Li Chengqiang, Chen Jinhu, Zhu Jian, Gong Guanzhong, Tao Cheng, Li Zhenjiang, Lu Jie, Yin Yong
Department of Radiation Oncology Physics, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan 250117, China.
J Cancer. 2019 Oct 15;10(24):6135-6141. doi: 10.7150/jca.32500. eCollection 2019.
Varian Halcyon is a novel machine with dual-layer leaves, single flattening filter free (FFF) energy and an enclosed bore. The purpose of this study was to compare the differences in dosimetry and plan parameters of intensity-modulated radiation therapy (IMRT) plans between the Halcyon and Trilogy accelerators. A total of 30 IMRT plans from cervical carcinoma patients were retrospectively analyzed on the Trilogy and Eclipse v13.5 treatment planning systems (TPSs). For each patient, a new plan based on Halcyon was created with the same planning parameters and optimization constraints using the Eclipse Version 15.1 TPS. To compare plan qualities, dosimetry parameters regarding planning target volume (PTV), organs at risk (OARs), monitor unit (MU) efficiency, segment size and treatment time were evaluated. Evaluation of the helical diode array system was performed with gamma-index analysis. The dose distribution of the target volume of the Halcyon and Trilogy plans showed no significant difference ( > 0.05). The mean doses of rectum and both femoral heads for Halcyon plans were significantly reduced compared to those for Trilogy plans ( < 0.05). Compared to Trilogy, Halcyon increased the number of MUs from 1542.9±248.3 MU to 2514.9±328.2 MU ( = 0.00) and decreased the delivery time from 11.28±1.36 min to 3.26±0.26 min ( = 0.00). The average segment areas of Halcyon plans for proximal and distal multileaf collimators (MLCs) were 42.1 ± 31.2 cm and 28.4 ± 23.7 cm, respectively, and that of Trilogy plans was 27.3 ± 16.9 cm. The mean gamma index (3 mm/3%) results for the Halcyon and Trilogy plans were 99.41±0.26 and 99.76±0.32 ( > 0.05), respectively. All Halcyon treatment plans were recognized as clinically acceptable and had statistically better OAR sparing with higher delivery efficiency. The Halcyon system exhibited fast treatment delivery of IMRT with good dosimetric agreement using ArcCHECK.
瓦里安速锐是一款新型设备，具有双层准直器叶片、单光子均一剂量率（FFF）能量以及封闭式孔径。本研究的目的是比较速锐加速器和 Trilogy 加速器在调强放射治疗（IMRT）计划中的剂量学和计划参数差异。对 Trilogy 和 Eclipse v13.5 治疗计划系统（TPS）上 30 例宫颈癌患者的 IMRT 计划进行了回顾性分析。对于每位患者，使用 Eclipse 版本 15.1 TPS，基于速锐创建具有相同计划参数和优化约束的新计划。为比较计划质量，评估了有关计划靶区（PTV）、危及器官（OARs）、监测单位（MU）效率、射野分段大小和治疗时间的剂量学参数。使用伽马指数分析对螺旋二极管阵列系统进行了评估。速锐和 Trilogy 计划靶区的剂量分布无显著差异（>0.05）。与 Trilogy 计划相比，速锐计划中直肠和双侧股骨头的平均剂量显著降低（<0.05）。与 Trilogy 相比，速锐的 MU 数量从 1542.9±248.3 MU 增加到 2514.9±328.2 MU（P = 0.00），治疗时间从 11.28±1.36 分钟减少到 3.26±0.26 分钟（P = 0.00）。速锐计划近端和远端多叶准直器（MLC）的平均射野分段面积分别为 42.1±31.2 cm²和 28.4±23.7 cm²，Trilogy 计划的为 27.3±16.9 cm²。速锐和 Trilogy 计划的平均伽马指数（3mm/3%）结果分别为 99.41±0.26 和 99.76±0.32（>0.05）。所有速锐治疗计划均被认为在临床上可接受，并且在统计学上对 OAR 的保护更好，治疗效率更高。速锐系统使用 ArcCHECK 实现了 IMRT 的快速治疗交付，剂量学一致性良好。
