Department of Radiation Oncology, Yamagata University Faculty of Medicine, Iida-nishi 2-2-2, Yamagata-shi, 990-9585 Yamagata, Japan.
Department of Radiation Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, 104-045 Tokyo, Japan.
J Radiat Res. 2020 Jul 6;61(4):563-574. doi: 10.1093/jrr/rraa018.
The purpose of this study was to clarify the opinions of radiation oncologists in Japan regarding treatment for lung cancer complicated with interstitial lung disease (ILD) by a questionnaire survey, and the risk of acute exacerbation (AE) after radiotherapy. Questionnaires were sent to all of the facilities in which radiation therapy is performed for lung cancer in Japan by using the mailing list of the Japanese Society for Radiation Oncology (JASTRO). The questionnaire survey was conducted to clarify who judges the existence of ILD, the indications for radiation therapy in cases of ILD-combined lung cancer, and the ratio of ILD-combined lung cancer in lung cancer patients treated with radiation therapy. Patients with ILD-combined lung cancer who received radiotherapy during the period from April 2014 to March 2015 were retrospectively analysed. Any cases of AE without any other obvious cause were included. ILD confirmation was performed by central radiologists using computed tomography images. A total of 47 facilities responded to the questionnaire. Radiation therapy was an option in cases of ILD-combined lung cancer in 39 (83%) of the facilities. The indication for radiation therapy was based on image findings in 35 (90%) of the 39 facilities in which radiation therapy was acceptable or was a choice in some cases of ILD. The final indication was based on the opinion of the pulmonologist in 29 (74%) of those 39 facilities. In fiscal year 2014, a total of 2128 patients in 38 facilities received chest irradiation. Seventy-eight (3.7%) of those 2128 patients had ILD-combined lung cancer. Sixty-seven patients were included in patient analysis. AE occurred in 5 patients (7.5%), and one of those 5 patients (20.0%) died from radiation-induced AE. The median period from radiotherapy to AE was 4 months (range, 2-7 months). The following four independent risk factors for AE were identified in univariate analysis: non-advanced age (<75 years), increased C-reactive protein level (≥0.3 mg/dl), adjuvant chemotherapy and ≥ Grade 2 radiation pneumonitis. Radiotherapy was an option for lung cancer even in cases with ILD in 83% (39/47) of the facilities in Japan. Seventy-eight (3.7%) of 2128 patients who received radiation therapy for lung cancer had ILD. Radiotherapy for ILD-combined lung cancer may induce AE at a substantial rate and AE can be life-threatening. Minimizing the risk of radiation pneumonitis might enable the risk of AE to be reduced.
本研究旨在通过问卷调查明确日本放射肿瘤学家对肺癌合并间质性肺病（ILD）治疗的意见，以及放疗后急性加重（AE）的风险。采用日本放射肿瘤学会（JASTRO）的邮寄名单，向日本所有开展肺癌放疗的机构发送问卷。调查明确判断ILD 存在的人员、ILD 合并肺癌放疗的适应证、以及接受放疗的肺癌患者中ILD 合并肺癌的比例。对 2014 年 4 月至 2015 年 3 月接受放疗的ILD 合并肺癌患者进行回顾性分析。任何无其他明显原因的 AE 均纳入研究。ILD 确认由中心放射科医生使用计算机断层扫描图像进行。共有 47 个机构对问卷做出了回应。39 个（83%）机构认为ILD 合并肺癌可以进行放疗。35 个（90%）接受放疗的机构将放疗适应证基于影像学表现，有些情况下则作为选择。39 个机构中的 29 个（74%）最终依据肺病学家的意见确定适应证。2014 财年，38 个机构的 2128 例患者接受了胸部照射。其中 78 例（3.7%）为ILD 合并肺癌。67 例患者纳入患者分析。5 例（7.5%）发生 AE，其中 1 例（20.0%）死于放射性 AE。放疗至 AE 的中位时间为 4 个月（范围 2-7 个月）。单因素分析确定 AE 的四个独立危险因素为：年龄<75 岁（非高龄）、C 反应蛋白水平升高（≥0.3mg/dl）、辅助化疗和≥2 级放射性肺炎。在日本的 47 个机构中，83%（39/47）认为肺癌即使合并ILD 也可以选择放疗。2128 例接受肺癌放疗的患者中，78 例（3.7%）患有ILD。ILD 合并肺癌的放疗可能会以相当高的比例诱发 AE，AE 可能危及生命。降低放射性肺炎的风险可能会降低 AE 的风险。
