伽玛刀剂量率是否会影响三叉神经痛放射外科治疗的结果？

Does the Gamma Knife dose rate affect outcomes in radiosurgery for trigeminal neuralgia?

机构信息

Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.

出版信息

J Neurosurg. 2010 Dec;113 Suppl:168-71. doi: 10.3171/2010.7.GKS101049.

DOI:10.3171/2010.7.GKS101049

PMID:21121798

Abstract

OBJECT

The object of this study was to determine whether the radiation dose rate affects clinical outcomes in patients who undergo stereotactic Gamma Knife surgery (GKS) to manage typical trigeminal neuralgia (TN).

METHODS

The authors retrospectively studied pain relief in 165 patients with medically intractable TN, who underwent 80-Gy GKS using a single 4-mm collimator between 1994 and 2005. No patient had received prior radiation treatment. The measured relative helmet output factor of the Gamma Knife was 0.8 throughout this interval, and the dose rate varied from 1.21 Gy/minute to 3.74 Gy/minute (median 2.06 Gy/minute). Irradiation time varied from 26.73 to 95.11 minutes. The authors divided patients into a low-dose-rate (LDR) group, in which the dose rate varied from 1.21 to 2.05 Gy/minute, and a high-dose-rate (HDR) group, in which the dose rate varied from 2.06 to 3.74 Gy/minute. Post-GKS, the patients' pain control was determined using the Barrow Neurological Institute (BNI) pain scale. There was no statistically significant difference between groups with respect to history of prior microvascular decompression (p = 0.410) or peripheral neuroablative procedures (p = 0.583). The length of symptoms in patients varied from 3 to 414 months with a median of 84 months (p = 0.698). Median follow-up was 26 months with a maximum of 139 months.

RESULTS

Initial pain relief was obtained in 71% of patients in the LDR group and 78% in the HDR group (p = 0.547). Patients who initially obtained improved pain relief (BNI Scores I-IIIa) after GKS maintained pain control for median durations of 52 months (LDR group) and 54 months (HDR group) (p = 0.403). New or increased facial sensory dysfunction was found in 14.5% of patients in the LDR group and in 19.3% of patients in the HDR group (p = 0.479).

CONCLUSIONS

The authors found that the GKS dose rate did not affect pain control or morbidity within the range of 1.21-3.74 Gy/minute. Cobalt 60 source decay did not affect outcomes of GKS for TN pain management, even for dose rates approximating a 2-half-life decay of the isotope.

摘要

目的

本研究旨在确定立体定向伽玛刀（GKS）治疗典型三叉神经痛（TN）患者的放射剂量率是否会影响临床结果。

方法

作者回顾性研究了 1994 年至 2005 年间 165 例药物难治性 TN 患者接受 80-Gy GKS 后的疼痛缓解情况。所有患者均未接受过放射治疗。在此期间，Gamma Knife 的测量相对头盔输出因子为 0.8，剂量率为 1.21Gy/minute 至 3.74Gy/minute（中位数 2.06Gy/minute）。照射时间为 26.73 至 95.11 分钟。作者将患者分为低剂量率（LDR）组和高剂量率（HDR）组，LDR 组的剂量率为 1.21 至 2.05Gy/minute，HDR 组的剂量率为 2.06 至 3.74Gy/minute。GKS 后，使用巴罗神经研究所（BNI）疼痛量表确定患者的疼痛控制情况。两组在微血管减压术（MVD）史（p = 0.410）或周围神经消融术史（p = 0.583）方面无统计学差异。患者的症状持续时间从 3 至 414 个月不等，中位数为 84 个月（p = 0.698）。中位随访时间为 26 个月，最长随访时间为 139 个月。

结果

LDR 组和 HDR 组分别有 71%和 78%的患者初始疼痛缓解（p = 0.547）。GKS 后疼痛缓解（BNI 评分 I-IIIa）的患者，LDR 组中位疼痛控制时间为 52 个月，HDR 组为 54 个月（p = 0.403）。LDR 组有 14.5%的患者出现新的或加重的面部感觉功能障碍，HDR 组有 19.3%的患者出现新的或加重的面部感觉功能障碍（p = 0.479）。