PROSTATE VOLUME BY RECTAL ULTRASONOGRAPHY
The ellipsoïd formula is unacceptable
Page 1/4
Abstract
The ellipsoïd formula is similar to the sphere formula as each radius takes its own value.
Volume = 4/3 * p * (D1 /2)*(D2 /2)*(D3 /2), where D = one of the 3 diameters,
Volume = D1*D2*D3 /1,91
Analysis of 200 prostatectomies compares the calculated volume to the actual volume as measured by the surgeon. Lack of legitimacy of the formula is quite evident for the following reasons :
1) irregular solids calculation must be founded on the closest regular solid. Now the actual prostate shifts from the sphere to the cone , with concave or convex limits, dense or hollow structures.
Knowing the three diameters by ultrasonography, various formulas were tested by changing the denominator. No one formula was found applicable to the common practice.
2) Density of the removed specimens is grossly dissimilar. Converting volume data into weight as a common procedure is unacceptable, in spite of being advocated by numerous world urological community leaders. Consequent treatment options based upon correlation between Prostatic Specific Antigen rate and the socalled prostatic tissue volume are highly hazardous
Only digital recording of calibrated slices of the prostate can bring a valuable result. No noninvasive technique can elicit the prostatic actual weight.
For a more precise and extensive approach see the full text in French : TEXTE FRANCAIS 

Prostatic adenoma as removed by suprapubic enucleation 