Accuracy of Three-Dimensional Ultrasonography in Volume Estimation of Cervical Carcinoma

Objective.To evaluate the accuracy of a three-dimensional (3D) ultrasound system in volume estimation of cervical carcinoma. Study design.Transvaginal 3D and two-dimensional (2D) scans on cervical carcinoma volumes were performed 1 day before surgery. The volume of cervical carcinoma measured from each surgical specimen was compared with the corresponding volume of the cervical tumor measured by a 3D ultrasound and with the conventional 2D ultrasound volume measurement calculated using the formula π/6 ×(R1×R2×R3), whereR1,R2, andR3were the maximal transverse, anteroposterior, and longitudinal length of tumor, respectively. Limits of agreement and 95% confidence intervals were calculated and systemic bias between the methods was analyzed. The Klotz test was also used to assess the statistical significance of the degree of dispersion. Results.A total of 61 cases, 55 with exophytic tumors and 6 with endocervical tumors, were examined in this study. The limits of agreement between the volume measured from specimen and tumor volume determined by ultrasound were +6.68 to −6.10 mL for 3D measurements and +12.46 to −10.98 mL for 2D measurements. The Klotz test showed the discrepancy in the degree of dispersion between 3D and 2D ultrasound measurements was statistically significant (P= 0.01). Conclusion.The true volume of cervical carcinoma is measured more accurately by a 3D ultrasound system than 2D ultrasound.