磁共振弥散加权成像在食管癌精确放疗中的应用价值

Application of diffusion-weighted magnetic resonance imaging in precise radiotherapy for esophageal carcinoma

目的探讨磁共振弥散加权成像（DWMRI）技术在食管癌精确放疗中的应用价值。方法2010--2011年经病理证实食管癌患者37例，放疗前均在CT机及MRI机下定位并靶区勾画。比较DWMRI与食管钡餐造影、食管镜、CT所示食管病变长度差异及CT与DWMRI所示病变最大横径、体积差异。正态分布且方差齐性资料用方差分析和配对t检验。结果食管钡餐造影、食管镜、CT、DWMRI所示病变长度分别为5．70、6．06、7．97、5．79cm，CT与其他3种方法所示病变长度均不同（F=4．88，P=0．003）；DWMRI、CT所示病变最大横径分别为3．79、3．81cm（t=-0．32，P=0．751），所示大体肿瘤体积分别为45．75、38．05cm^3（t=5．30，P=0．001）。CT与DWMRI共同诊断53个淋巴结转移，DWMRI排除25个CT诊断阳性的淋巴结，15个淋巴结DWMRI显示高信号而CT诊断阴性，其中6个为食管旁淋巴结。DWMRI使6例患者的临床分期发生改变。结论DWMRI所示病变长度与食管钡餐造影结果最为接近；DWMRI易发现与食管粘连的食管旁沟肿大淋巴结，DWMRI可使部分患者靶区范围和临床分期发生改变。

Objective To explore the application of diffusion-weighted magnetic resonance imaging （DWMRI） in precise radiotherapy of esophageal carcinoma. Methods Thirty-seven patients with biopsy- proven esophageal cancer from March 2010 to January 2011 were included. To delineate the gross tumor volume （GTV） using CT and DWMRI images, each patient was examined by DWMRI and CT scan using the same position before radiotherapy. To compare the maximum diameters and volumes of tumor between CT and DWMRI. The tumor lengths measured by esophagogram, esophagoscope, CT and DWMRI were compared. Results Tumor lengths under esophagogram, esophagoscope, CT and DWMR1 were 5.70 cm, 6. 06 cm, 7. 97 cm and 5.79 cm respectively. The lengths between CT and esophagogram, CT and esophagoscope, CT and DWMRI had statistical significance respectively （F = 4. 88, P = 0. 003 ）. The maximum diameters of tumor shown on CT and DWMRI were 3.79 cm and 3.81 em respectively （t = -0. 32,P =0. 751 ）. The GTV were 45.75 cm3 and 38.05 cm3 in CT and DWMRI respectively （ t = 5.30, P =0. 001 ）. 53 lymph nodes were assessed positive on both CT and DWMRI. DWMRI excluded 25 positive lymph nodes assessed by CT; also confirmed 15 negative lymph nodes excluded by CT, 6 of which were paraesophageal lymph nodes. The addition of DWMRI information altered the clinical stage in 6 patients. Conclusions Tumor lengths measured on DWMRI and esophagogram had the optimal approximation. It was easy to find paraesophageal lymph nodes via DWMRI. With the addition of DWMRI information, the target range and clinical stage were alerted in some patients.