3.0\xa0T MRI IVIM-DWI for predicting the efficacy of neoadjuvant chemoradiation for locally advanced rectal cancer

Hongbo Hu,Sheng Zhao,Huijie Jiang,Song Wang,Hao Jiang,Wenbin Pan

doi:10.1007/s00261-020-02594-4

Abstract

PurposeThe purpose of this study was to determine the diagnostic performance of intravoxel incoherent motion (IVIM) on assessing response to neoadjuvant chemoradiation (nCRT) in patients with Locally Advanced Rectal Cancer (LARC).Methods50 patients with rectal cancer who underwent magnetic resonance (MR) imaging before and after nCRT, the values of pre-nCRT and post-nCRT IVIM-DWI parameters apparent diffusion coefficient (ADC), diffusion coefficient (D), false diffusion coefficient (D*), and perfusion fraction (f), together with the percentage changes (∆% parametric value) induced by nCRT were calculated. According to the patient's response to nCRT, the patients were divided into pathological complete response (pCR) and non-pCR groups, Good Response (GR) group and Poor Response (PR) group, and the above values were compared between different groups. Univariate and multiple logistic regression analysis were done to investigate the relation between different parameters and patient nCRT. Draw ROC curve according to sensitivity and specificity, and compare its diagnostic efficacy.ResultsThere were no significant differences in the baseline data of 50 patients. After nCRT, the ADC and D values for LARC increased significantly (all p < 0.05). The pCR group (n = 9) had higher preD*, pref, postD*, ∆%ADC and ∆%D values than the non-pCR group (n = 41) (all p < 0.05). The GR group (n = 17) exhibited higher post D, ∆%ADC and ∆%D values than the PR group (n = 33) (all p < 0.05). From the results of Logistic regression analysis found that ∆%ADC and ∆%D were significantly correlated with patients' response to nCRT. Based on ROC analysis, ∆%D had a higher area under the curve value than ∆%ADC (p = 0.009) in discriminating the pCR from non-pCR groups.ConclusionsIVIM-DWI technology may be helpful in identifying the pCR and GR patients to nCRT for LARC.

Highlights

Colorectal cancer (CRC) is one of the most common malignancies with high morbidity and mortality in the world
Not all patients can benefit from Neoadjuvant chemoradiotherapy (nCRT), tumor downstaging in patients with locally advanced rectal cancer (LARC), tumor regression differs from patient to patient, ranging from pathological complete response (pCR), intermediate regression, or even a complete lack of response
We focused on the diagnostic efficacy of intravoxel incoherent motion (IVIM)-DWI in the evaluation of nCRT in the treatment of LARC, and we evaluated the therapeutic effect of patients through pathological results

Summary

Introduction

Colorectal cancer (CRC) is one of the most common malignancies with high morbidity and mortality in the world. The incidence of colorectal cancer in China has increased year by year, 60–70% of these cases are of locally advanced rectal cancer (LARC) [1, 2]. Neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME) has become a standard treatment in patients with locally advanced rectal cancer (LARC), which could decrease the loco-regional recurrence rate and even increase overall survival. The current clinical data show that after nCRT and other neoadjuvant therapy, about 20% of rectal cancer patients can even achieve pathological complete response [5, 6]. Not all patients can benefit from nCRT, tumor downstaging in patients with LARC, tumor regression differs from patient to patient, ranging from pCR, intermediate regression, or even a complete lack of response.

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