The impact of target positioning error and tumor size on radiobiological parameters in robotic stereotactic radiosurgery for metastatic brain tumors
The impact of target positioning error and tumor size on radiobiological parameters in robotic stereotactic radiosurgery for metastatic brain tumors
复制标题
机器人立体定向放射外科治疗转移性脑肿瘤中靶点定位误差和肿瘤大小对放射生物学参数的影响
DOI：
10.1007/s12194-022-00655-5
复制
发表时间：
2022
影响因子：
1.6
通讯作者：
Onda Kiyoshi
中科院分区：
文献类型：
--
作者：
Takizawa Takeshi;Tanabe Satoshi;Nakano Hisashi;Utsunomiya Satoru;Sakai Madoka;Maruyama Katsuya;Takeuchi Shigekazu;Nakano Toshimichi;Ohta Atsushi;Kaidu Motoki;Ishikawa Hiroyuki;Onda Kiyoshi
本研究旨在评价射波刀立体定向放射外科（SRS）治疗不同大小脑转移瘤中靶点定位误差（TPE）对放射生物学参数（如肿瘤控制概率（TCP）和正常组织并发症概率（NTCP））的影响。使用射波刀的圆锥体为直径（φ）为5、7.5、10、15和20 mm的球形大体肿瘤体积（GTV）创建参考SRS计划，在头部体模的计算机断层扫描图像上勾画轮廓。随后，通过使用相同的射束布置将射束中心相对于参考平面在三维上移动0.1-2.0 mm来创建涉及TPE的平面。评价了每个计划的符合性指数（CI）、基于广义等效均匀剂量（gEUD）的TCP和估计脑坏死的NTCP。当gEUD参数“a”设置为− 10时，参考平面在φ5 mm GTV处的CI和TCP分别为0.90和80.8%。涉及0.5 mm、1.0 mm和2.0 mm TPE的计划的相应值分别为0.62和77.4%、0.40和62.9%以及0.12和7.2%。相比之下，所有GTV的NTCP是相同的。在φ5 mm和φ20 mm GTV下，涉及2 mm TPE的计划的TCP分别为7.2%和68.8%。在φ5 mm和φ20 mm GTV下，对应于TCP减少率为3%的TPE分别为0.41和0.99 mm。TPE对使用射波刀治疗转移性脑肿瘤的SRS中的TCP有显著影响，特别是对于小GTV。
This study aimed to evaluate the effect of target positioning error (TPE) on radiobiological parameters, such as tumor control probability (TCP) and normal tissue complication probability (NTCP), in stereotactic radiosurgery (SRS) for metastatic brain tumors of different sizes using CyberKnife. The reference SRS plans were created using the circular cone of the CyberKnife for each spherical gross tumor volume (GTV) with diameters (φ) of 5, 7.5, 10, 15, and 20 mm, contoured on computed tomography images of the head phantom. Subsequently, plans involving TPE were created by shifting the beam center by 0.1–2.0 mm in three dimensions relative to the reference plans using the same beam arrangements. Conformity index (CI), generalized equivalent uniform dose (gEUD)-based TCP, and NTCP of estimated brain necrosis were evaluated for each plan. When the gEUD parameter “a” was set to − 10, the CI and TCP for the reference plan at the φ5-mm GTV were 0.90 and 80.8%, respectively. The corresponding values for plans involving TPE of 0.5-mm, 1.0-mm, and 2.0-mm were 0.62 and 77.4%, 0.40 and 62.9%, and 0.12 and 7.2%, respectively. In contrast, the NTCP for all GTVs were the same. The TCP for the plans involving a TPE of 2-mm was 7.2% and 68.8% at theφ5-mm andφ20-mm GTV, respectively. The TPEs corresponding to a TCP reduction rate of 3% at theφ5-mm andφ20-mm GTV were 0.41 and 0.99 mm, respectively. TPE had a significant effect on TCP in SRS for metastatic brain tumors using CyberKnife, particularly for small GTVs.