Shinya Fujii1,2, Stephanie Nougaret2,3, Laure Escal3, David Azria4, Eric Assenat5, Philippe Rouanet6, Caroline Reinhold2, Boris Guiu3. 1. Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, Yonago, Japan. 2. Department of Abdominal Imaging, MUHC McGill University, Montreal, Canada. 3. Department of Imaging, CHU Montpellier, St Eloi Hospital, Montpellier, France. 4. Department of Radiotherapy, ICM, Montpellier, France. 5. Department of Oncology, CHU Montpellier, France. 6. Department of Surgery, ICM, Montpellier, France.
Abstract
BACKGROUND: To evaluate the relationship between MR measurements and the pathological tumor regression grade (pTRG). METHODS: Two 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). RESULTS: In 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. CONCLUSION: The 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.
BACKGROUND: To evaluate the relationship between MR measurements and the pathological tumor regression grade (pTRG). METHODS: Two 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). RESULTS: In 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. CONCLUSION: The 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.
Authors: Stephanie Nougaret; Caroline Reinhold; Shaza S Alsharif; Helen Addley; Jocelyne Arceneau; Nicolas Molinari; Boris Guiu; Evis Sala Journal: Radiology Date: 2015-04-30 Impact factor: 11.105