SIB-IMRT技术在颈及胸上段食管癌中的临床应用

Clinical application of simultaneous integrated boost intensity-modulated radiation therapy in cervical and upper esophageal carcinoma

目的全程局部同步推量调强放疗（（simultaneous integrated boost intensity modulated radiation therapy,SIB-IMRT）技术的生物效应剂量具有可行性，但目前有前食管癌SIB-IMRT临床疗效的研究相对有限。本研究旨在观察颈及胸上段食管癌患者SIB-IMRT的急性毒副作用、生存情况及治疗失败原因。方法收集2006—01—01—2012—08—01河北医科大学第四医院63例颈及胸上段食管鳞癌患者接受SIB-IMRT，计划靶体积（planning target volume，PTV）处方剂量50．4～60．0Gy／28-30次（1．8～2．0Gy／次），大体肿瘤体积（grosstumorvolume，GTV）处方剂量60～66Gy／28-30次（2．00～2．27Gy／次），1次／d，5次／周，全程放疗时间为5．5～6周。观察其近期疗效、急性毒副作用、治疗失败方式及1、3、5年局部控制率和生存率。结果随访率98．4％，随访结束后存活患者的中位随访时间为42个月。全组近期总有效率96．8％（61／63）。全组1、3、5年局部控制率分别为68．8％、57．1％和47．2％，生存率分别为82．5％、45．7％和31．6％，中位生存期24个月。全组单因素分析显示，瘤体最大直径是影响生存的因素，x2=8．75，P=0．003；而性别、年龄、原发部位、造影长度、N分期、选择性淋巴引流区照射和化疗与生存无明显相关。Cox多因素分析显示，瘤体最大直径影响生存的独立因素，x2=7．33，P=0．007。1、2级急性放射性肺炎的发生率分别为12．7％（8／63）和3．2％（2／63），1、2、3级急性放射性食管炎的发生率分别为58．7％（37／63）、6．3％（4／63）和1．6％（1／63），无4度骨髓抑制的发生。肿瘤局部未控和复发占总治疗失败的58．3％（21／36）。结论SIB-IMRT治疗颈及胸上段食管癌有效，且患者耐受性好，瘤体最大直径为影响生存的独立预后因素，肿瘤局部未控和复发仍为治疗失败的主要原因。其长期生存及远期并发症有待于进一步观察。

OBJECTIVE The biological effective dose of simultaneous integrated boost intensity-modulated radiation therapy （SIB-IMRT） is feasible. However, the clinical research on SIB-IMRT in patients with esophageal carninoma re- mains limited. The study was to observe the acute toxicities, survival and patterns of failures of SIB-IMRT in patients with cervical and upper esophageal carcinoma. METHODS Sixty-three patients of cervical and upper esophageal squamous cell carcinoma from January 1, 2006 to August 1, 2012 in the fourth hospital of hebei medical university treated with SIB-IMRT were included in the study. The prescribed dose of planning target volume （PTV） was 50.4-60.0 Gy/28- 30 fractions （1.8-2.0 Gy/fraction） and the dose for gross tumor volume （GTV） was 60- 66 Gy/28- 30 fractions （2.0-2.27 Gy/fraction） simultaneously. The total treatment time was about 5.5-6.0 weeks （1 time a day, 5 times a week）. The short-term effects, acute toxicities, patterns of failures, 1-, 3- and 5-year local control rates and survival rates were observed. RESULTS The follow-up rate was 98. 4%. The median follow-up time for alive patients was 42 months. The overall response rate （CR＋PR） was 96.8% （61/63）. The 1-, 3- and 5-years local control rates were 68.8%, 57.1% and 47.2% respectively. The 1-, 3- and 5-years survival rates were 82.5%, 45.7% and 31.6% respectively with a median survival time of 24 months. Univariate analysis showed that the maximum diameter of tumor was the prognostic factors x2 =8.75, P=0. 003）. However, gender, age, primary site, lesion length in barium esophagogram,N stage, elective nodal irradiation and chemotherapy were not correlated with prognosis. Multivariate analysis showed that the maximum diameter of tumor was independent prognostic factor （x2 = 7.33, P= 0. 007）. The grade l, 2 acute pneumonitis incidence rates were 12.7 % （8/63）, 3.2 % （2/63） respectively. Grade 1, 2, 3 acute esophagitis incidence rates were 58.7%（37/63）, 6.3%（4/63）, 1.6%（1/63） respectively. No bone marrow suppression of grade 4 was ob- served. The local failure accounted for 58.3%（21/36） of all treatment-related failures. CONCLUSIONS The SIB IMRT technique for cervical and upper esophageal carcinoma is feasible, effective and well tolerated. The maximum diameter of tumor is independent prognostic factor. Local failure is still the main reason of treatment failures. The long term survival and late toxicities are still needed to be observed.