Purpose

This study analyzes the outcomes and toxicity of stereotactic body radiation therapy (SBRT) as salvage treatment for recurrent non-small cell lung cancer (NSCLC).

Methods and Materials

This retrospective analysis considered patients treated with thoracic SBRT and a history of prior external beam radiation therapy (EBRT), SBRT, or surgical resection for NSCLC. Follow-up included positron emission tomography and computed tomography imaging at 2- to 3-month intervals. Key outcomes were presented with the Kaplan–Meier method.

Results

Forty patients with 52 treatments were included at a mean of 11.82 months after treatment with EBRT (n = 21), SBRT (n = 15), surgical resection (n = 9), and SBRT after EBRT (n = 7). Median imaging and clinical follow-up were 13.39 and 19.01 months, respectively. SBRT delivered a median dose of 40 Gy in 4 fractions. Median biologically effective dose (BED) was 79.60 Gy. Median gross tumor volume and planning target volume were 10.80 and 26.25 cm³, respectively. Local control was 65%, with a median time to local failure of 13.52 months. Local control was 87% after previous SBRT but only 33% after surgery. Median overall survival was 24.46 months, and median progression-free survival (PFS) was 14.11 months. Patients presenting after previous SBRT had improved local control (P = .021), and the same result was obtained including patients with SBRT after EBRT (P = .0037). Treatments after surgical resection trended toward worse local control (P = .061). Patients with BED ≥80 Gy had improved local PFS (P = .032), PFS (P = .021), time without any treatment failure (P = .033), and time to local failure (P = .041). Using the Kaplan–Meier method, BED ≥80 Gy was predictive of improved local PFS (P = .01) and PFS (P < .005). Toxicity consisted of 10 instances of grade <3 toxicity (16%) and no grade ≥3 toxicity.

Conclusions

Salvage treatment for recurrent NSCLC with SBRT was effective and well tolerated, particularly after initial treatment with SBRT. When possible, salvage SBRT should aim to achieve a BED of ≥80 Gy.

中文翻译：

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立体定向放射治疗复发性非小细胞肺癌的抢救性治疗。

目的

本研究分析了立体定向放射治疗 (SBRT) 作为复发性非小细胞肺癌 (NSCLC) 抢救治疗的结果和毒性。

方法和材料

该回顾性分析考虑了接受胸部 SBRT 治疗且既往有外照射放疗 (EBRT)、SBRT 或 NSCLC 手术切除史的患者。随访包括每隔 2 至 3 个月进行一次正电子发射断层扫描和计算机断层扫描。主要结果用 Kaplan-Meier 方法呈现。

结果

40 名患者在接受 EBRT（n = 21）、SBRT（n = 15）、手术切除（n = 9）和 EBRT 后 SBRT（n = 7）治疗后的平均 11.82 个月内纳入了 52 次治疗。中位影像学和临床随访时间分别为 13.39 和 19.01 个月。SBRT 分 4 次提供 40 Gy 的中位剂量。中位生物有效剂量 (BED) 为 79.60 Gy。中位总肿瘤体积和计划靶体积分别为 10.80 和 26.25 cm ³。局部控制率为 65%，局部失败的中位时间为 13.52 个月。先前 SBRT 后局部控制率为 87%，但手术后仅为 33%。中位总生存期为 24.46 个月，中位无进展生存期 (PFS) 为 14.11 个月。既往 SBRT 后就诊的患者局部控制有所改善（P= .021)，并且在 EBRT 后接受 SBRT 的患者中也获得了相同的结果 ( P = .0037)。手术切除后的治疗趋向于更差的局部控制 ( P = .061)。BED ≥ 80 Gy 的患者改善了局部 PFS ( P = .032)、PFS ( P = .021)、无任何治疗失败的时间 ( P = .033) 和局部失败的时间 ( P = .041)。使用 Kaplan-Meier 方法，BED ≥80 Gy 可预测改善的局部 PFS ( P = .01) 和 PFS ( P < .005)。毒性包括 10 例 <3 级毒性 (16%) 和无 3 级以上毒性。

结论

SBRT 对复发性 NSCLC 的挽救治疗有效且耐受性良好，特别是在 SBRT 初始治疗后。在可能的情况下，挽救性 SBRT 的目标应该是达到 ≥ 80 Gy 的 BED。