直肠癌新辅助同步加量调强放疗对侧方淋巴结转移的影响

Effect of simultaneous integrated boost intensity-modulated radiation therapy on lateral lymph node metastasis in rectal cancer

目的在侧方淋巴结转移的直肠癌中,评估侧方淋巴结加量放疗的疗效及安全性。方法2016年1月至2022年12月入组103例合并侧方淋巴结转移的直肠癌患者,按随机数表法分为加量放疗组52例和常规放疗组51例。加量放疗组在盆腔放疗50 Gy的基础上,侧方淋巴结同步加量放疗至60 Gy。常规放疗仅盆腔放疗剂量50 Gy。研究首要终点为侧方复发率,比较两组的疗效及不良反应。结果加量放疗组和常规放疗组新辅助放疗的不良反应及手术并发症相仿,侧方淋巴结治疗有效率分别为76.9%和56.9%(χ^(2)=4.69,P=0.03),局部复发率分别为7.7%和25.5%(χ^(2)=5.92,P=0.015),侧方复发率分别为3.8%和23.5%(χ^(2)=8.49,P=0.004)。单因素分析显示,同步加量放疗、放疗后侧方淋巴结短径<5 mm以及术后淋巴结病理阴性为侧方复发相关因素;多因素回归分析显示,加量放疗(HR=6.42,95%CI:1.40~29.49)及放疗后侧方淋巴结短径<5 mm(HR=0.17,95%CI:0.04~0.66)为侧方复发的独立相关因素。两组3年无病生存率(DFS)分别为73.25%和62.6%(P>0.05),3年总生存率(OS)分别为87%和82.5%(P>0.05)。结论侧方淋巴结转移直肠癌同步加量放疗安全有效,加量放疗和新辅助治疗后侧方淋巴结短径<5 mm是侧方复发的独立影响因素。

ObjectiveTo evaluate the efficacy and safety of simultaneous integrated boost intensity-modulated radiation therapy(SIB-IMRT)for rectal cancer with lateral lymph node metastasis(LLNM).MethodsFrom January 2016 to December 2022,103 rectal cancer patients with LLNM were enrolled.The patients were divided into SIB-IMRT group(52 cases)and conventional chemoradiotherapy(CRT)group(51 cases)using the random number table method.The dose was 50 Gy for the pelvis with 60 Gy of SIB-IMRT for the LLNM in the SIB-IMRT group.The dose was 50 Gy for the pelvis in the CRT group.The primary endpoint was the lateral recurrence rate.The efficacy and adverse reactions of the two groups were compared.ResultsThe adverse reactions and surgical complications after neoadjuvant radiotherapy were comparable between the two groups.The response rates of LLNM treatment were 76.9%and 56.9%,respectively,in the two groups(χ^(2)=4.69,P=0.03).The SIB-IMRT group and CRT group had a local recurrence rate of 7.7%and 25.5%(χ^(2)=5.92,P=0.015),respectively,and a lateral recurrence rate of 3.8%and 23.5%(χ^(2)=8.49,P=0.004),respectively.Univariate analysis showed that the SIB-IMRT,short axis of lateral lymph nodes<5 mm after radiotherapy,and negative result in the postoperative lymph node pathological examination were factors associated with lateral recurrence.Multivariable regression analysis demonstrated that the SIB-IMRT(HR=6.42,95%CI:1.40-29.49)and short axis of lateral lymph nodes<5 mm after radiotherapy(HR=0.17,95%CI:0.04-0.66)were independent factors associated with lateral recurrence.The two groups had a 3-year disease-free survival of 73.25%and 62.6%(P>0.05),respectively,and a 3-year overall survival of 87%and 82.5%(P>0.05),respectively.ConclusionsThe SIB-IMRT is safe and effective for rectal cancer with LLNM.The short axis of lateral lymph nodes<5 mm after neoadjuvant radiotherapy and SIB-IMRT is an independent risk factor for lateral recurrence.