食管癌大体肿瘤靶区的体积分级与病理T分期的关系

目的 拟定出食管癌大体肿瘤靶区(GTV)的体积分级界限值,为非手术治疗食管癌的临床分期提供依据.方法 将607例行根治性切除术的胸段食管癌患者的术前CT图像传输到三维适形放疗计划系统中,勾画出食管病变局部的GTV,并计算GTV的体积大小.比较术后不同病理T分期时GTV体积的差异,分析GTV体积与病理T分期的关系及其对预后的影响.以各病理T分期的GTV体积中位值为依据,并考虑生存曲线的分离程度,筛选出合适的GTV体积分级界限值.结果 食管癌GTV的长度、最大直径和体积均与术后病理T分期呈正相关(均P<0.001).除术后病理T3期与T4期的GTV长度、最大直径和体积差异未见统计学意义外,其他各病理T分期的上述指标间的差异均有统计学意义(均P<0.001).以术后不同病理T分期的GTV体积中位值为依据,将食管癌GTV体积分为3级,即≤5.0 cm3、5.1～13.0 cm3和>13.0 cm3,与病理T1、T2、T3～4期的符合率达73.8%,两者的一致性较好(Kappa=0.40).GTV体积1、2、3级患者的术后5年生存率分别为78.1%、31.5%和33.5%(P<0.0001).综合考虑预后情况后,将食管癌GTV体积分为4级,即≤5.0cm3、5.1～13.0 cm3、13.1-39.0 cm3和>39.0 cm3,与术后病理T分期的符合率仅为54.7%,GTV体积四分级与术后病理T分期间的一致性较差(Kappa=0.24).GTV体积1、2、3、4级患者的术后5年生存率分别为78.1%、31.5%、36.2%和27.5%(P<0.0001).结论 食管癌GTV长度、最大直径和体积均与术后病理T分期呈正相关关系,GTV体积的三分级标准与术后病理T分期的一致性较好.

Exploration of the classification of gross tumor volume and pathological staging of esophageal carcinoma

Objective Using the volume calculating function of treatment planning system of 3DCRT to work out the value of GTV standard classifications and to provide the reference for clinical staging of esophageal carcinoma. Methods Six hundred and seven patients underwent radical resection of thoracic esophageal carcinoma in our hospital, and their pre-operative CT images were transmitted in digital format to the three-dimensional conformal radiotherapy planning system by the network. Esophageal lesion GTV targets were outlined, and their volumes were automatically computed by the planning system. Compared the differences of the GTV volumes in different pathological T stages, and analyzed the relationship between GTV volumes and pathological T stages. According to the median volume of GTV at different pathological T stages, divided the values of GTV volume coresponding to different T stages and selected the suitable classification standard of GTV volume. Results The esophageal carcinoma GTV length, maximum diameter and volume were related to pathological T staging and with a positive correlation (all P < 0. 001 ). The Spearman correlation coefficient (r) was 0.376, 0.466 and 0.464, respectively, P < 0.001. Except that the length, maximum diameter and volume of GTV in pathological T3 and T4 had no significant difference, other indicators of the pathological T stages showed significant differences between the groups (P < 0. 001 ). According to the median volume of GTV at different pathological T stages, the GTV volumes were divided into three grades; ≤5.0 cm3,5. 1-13.0 cm3,and > 13.0 cm3. When compared them with pathological T1, T2, and T3 -T4 stages, the coincidence rate was 73. 8%. The consistency was good between the GTV volume grades and pathological T stages ( Kappa = 0. 40, P < 0. 001 ). Hie overall 5-year survival rates of GTV grades 1,2,3 were 78. 1% , 31.5% and 33. 5% , respectively (P < 0. 0001). If the GTVs were divided into four grades; ≤5.0 cm3,5.1-13.0 cm3,13.1-39.0 cm3 ,and >39.0 cm3, the coincidence rate of GTV volume grades and pathology T staging was only 54. 7% , and the consistency was poor, Kappa = 0.24,P<0.001. The overall 5-year survival rate of GTV 1, 2, 3, 4 were 78. 1% , 31.5% , 36.2% and 27.5%, respectively ( P < 0.0001). Conclusion The length, maximum diameter and volume of esophageal carcinoma GTV are related to pathological T staging with a positive correlation. The classification that esophageal carcinoma GTVs divided into three grades has a good coincidence with the pathological T staging.