Nagano Osamu, Higuchi Yoshinori, Serizawa Toru, Ono Junichi, Matsuda Shinji, Yamakami Iwao, Saeki Naokatsu
Department of Neurological Surgery, Chiba University, Graduate School of Medicine, Chiba, Japan.
J Neurosurg. 2008 Nov;109(5):811-6. doi: 10.3171/JNS/2008/109/11/0811.
The authors prospectively analyzed volume changes in vestibular schwannomas (VSs) after stereotactic radiosurgery.
One hundred consecutive patients with unilateral VS treated with Gamma Knife surgery (GKS) at Chiba Cardiovascular Center between 1998 and 2006 were analyzed in this study. For each lesion the Gd-enhanced volume was measured serially every 3 months in the 1st year, then every 6 months thereafter, using volumetric software. The frequency and degree of transient tumor expansion were documented and possible prognostic factors were analyzed. Concurrently, neurological deterioration involving trigeminal, facial, and cochlear nerve functions were also assessed.
The mean observation period was 65 months (range 25-100 months). There were 32 men and 68 women, whose mean age was 59.1 years (range 29-80 years). Tumor volumes at GKS averaged 2.7 cm3 (range 0.1-13.2 cm3), and the lesions were irradiated at the mean 52.2% isodose line for the tumor margin (range 50-67%), with a mean dose of 12.2 Gy (range 10.5-13 Gy) at the periphery. The tumor volume was increased by 23% at 3 months and 27% at 6 months. Tumors shrank to their initial size over a mean period of 12 months. The maximum volume increase was < 10% (no significant increase) in 26 patients, 10-30% in 23, 30-50% in 22, 50-100% in 16, and > 100% in 13. The peak tumor expansion averaged 47% (range 0-613%). A high-dose (> or = 3.5 Gy/min) treatment appears to be the greatest risk factor for transient tumor expansion, although the difference did not reach statistical significance. Transient facial palsy and facial dysesthesia correlated strongly with tumor expansion, but only half of the hearing loss was coincident with this phenomenon.
Transient expansion of VSs after GKS was found to be much more frequent than previously reported, strongly suggesting a correlation with deterioration of facial and trigeminal nerve functions.
作者前瞻性分析了立体定向放射外科治疗后前庭神经鞘瘤（VSs）的体积变化。
本研究分析了1998年至2006年期间在千叶心血管中心接受伽玛刀手术（GKS）治疗的100例连续单侧VS患者。对于每个病灶，在第1年每3个月使用容积软件连续测量钆增强体积，此后每6个月测量一次。记录短暂性肿瘤增大的频率和程度，并分析可能的预后因素。同时，还评估了涉及三叉神经、面神经和耳蜗神经功能的神经功能恶化情况。
平均观察期为65个月（范围25 - 100个月）。男性32例，女性68例，平均年龄59.1岁（范围29 - 80岁）。GKS时肿瘤体积平均为2.7 cm³（范围0.1 - 13.2 cm³），病灶在肿瘤边缘的平均52.2%等剂量线处接受照射（范围50 - 67%），周边平均剂量为12.2 Gy（范围10.5 - 13 Gy）。肿瘤体积在3个月时增加23%，6个月时增加27%。肿瘤在平均12个月的时间内缩小至初始大小。26例患者最大体积增加<10%（无显著增加），23例为10 - 30%，22例为30 - 50%，16例为50 - 100%，13例>100%。肿瘤增大峰值平均为47%（范围0 -
