立体定向全身放射治疗 (SBRT) 广泛用于治疗 I 期无法手术的非小细胞肺癌 (NSCLC)，但随机临床试验 (RCT) 的结果各不相同，并且对治疗中心位置肿瘤的担忧仍然存在。 检验 SBRT 是否会改善局部肿瘤对照 (LC) 与大分割传统放疗 (CRT) 进行比较。这项 3 期随机对照试验在加拿大 16 个中心进行。医学上无法手术的 I 期 (≤5 cm) NSCLC 患者以 2:1 的比例随机分配至 48 Gy 的 SBRT（4 次周围型 NSCLC）或 60 Gy 的 8 次（中心性 NSCLC）与 60 Gy 的 CRT（15 次）。收集2014年5月至2020年1月的数据，分析2022年7月至2023年7月的数据。SBRT或CRT。主要目的是确定SBRT与基于LC的3年CRT相比的有效性。次要结局包括无事件生存期、总生存期和毒性反应。所有辐射计划均需接受实时/最终审查。地方性的失败由中央裁决。该研究旨在检测 SBRT 的 3 年 LC 改善率从 75% 提高到 87.5%。目标样本量为 324 名患者。在 233 名患者中，119 名（51.1%）为男性，平均（SD）年龄为 75.4（7.7）岁；中位随访时间 (IQR) 为 36.1 (26.4-52.8) 个月。共有 154 名患者接受了 SBRT，79 名患者接受了 CRT。 SBRT 的 3 年 LC 为 87.6%（95% CI，81.9%-93.4%），CRT 的 3 年 LC 为 81.2%（95% CI，71.9%-90.5%）（风险比 [HR]，0.61；95% CI， 0.31-1.20；P = .15)。无事件生存的 HR 为 1.02（95% CI，0.72-1.45；P = .87），总生存的 HR 为 1.18（95% CI，0.80-1.76；P = .40）。观察到最小的急性毒性作用。在随机接受 SBRT 的患者中，45 例中心性 NSCLC 患者中有 5 例（11%）发生晚期 3 级或 4 级毒性反应，109 例周围型 NSCLC 患者中有 2 例（1.8%）发生晚期 3 级或 4 级毒性反应；在随机接受 CRT 的患者中，19 例中的 1 例 (5%) 患有中心性 NSCLC，60 例中的​​ 1 例 (2%) 患有周围性 NSCLC。一名因超中心病变（目标与近端支气管重叠）接受 SBRT 的患者可能出现了与治疗相关的 5 级事件（咯血）。该 RCT 将肺部 SBRT 与包括中心/超中心肿瘤的大分割 CRT 进行了比较。各组之间的 LC 没有检测到差异。严重毒性作用有限，包括患有中央肿瘤的患者。该试验提供了评估 SBRT 的重要前瞻性数据；然而，对于外周和中枢性 NSCLC，SBRT 是否比 CRT 更有效，还需要进一步研究。ClinicalTrials.gov 标识符：NCT03924869。

Stereotactic body radiotherapy (SBRT) is widely used for stage I medically inoperable non-small cell lung cancer (NSCLC), yet varied results from randomized clinical trials (RCTs) and concerns in treating centrally located tumors persist.To examine whether SBRT would improve local control (LC) compared with hypofractionated conventional radiotherapy (CRT).This phase 3 RCT was conducted in 16 Canadian centers. Patients with medically inoperable stage I (≤5 cm) NSCLC were randomized 2:1 to SBRT of 48 Gy in 4 fractions (peripheral NSCLC) or 60 Gy in 8 fractions (central NSCLC) vs CRT of 60 Gy in 15 fractions. Data were collected from May 2014 to January 2020, and data were analyzed from July 2022 to July 2023.SBRT or CRT.The primary objective was to determine the effectiveness of SBRT compared with CRT based on LC at 3 years. Secondary outcomes included event-free survival, overall survival, and toxic effects. All radiation plans were subject to real-time/final review. Local failures were centrally adjudicated. The study was designed to detect a 3-year LC improvement of SBRT from 75% to 87.5%. The target sample size was 324 patients.Of 233 included patients, 119 (51.1%) were male, and the mean (SD) age was 75.4 (7.7) years; the median (IQR) follow-up was 36.1 (26.4-52.8) months. A total of 154 patients received SBRT and 79 received CRT. The 3-year LC was 87.6% (95% CI, 81.9%-93.4%) for SBRT and 81.2% (95% CI, 71.9%-90.5%) for CRT (hazard ratio [HR], 0.61; 95% CI, 0.31-1.20; P = .15). The HR was 1.02 (95% CI, 0.72-1.45; P = .87) for event-free survival and 1.18 (95% CI, 0.80-1.76; P = .40) for overall survival. Minimal acute toxic effects were observed. Among those randomized to SBRT, late grade 3 or 4 toxic effects occurred in 5 of 45 (11%) with central NSCLC and 2 of 109 (1.8%) with peripheral NSCLC; among those randomized to CRT, in 1 of 19 (5%) with central NSCLC and 1 of 60 (2%) with peripheral NSCLC. One patient who received SBRT for an ultracentral lesion (target overlapping proximal bronchus) experienced a possible treatment-related grade 5 event (hemoptysis).This RCT compared lung SBRT with hypofractionated CRT that included central/ultracentral tumors. No difference was detected in LC between groups. Severe toxic effects were limited, including patients with central tumors. The trial provides important prospective data evaluating SBRT; however, further research is necessary to determine if SBRT is more effective than CRT for peripheral and central NSCLC.ClinicalTrials.gov Identifier: NCT03924869.