Calculation of breast volumes from mammogram: Comparison of four separate equations relative to mastectomy specimen volumes.

BACKGROUND AND OBJECTIVES

Accurately assessing breast volume (BV) relative to the volume of breast tissue to be removed could help objectively determine the optimal surgical candidates for breast conserving surgery. The objective of this study was to determine the optimal mammography-based method of BV estimation.

METHODS

Mammography data was obtained for patients who underwent mastectomy for breast cancer from 2005 to 2015. This data was used to calculate BV using four previously published equations. Results were compared to mastectomy specimen volumes calculated from specimen weights and breast density. Five practitioners then independently assessed reproducibility and ease of use.

RESULTS

Complete mammographic measurements were available for 65 breasts from 45 patients. Median age was 58 years (range 19-82). Mammographic breast density scores were available for 62 breasts. Of the 65 mastectomies performed, 16 (36%) were simple mastectomies. The equation BV = 1/3πR R H most closely approximated actual breast specimen volumes (R = 0.89, P < 0.0001). Internal correlation of calculated BV was excellent among all practitioners (lowest Pearson R = 0.963).

CONCLUSIONS

Breast volumes can be reliably estimated utilizing measurements from a preoperative mammogram. This low-cost method of volumetric analysis can be employed to guide surgical decision making in treatment of patients with invasive breast cancer.