Application value of different sequences magnetic resonance imaging in rectal cancer re-staging after neoadjuvant chemoradiation therapy / 中国医师进修杂志

ABSTRACT

Objective@#To evaluate the value of different sequences magnetic resonance imaging (MRI) in rectal cancer re-staging after neoadjuvant chemoradiation therapy (NCRT).@*Methods@#The clinical data of 117 patients with rectal cancer who underwent NCRT before surgery operation in Peking University cancer hospital from January 2016 to December 2018 were retrospectively analyzed. Among 117 patients, 101 patients underwent MRI scanning before and after NCRT, and 16 patient underwent MRI scanning after NCRT; T2 weighted imaging (T2WI) and diffusion weighted imaging (DWI) scanning were performed in all patients, and dynamic contrast enhancement (DCE) scanning was performed in 96 patients. T2WI, T2WI combined with DWI, T2WI combined with DCE were used for T re-staging of rectal cancer after NCRT respectively, and the results of which were compared with those of pathology after operation.@*Results@#The sensitivity of diagnosis of ypT0-2 rectal cancer after NCRT using T2WI combined with DWI, T2WI combined with DCE respectively was significantly higher than that using T2WI 52.7% (29/55) and 30.4% (14/46) vs. 10.9% (6/55), and there was statistical difference (P<0.05). The accuracy rate and specificity of diagnosis of ypT3 and ypT4 rectal cancer after NCRT using T2WI combined with DWI were significantly higher than that using T2WI, with an accuracy rate of 60.7% (71/117) vs. 47.0%(55/117) and 92.3% (108/117) vs. 80.3% (94/117), and a specificity of 55.9% (33/59) vs. 23.7% (14/59) and 92.9% (105/113) vs. 80.5% (91/113), and there were statistical differences (P<0.05). The accuracy rate of down-staging after NCRT using T2WI combined with DWI was significantly higher than that using T2WI 72.3% (73/101) vs. 58.4% (59/101), and there was statistical difference (P<0.05); there was no significant difference in accuracy rate between using T2WI and using T2WI combined with DWI and between using T2WI combined with DWI and using T2WI combined with DCE (P > 0.05).@*Conclusions@#T2WI combined with DWI is superior to T2WI in re-staging of rectal cancer after NCRT.