AIM: Strain elastography is a novel approach to rectal tumour evaluation. Primary aim of this study was to correlate elastography to pT-stages of rectal tumours and to assess the ability of the method to differentiate rectal adenomas (pT0) from early rectal cancer (pT1-2). Secondary aims were to compare elastography with endorectal ultrasonography (ERUS) and to propose a combined strain elastography and ERUS staging algorithm. METHOD: 120 consecutive patients with a suspected rectal tumour were examined in this staging study. Patients receiving surgery without neo-adjuvant radiotherapy were included (n=59). All patients were examined with ERUS and elastography. Treatment decisions were made by multidisciplinary team (MDT) assessment, without considering the strain elastography examination. RESULTS: Histopathology identified 21 adenomas, 13 pT1, 9 pT2, 15 pT3 and one pT4. Mean elastography strain ratios (SR) were predictive of T stage (p=0.01). Differentiation of adenomas from early rectal cancer (pT1-2) had sensitivity, specificity and accuracy of 0.82, 0.86 and 0.84 for elastography and 0.82, 0.62 and 0.72 for ERUS. A combined staging algorithm was developed to identify tumours eligible for local resection. Based on MDT evaluation 32% tumours later identified as pT0 or pT1 were treated with total mesorectal excision, even though a local excision might have sufficed. Combined ERUS and elastography evaluation would have significantly reduced this number to 9% (p = 0.008). CONCLUSION: Elastography may improve the staging of adenomas and early rectal cancer compared to ERUS alone. Combined ERUS and elastography assessment is likely to further improve the selection of patients for local resection. This article is protected by copyright. All rights reserved.
Colorectal Disease, 2015, Vol 17, Issue 1, p. 50-56