Walsh R M, Bath A P, Bance M L, Keller A, Rutka J A
Department of Otolaryngology, University Health Network, Toronto General Hospital, University of Toronto, Ontario, Canada.
Am J Otol. 2000 Sep;21(5):716-21.
To compare two methods for measuring the size and growth rate of extracanalicular vestibular schwannomas: the method recommended in 1995 by the American Academy of Otolaryngology--Head Neck Surgery (AAO-HNS) and the maximum cerebellopontine angle (CPA) tumor diameter, i.e., the method often used in radiologic reports.
Retrospective clinical study.
Tertiary referral center.
Fifty-four patients with a radiologic diagnosis of unilateral extracanalicular vestibular schwannoma whose tumors were managed conservatively for a mean duration of 39.8 months (range 12-194 months).
The extracanalicular component was measured by use of high-resolution magnetic resonance imaging (2- to 3-mm axial slices) at 6- to 12-month intervals.
Tumor diameter was calculated by two methods. In the AAO-HNS method, the axial image with the largest extracanalicular tumor diameter was selected, and the maximum anteroposterior (A-P) and medial-lateral (M-L) tumor diameters were calculated. The A-P diameter was calculated parallel to the posterior surface of the petrous temporal bone, and the M-L diameter was calculated perpendicular to it. The size of the tumor was calculated as the square root of the product of these two diameters. In the maximum CPA method, the maximum CPA tumor diameter in any direction was also measured.
There was no significant difference between the two methods for measuring the extracanalicular tumor size and growth rate, although the maximum CPA diameter method was consistently greater than the AAO-HNS method. There was a strong positive correlation between the two methods for assessing tumor size and growth. The A-P and M-L extracanalicular tumor diameters also showed a strong positive correlation, suggesting that the extracanalicular portion of vestibular schwannomas tends to enlarge equally in both these directions.
There is a strong positive correlation between these two methods for assessing both the tumor size and the growth rate of extracanalicular vestibular schwannomas. However, because vestibular schwannomas tend to grow in both the A-P and the M-L directions, this suggests that the AAO-HNS method is preferable.
比较两种测量管外前庭神经鞘瘤大小及生长速率的方法：美国耳鼻咽喉-头颈外科学会（AAO-HNS）1995年推荐的方法和最大桥小脑角（CPA）肿瘤直径，即放射学报告中常用的方法。
回顾性临床研究。
三级转诊中心。
54例经放射学诊断为单侧管外前庭神经鞘瘤的患者，其肿瘤接受了平均39.8个月（范围12 - 194个月）的保守治疗。
通过高分辨率磁共振成像（2至3毫米轴向切片），每隔6至12个月测量管外部分。
用两种方法计算肿瘤直径。在AAO-HNS方法中，选择管外肿瘤直径最大的轴向图像，计算最大前后径（A-P）和内外径（M-L）。A-P直径平行于颞骨岩部后表面计算，M-L直径垂直于该表面计算。肿瘤大小通过这两个直径乘积的平方根计算。在最大CPA方法中，也测量任意方向的最大CPA肿瘤直径。
两种测量管外肿瘤大小及生长速率的方法之间无显著差异，尽管最大CPA直径法始终大于AAO-HNS法。两种评估肿瘤大小及生长的方法之间存在强正相关。管外肿瘤的A-P和M-L直径也显示出强正相关，表明前庭神经鞘瘤的管外部分在这两个方向上倾向于同等程度地增大。
这两种评估管外前庭神经鞘瘤肿瘤大小及生长速率的方法之间存在强正相关。然而，由于前庭神经鞘瘤倾向于在A-P和M-L两个方向生长，这表明AAO-HNS方法更可取。
