Relationship of computed tomography tumour volume to patient survival in carcinoma of the cervix treated by radical radiotherapy

Abstract
In this retrospective study tumour volume was calculated by two different methods from the staging computed tomographic scans obtained in 1987 of 20 patients with carcinoma of the cervix. All patients underwent treatment by radical radiotherapy and the survival figures at 5 years were analysed. The aim was to identify the nature of the relationship between the true tumour volume and tumour volume obtained by measuring the maximum dimensions in each plane ("cuboid" volume). Significant correlation between the product of height x width x depth and true tumour volume was demonstrated (r = 0.983). A multivariate analysis of survival demonstrated a significantly increased relative risk for positive nodes (p < 0.03) and tumour depth > 3.8 cm (p < 0.04) or tumour width > 5.0 cm (p < 0.03). A significant difference (p < 0.02) between the median tumour volumes for early and late stage disease was present irrespective of the method used to calculate tumour volume. This study demonstrates that cuboid tumour volume can be a good reflection of the true volume; in addition, positive nodes, tumour depth and tumour width are significant determinants of survival.