MR imaging of locally advanced low rectal cancer: Relationships between imaging findings and the pathological tumor regression grade

作者：Fujii Shinya^*; Nougaret Stephanie; Escal Laure; Azria David; Assenat Eric; Rouanet Philippe; Reinhold Caroline; Guiu Boris

来源：Journal of Magnetic Resonance Imaging, 2015, 42(2): 421-426.

DOI：10.1002/jmri.24783

• MRI
• rectal cancer
• chemoradiation therapy
• tumor regression grade

BackgroundTo evaluate the relationship between MR measurements and the pathological tumor regression grade (pTRG).
MethodsTwo radiologists independently reviewed the pre- and postchemoradiation therapy (CRT) rectal MR images of 73 consecutive patients with locally advanced low rectal cancer who underwent neoadjuvant CRT and subsequent surgery and measured tumor diameter, area, signal intensity (SI). The percentage reduction rate for each parameter was calculated. The absolute SI ratio reduction rate was defined as the absolute value of the SI ratio reduction rate. The Kruskal-Wallis test and multivariate analysis were performed to assess the correlation between each parameter and the pTRG. Receiver operating characteristic (ROC) curves were plotted for predicting favorable regression outcomes (pTRG 3-4).
ResultsIn multivariate analysis, the absolute SI ratio reduction rate was a significant predictor of pTRG for both radiologists. Area under the ROC curve (Az) values were 0.77-0.709 for diameter reduction rate, 0.757-0.694 for area, 0.652-0.648 for the SI ratio, 0.736-0.837 for the absolute SI ratio.
ConclusionThe absolute SI ratio reduction rate was significantly associated with pTRG and predicted favorable responses to CRT. Measurement of the diameter reduction rate is convenient and reliable in predicting favorable responses. J. Magn. Reson. Imaging 2015;42:421-426.

• 出版日期2015-8