Volume Measurement by Diffusion-Weighted Imaging in Cervical Cancer.

BACKGROUND The aim of this paper was to evaluate the validity of tumor volume measurement using diffusion-weighted (DW) imaging in cervical cancer. METHODS In this retrospective study, 22 patients, who underwent preoperative 3.0 T MR examinations with DW imaging were evaluated. Tumor volume measurement by oblique axial (short axis to the uterine cervix) T2-weighted imaging was performed by manually outlining the tumor on the monitor. The area of tumor in each slice was multiplied by the slice profile (slice thickness plus intersection gap), and the total tumor volume was calculated by summation of these obtained volumes. Meanwhile, one experienced radiological technologist generated three-dimensional DW images of cervical cancer using a volume-rendering algorithm at a computer workstation, and tumor volume was automatically calculated in the workstation. Analysis via the intraclass correlation coefficient (ICC) and Bland-Altman plots were used to assess the validity and reliability of these methods. RESULTS Between tumor volumes measured by T2-weighted imaging methods and DW imaging methods, the ICC was excellent (0.962). The 95% limits of agreement of volume measurement were -52.7 and 35.7 mL (mean difference, -8.5 mL). In regards to intra-observer variability, the ICC was excellent (0.963). The 95% limits of agreement of volume measurement were -42.2 and 47.4 mL (mean difference, 2.6 mL). CONCLUSION DW imaging can be used to measure cervical cancer volume.