Flickinger J C, Kondziolka D, Pollock B E, Lunsford L D
Department of Radiation Oncology, University of Pittsburgh School of Medicine, PA, USA.
Int J Radiat Oncol Biol Phys. 1996 Sep 1;36(2):275-80. doi: 10.1016/s0360-3016(96)00335-5.
To define changes in treatment technique for vestibular schwannoma radiosurgery and to relate them to changes in outcome, a large single institution experience was reviewed.
Two hundred seventy-three patients with unilateral vestibular schwannomas underwent Gamma knife radiosurgery: 118 with computed tomography (CT) treatment planning during 1987-1991, and 155 with magnetic resonance imaging (MR) treatment planning in 1991-1994. Mean treatment parameters differed between the CT and MR groups: minimum tumor dose (D(min)) was 17 vs. 14 Gy, number of isocenters was 3.4 vs. 5.8, and volume was 3.5 vs 2.7 cc., respectively.
The actuarial 7-year clinical tumor control rate (no requirement for surgical intervention) for the entire series was 96.4 +/- 2.3%, with a radiographic tumor control rate of 91.0 +/- 3.4%; these rates were similar for the CT and MR groups. Significantly lower rates of postradiosurgery facial, trigeminal, and auditory neuropathy were observed in the MR group compared to the CT group. Multivariate analyses found significant independent correlations of increasing rates of facial and trigeminal neuropathy with increasing transverse tumor diameter and D(min), as well as with CT treatment planning (compared to MR). Decreased hearing was similarly correlated with diameter and CT planning but not with D(min).
Changes in radiosurgery technique and the use of lower doses improved the outcome after vestibular schwannoma radiosurgery by decreasing cranial neuropathy rates. MR-based treatment planning appears to have significantly contributed to this improvement. Despite decreases in radiation dose, no change in the high rate of tumor control has yet been observed.
为明确前庭神经鞘瘤放射外科治疗技术的变化及其与治疗结果变化的关系，我们回顾了一家大型单一机构的经验。
273例单侧前庭神经鞘瘤患者接受了伽玛刀放射外科治疗：1987 - 1991年期间118例采用计算机断层扫描（CT）进行治疗计划，1991 - 1994年期间155例采用磁共振成像（MR）进行治疗计划。CT组和MR组的平均治疗参数有所不同：最小肿瘤剂量（D(min)）分别为17 Gy和14 Gy，等中心点数量分别为3.4个和5.8个，肿瘤体积分别为3.5 cc和2.7 cc。
整个系列的7年精算临床肿瘤控制率（无需手术干预）为96.4±2.3%，影像学肿瘤控制率为91.0±3.4%；CT组和MR组的这些比率相似。与CT组相比，MR组放射外科治疗后面部神经、三叉神经和听觉神经病变的发生率显著更低。多变量分析发现，面部神经和三叉神经病变发生率增加与肿瘤横向直径增大、D(min)增加以及采用CT治疗计划（与MR相比）存在显著的独立相关性。听力下降同样与肿瘤直径以及CT计划相关，但与D(min)无关。
放射外科技术的改变和较低剂量的使用通过降低颅神经病变率改善了前庭神经鞘瘤放射外科治疗的结果。基于MR的治疗计划似乎对这一改善有显著贡献。尽管辐射剂量降低，但尚未观察到肿瘤高控制率的变化。
