Diagnostic performances of the endoscopist alone (before AI) increased non-significantly after reviewing the CADx characterizations of both AI4CRP and CAD EYE (AI-assisted endoscopist). Diagnostic performances of the AI-assisted endoscopist were higher compared to both CADx-systems, except for specificity for which CAD EYE performed best.CONCLUSIONReal-time use of AI4CRP was feasible. Objective confidence values provided by a CADx is novel and self-critical AI4CRP showed higher diagnostic performances compared to AI4CRP.van der Zander QEW, Schreuder RM, Thijssen A, Kusters CHJ, Dehghani N, Scheeve T, Winkens B, van der Ende - van Loon MCM, de With PHN, van der Sommen F, Masclee AAM, Schoon EJ. Artificial intelligence for characterization of diminutive colorectal polyps: A feasibility study comparing two computer-aided diagnosis systems. Artif Intell Gastrointest Endosc 2024; 5(1): 90574 [DOI: 10.37126/aige.v5.i1.90574

Development and external validation of a model to predict complex treatment after RFA for Barrett's esophagus with early neoplasia

Background & Aims: Endoscopic eradication therapy for Barrett's esophagus (BE)-related neoplasia is safe and leads to complete eradication in the majority of patients. However, a subgroup will experience a more complex treatment course with a risk for failure or disease progression. Early identification of these patients may improve patient counseling and treatment outcomes. We aimed to develop a prognostic model for a complex treatment course. Methods: We collected data from a nationwide registry that captures outcomes for all patients undergoing endoscopic eradication therapy for early BE neoplasia. A complex treatment course was defined as neoplastic progression, treatment failure, or the need for endoscopic resection during the radiofrequency ablation treatment phase. We developed a prognostic model using logistic regression. We externally validated our model in an independent registry. Results: A total of 1386 patients were included, of whom 78 (6%) had a complex treatment course. Our model identified patients with a BE length of 9 cm or longer with a visible lesion containing high-grade dysplasia/cancer, and patients with less than 50% squamous conversion after radiofrequency ablation were identified as high risk for a complex treatment. This applied to 8% of the study population and included 93% of all treatment failures and 76% of all patients with advanced neoplastic progression. The model appeared robust in multiple sensitivity analyses and performed well in external validation (area under the curve, 0.84). Conclusions: We developed a prognostic model that identified patients with a BE length of 9 cm or longer and high-grade dysplasia/esophageal adenocarcinoma and those with poor squamous regeneration as high risk for a complex treatment course. The good performance in external validation suggests that it may be used in clinical management (Netherlands Trial Register: NL7039)

Active surveillance of oesophageal cancer after response to neoadjuvant chemoradiotherapy:dysphagia is uncommon

BACKGROUND: Active surveillance is being investigated as an alternative to standard surgery after neoadjuvant chemoradiotherapy for oesophageal cancer. It is unknown whether dysphagia persists or develops when the oesophagus is preserved after neoadjuvant chemoradiotherapy. The aim of this study was to assess the prevalence and severity of dysphagia during active surveillance in patients with an ongoing response. METHODS: Patients who underwent active surveillance were identified from the Surgery As Needed for Oesophageal cancer ('SANO') trial. Patients without evidence of residual oesophageal cancer until at least 6 months after neoadjuvant chemoradiotherapy were included. Study endpoints were assessed at time points that patients were cancer-free and remained cancer-free for the next 4 months. Dysphagia scores were evaluated at 6, 9, 12, and 16 months after neoadjuvant chemoradiotherapy. Scores were based on the European Organisation for Research and Treatment of Cancer oesophago-gastric quality-of-life questionnaire 25 (EORTC QLQ-OG25) (range 0-100; no to severe dysphagia). The rate of patients with a (non-)traversable stenosis was determined based on all available endoscopy reports. RESULTS: In total, 131 patients were included, of whom 93 (71.0 per cent) had adenocarcinoma, 93 (71.0 per cent) had a cT3-4a tumour, and 33 (25.2 per cent) had a tumour circumference of greater than 75 per cent at endoscopy; 60.8 to 71.0 per cent of patients completed questionnaires per time point after neoadjuvant chemoradiotherapy. At all time points after neoadjuvant chemoradiotherapy, median dysphagia scores were 0 (interquartile range 0-0). Two patients (1.5 per cent) underwent an intervention for a stenosis: one underwent successful endoscopic dilatation; and the other patient required temporary tube feeding. Notably, these patients did not participate in questionnaires. CONCLUSION: Dysphagia and clinically relevant stenosis are uncommon during active surveillance.</p

Active surveillance of oesophageal cancer after response to neoadjuvant chemoradiotherapy:dysphagia is uncommon

BACKGROUND: Active surveillance is being investigated as an alternative to standard surgery after neoadjuvant chemoradiotherapy for oesophageal cancer. It is unknown whether dysphagia persists or develops when the oesophagus is preserved after neoadjuvant chemoradiotherapy. The aim of this study was to assess the prevalence and severity of dysphagia during active surveillance in patients with an ongoing response. METHODS: Patients who underwent active surveillance were identified from the Surgery As Needed for Oesophageal cancer ('SANO') trial. Patients without evidence of residual oesophageal cancer until at least 6 months after neoadjuvant chemoradiotherapy were included. Study endpoints were assessed at time points that patients were cancer-free and remained cancer-free for the next 4 months. Dysphagia scores were evaluated at 6, 9, 12, and 16 months after neoadjuvant chemoradiotherapy. Scores were based on the European Organisation for Research and Treatment of Cancer oesophago-gastric quality-of-life questionnaire 25 (EORTC QLQ-OG25) (range 0-100; no to severe dysphagia). The rate of patients with a (non-)traversable stenosis was determined based on all available endoscopy reports. RESULTS: In total, 131 patients were included, of whom 93 (71.0 per cent) had adenocarcinoma, 93 (71.0 per cent) had a cT3-4a tumour, and 33 (25.2 per cent) had a tumour circumference of greater than 75 per cent at endoscopy; 60.8 to 71.0 per cent of patients completed questionnaires per time point after neoadjuvant chemoradiotherapy. At all time points after neoadjuvant chemoradiotherapy, median dysphagia scores were 0 (interquartile range 0-0). Two patients (1.5 per cent) underwent an intervention for a stenosis: one underwent successful endoscopic dilatation; and the other patient required temporary tube feeding. Notably, these patients did not participate in questionnaires. CONCLUSION: Dysphagia and clinically relevant stenosis are uncommon during active surveillance.</p

Incidence and outcomes of poor healing and poor squamous regeneration after radiofrequency ablation therapy for early Barrett's neoplasia

BACKGROUND: Although endoscopic eradication therapy with radiofrequency ablation (RFA) is effective in most Barrett's Esophagus (BE) patients, some might experience poor healing (PH) and/or poor squamous regeneration (PSR). We aimed to evaluate PH/PSR incidence and treatment outcomes. METHODS: We included all patients treated with RFA for early BE neoplasia, from a nationwide Dutch registry based on a joint treatment protocol. PH was defined as active inflammatory changes or visible ulcerations ≥3 months post-RFA, PSR as <50% squamous regeneration, and treatment success as complete eradication of BE (CE-BE). Results 1,386 patients (median BE C2M5) underwent RFA with baseline low-grade dysplasia (27%), high-grade dysplasia (30%), or early cancer (43%). In all 134 patients with PH (10%), additional time and acid suppression resulted in complete esophageal healing. 67/134 (50%) had normal regeneration with 97% CE-BE. In total, 74 patients had PSR (5%). As compared to patients with normal squamous regeneration, PSR patients had a higher risk for treatment failure (64% versus 2%, RR 27 [95% CI 18-40]) and progression to advanced disease (15% versus <1%, RR 30 [95% CI 12-81]). Higher BMI, longer BE, reflux esophagitis, and <50% squamous regeneration after baseline endoscopic resection were independently associated with PSR in multivariable logistic regression. Conclusions In half of the patients with PH, additional time and acid suppression may lead to normal squamous regeneration and excellent treatment outcomes. However, if patients experience PSR, the risk for treatment failure and progression to advanced disease is significantly increased with a relative risk of 27 and 30, respectively