You get what you expect? A critical appraisal of imaging methodology in endosonographic cancer staging

Abstract

Background and aims: After an initial period of excellent results with newly introduced imaging procedures, the accuracy of most imaging methods declines in later publications. This effect may be due to various methodological factors involved in the research. Using the example of endoscopic ultrasound (EUS), this study aimed to elucidate one of the factors possibly concerned-namely, the extent to which the examiners are adequately blinded. Methods: Well documented videotapes of EUS examinations of 101 patients with resected tumours of the oesophagus (n=32), stomach (n=33), or pancreas (n=36) were evaluated in three different ways: firstly, retrospective analysis under routine clinical conditions; secondly, evaluation of EUS videotapes in a strictly blinded fashion; and thirdly, evaluation of the same videotapes but with additional information from the video endoscopic appearance (oesophageal/gastric cancer) or from computed tomography results (pancreatic cancer). Histopathological T staging was used as the reference method. Results: The accuracy of EUS in T staging was 73% under routine conditions. This value fell significantly to 53% for the blinded evaluation but increased again to 62% for the unblinded evaluation. The sensitivity of staging T1/T2 tumours was 72% (routine EUS), 59% (blinded EUS), and 70% (unblinded EUS). The respective values for advanced tumours were 85%, 74%, and 72%. Conclusions: The accuracy of EUS for T staging in clinical practice appears to be lower than has previously been reported. In addition, blinded analysis produced significantly poorer results, which improved when another test was added. It may be speculated that better results with routine EUS obtained in a clinical setting are due to additional sources of information.

Systematic review: Bias in imaging studies - the effect of manipulating clinical context, recall bias and reporting intensity

“…The secondary search (Table 2) identified 2828 publications with the full text retrieved for 34: ultimately 6 were included [6,13,[26][27][28][29] and 28 rejected because the research focused on case-specific information. The tertiary search (Table 3) identified 74 MeSH terms which were combined into 18 Boolean search strings: These identified 111 potential articles with a further 2 via snowballing; 5 articles were ultimately included [11,12,[30][31][32]. Overall, 11247 abstracts were reviewed, 201 full articles retrieved, and 12 ultimately included for systematic review ( Table 4).…”

Clinical Staging of Adenocarcinoma of the Esophagogastric Junction

“…The accuracy of conventional EUS in differentiating lower T-cate gories uT1/T2 from advanced categories uT3/T4 in gastric and esophageal cancers were 93% and 91% in very experienced hands, res pectively. Some studies, however, showed a lower accuracy for T-staging in the daily clinical routine and it is obvious that reported ac curacies are clearly lower in more recent stud ies (Meining et al 2002). Unfortunately, the accuracy of EUS is highly dependent on the experience of the examiner and showed only a rather modest performance in some studies (Meining et al 2003;Polkowski et al 2004).…”

R1-Resektion in der Chirurgie des oberen Gastrointestinaltrakts

“…[18]. Auf die hohe Untersucherabhängig-keit wurde allerdings erst kürzlich hingewiesen [19,20]. Die Genauigkeit des endoskopischen Ultraschalls zur Vorhersage der R0-Resektabilität wurde beim Adenokarzinom des Ösophagus mit 89% als sehr zufrieden stellend angegeben; beim Plattenepithelkarzinom des Ösophagus war sie mit 64% allerdings nur mäßig.…”