Weight to volume conversion: an easy and practical breast volume estimation

Accurate breast volume estimation is essential for symmetrical breast reconstruction. Easy conversion of the weight of the resected breast tissue to volume could result in precise volume measurements. This study aimed to introduce the use of a mathematical constant (k) to estimate the breast volume from the weight.

Eighty-nine female patients with breast cancer who underwent surgery at King Chulalongkorn Memorial Hospital between September 2010 and February 2011 were enrolled in this prospective study. The mammographic density of each patient was classified according to the breast imaging reporting and data system (BI-RADS) into groups a, b, c, and d. The breast density number and mathematical constant (k) were calculated, and the data matched. This technique was validated by comparing the measured and calculated volumes.

Sixty-six, 22, and 1 patients underwent total mastectomies (TMs), skin-sparing mastectomies (SSMs), and nipple-sparing mastectomies (NSMs), respectively. The breast densities were 1.0629, 1.1545, and 1.2233 g/mL, and the constant number (k) was 0.9409, 0.8662, and 0.8175 for BI-RADS a, combined BI-RADS b and c, and BI-RADS d, respectively. The validation process showed no significant differences between the measured and calculated volumes [95% confidence interval (95% CI)]. The correlation coefficient (r) was 0.984.

Accurate breast volume estimation is a key factor in achieving symmetry in breast reconstruction. Combining existing data, including the weight of the resected breast tissue and mammographic density findings, an easy and accurate method to calculate the resected breast volume was introduced.