Diagnostic performance of MRI for assessment of response to neoadjuvant chemoradiotherapy in oesophageal cancer.

ABSTRACT: BACKGROUND:Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non-surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2-weighted (T2W) and diffusion-weighted (DW) MRI. METHODS:Patients with locally advanced oesophageal cancer who underwent T2W- and DW-MRI (1·5?T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five-point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW-MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated. RESULTS:Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W-MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W?+?DW-MRI were 90-97 and 42-50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W-MRI, and 0·71, 0·70 and 0·70 on T2W?+?DW-MRI (P?=?0·441, P?=?0·611 and P?=?0·828 for readers 1, 2 and 3 respectively). The ? value for interobserver agreement improved from 0·24-0·55 on T2W-MRI to 0·55-0·71 with DW-MRI. CONCLUSION:Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.

SUBMITTER: Vollenbrock SE 

PROVIDER: S-EPMC6594024 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature