BACKGROUND To the best of our knowledge, no study has reported mediastinal shift accompanied with obstructive atelectasis due to bulky primary esophageal tumor components treated with adaptive radiotherapy and concurrent chemotherapy. CASE PRESENTATION Here we report the case of a 65-year-old male patient diagnosed with locally advanced thoracic esophageal squamous cell cancer, clinical T4bN1M0, stage IVA. Bronchoscopy and computed tomography (CT) revealed an almost complete obstruction of the lumen of the left bronchus due to compression by bulky primary esophageal tumor components. On admission, the patient presented with dyspnea and decreased arterial oxygen saturation. Chest radiography and CT on admission revealed mediastinal shift with left atelectasis, as opposed to findings from the chest radiography performed 26 days before admission. Because of the patient's overall good condition, we recommended definitive chemoradiotherapy instead of palliative bronchial stent placement. After obtaining the patient's consent, chemoradiotherapy was initiated on the following day and it comprised three-dimensional conformal radiotherapy with 60 Gy in 30 fractions with concurrent administration of cisplatin and 5-fluorouracil. During chemoradiotherapy, tumor location was monitored with cone-beam CT and chest radiography. Chemoradiotherapy on day 8 revealed no evidence of the mediastinal shift. CT simulation was reperformed to adjust the radiotherapy fields to account for geometrical changes induced by the absence of the mediastinal shift. Subsequently, the mediastinal shift and bronchial obstruction did not recur during the course of chemoradiotherapy. The patient completed the planned radiotherapy with concurrent and adjuvant chemotherapy, and no non-hematological grade ≥ 3 adverse events were observed. Complete response was confirmed 7 months after initiating chemoradiotherapy. Currently, no disease recurrence, dysphagia, or respiratory symptoms have been reported at 13 months after initiating chemoradiotherapy. CONCLUSIONS In this study, a bulky primary esophageal tumor caused mediastinal shift due to ipsilateral bronchial obstruction. The close follow-up for monitoring resolution of the mediastinal shift during the course of chemoradiotherapy enabled adequate dose delivery to targets, thus reflecting the geometrical changes induced by the absence of the mediastinal shift. Adaptive radiotherapy technique was crucial for favorable patient outcomes in this challenging clinical situation.

中文翻译：

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局部晚期食管癌伴肺不张的适应性放射治疗：病例报告。

背景技术据我们所知，尚无任何研究报道因适应性放疗和同步化疗导致的原发性食管肿瘤大而引起纵隔移位并伴有阻塞性肺不张。病例介绍在这里，我们报告一例65岁的男性患者，该患者被诊断为局部晚期胸段食管鳞状细胞癌，临床T4bN1M0，IVA期。支气管镜和计算机断层扫描（CT）显示，由于庞大的食管原发性肿瘤成分的压迫，左支气管腔几乎完全阻塞。入院时，患者出现呼吸困难和动脉血氧饱和度降低。入院时胸部X光片和CT显示纵隔移位伴左肺不张，与入院前26天进行的胸部X光片发现相​​反。由于患者的总体状况良好，我们建议采用确定性放化疗而不是姑息性支气管支架置入术。在征得患者同意后，第二天开始放化疗，它包括在30个部分中以60 Gy进行三维适形放疗，同时给予顺铂和5-氟尿嘧啶。在放化疗期间，通过锥形束CT和胸部X射线照相术监测肿瘤的位置。在第8天的放化疗中没有发现纵隔移位的迹象。重新进行CT模拟以调整放疗范围，以解决因缺乏纵隔移位而引起的几何变化。随后，在放化疗过程中没有发生纵隔移位和支气管阻塞。患者完成了计划的放疗并发和辅助化疗，未观察到非血液学≥3级不良事件。开始放化疗后7个月，确认完全缓解。目前，开始放化疗后13个月没有疾病复发，吞咽困难或呼吸道症状的报道。结论在这项研究中，由于同侧支气管阻塞，一个巨大的食管原发性肿瘤引起纵隔移位。在化学放疗过程中进行密切跟踪以监测纵隔移位的解决情况，从而能够将足够的剂量递送至靶标，从而反映出由于不存在纵隔移位而引起的几何变化。在这种具有挑战性的临床情况下，自适应放疗技术对于患者取得良好的治疗效果至关重要。