Neurosurgery, Klinik Im Park, Seestrasse 220, 8027, Zürich, Switzerland.
Acta Neurochir (Wien). 2013 Jan;155(1):71-4; discussion 74. doi: 10.1007/s00701-012-1553-4. Epub 2012 Nov 17.
Patients with vestibular schwannomas (VS) are either assigned to watchful waiting, microsurgical resection, or radiosurgery. Decision making on how to proceed is based on parameters such as age, tumor growth, loss of hearing, and the tumor's Koos grading.
In order to correlate Koos grading with tumor volume, patient records of 235 patients with VS who underwent Gamma Knife radiosurgery (GKRS) were retrospectively reviewed.
From 1994 to 2009, 235 consecutive patients underwent GKRS for sporadic VS at the Zurich Gamma Knife Center. Median follow up was 62.8 ± 33.0 months. Of the 235 tumors, 32 (13.6 %) were graded Koos I with a volume of 0.25 ± 0.3 cc; 71 (30.2 %) were graded Koos II with a volume of 0.57 ± 0.54 cc; 70 (29.8 %) were graded Koos III with a volume of 1.82 ± 1.88 cc; and 62 (26.4 %) were graded Koos IV with a volume of 4.17 ± 2.75 cc. Tumor progression was defined as a volume increase > 20 % at 2 years or later following GKRS. Overall tumor progression occurred in 21/235 (8.9 %) patients at 3.4 ± 0.9 years. Tumor progression did not differ statistically significantly in the various Koos grades: 1/32 (3.1 %) patients with VS Koos Grade I, 7/71 (9.8 %) patients with VS Koos Grade II, 6/70 (8.6 %) patients with VS Koos Grade III, and 7/62 (11.3 %) patients with VS Koos Grade IV.
To our knowledge, this is the first work correlating the various Koos grades of VS to their respective tumor volumes. In our patients, tumor volumes of VS Koos Grade IV were limited because all of our patients were eligible for radiosurgery. In our series, the outcome following GKRS for patients with VS Koos Grade IV tumors did not differ from patients with VS Koos Grades I-III. We therefore suggest to limit Koos Grade IV VS to tumor volumes < 6 cc that may be eligible for radiosurgery, and introduce an additional VS Grade V for large VS with tumor volumes of > 6 cc that may not be eligible for radiosurgery.
前庭神经鞘瘤（VS）患者要么选择观察等待，要么选择显微手术切除，要么选择放射外科治疗。如何进行决策取决于年龄、肿瘤生长、听力丧失以及肿瘤的 Koos 分级等参数。
为了将 Koos 分级与肿瘤体积相关联，我们回顾性分析了 235 例在苏黎世伽玛刀中心接受伽玛刀放射外科治疗（GKRS）的 VS 患者的病历。
1994 年至 2009 年，235 例散发性 VS 患者在苏黎世伽玛刀中心接受 GKRS 治疗。中位随访时间为 62.8 ± 33.0 个月。在 235 个肿瘤中，32 个（13.6%）为 Koos I 级，体积为 0.25 ± 0.3 cc；71 个（30.2%）为 Koos II 级，体积为 0.57 ± 0.54 cc；70 个（29.8%）为 Koos III 级，体积为 1.82 ± 1.88 cc；62 个（26.4%）为 Koos IV 级，体积为 4.17 ± 2.75 cc。肿瘤进展定义为 GKRS 后 2 年或更长时间体积增加>20%。在 3.4 ± 0.9 年时，21/235（8.9%）例患者发生总体肿瘤进展。在不同的 Koos 分级中，肿瘤进展的发生率无统计学差异：VS Koos 分级 I 级患者中有 1/32（3.1%）例肿瘤进展，VS Koos 分级 II 级患者中有 7/71（9.8%）例肿瘤进展，VS Koos 分级 III 级患者中有 6/70（8.6%）例肿瘤进展，VS Koos 分级 IV 级患者中有 7/62（11.3%）例肿瘤进展。
据我们所知，这是第一项将不同的 VS Koos 分级与其各自的肿瘤体积相关联的工作。在我们的患者中，VS Koos 分级 IV 级肿瘤的体积受到限制，因为我们所有的患者都符合放射外科治疗的条件。在我们的系列研究中，GKRS 治疗 VS Koos 分级 IV 级肿瘤患者的结果与 VS Koos 分级 I-III 级患者无差异。因此，我们建议将 VS Koos 分级 IV 级肿瘤的体积限制在 6 cc 以下，这些肿瘤可能有资格接受放射外科治疗，并引入另外的 VS 分级 V，用于体积大于 6 cc、可能没有资格接受放射外科治疗的大型 VS 肿瘤。
