Department of Neurosurgery, Koto Memorial Hospital, 2-1 Hiramatsu-cho, Higashiohmi-shi, Shiga, 527-0134, Japan.
Acta Neurochir (Wien). 2022 Sep;164(9):2465-2471. doi: 10.1007/s00701-022-05291-x. Epub 2022 Jul 22.
Meningiomas have vascular supply from the tumor attachment on the dura mater. Gamma Knife radiosurgery (GKS) is known to have a vascular obliterating effect. This study aims to determine the benefits of high-dose irradiation to the tumor attachment compared to conventional dose planning in the long-term control of tumor growth with GKS.
Two different dose plannings were retrospectively compared in 75 patients with meningioma treated with GKS as a primary treatment. Forty-three patients were irradiated over 20 Gy to the tumor attachment. The remaining 32 patients were treated with conventional-dose planning. Tumor growth control, reduction of enhancement on the gadolinium-enhanced magnetic resonance imaging (MRI), and neurological status were retrospectively assessed.
The maximum dose on the tumor attachment was significantly higher in the high-dose group (23 Gy) than in the conventional group (16 Gy). The tumor margin was irradiated with the median of the 50% isodose line in both groups. The prescription doses resulted in 14 Gy and 12 Gy, respectively. The tumor control rate achieved 91% in both groups during the median follow-up period of 54 months. A decrease of enhancement on follow-up MRI was noted in one patient in each group. Kaplan-Meier analysis revealed no statistical difference in the progression-free survival between the two groups. The number of patients with improved neurological status showed no statistical difference.
No obvious benefit of high-dose irradiation to the tumor attachment and margin was found in tumor control and neurological status in the long term.
脑膜瘤的血管供应来自硬脑膜上的肿瘤附着处。伽玛刀放射外科（GKS）已知具有血管闭塞作用。本研究旨在确定与常规剂量规划相比，GKS 对肿瘤附着处以高剂量照射在长期控制肿瘤生长方面的益处。
回顾性比较了 75 例脑膜瘤患者的两种不同剂量规划，这些患者均接受 GKS 作为主要治疗方法。43 例患者的肿瘤附着处以 20Gy 以上剂量照射。其余 32 例患者接受常规剂量规划。回顾性评估肿瘤生长控制、钆增强磁共振成像（MRI）增强减少以及神经状态。
高剂量组（23Gy）肿瘤附着处的最大剂量明显高于常规剂量组（16Gy）。两组肿瘤边缘均以 50%等剂量线的中位数进行照射。处方剂量分别为 14Gy 和 12Gy。在中位随访 54 个月期间，两组的肿瘤控制率均达到 91%。每组均有 1 例患者在随访 MRI 上出现增强减少。Kaplan-Meier 分析显示两组患者在无进展生存方面无统计学差异。神经状态改善的患者数量也无统计学差异。
在长期肿瘤控制和神经状态方面，肿瘤附着处和边缘的高剂量照射没有明显获益。
