Barsky Andrew R, Lin Hui, Mendes Amberly, Dreyfuss Alexandra, Wright Christopher, Anstadt Emily J, Berman Abigail T, Levin William P, Cengel Keith A, Anderson Nathan, Dong Lei, Metz James M, Li Taoran, Feigenberg Steven
Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, USA.
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA.
Cureus. 2020 Sep 9;12(9):e10325. doi: 10.7759/cureus.10325.
Introduction Modern technologies, like intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT), have improved the therapeutic ratio of thoracic radiotherapy (TRT) for lung cancer (LC). Halcyon™ (Varian Medical Systems, Palo Alto, CA, USA), a novel 6MV-flattening-filter-free O-ring linear accelerator (6X-FFF ORL), was designed to deliver IMRT and VMAT with greater speed than a C-arm linac. Herein, we report our initial clinical experience treating patients with LC on this linac. Methods All patients who received TRT for LC on the 6X-FFF ORL at our institution were retrospectively identified. Patients' clinicopathologic data, radiotherapy details, early disease-control and toxicity outcomes, dosimetric data, couch corrections, and treatment times are reported. Results Between 10/2018-12/2019, 30 consecutive patients (median age 66 years, range 54-94 years) received definitive or post-operative TRT for LC (median 66 Gy/33 fractions; range 5-70 Gy/2-37 fractions) following four-dimensional computed tomography (CT) simulation (97%) using daily kilovoltage KV cone-beam CT (CBCT) (100%) on a 6X-FFF ORL for non-small cell LC (84%) or small cell LC (16%), with 53% receiving VMAT, 43% receiving static-field IMRT, and 77% receiving concurrent systemic therapy. All plans were approved through institutional peer review. The average three-dimensional vector couch correction based on CBCT guidance was 0.90 ± 0.50 cm. The average beam-on and beam on plus CBCT times were 1.7 ± 1.1 min, and 5.0 ± 3.2 min, respectively. Grade 3 dyspnea and fatigue occurred in 3% and 3% of patients, respectively. There were no grade ≥4 toxicities. Conclusion In this first clinical report of TRT for LC on a 6X-FFF ORL, daily CBCT-guided treatment was fast and safe with respect to dosimetry and clinical outcomes. Thus, use of this linac for TRT may increase LC patient throughput without a detriment in radiotherapy quality.
引言 现代技术，如调强放疗（IMRT）和容积调强弧形放疗（VMAT），提高了肺癌（LC）胸部放疗（TRT）的治疗比。Halcyon™（美国瓦里安医疗系统公司，加利福尼亚州帕洛阿尔托）是一种新型的6MV无均整器O型环直线加速器（6X-FFF ORL），其设计目的是比C型臂直线加速器更快地实施IMRT和VMAT。在此，我们报告我们使用该直线加速器治疗LC患者的初步临床经验。方法 回顾性确定在我们机构使用6X-FFF ORL接受LC的TRT的所有患者。报告患者的临床病理数据、放疗细节、早期疾病控制和毒性结果、剂量学数据、治疗床校正和治疗时间。结果 在2018年10月至2019年12月期间，30例连续患者（中位年龄66岁，范围54-94岁）在使用每日千伏（KV）锥形束CT（CBCT）（100%）进行四维计算机断层扫描（CT）模拟（97%）后，接受了针对LC的根治性或术后TRT（中位66 Gy/33次分割；范围5-70 Gy/2-37次分割），用于非小细胞LC（84%）或小细胞LC（16%），其中53%接受VMAT，43%接受静态野IMRT，77%接受同步全身治疗。所有计划均通过机构同行评审。基于CBCT引导的平均三维矢量治疗床校正为0.90±0.50 cm。平均照射时间和照射加CBCT时间分别为1.7±1.1分钟和5.0±3.2分钟。3%的患者发生3级呼吸困难，3%的患者发生3级疲劳。没有≥4级毒性反应。结论 在这份关于使用6X-FFF ORL进行LC的TRT的首份临床报告中，就剂量学和临床结果而言，每日CBCT引导的治疗快速且安全。因此，使用该直线加速器进行TRT可能会提高LC患者的治疗通量，而不会损害放疗质量。
