Estimating Implant Volume and Mastectomy-Specimen Volume by Measuring Breast Volume With a 3-Dimensional Scanner

Three-Dimensional Printing in Breast Reconstruction: Current and Promising Applications

Three-dimensional (3D) printing is dramatically improving breast reconstruction by offering customized and precise interventions at various stages of the surgical process. In preoperative planning, 3D imaging techniques, such as computer-aided design, allow the creation of detailed breast models for surgical simulation, optimizing surgical outcomes and reducing complications. During surgery, 3D printing makes it possible to customize implants and precisely shape autologous tissue flaps with customized molds and scaffolds. This not only improves the aesthetic appearance, but also conforms to the patient's natural anatomy. In addition, 3D printed scaffolds facilitate tissue engineering, potentially favoring the development and integration of autologous adipose tissue, thus avoiding implant-related complications. Postoperatively, 3D imaging allows an accurate assessment of breast volume and symmetry, which is crucial in assessing the success of reconstruction. The technology is also a key educational tool, enhancing surgeon training through realistic anatomical models and surgical simulations. As the field evolves, the integration of 3D printing with emerging technologies such as biodegradable materials and advanced imaging promises to further refine breast reconstruction techniques and outcomes. This study aims to explore the various applications of 3D printing in breast reconstruction, addressing current challenges and future opportunities.

Three-Dimensional Surface Analysis for Preoperative Prediction of Breast Volume: A Validation Study

BACKGROUND

Few studies have examined whether preoperative three-dimensional surface imaging can accurately predict breast volume. Reliably predicting breast volume preoperatively can assist with breast reconstruction planning, patient education, and perioperative risk stratification.

METHODS

The authors conducted a review of patients who underwent mastectomy from 2020 to 2021 and included all patients who had preoperative VECTRA XT three-dimensional imaging. VECTRA Analysis Module (VAM) and VECTRA Body Sculptor (VBS) were used for volumetric analysis using standard anatomical breast borders. Breast weights were obtained intraoperatively. Predictive accuracy was defined as VAM estimates ±10% of mastectomy specimen weight or ±100 g of mastectomy weight.

RESULTS

The study included 179 patients (266 breasts). There was no significant difference ( P = 0.22) between mean mastectomy weight of 620.8 ± 360.3 g and mean VAM estimate of 609.5 ± 361.9 g. Mean VBS estimate was 498.9 ± 337.6 g, which differed from mean mastectomy weight ( P < 0.001). When defining predictive accuracy as ±100 g, 58.7% of VAM and 44.4% of VBS estimates were accurate. Body mass index, body surface area, and ptosis grade significantly affected VAM and VBS breast volume predictions.

CONCLUSIONS

VAM is more accurate at predicting mastectomy weight than VBS, likely because of VAM's analysis of surface topography rather than discrete surface landmarks. Discrepancies between VECTRA estimates and mastectomy weight were likely attributable to differences between surgical mastectomy borders and breast borders used in volumetric analysis. Surgeons should consider the physical characteristics of patients when using three-dimensional imaging.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, I.

Estimation of Mastectomy Volume Using Preoperative Mastectomy Simulation Images Acquired by the Vectra H2 System

Preoperative prediction of breast volume is very important in planning breast reconstruction. In this study, we assessed the usefulness of a novel method for preoperative estimation of mastectomy volume by comparing the weight of actual mastectomy specimens with the values predicted by the developed method using the Vectra H2.

Methods

All patients underwent skin-sparing mastectomy and immediate autologous breast reconstruction. Preoperatively, the patient's breast was scanned using the Vectra H2 and a postmastectomy simulation image was constructed on a personal computer. The estimated mastectomy volume was calculated by comparing the preoperative and postmastectomy three-dimensional simulation images. Correlation coefficients with the estimated mastectomy volume were calculated for the actual mastectomy weight and the transplanted flap weight.

Results

Forty-five breasts of 42 patients were prospectively analyzed. The correlations with the estimated mastectomy volume were r = 0.95 (P < 0.0001) for actual mastectomy weight and r = 0.84 (P < 0.0001) for transplanted free-flap weight. The mastectomy weight estimation formula obtained by linear regression analysis using the estimated mastectomy volume was 0.98 × estimated mastectomy volume + 5.4 (coefficient of determination R2 = 0.90, P < 0.0001). The root-mean-square error for the mastectomy weight estimation formula was 38 g.

Conclusions

We used the Vectra H2 system to predict mastectomy volume. The predictions provided by this method were highly accurate. Three-dimensional imaging is a noncontact, noninvasive measurement method that is both accurate and simple to perform. Use of this effective tool for volume prediction is expected to increase in the future.

Patient Self-reported Breast Cup Size and Resultant Mastectomy Specimen Weight: Implications for Reconstructive Breast Surgery

Breast cup sizing irregularities exist due to discrepancy between garment manufacturers and patient reported measurements making it difficult to assess true preoperative and definitive postoperative breast cup size. This study aims to evaluate the association between patient self-reported breast cup size and mastectomy specimen weight as a way to determine postreconstruction breast cup size.

METHODS

This is a retrospective study that evaluated patients who underwent bilateral mastectomy at an academic center between 2019-2021. Cup size and mastectomy weight were our only independent and dependent variables, respectively. Covariates that were assessed included chest circumference, surgical oncologist, BMI, race, and age.

RESULTS

243 patients were evaluated as a part of this study who underwent either total-simple (TS; 29), skin-sparing (SS; 146), or nipple-sparing (NS; 68) bilateral mastectomy. There were positively weak correlations using nonparametric correlation analysis for breast cup size to mastectomy weight in patients who underwent TS (r = 0.375; p = 0.004), SS (r = 0.353; p <0.001), and NS (r = 0.246; p = 0.004) mastectomy. The multivariate linear regression for TS (R₂=0.520; p < 0.001), SS (R₂=0.573; p < 0.001) and NS (R2=0.396; p < 0.001) mastectomy were significant. Covariates assessed in the regression showed BMI significant for all types, age for TS type, and SS type for breast surgeon and chest circumference.

CONCLUSIONS

There is a positively weak correlation between preoperative breast cup size and mastectomy weight, providing evidence for the difficulty of estimating postoperative breast cup size. Thus, the conversation with the patient should focus on breast appearance and quality of life rather than postreconstruction breast size.

Is 3-Dimensional Scanning Really Helpful in Implant-Based Breast Reconstruction?: A Prospective Study

BACKGROUND

Breast reconstruction is an integral part of breast cancer treatment, and implant-based breast reconstruction is the most commonly used method worldwide. However, there is still no technique that allows surgeons to predict the volume of the required implant. Although computed tomography and magnetic resonance imaging provide adequate representations of the breast, these procedures are time-consuming, expensive, and expose patients to radiation. Therefore, there is a need for safer, noninvasive alternatives for preoperative breast volume measurements.

PATIENTS AND METHODS

This study is a prospective review of 12 patients with early-stage breast cancer who underwent nipple-sparing mastectomy and immediate breast reconstruction with implants. Preoperatively, the Artec Eva 3D scanner was used to acquire volumetric measurements of the breasts. Intraoperatively, the volume of the mastectomy specimen was measured using the water displacement method. Correlations among the preoperative breast, mastectomy specimen, and estimated and final implant volumes were analyzed through Pearson correlation coefficient. A correction prediction factor of 85% was applied where necessary. Patient and physician satisfaction were evaluated 3 months postoperatively.

RESULTS

Our study found a statistically significant correlation between the preoperative breast volumes measured by the Artec Eva 3D scanner and intraoperative mastectomy specimen volumes (r = 0.6578). There was no correlation between the preoperative breast volumes and final implant volumes, mastectomy specimen volumes and final implant volumes, and estimated implant volumes and final implant volumes.

CONCLUSIONS

Although the Artec Eva 3D scanner can offer relatively accurate measurement of breast volumes, multiple studies still need to be done to determine how these data can be applied to the mastectomy procedure and breast implant selection. It may be more applicable for preoperative planning in breast augmentation surgery. Future surgeons should also take into account that variabilities in natural breast size, tumor size, cancer stage, and in patient and physician preferences all influence the outcome of breast reconstruction surgery.

Predictive value of 3D imaging to guide implant selection in immediate breast reconstruction

Background

Pre-operative estimation of breast mound volume for immediate breast reconstruction is necessary for operative planning, especially in direct-to-implant reconstruction. Our purpose was to investigate the relationship between pre-operative predictions of breast mound weight from 3D imaging and actual mastectomy weight and implant size.

Methods

A retrospective chart review of all patients who had previously undergone nipple-sparing mastectomy (NSM) by a single surgeon was performed. Pre-operative 3D images were reviewed and calculations of breast mound weight were performed by three independent reviewers. Intra-operative mastectomy weight and final implant weight were collected from patient charts. A regression analysis between calculated and actual values was performed.

Results

There were 59 reconstructed breasts included. Pre-operative 3D imaging-guided breast weight calculations were similar across reviewers (R=0.96). Pre-operative calculations of breast weight were 49.4g (SD=134.0) smaller than actual mastectomy specimens. Mastectomy specimens were 41.0g (SD=130.2) smaller than final implant sizes. Thereby, the relationship was as follows: Pre-operative calculated breast weight < actual Mastectomy weight < implant weight. Mastectomy weight and final implant size had linear relationships with pre-operative calculations of breast weight. Formulas for predicting mastectomy weight [mastectomy weight = 63.2 + 0.95 (pre-operative calculated weight)] and implant size [Implant weight = 209.7+ 0.56 (pre-operative calculated weight)] from pre-operative calculations of breast weight were generated.

Conclusions

Three-dimensional scanning technologies may be a useful tool to predict implant sizes for direct-to-implant breast reconstruction. Final implant size was heavier than intra-operative mastectomy weight and pre-operative calculated breast mound weight.

A Prospective Investigation of Predictive Parameters for Preoperative Volume Assessment in Breast Reconstruction

Preoperative breast volume estimation is very important for the success of the breast surgery. In this study four different breast volume determination methods were compared. The end-point of this prospective study was to evaluate the concordance between different modalities of breast volume assessment (MRI, BREAST-V, mastectomy specimen weight, conversion from weight to volume of mastectomy specimen) and the breast prosthetic volume implanted. The study enrolled 64 patients between 2017 and 2019, who had all been treated by the same surgeons for monolateral nipple–areola complex-sparing mastectomy and implant breast reconstruction. Only patients who had a breast reconstruction classified as “excellent” from an objective (BCCT.core software) and subjective (questionnaire) point of view at the 6-month interval after the operation were included in the study. Data analysis highlighted a strong correlation between the volumes of the chosen prostheses and the weights of mastectomy converted into volume, especially for patients with grades B and C parenchymal density. The values of the agreement between the volumes of the chosen prostheses and the assessments from MRI and BREAST -V proved to be lower than expected from the literature. None of the four studied methods presented any strong correlation with the initial breast width. Our results suggest that conversion from weight to volume of mastectomy specimen should be used to assist in determining the volume of the breast implant to be implanted. This method would help the reconstructive surgeon guide the choice of the most appropriate implant preoperatively.

Mammography with a fully automated breast volumetric software as a novel method for estimating the preoperative breast volume prior to mastectomy

Purpose

Increasing interest in maintaining a positive body image following breast cancer surgery has become an important aspect of reconstruction surgery. Volume matching of the reconstructed breast to natural breasts is the most important consideration. This study aimed to explore the feasibility of using mammography with a fully automated breast volumetric software to measure the preoperative breast volume in patients with breast cancer.

Methods

We evaluated patients who underwent a total mastectomy between July 2016 and February 2021. The specimen volume following total mastectomy was compared with breast volume estimates using a fully automated volumetric software (Quantra ver. 2.1.1) and 4 other previously described mammography-based prediction methods. The association between the estimates and mastectomy specimen volume was assessed using Pearson correlation and Bland-Altman analysis.

Results

Sixty-six patients were included. Compared with previously described mammography-based methods, Quantra estimates were more strongly correlated with mastectomy specimen volume in the entire, fatty, and dense breast groups (r = 0.920, 0.921, and 0.915, respectively; P < 0.001). In applying Quantra estimates for measuring preoperative breast volume, we adjusted a simple equation: mastectomy specimen volume = Quantra estimate × 0.8.

Conclusion

Mammography with a fully automated breast volumetric software can be useful for measuring preoperative breast volume in patients with breast cancer who undergo reconstruction surgery.

Measuring Differential Volume Using the Subtraction Tool for Three-Dimensional Breast Volumetry: A Proof of Concept Study

Background. Three-dimensional (3D) photography provides a promising means of breast volumetry. Sources of error using a single-captured surface to calculate breast volume include inaccurate designation of breast boundaries and prediction of the invisible chest wall generated by computer software. An alternative approach is to measure differential volume using subtraction of 2 captured surfaces. Objectives. To explore 3D breast volumetry using the subtraction of superimposed images to calculate differential volume. To assess optimal patient positioning for accurate volumetric assessment. Methods. Known volumes of breast enhancers simulated volumetric changes to the breast (n = 12). 3D photographs were taken (3dMDtorso) with the subject positioned upright at 90° and posteriorly inclined at 30°. Patient position, breathing, distance and camera calibration were standardised. Volumetric analysis was performed using 3dMDvultus software. Results. A statistically significant difference was found between actual volume and measured volumes with subjects positioned at 90° (P < .05). No statistical difference was found at 30° (P = .078), but subsequent Bland–Altman analysis showed evidence of proportional bias (P < .05). There was good correlation between measured and actual volumes in both positions (r = .77 and r = .85, respectively). Univariate analyses showed breast enhancer volumes of 195 mL and 295 mL to incur bias. The coefficient of variation was 5.76% for single observer analysis. Conclusion. Positioning the subject at a 30° posterior incline provides more accurate results from better exposure of the inferior breast. The subtraction tool is a novel method of measuring differential volume. Future studies should explore methodology for application into the clinical setting.