Department of Radiation Oncology, University of Florida, College of Medicine, Jacksonville, FL, USA.
Department of Medicine, Division of Hematology and Medical Oncology, University of Florida, College of Medicine, Jacksonville, FL, USA.
Acta Oncol. 2020 Oct;59(10):1164-1170. doi: 10.1080/0284186X.2020.1759821. Epub 2020 May 12.
The treatment of centrally-located early-stage non-small cell lung cancer (NSCLC) with image-guided stereotactic body radiotherapy (SBRT) is challenging due to the proximity of critical normal structures to the tumor target. The purpose of this study was to report the results of our experience in treating centrally-located early-stage NSCLC with hypofractionated proton therapy (PT).
Between 2009 and 2018, 23 patients with T1-T2N0M0 NSCLC (T1, 46%; T2, 54%) were treated with image-guided hypofractionated double-scattering PT. The median age at the time of treatment was 74 years (range, 58-88). Patients underwent 4-dimensional computed tomography (CT) simulation following fiducial marker placement, and daily image guidance was performed. All patients were treated with 60 GyRBE in 10 fractions. Patients were assessed for CTCAEv4 toxicities weekly during treatment, and at regular follow-up intervals with CT imaging for tumor assessment. Overall survival, cause-specific survival, local control, regional control, and metastases-free survival were evaluated using cumulative incidence with competing risks.
Median follow-up for all patients was 3.2 years (range, 0.2-9.2 years). Overall survival rates at 3 and 5 years were 81% and 50% (95% CI, 27-79%), respectively. Cause-specific survival rates at 3 and 5 years were 81% and 71% (95% CI, 46-92%). The 3-year local, regional, and distant control rates were 90%, 81%, and 87%, respectively. Three patients (13%) experienced local recurrences as their first recurrence, at a median time of 28 months from completion of radiation (range, 18-61 months). Two patients (9%) experienced late grade 3 toxicities, including 1 patient who developed a bronchial stricture that required stent placement.
Image-guided hypofractionated PT for centrally-located early-stage NSCLC provides excellent local control with low rates of grade ≥3 toxicities. For tumors in sensitive locations, PT may provide safer treatment than photon-based treatments due to its dosimetric advantages.
由于肿瘤靶区与关键正常结构毗邻，使用影像引导立体定向体放射治疗（SBRT）治疗中央型早期非小细胞肺癌（NSCLC）具有挑战性。本研究的目的是报告我们使用低分割质子治疗（PT）治疗中央型早期 NSCLC 的经验结果。
在 2009 年至 2018 年间，23 例 T1-T2N0M0 NSCLC（T1，46%；T2，54%）患者接受了图像引导的低分割双散射 PT 治疗。治疗时的中位年龄为 74 岁（范围，58-88 岁）。患者在放置基准标记后进行了 4 维 CT 模拟，并进行了每日图像引导。所有患者均接受 60 GyRBE 的 10 次分割治疗。在治疗期间每周对所有患者进行 CTCAEv4 毒性评估，并用 CT 成像定期随访肿瘤评估。使用累积发生率和竞争风险评估总生存率、疾病特异性生存率、局部控制率、区域控制率和无转移生存率。
所有患者的中位随访时间为 3.2 年（范围，0.2-9.2 年）。3 年和 5 年的总生存率分别为 81%和 50%（95%CI，27-79%）。3 年和 5 年的疾病特异性生存率分别为 81%和 71%（95%CI，46-92%）。3 年局部、区域和远处控制率分别为 90%、81%和 87%。3 名患者（13%）出现局部复发，其中 2 名患者（9%）出现晚期 3 级毒性，包括 1 名患者发生支气管狭窄，需要支架植入。
影像引导的低分割 PT 治疗中央型早期 NSCLC 可提供优异的局部控制率，且 3 级以上毒性反应发生率低。对于位于敏感部位的肿瘤，由于 PT 的剂量学优势，它可能比光子治疗更安全。
