Table 3.

Appropriate intraprocedure (resection) QIs after round 2 voting with the median score, MAD-M, BIOMED analysis, p value, IPRAS analysis and the performance threshold

Intraprocedure QIs (resection)	Median score	MAD-M	BIOMED analysis	P value	IPRAS analysis	Performance threshold, median % (range)
Adherence to the Prague and Paris classifications is mandatory.	9	0.1	No disagreement	1	No disagreement	95 (80–100)
Aspirational performance target: 95% (range: 80–100). Evidence summary: Several studies have investigated the validity of the Prague circumferential and maximum length classification showing high overall validity for the endoscopic assessment of visualised BE lengths among expert endoscopists, community hospital endoscopists and trainees. The BSG guidelines recommend endoscopic reporting be performed using the Prague criteria.2 Description of lesion morphology using the Paris classification is based on the Japanese system used to classify early gastric cancer. This provides information on the likelihood of invasion of cancer and helps communication between endoscopists. Description of lesion morphology using the Paris classification improves lesion recognition at the time of endoscopic therapy. It gives an indication of the likelihood of invasive cancer and aids communication between clinicians. The BSG recommends the use of Paris classification for all visible lesions; therefore, adherence to the Prague and Paris classifications is recommended.
All patients undergoing BET and follow-up should have assessment with high-definition white light endoscopy with (virtual) chromoendoscopy.	9	0.4	No disagreement	1	No disagreement	93 (80–100)
Aspirational performance target: 93% (range: 80–100). Evidence summary: Endoscopy in patients with BE should be performed with careful inspection of the columnar-lined oesophagus using HD-WLE, with biopsy of any suspicious areas followed by four-quadrant biopsies of the BE metaplasia. The use of the HD-WLE is associated with improved detection of dysplasia during routine BE surveillance. In addition, chromoendoscopy allows for detailed imaging of the mucosal and vascular surface patterns in BE. Recent studies have shown that imaging techniques such as chromoendoscopy or virtual chromoendoscopy increase the diagnostic yield for identification of dysplasia or cancer in patients with BE; however, the evidence for advanced endoscopy boosting dysplasia detection rate on a per-patient basis is slim.11 The application of a dilute AA solution to the BE mucosa results in mucosal colour change and highlights mucosal patterns more clearly, facilitating sensitive and specific identification of potentially neoplastic areas. Furthermore, the premature loss of aceto-whitening in areas of the mucosa and the speed at which it disappears are also associated with the presence of early neoplasia. The efficacy of AA chromoendoscopy has been demonstrated in few studies showing a sensitivity and specificity of up to 98% and 96%, respectively. Three main virtual chromoendoscopy modalities are currently available: NBI (Olympus), the i-Scan imaging system (Pentax) and BLI (Fujifilm). Recent studies have indicated the potential of NBI as a replacement for AA chromoendoscopy with an accuracy of 92%, and sensitivity and specificity of 91% and 93%, respectively, in the identification of early dysplastic lesions on still images.12 Other studies have also shown that i-Scan can improve neoplasia detection in patients with BE with an impressive accuracy and sensitivity of up to 94% and 83%, respectively. The use of i-Scan in combination with zoom magnified endoscopy and the addition of AA can also provide further improvement in dysplasia detection rate. A recent study by Subramaniam et al validated a classification system for BLI which identifies dysplastic BE tissue with sensitivity and specificity of 96%, based on both increased pit pattern irregularity and the presence of disordered and dilated microvessels.13 Currently, only AA and NBI have reached the ASGE PIVI requirement. The current data on advanced imaging modalities in improving dysplasia yield are encouraging, but the data do not provide evidence on how these modalities can impact EET. Most studies to date have either been performed using still images or have been limited to high-volume BE referral centres. The expert panel has therefore suggested that all patients undergoing BET and follow-up should have assessment with HD-WLE with chromoendoscopy or virtual chromoendoscopy.
All visible lesions should be entirely resected with EMR or ESD.	9	0.3	No disagreement	1	No disagreement	93 (80–100)
Aspirational performance target: 93% (range: 80–100). Evidence summary: ER is the cornerstone of endoscopic therapy of early oesophageal neoplasia which aims to provide accurate histological staging with therapeutic intent. ER of early BE neoplasia with multiband mucosectomy is effective and safe. A large number of studies have shown long-term complete remission rate of 85%–96%, with bleeding rates ranging from 0.7% to 7.9% and perforation rates ranging from 0.2% to 2.3%.14 EMR of all visible lesions has been shown to upgrade the pathological diagnosis in 39% of all patients. Most of the change was associated with upgrading of grade of dysplasia and neoplasia. EMR for all visible lesions has been recommended by the ASGE. In addition the provision of EMR specimens to the pathology department results in an improvement in interobserver agreement among pathologists compared with biopsy specimens only. ESD for early-stage BE neoplasia is also a feasible treatment option as it allows en-bloc resection and accurate histopathological analysis of lateral resection margins in BE neoplasia. Multiple studies have shown high en-bloc resection rates ranging from 89% to 98.6% and R0 resection rates ranging from 72.4% to 87%, with acceptable perforation (0%–8.3%), bleeding (1.4%–1.7%) and stricture rates (2.1%–11.6%). When curative resections are achieved, good oncological outcomes are likely in the management of early-stage BE neoplasia by ESD. The ESGE recommendations (2015) state that EMR is acceptable for resecting lesions confined to the mucosa, regardless of the size, but ESD may be considered for lesions larger than 15 mm, poorly lifting tumours and lesions at risk for SM invasion.15 These data show that EMR and ESD are effective treatment modalities in the staging and treatment of early BE neoplasia with acceptable side effect profiles. It is however important to mention that operator skill and experience will have significant effect on patient outcome, and therefore good training is paramount.
The use of EUS is not routinely recommended for patients undergoing BET.	8.5	0.6	No disagreement	1	No disagreement	90 (70–100)
Aspirational performance target: 90% (range: 70–100). Evidence summary: A systematic review and meta-analysis by Qumseya et al 16 showed that EUS was able to detect only 14% of patients presenting with advanced disease and 4% of patients with advanced disease in the absence of nodules. A prospective study by May et al compared staging of early oesophageal neoplasia using HR endoscopy with staging using HR endosonography. The accuracy of the endoscopic and endosonographic staging was 83.4% and 79.6%, respectively. Sensitivity for mucosal tumours was more than 90% (EUS 91.2%, endoscopy 94.1%), while sensitivity for submucosal tumours was 48% for EUS and 56% for endoscopic staging. A combination of the two techniques increased the sensitivity for submucosal tumours to 60%. The overall diagnostic accuracy of both HR endoscopy and HR endosonography in early oesophageal cancer is approximately 80% with no significant differences between the two techniques.17 EUS can provide staging in patients with BE neoplasia; however, there is a significant degree of overstaging and understaging when compared with ER. The expert panel agreed that EUS is not recommended for the work-up of patients with early oesophageal neoplasia, but only to exclude T2 disease or nodal involvement.
Lesions with SM invasion are only to be considered for curative BET if deemed to present a low risk of metastasis.	8.5	0.6	No disagreement	1	No disagreement	90 (80–100)
Aspirational performance target: 90% (range: 80–100). Evidence summary: Neoplastic lesions confined to the mucosa have a better prognosis when compared with those invading the submucosa. LN metastasis and recurrence of the tumour correlate with the depth of invasion of the lesion into deeper tissue layers. Depth of tumour invasion, grade of differentiation and lymphatic involvement are important decision-making factors. Lesions confined to the mucosa and SM1 have a very low risk of lymphovascular invasion; however, invasion beyond SM1 (>500 μm measured from the deepest fibre of the muscularis mucosae) is at increased risk of developing recurrent disease within 5 years.18 EET is used to treat superficial neoplasms in BE, but cannot cure cancers that have metastasised to LN. The risk of occult LN metastases for patients with mucosal neoplasms in BE is in the range of 1%–2%.19 Oesophagectomy has a mortality rate that often exceeds 2% with substantial morbidity. Therefore, the risk of LN metastases alone does not warrant the choice of oesophagectomy over ET for HGD and IMC in BE.19 A study by Manner et al concluded that the rate of LN metastasis in pT1b SM1 early adenocarcinoma with histologically low-risk pattern was 2%, which was lower than the mortality rate of oesophagectomy (3%); high-risk lesions, however, had an LN metastasis risk of 9%, suggesting that ET may be used as an alternative to surgery in low-risk lesions only.20 The expert panel has therefore recommended that only low-risk lesions with SM invasion should be considered for curative BET, and all patients with high-risk SM lesions should be considered for surgery (unless not suitable due to comorbidities) following discussion at MDT and with the patient.

AA, acetic acid; ASGE, Americal society for gastrointestinal endoscopy; BE, Barrett’s oesophagus; BET, Barrett’s endotherapy; BLI, blue laser imaging; BSG, British Society of Gastroenterology; EET, endoscopic eradication therapy; EMR, endoscopic mucosal resection; ER, endoscopic resection; ESD, endoscopic submucosal dissection; ESGE, European Society of Gastrointestinal Endoscopy; ET, endoscopic therapy; EUS, rndoscopic ultrasound; HD-WLE, high definition white light endoscopy; HGD, high grade dysplasia; HR, high resolution; IMC, intramucosal carcinoma; IPRAS, interpercentile range adjusted for symmetry; LN, lymph node; MAD-M, mean absolute deviation from the median; MDT, multidisciplinary team; NBI, narrow band imaging; PIVI, Preservation and incorporation of valuable endoscopic innovations; QI, quality indicator; SM, submucosal.