T4N (+)Ⅲ期食管胸中下段癌3DRT长期生存分析

目的 观察T₄N (+)Ⅲ期食管胸中下段癌IMRT长期生存情况及不良反应。方法 2004-2010年间300例T₄N (+)Ⅲ期食管中下段癌患者采用3DCRT 202例、IMRT 98例,常规分割照射剂量60 Gy。比较两种不同治疗方式的长期生存情况及不良反应。Kaplan Meier法计算生存率并Logrank法检验。结果 5、7年样本量分别为239、120例。3DCRT和IMRT组1、3、5、7年LC率分别为64.4%、40.6%、38.3%、34.2%和68.3%、55.3%、51.9%、51.9%(P=0.048),OS率分别为54.5%、19.8%、14.7%、10.9%和63.3%、34.7%、24.4%、20.3%(P=0.013)。分层分析显示年龄>65岁、放疗前食管造影长度>8.0 cm、CT最大横径>4.6 cm、GTV>60 cm³、邻近组织或器官受累、非手术 N₂期、未行化疗者,IMRT组OS率高于3DCRT组(P=0.022、0.003、0.022、0.034、0.016、0.044、0.047)。IMRT组GTVD_min、GTVD₁₀₀高于3DCRT组(P=0.000、0.000),脊髓D_max低于3DCRT组(P=0.000)。IMRT组急性放射性食管炎发生率明显高于3DCRT组,以轻度(1-2级)食管炎为著(P=0.000)。3DCRT组死于肿瘤局部因素的比率明显高于IMRT组(P=0.039)。结论 局部晚期食管胸中下段癌IMRT安全有效,LC率明显提高,正常组织保护良好,长期生存获益显著。基于回顾分析结果还有待前瞻性随机对照研究的证实。

Long term survival analysis of middle and lower thoracic esophageal carcinoma of stage T4 N (+) treated with 3DRT

Objective To observe the long-term survival and adverse reactions in patients with stage T₄N (+) Ⅲ middle and lower thoracic esophageal carcinoma undergoing intensity-modulated radiotherapy (IMRT). Methods From 2004 to 2010, 300 patients with stage T₄N (+) Ⅲ middle and lower thoracic esophageal carcinoma, consisting of 202 treated with three-dimensional conformal radiotherapy (3DCRT) and 98 treated with IMRT, were enrolled as subjects. All patients received conventionally fractionated radiotherapy with a prescribed dose of 60 Gy. The long-term survival and adverse reactions were compared between patients treated with the two different radiotherapy regimens. The survival rates were calculated by the Kaplan-Meier method and analyzed by the log-rank test. Results The 5-and 7-year sample sizes were 239 and 120, respectively. The 3DCRT group had significantly lower 1-, 3-, 5-, and 7-year local control (LC) and overall survival (OS) rates than the IMRT group (64.4% vs. 68.3%, 40.6% vs. 55.3%, 38.3% vs. 51.9%, 34.2% vs. 51.9%, P=0.048;54.5% vs. 63.3%, 19.8% vs. 34.7%, 14.7% vs. 24.4%, 10.9% vs. 20.3%, P=0.013). The stratified analysis showed that for patients older than 65 years, with the length of esophageal lesion>8.0 cm before radiotherapy, the largest diameter of esophageal lesion in computed tomography image>4.6 cm, gross tumor volume (GTV)>60 cm³, metastases to adjacent tissues or organs, stage N₂, and without chemotherapy, the IMRT group had a significantly higher OS rate than the 3DCRT group (P=0.022,0.003,0.022,0.034,0.016,0.044,0.047). The GTVD_min and GTVD₁₀₀ were significantly higher in the IMRT group than in the 3DCRT group (P=0.000,0.000), while the D_max of the spinal cord was significantly lower in the IMRT group than in the 3DCRT group (P=0.000). Compared with the 3DCRT group, the IMRT group had a significantly higher incidence of acute radiation-induced esophagitis, particularly grade 1-2 esophagitis (P=0.000). The mortality rate caused by local tumor was significantly higher in the 3DCRT group than in the IMRT group (P=0.039). Conclusions In the treatment of locally advanced middle and lower thoracic esophageal carcinoma, IMRT is safe and effective;it significantly improves the LC rate and long-term survival without severe toxicity to normal tissues. The results of this retrospective study need to be confirmed by prospective randomized controlled studies.