Estimation of liver tumor volume using different formulas - an experimental study in rats.

Experimental solitary ellipsoid liver tumors in the rat can be induced by inoculation of a tumor-cell suspension of known potency into the liver parenchyma. During laparotomy, the largest (a) and the smallest (b) superficial diameters of the tumor were measured on the surface of the liver with vernier calipers. Four different formulas have been tested and compared with the actual volume from the extirpated tumor and tumor weight. Within the size range of 15-700 mm3, based on the calculation of the difference between logarithmic tumor volume from the different formulas versus logarithmic volume of extirpated and dissected tumors and regression analyses, volume of the unremoved liver tumor can be best calculated according to the formula V = a x b2/2.