Medélez-Borbonio Rafael, Perdomo-Pantoja Alexander, Serrano-Rubio Alejandro Apolinar, Tomberlin Colson, Revuelta-Gutiérrez Rogelio, Moreno-Jiménez Sergio
Department of Neurosurgery, National Institute of Neurology and Neurosurgery "Manuel Velasco Suarez", Mexico City, Mexico.
Department of Neurosurgery, National Institute of Neurology and Neurosurgery "Manuel Velasco Suarez", Mexico City, Mexico; Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, USA.
Neurocirugia (Astur : Engl Ed). 2019 May-Jun;30(3):105-114. doi: 10.1016/j.neucir.2018.10.001. Epub 2018 Nov 10.
To describe the anatomical measurements of the trigeminal nerve in patients with trigeminal neuralgia (TN) during Linac (linear accelerator)-based stereotactic radiosurgery (SRS) simulation, targeting the root entry zone (REZ), with a 30% isodose line tangential to the pons, using 4-mm and 6-mm collimators.
In this retrospective study, 53 TN patients, who underwent Fiesta sequence scanning prior to any treatment modality, were assessed. Bilateral measurements were obtained from the cisternal segment of the trigeminal nerve, the trigeminal-pontine angle, and the lateral width of the pontine cistern on the Fiesta MRI sequence. Linac-based SRS simulations were estimated with a radiation dosage of 90Gy to 30% isodose line tangential to the pons, with both 4- and 6-mm collimators. Distances from the calculated targets to the pons and the Gasserian ganglion were measured for later analysis. The statistical analysis was performed comparing the affected side against the unaffected side.
Right trigeminal nerve was affected in 36 patients (67.9%), and left one in 17 (32.1%) patients. The mean length of the trigeminal nerve was 9.8mm (range: 4.6-16.8mm) on the affected side, and 10.5mm (range: 5.6-18.4mm) on the unaffected side (p=.02). The mean trigeminal-pontine angle was 12.5° (range: 5.4° to 19.5°) on the affected side, and 10.2° (range: 5.0° to 30.5°) on the unaffected side (p=.01). In the simulations, the distances from the estimated targets to the pons and the Gasserian ganglion were not statistically different between sides. The variation of target-pons and target-ganglion distances was statistically significant on the affected side with the change of collimators (p<.001).
In this anatomical study, significant differences were identified in the length of the affected trigeminal nerve and trigeminal-pontine angle compared to the unaffected side in TN patients in Fiesta sequences prior to surgery or radiosurgery. Significant variation of the target location was found on the REZ between the 4- and 6-collimators during the Linac-based SRS simulations with the estimated radiation dosage of 90Gy and 30% isodose line tangential to the pons.
描述在基于直线加速器（Linac）的立体定向放射外科治疗（SRS）模拟过程中，针对三叉神经痛（TN）患者三叉神经的解剖学测量结果，靶点为神经根入区（REZ），使用4毫米和6毫米准直器，30%等剂量线与脑桥相切。
在这项回顾性研究中，对53例在接受任何治疗方式之前进行了Fiesta序列扫描的TN患者进行了评估。在Fiesta MRI序列上从三叉神经脑池段、三叉神经-脑桥角和脑桥脑池的外侧宽度进行双侧测量。基于直线加速器的SRS模拟采用90Gy的辐射剂量，30%等剂量线与脑桥相切，使用4毫米和6毫米准直器。测量计算出的靶点到脑桥和半月神经节的距离以供后续分析。进行统计学分析，比较患侧与健侧。
36例患者（67.9%）右侧三叉神经受累，17例患者（32.1%）左侧三叉神经受累。患侧三叉神经的平均长度为9.8毫米（范围：4.6 - 16.8毫米），健侧为10.5毫米（范围：5.6 - 18.4毫米）（p = 0.02）。患侧三叉神经-脑桥角的平均角度为12.5°（范围：5.4°至19.5°），健侧为10.2°（范围：5.0°至30.5°）（p = 0.01）。在模拟中，估计靶点到脑桥和半月神经节的距离在两侧之间无统计学差异。随着准直器的变化，患侧靶点到脑桥和靶点到神经节的距离变化具有统计学意义（p < 0.001）。
在这项解剖学研究中，在手术或放射外科治疗前的Fiesta序列中，TN患者患侧三叉神经的长度和三叉神经-脑桥角与健侧相比存在显著差异。在基于直线加速器的SRS模拟中，当估计辐射剂量为90Gy且30%等剂量线与脑桥相切时，4毫米和6毫米准直器之间的REZ靶点位置存在显著变化。
