gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

Correlations between 2D and 3D measurements of vestibular schwannomas: Influence on the treatment modality

Meeting Abstract

  • corresponding author P.-H. Roche - Service de Neurochirurgie, CHU Sainte Marguerite, Marseille
  • S. Robitail - Département d'information médicale, CHU Sainte Marguerite, Marseille
  • Gourg G. Pech - Service de Neurochirurgie, CHU Sainte Marguerite, Marseille
  • J. Régis - Service de Neurochirurgie stéréotaxique et fonctionnelle, CHU Timone, Marseille

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc11.05.-01.03

The electronic version of this article is the complete one and can be found online at:

Published: May 4, 2005

© 2005 Roche et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




Various methods have been used to report the tumour size of vestibular schwannomas (VS) which is a major parameter to select a radiosurgical or microsurgical treatment. The aim of this study was to clarify the most appropriate method to represent the tumour volume and to determine the most accurate indicator of brain compression.


We studied the stereotactic magnetic resonance imaging obtained from 58 VS that were scheduled for a gamma knife radiosurgery. Measures of the tumours and posterior fossa were calculated using a gammaplan workstation. Correlations between the actual tumour volume and various tumour measurements (main diameters and simplified models of volumes) were assessed with the Spearman’s correlation coefficient. The predictions of brain compression (Koos IV versus Koos II or III) following various parameters, such as actual tumour volume, pons-to-petrous diameter, maximum diameter in the cerebellopontine angle and ratio between the tumour volume and the posterior fossa volume, were assessed by analyzing the corresponding receiver operating characteristic curves.


The simplest method to approximate the tumour volume was the maximum CPA diameter of the VS (Spearman’s Rho = 0.94). The simplest measurement to represent the effect of brain compression was the pons-to-petrous diameter. Using a 80% threshold value for sensitivity and specificity, neuroagressiveness could be strongly predicted from a 1997 cubic millimeters cut-off value for the tumour volume and from a 14.5 mm cut-off value for the pons-to-petrous diameter.


The actual tumour volume and its relationship with the posterior fossa volume are sofisticated 3D computarized data that are strongly predictive of the VS behaviour. However, simple parameters such the maximum CPA diameter and pons-to-petrous diameter are appropriate ways to approximate the volume, estimate the brain compression and influence the treatment modality.