Parametrial invasion in carcinoma of cervix: role of MRI measured tumour volume.

The aim of the study was to determine the correlation between MRI measured tumour volume and parametrial invasion on histology in the evaluation of carcinoma of the cervix showing full thickness stromal invasion (FTSI). Original MR images of 159 surgical cases of carcinoma of the cervix retrieved from the MR image bank of the department were analysed retrospectively. Tumour volume from the maximum tumour diameters in each case was computed using the standard formula for an ellipse and correlated with parametrial invasion on histology. Of 105 cases showing FTSI on axial T(2) weighted MRI, tumour volume between the two groups of cases, with parametrial invasion (n=27) and without parametrial invasion (n=78), shows a statistically significant difference (p=0.006). Best accuracy of 60.95%, sensitivity 59.26% and specificity 61.54% was found for tumour volume of 36.39 cm(3). The study concludes that MRI measured tumour volume is associated with low accuracy in the evaluation of parametrial invasion in carcinoma of cervix showing FTSI in axial T(2) weighted MR images and may not help as an additional diagnostic criterion to predict parametrial invasion pre-operatively.