Zhao J J, Bi N, Zhang T, Wang J Y, Deng L, Wang X, Chen D F, Dai J R, Wang L H
Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100021, China.
Department of Radiation Oncology, National Cancer Center/Cancer Hospital and Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen 518116, China.
Zhonghua Zhong Liu Za Zhi. 2023 Jul 23;45(7):627-633. doi: 10.3760/cma.j.cn112152-20221031-00733.
To compare the incidence of radiation-related toxicities between conventional and hypofractionated intensity-modulated radiation therapy (IMRT) for limited-stage small cell lung cancer (SCLC), and to explore the risk factors of hypofractionated radiotherapy-induced toxicities. Data were retrospectively collected from consecutive limited-stage SCLC patients treated with definitive concurrent chemoradiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from March 2016 to April 2022. The enrolled patients were divided into two groups according to radiation fractionated regimens. Common Terminology Criteria for Adverse Events (CTCAE, version 5.0) was used to evaluate the grade of radiation esophagus injuries and lung injuries. Logistic regression analyses were used to identify factors associated with radiation-related toxicities in the hypofractionated radiotherapy group. Among 211 enrolled patients, 108 cases underwent conventional IMRT and 103 patients received hypofractionated IMRT. The cumulative incidences of acute esophagitis grade ≥2 [38.9% (42/108) vs 35.0% (36/103), =0.895] and grade ≥ 3 [1.9% (2/108) vs 5.8% (6/103), =0.132] were similar between conventional and hypofractionated IMRT group. Late esophagus injuries grade ≥2 occurred in one patient in either group. No differences in the cumulative incidence of acute pneumonitis grade ≥2[12.0% (13/108) vs 5.8% (6/103), =0.172] and late lung injuries grade ≥2[5.6% (6/108) vs 10.7% (11/103), =0.277] were observed. There was no grade ≥3 lung injuries occurred in either group. Using multiple regression analysis, mean esophageal dose ≥13 Gy (=3.33, 95% : 1.23-9.01, =0.018) and the overlapping volume between planning target volume (PTV) and esophageal ≥8 cm(3)(=3.99, 95% : 1.24-12.79, =0.020) were identified as the independent risk factors associated with acute esophagitis grade ≥2 in the hypofractionated radiotherapy group. Acute pneumonitis grade ≥2 was correlated with presence of chronic obstructive pulmonary disease (COPD, =0.025). Late lung injuries grade ≥2 was correlated with tumor location(=0.036). Hypofractionated IMRT are tolerated with manageable toxicities for limited-stage SCLC patients treated with IMRT. Mean esophageal dose and the overlapping volume between PTV and esophageal are independently predictive factors of acute esophagitis grade ≥2, and COPD and tumor location are valuable factors of lung injuries for limited-stage SCLC patients receiving hyofractionated radiotherapy. Prospective studies are needed to confirm these results.
比较局限期小细胞肺癌（SCLC）患者接受常规分割与大分割调强放射治疗（IMRT）后放射性毒性的发生率，并探讨大分割放疗所致毒性的危险因素。回顾性收集2016年3月至2022年4月在中国医学科学院肿瘤医院接受根治性同步放化疗的连续局限期SCLC患者的数据。根据放疗分割方案将纳入患者分为两组。采用《不良事件通用术语标准》（CTCAE，第5.0版）评估放射性食管损伤和肺损伤的分级。采用逻辑回归分析确定大分割放疗组中与放射性毒性相关的因素。在211例纳入患者中，108例行常规IMRT，103例接受大分割IMRT。常规IMRT组与大分割IMRT组之间，≥2级急性食管炎的累积发生率[38.9%（42/108）对35.0%（36/103），P = 0.895]和≥3级急性食管炎的累积发生率[1.9%（2/108）对5.8%（6/103），P = 0.132]相似。两组均有1例患者发生≥2级晚期食管损伤。≥2级急性肺炎的累积发生率[12.0%（13/108）对5.8%（6/103），P = 0.172]和≥2级晚期肺损伤的累积发生率[5.6%（6/108）对10.7%（11/103），P = 0.277]无差异。两组均未发生≥3级肺损伤。多因素回归分析显示，大分割放疗组中，平均食管剂量≥13 Gy（P = 3.33，95%CI：1.23 - 9.01，P = 0.018）以及计划靶区（PTV）与食管的重叠体积≥8 cm³（P = 3.99，95%CI：1.24 - 12.79，P = 0.020）被确定为与≥2级急性食管炎相关的独立危险因素。≥2级急性肺炎与慢性阻塞性肺疾病（COPD）的存在相关（P = 0.025）。≥2级晚期肺损伤与肿瘤位置相关（P = 0.036）。对于接受IMRT治疗的局限期SCLC患者，大分割IMRT的耐受性良好，毒性可控。平均食管剂量以及PTV与食管的重叠体积是≥2级急性食管炎的独立预测因素，而COPD和肿瘤位置是接受大分割放疗的局限期SCLC患者发生肺损伤的重要因素。需要前瞻性研究来证实这些结果。
