Objective breast symmetry analysis with the breast analyzing tool (BAT): improved tool for clinical trials

Objective cosmetic analysis is important to evaluate the cosmetic outcome after breast surgery or breast radiotherapy. For this purpose, we aimed to improve our recently developed objective scoring software, the Breast Analyzing Tool (BAT^®).

A questionnaire about important factors for breast symmetry was handed out to ten experts (surgeons) and eight non-experts (students). Using these factors, the first-generation BAT^® software formula has been modified and the breast symmetry index (BSI) from 129 women after breast surgery has been calculated by the first author with this new BAT^® formula. The resulting BSI values of these 129 breast cancer patients were then correlated with subjective symmetry scores from the 18 observers using the Harris scale. The BSI of ten images was also calculated from five observers different from the first author to calculate inter-rater reliability. In a second phase, the new BAT^® formula was validated and correlated with subjective scores of additional 50 women after breast surgery.

The inter-rater reliability analysis of the objective evaluation by the BAT^® from five individuals showed an ICC of 0.992 with almost no difference between different observers. All subjective scores of 50 patients correlated with the modified BSI score with a high Pearson correlation coefficient of 0.909 (p < .001) which was better compared to the old software (r = 0.769; p < .001).

The modified BAT^® software improves the correlation between subjective and objective BSI values, and may be a new standard for trials evaluating breast symmetry.