Roel Bogie

Chapter 2

colorectal neoplasms, with special attention for NP-CRNs. A case-based discussion was induced to find out how experts assessed the LSTs. These key principles were later on used in the LST training module. Each rater received a personal account to access an online web-system ( Figure 2.3 ). The observers were familiar with the study goals, but were not informed about the suspected proportion of Kudo subtypes of LSTs, the resection method used, and the lesion histopathology. Raters were blinded from the entries of their peers. Clinical records (e.g. patient’s age, gender, medical history, indication for colonoscopy, lesion size and the location of the lesion) were presented in the upper right corner ( Figure 2.3 , Area A). We attempted to mimic the real life situation in which the same information is available to the endoscopist. Lesion size as measured at the time of colonoscopy was shown since this feature is more difficult to estimate on still images. At least 3 endoscopic images were presented for each LST, using HD white light colonoscopy (one image) and dye-based chromoendoscopy (one long-view image and one short-view image). Dye-based chromoendoscopy was employed in all cases to clarify the lesion border and to assess the endoscopic shape ( Figure 2.3 , Area B). Raters could deliberately navigate back and forth through the images using the arrows. Then the raters were asked to complete a survey, comprising the following questions: (I) What is the endoscopic Kudo LST classification subtype of the lesion? (4 options; LST-G-H, LST-G-NM, LST NG-FE and LST-NG-PD); (II) What is the Paris classification subtype of the lesion? (9 options; 0-Ip, 0-Is, 0-Ips, 0-IIa, 0-IIb, 0-IIc, 0-IIa+IIc, 0-IIa+Is and other [specified by rater by using comments]); (III)What is the best therapeutic plan? (4 options; EMR, ESD, surgery and other [specified by using comments]); and (IV) How was the image quality? (3 options; excellent, good and sufficient) ( Figure 2.3 , Area C). The raters were encouraged to provide specific comments where applicable. After completing all questions, the case could be submitted and transition was made to a new case. The raters were not allowed to navigate back to the previous case. Raters were able to pause the survey and continue at a later moment. After completing the last case, the module was locked. After completion of the test by all experts, IOA and specifically difficulties in the classification were discussed within the core-group (Step 3). We developed a LST trainingmodule (Step 4) in the detection of LSTs, in applying the endoscopic Kudo classification and Paris classification of LSTs, and selecting the therapy of choice. This comprised scientific information and case-based photo documentation, videos and illustrations. All experts provided input to the development of the training module. The original case-based discussion and the feedback on the expert test were incorporated. The training module consisted of a video with two times five LST cases with feedback for practicing the endoscopic Kudo LST classification in between (5 after short introduction, 5 at end before summary). The video contained scientific information about LSTs, including the classification, the risk of submucosal invasion and recurrence risk. A stepwise approach for diagnosing LSTs was applied, including tips and tricks of experts. Special attention was payed to the use of chromoendoscopy, submucosal injection and air insufflation. Cases provided during the training module were different cases than in the tests. Trainees were allowed to do the training module multiple times when desired.

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