Measurement of tumor size in adult glioblastoma: classical cross-sectional criteria on 2D MRI or volumetric criteria on high resolution 3D MRI?

Abstract

Objective: To investigate the added value of volume on post-contrast three dimensional (3D) T1-weighted image (T1WI) over classical cross-sectional area on two dimensional (2D) T1WI in evaluating tumor response in glioblastoma multiforme (GBM).

Methods: Tumor cross-sectional area and volume measurements were performed on 104 MRI studies from 42 adult patients with GBM on post-contrast 5 mm 2D T1WI and isotropic high resolution 3D T1WI, respectively. 52 pairs of MRI scans were analyzed for relative change. Radiographic responses were determined based on change in either area or volume.

Results: A high correlation was revealed between tumor size measured by area on thick 2D and volume on high resolution 3D MRI in 104 scans (r=0.82, p<0.001). When four tumor response criteria were used according to the percentage changes (complete response/partial response/stable disease/progression), the kappa coefficient between the area on 2D and volume on 3D was 0.68 (p<0.05) with an overall agreement of 81%.

Conclusions: Tumor cross-sectional area on post-contrast 2D T1WI appears comparable to volume on 3D T1WI and should still be a practical alternate of volume on 3D for evaluating tumor response.