Improved accuracy of breast volume calculation from 3D surface imaging data using statistical shape models

Assessment of Three Breast Volume Measurement Techniques: Single Marking, MRI and Crisalix 3D Software®

INTRODUCTION

Measuring breast volume is important to obtain satisfactory breast surgery results, and many techniques are used for this purpose. Thus, the aim of the present study was to compare 3 breast volume techniques: Pessoa's single marking technique, magnetic resonance imaging (MRI) and Crisalix 3D software®.

METHODS

Fourteen patients indicated for mammoplasty were selected. Three breast volume measurement techniques were compared: Pessoa's single marking technique, MRI and Crisalix 3D software®. The volumes were tabulated and analyzed using R software.

RESULTS

Average age was 30.93 ± 10.25 years. The breast volume was 1554.54 ± 512.54 cm3, as measured by the MRI technique (considered the gold standard), 1199.64 ± 403.13 cm3 using Crisalix 3D software® and 1518.04 ± 468.72 cm3 by Pessoa's single marking technique. Comparison between the Crisalix 3D software® and MRI techniques using the pairwise t test demonstrated a statistically significant difference (t = 4.3957, df = 27, p value = 0001543), but no significant difference between the single marking and MRI techniques (t = 1.3841, df = 27, p value = 0.1777).

CONCLUSION

When compared to MRI, breast volume measurement using Pessoa's single marking technique showed no statistically significant difference between them. However, the Crisalix 3D® technique exhibited a difference in relation to MRI. Anthropometric measurements are useful in measuring breast volume because they are easy to obtain, practical and inexpensive, and should be part of a plastic surgeon's arsenal.

LEVEL OF EVIDENCE IV

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Reliability and Measurement Error of Breast Volume Calculation Using Three-Dimensional Surface Imaging

Background: Breast lymphedema after breast cancer is challenging to quantify. Three-dimensional (3D) surface imaging is one available technique to measure breast volume, however, the measurement properties of available software programs have not been fully determined. The aim of this study was to determine equivalency of measurements with two software programs as well as reliability, standard error of measurement (SEM), and smallest detectable change (SDC). Methods and Results: Retrospective three-dimensional surface imaging (3D-SI) of 100 breasts taken before or after breast conserving surgery for breast cancer were retrieved for reliability analysis. Three assessors followed a standardized measurement technique using two software programs, Vectra^® 3D Analysis Module (VAM) and Breast Sculptor^®. Mean breast volume was 489.9 ± 206 cc using VAM and 480.1 ± 229.1 cc using Breast Sculptor. Lin's concordance showed poor agreement between programs (0.81-0.88). Measurements using VAM had excellent intra- and inter-rater reliability with SEM = 4.1% for one assessor and 8.7% for multiple assessors. Breast Sculptor also had excellent intra-rater and substantial inter-rater reliability but the SEM was much larger at 14.5% (intra-rater) and 19.1% (inter-rater). The SDC value was lowest for VAM and a single rater with 56 cc indicating a meaningful change beyond measurement error. Conclusion: Breast volume measurements captured with 3D-SI using VECTRA-XT are highly reliable, but the volumes, SEM, and SDC varied between the two software programs. Measurement error was lowest with VAM software. Although the usefulness of VECTRA-XT and VAM software to detect change in breast volume is promising, further solutions to reduce measurement error are required to improve clinical utility to measure breast lymphedema.

Intraoperative 3D Comparison of Round and Anatomical Breast Implants: Dispelling a Myth

Background: Thanks to 3D imaging, it is possible to measure the influence of different parameters on breast augmentation. In this study, we compare the effect of different shapes and sizes of breast implants on the topography of the resulting breast. Furthermore, the impact of different breast implants on inter-landmark distances and on changes of the nipple position was assessed. Methods: This interventional prospective study was carried out on 10 female patients after collecting informed consent. 3D scans of the native and augmented breasts were performed intraoperatively with small, medium, and large sizes of both anatomical and round implants, resulting in a total of n = 130 single breast scans. These scans were analyzed for topographic shift quantification, nipple migration, and inter-landmark distances of the breast. Results: Implant size, but not implant shape leads to significant topographic shifts of the breast (p < 0.001 and p = 0.900, respectively). Both round and anatomical implants lead to a significantly higher volumetric increase in the upper quadrants compared to the lower quadrants (p < 0.001). Nipple migration into the superomedial quadrant was seen in about 90% of augmentations. No evident differences in inter-landmark distances were observed when round and anatomical implants of different sizes were compared. Conclusions: Implant size rather than shape influences the postoperative aesthetic results. No significant difference in topographic shift was found comparing round and anatomical implants, suggesting that both implant shapes result in comparable aesthetic outcomes.

3D Breast Volume Estimation

INTRODUCTION

Breast volume estimation is considered crucial for breast cancer surgery planning. A single, easy, and reproducible method to estimate breast volume is not available. This study aims to evaluate, in patients proposed for mastectomy, the accuracy of the calculation of breast volume from a low-cost 3D surface scan (Microsoft Kinect) compared to the breast MRI and water displacement technique.

MATERIAL AND METHODS

Patients with a Tis/T1-T3 breast cancer proposed for mastectomy between July 2015 and March 2017 were assessed for inclusion in the study. Breast volume calculations were performed using a 3D surface scan and the breast MRI and water displacement technique. Agreement between volumes obtained with both methods was assessed with the Spearman and Pearson correlation coefficients.

RESULTS

Eighteen patients with invasive breast cancer were included in the study and submitted to mastectomy. The level of agreement of the 3D breast volume compared to surgical specimens and breast MRI volumes was evaluated. For mastectomy specimen volume, an average (standard deviation) of 0.823 (0.027) and 0.875 (0.026) was obtained for the Pearson and Spearman correlations, respectively. With respect to MRI annotation, we obtained 0.828 (0.038) and 0.715 (0.018).

DISCUSSION

Although values obtained by both methodologies still differ, the strong linear correlation coefficient suggests that 3D breast volume measurement using a low-cost surface scan device is feasible and can approximate both the MRI breast volume and mastectomy specimen with sufficient accuracy.

CONCLUSION

3D breast volume measurement using a depth-sensor low-cost surface scan device is feasible and can parallel MRI breast and mastectomy specimen volumes with enough accuracy. Differences between methods need further development to reach clinical applicability. A possible approach could be the fusion of breast MRI and the 3D surface scan to harmonize anatomic limits and improve volume delimitation.