中国全科医学2018，Vol.21Issue(6)：658-664,7.DOI:10.3969/j.issn.1007-9572.2018.00.001
常规弥散加权成像表观弥散系数在局部进展期直肠癌新辅助放化疗疗效评价中的应用价值
Value of Apparent Diffusion Coefficient Calculated Using Conventional Diffusion-weighted Imaging in Assessing the Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer
摘要
Abstract
Objective To assess the value of apparent diffusion coefficient (ADC) calculated using conventional diffusion-weighted imaging (DWI) in evaluating the response to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC). Methods Between January 2014 and September 2015, 56 consecutive patients diagnosed with LARC (T3, T4, and / or lymph node positive) were prospectively enrolled and underwent pre- and post-neoadjuvant CRT MRI using a 3.0 T MRI scanner in Fudan University Shanghai Cancer Center. DWI sequences were performed with b values of 0, 700, 1 400, and 2 100 s/mm2, respectively. Regions of interest (ROI) were manually drawn on each cross-sectional area of the primary lesions, simultaneously avoiding the encircle distortion artifacts and macroscopically visible necrotic or cystic portions in the axial ADC map deriving from T2-weighted images. Then, the value of ADCpre, ADCpost, and ADCratiowere obtained.Pathological complete remission (pCR), tumor regression grade (TRG) and tumor downstaging (T-downstaging) were used as the evaluation criteria. Downstaging was determined by comparing the pretreatment and postoperative pathologic classifications. Patients with ypT0-2N0 (the "yp" prefix indicates final staging after CRT [y] and postoperative pathologic examination [p]) were defined as T-downstaging, those with TRG 0 or TRG 1 were classified as good responders, whereas the remaining patients with TRG 2-3 were classified as poor responders, and if no tumor cells were identified in the resected specimen and only fibrotic mass or acellular mucin pools were present, the type of response was considered as complete response (ypT0N0) and the patient was labeled as pCR. Results The ADCpostand ADCratiovalues in pCR patients were much higher than those in non-pCR patients (P<0.05), as well as in the evaluation criteria of TRG and T-downstaging (P<0.05). The optimal cutoff value for the identification of patients with pCR was ≤ 0.82×10-3mm2/s for ADCpre{during which its AUC was 0.583〔95%CI(0.44,0.71)〕, with 57.1%(8/14) sensitivity, 69.0%(29/42) specificity, and 66.1%(37/56) accuracy, respectively}, >1.17×10-3mm2/s for ADCpost{ during which its AUC was 0.823〔95%CI(0.70,0.91)〕 with 92.9%(13/14) sensitivity, 66.7%(28/42) specificity, and 73.2%(41/56)accuracy, respectively} and > 0.43 for ADCratio{ during which its AUC was 0.793〔95%CI(0.66,0.89)〕with 78.6%(11/14)sensitivity, 73.8%(31/42) specificity, and 75.0%(42/56)accuracy, respectively}. In addition, the optimal cutoff value for the identification of patients with TRG0-1 was ≤0.88×10-3mm2/s for ADCpre{ during which its AUC was 0.567〔95%CI(0.43,0.70)〕, with 77.3%(17/22) sensitivity, 50.0%(17/34)specificity, and 60.7%(34/56) accuracy, respectively}, >0.20×10-3mm2/s for ADCpost{ during which its AUC was 0.773〔95%CI(0.64,0.87)〕, with 72.7% (16/22) sensitivity, 79.4%(27/34) specificity, and 76.8%(43/56)accuracy, respectively} and >0.37 for ADCratio{ during which its AUC was 0.721〔95%CI(0.59,0.83)〕, with 68.2%(15/22)sensitivity, 70.6%(24/34) specificity, and 69.6% (39/56)accuracy, respectively}. Finally, the optimal cutoff value for the identification of patients with T-downstaging was≤0.82×10-3mm2/s for ADCpre{ during which its AUC was 0.545〔95%CI(0.41,0.68)〕, with 46.2%(12/26) sensitivity, 70.0%(21/30)specificity, and 58.9%(33/56)accuracy, respectively}, >1.23×10-3mm2/s for ADCpost{ during which its AUC was 0.747〔95%CI(0.61,0.85)〕, with 57.7%(15/26)sensitivity, 90.0%(27/30)specificity, and 75.0%(42/56) accuracy, respectively} and >0.59 for ADCratio{ during which its AUC was 0.682〔95%CI(0.54,0.80)〕, with 46.2%(12/26) sensitivity, 90.0%(27/30)specificity, and 69.6%(39/56)accuracy, respectively}. Conclusion The ADCpostand ADCratiohave high-level capabilities for identifying the response to neoadjuvant CRT in LARC patients.关键词
直肠肿瘤/弥散磁共振成像/病理完全缓解Key words
Rectal neoplasms/Diffusion magnetic resonance imaging/Pathological complete response分类
医药卫生引用本文复制引用
胡飞翔,张换,汤伟,彭卫军,童彤..常规弥散加权成像表观弥散系数在局部进展期直肠癌新辅助放化疗疗效评价中的应用价值[J].中国全科医学,2018,21(6):658-664,7.基金项目
国家自然科学基金资助项目(81501437) （81501437）
