Volume Measurement of Vestibular Schwannoma Using New Software

Oh, Seung Ha; Lee, Seung Sin; Lee, Kang Jin; Hwang, Chan Ho; Ahn, Soon Hyun; Chang, Sun O; Kim, Chong Sun; Chung, Jin Wook

Abstract

BACKGROUND AND OBJECTIVES: Vestibular schwannomas are intracranial neoplasms that compress adjacent structures as their volume grows. Although the clinically relevant parameter is most likely tumor volume, current clinical decisions are based on two-dimensional measurements of tumor diameter. This study was conducted to introduce a new software for accurate measurement of vestibular schwannoma volume and to determine the relationship between diameter and volume. Material and Method: Twenty-eight patients who had no previous treatment before MRI were included in this study. Diameter of the vestibular schwannoma was measured according to AAO guidelines and spherical volume was calculated from the diameter. For the accurate volume measurement of the vestibular schwannoma, we used a new software (Rapidia, 3D Med Co) developed in Korea. Paired t-test was used for the statistical analysis of correlation between the measured and calculated volumes.
RESULTS
The difference between the measured and calculated volumes was statistically not significant (p=.120). However, as tumor size increased greater than 2 cm in diameter, our measured volume result was smaller than the calculated volume, although statistically not significant (p=.067).
CONCLUSION
These results were due to tumor configuration, which was wider in the axial plane than in the longitudinal plane. From these results, we can realize that initial tumor growth was spherical, and as the size increased, it was distorted by the adjacent structures. These results suggest that special attention is needed in making clinical decisions on larger tumors, especially greater than 2 cm in diameter.