Kowalchuk Roman O, Waters Michael R, Richardson K Martin, Spencer Kelly M, Larner James M, Kersh Charles R
Radiosurgery Center, University of Virginia/Riverside, Newport News, VA, USA.
Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA.
J Thorac Dis. 2021 Feb;13(2):642-652. doi: 10.21037/jtd-20-2659.
Stereotactic body radiation therapy (SBRT) is an effective treatment modality for non-small cell lung cancer (NSCLC); however, there are concerns regarding potential toxicity for centrally located tumors.
This retrospective study considered patients with SBRT for central lung NSCLC (defined as a tumor within 2 cm of any mediastinal critical structure). The institutional protocol was that patients with central tumors received SBRT less frequently than daily-generally once or twice weekly.
A total of 115 patients with 148 lesions were treated with SBRT to a median 45 [560] Gy in 4 [15] fractions over a median 5.3 [018] days. Many patients treated with this method presented with advanced disease: 58 treatments involved nodal targets, and 42 had stage 3 disease. 52% of patients had chronic obstructive pulmonary disease (COPD), and only 49% had a biopsy, often due to concerns regarding other medical comorbidities. Rates of prior chemotherapy, thoracic surgery, and thoracic radiotherapy were 32%, 21%, and 49%, respectively. Via the Kaplan-Meier method, 2-year overall survival was 65%, and 2-year local control was 77%. Two-year local-progression free survival was 53%, and 2-year progression-survival was 48%. Treatments for stage 3 disease had an impressive 82% 2-year local control that was comparable to early stage treatments. Patients with stage 3 disease had a 2-year overall survival of 59%, which trended towards decreased overall survival compared to early stage patients. There were 13 grade 1 (9%) and 14 grade 2 (9%) toxicities. There were no reported grade ≥3 acute or late toxicities and only 3 cases of pneumonitis.
Our series demonstrates encouraging local control with low rates of toxicity for central lung SBRT, including many stage 3 patients. This may be the result of the relatively large inter-fraction interval. This interval may allow for greater tumor effects (such as reoxygenation) and improved tolerance from normal tissues.
立体定向体部放射治疗（SBRT）是治疗非小细胞肺癌（NSCLC）的一种有效方法；然而，对于中心型肿瘤的潜在毒性存在担忧。
这项回顾性研究纳入了接受SBRT治疗的中心型肺NSCLC患者（定义为距离任何纵隔关键结构2 cm以内的肿瘤）。机构方案是，中心型肿瘤患者接受SBRT的频率低于每日一次，通常为每周一次或两次。
共有115例患者的148个病灶接受了SBRT治疗，中位剂量为45 [560] Gy，分4 [15]次给予，中位疗程为5.3 [018]天。许多接受该方法治疗的患者病情已进展：58次治疗涉及淋巴结靶区，42例为3期疾病。52%的患者患有慢性阻塞性肺疾病（COPD），只有49%的患者进行了活检，这通常是由于对其他合并症的担忧。既往化疗、胸外科手术和胸部放疗的比例分别为32%、21%和49%。通过Kaplan-Meier方法，2年总生存率为65%，2年局部控制率为77%。2年局部无进展生存率为53%，2年进展生存率为48%。3期疾病的治疗2年局部控制率高达82%，与早期疾病治疗相当。3期疾病患者的2年总生存率为59%，与早期患者相比，总生存率呈下降趋势。有13例1级（9%）和14例2级（9%）毒性反应。未报告≥3级急性或晚期毒性反应，仅3例肺炎。
我们的系列研究表明，对于中心型肺SBRT，包括许多3期患者，局部控制效果令人鼓舞，毒性发生率较低。这可能是由于相对较大的分次间隔所致。该间隔可能允许更大的肿瘤效应（如再氧合）并提高正常组织的耐受性。
