Comparison of ABC/2 estimation and a volumetric computerized method for measurement of meningiomas using magnetic...

Measurement of tumor growth rates over time for patients with meningiomas has important prognostic and therapeutic implications. Our objective was to compare two methods of measuring meningioma volume: (1) the simplified ellipsoid (ABC/2) method; and (2) perimetric volume measurements using imaging software modules.

Patients with conservatively managed meningiomas for at least 1.5 years were retrospectively identified from the VCU Brain and Spine Tumor Registry over a 10-year period (2005-2015). Tumor volumes were independently measured using the simplified ellipsoid and computerized perimetric methods. Intra class correlations (CC) and Bland-Altman analyses were performed.

A total of 26 patients representing 29 tumors were identified. Across 146 images, there were 24 (16%) images that were non-measurable using standard application commands with the computerized perimetric method. The mean volume obtained using the ABC/2 and computerized perimetric methods were 3.2 ± 3.4 cm³ and 3.4 ± 3.5 cm³, respectively. The mean volume difference was 0.2 cm³ (SE = 0.12; p = 0.10) across measurement methods. The concordance correlation coefficient (CCC) between methods was 0.95 (95% CI 0.91, 0.98).

There is excellent correlation between the simplified ellipsoid and computerized perimetric methods of volumetric analysis for conservatively managed meningiomas. The simplified ellipsoid method remains an excellent method for meningioma volume assessment and had an advantage over the perimetric method which failed to allow measurement of roughly one in six tumors on imaging.