Liu Xianfeng, Huang Erliang, Wang Ying, He Yanan, Luo Huanli, Zhong Mingsong, Qiu Da, Li Chao, Yang Han, He Guanglei, Zhou Juan, Jin Fu
Department of Radiation Oncology, Chongqing Cancer Institute & Hospital & Cancer Center, Shapingba District, Chongqing, 400030, China.
Department of Medical Equipment Guangzhou Women and Children's Medical Center, Guangzhou, 510623, People's Republic of China.
Radiat Oncol. 2017 Apr 27;12(1):76. doi: 10.1186/s13014-017-0812-1.
The aim of this study was to compare radiotherapy plans for Stage I-II nasal natural killer/T-cell lymphoma (NNKTL) using helical tomotherapy (HT), volumetric-modulated arc therapy (VMAT), Fixed-Field intensity-modulated radiotherapy (IMRT), and three-dimensional conformal radiotherapy (3D-CRT).
Eight patents with Stage I-II NNKTL treated with IMRT were re-planned for HT, VMAT (two full arcs), and 3D-CRT. The quality of target coverage, the exposure of normal tissue and the efficiency of radiation delivery were analyzed.
HT showed significant improvement over IMRT in terms of D, cold spot volume and homogeneity index (HI) of planning target volume (PTV). VMAT provided best dose uniformity (p = 0.000) to PTV, while HT had best dose homogeneity among the four radiotherapy techniques (p = 0.000) to PTV. VMAT obviously reduced treatment time (p = 0.010; 0.000) compared to HT and IMRT. Mean dose of left and right optic nerve was significantly reduced by IMRT compared to HT (19.86%, p = 0.000; 21.40%, p = 0.002) and VMAT (8.97%, p = 0.002; 9.35%, p = 0.001), and maximum dose of left lens of VMAT increased over the HT (36.25%, p = 0.043) and IMRT (40.65%, p = 0.001).
The unexpected results show that both HT and VMAT can achieve higher conformal treatment plans while getting worse organs at risk (OARs) sparing than IMRT for patients with Stage I-II NNKTL. VMAT requires the shortest delivery time, and IMRT delivers the lowest dose to most OARs. The results could provide guidance for selecting proper radiation technologies for different cases.
本研究旨在比较螺旋断层放射治疗（HT）、容积调强弧形放疗（VMAT）、固定野调强放疗（IMRT）和三维适形放疗（3D-CRT）用于I-II期鼻腔自然杀伤/T细胞淋巴瘤（NNKTL）的放射治疗计划。
对8例接受IMRT治疗的I-II期NNKTL患者重新制定HT、VMAT（两个全弧）和3D-CRT计划。分析靶区覆盖质量、正常组织受照情况及放射治疗效率。
HT在计划靶区（PTV）的D、冷点体积和均匀性指数（HI）方面较IMRT有显著改善。VMAT为PTV提供了最佳的剂量均匀性（p = 0.000），而HT在四种放射治疗技术中对PTV的剂量均匀性最佳（p = 0.000）。与HT和IMRT相比，VMAT明显缩短了治疗时间（p = 0.010；0.000）。与HT（19.86%，p = 0.000；21.40%，p = 0.002）和VMAT（8.97%，p = 0.002；9.35%，p = 0.001）相比，IMRT显著降低了左右视神经的平均剂量，VMAT左晶状体的最大剂量高于HT（36.25%，p = 0.043）和IMRT（40.65%，p = 0.001）。
意外结果表明，对于I-II期NNKTL患者，HT和VMAT均可实现更高的适形治疗计划，但与IMRT相比，危及器官（OARs）的保护效果较差。VMAT所需的治疗时间最短，而IMRT对大多数OARs的剂量最低。研究结果可为不同病例选择合适的放射技术提供指导。
