Preoperative breast volume evaluation of one-stage immediate breast reconstruction using three-dimensional surface imaging and a printed mold

Automatic segmentation of MRI in prospective breast volume evaluation: Comparison of different assessments for immediate breast reconstruction

BACKGROUND

Assessment of breast volume is essential in preoperative planning of immediate breast reconstruction (IBR) surgery to achieve satisfactory cosmetic outcome. This study introduced a breast volume measurement tool that can be used to perform automatic segmentation of magnetic resonance images (MRI) and calculation of breast volume. We compared the accuracy and reliability of this measurement method with four other conventional modalities.

METHODS

Patients who were scheduled to undergo mastectomy with IBR between 2016 and 2021 were enrolled in the study. Five different breast volume assessments, including automatic segmentation of MRI, manual segmentation of MRI, 3D surface imaging, mammography, and the BREAST-V formula, were used to evaluate different breast volumes. The results were validated using water displacement volumes of the mastectomy specimens.

RESULTS

In this pilot study, a total of 50 female patients met the inclusion criteria and contributed 54 breast specimens to the volumetric analysis. There was a strong linear association between the MRI and water displacement methods (automatic segmentation: r = 0.911, p < 0.001; manual segmentation: r = 0.924, p < 0.001), followed by 3D surface imaging (r = 0.858, p < 0.001), mammography (r = 0.841, p < 0.001), and Breast-V formula (r = 0.838, p < 0.001). Breast volumes measured using automatic and manual segmentation of MRI had lower mean relative errors (30.3% ± 22.0% and 28.9% ± 19.8, respectively) than 3D surface imaging (38.9% ± 31.2), Breast-V formula (44.8% ± 25.8), and mammography (60.3% ± 37.6).

CONCLUSION

Breast volume assessment using the MRI methods had better accuracy and reliability than the other methods used in our study. Breast volume measurement using automatic segmentation of MRI could be more efficient compared to the conventional methods.

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.

Radiological Society of North America (RSNA) 3D Printing Special Interest Group (SIG) clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: breast conditions

The use of medical 3D printing has expanded dramatically for breast diseases. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides updated appropriateness criteria for breast 3D printing in various clinical scenarios. Evidence-based appropriateness criteria are provided for the following clinical scenarios: benign breast lesions and high-risk breast lesions, breast cancer, breast reconstruction, and breast radiation (treatment planning and radiation delivery).

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.

3D and 4D Printing in the Fight against Breast Cancer

Breast cancer is the second most common cancer worldwide, characterized by a high incidence and mortality rate. Despite the advances achieved in cancer management, improvements in the quality of life of breast cancer survivors are urgent. Moreover, considering the heterogeneity that characterizes tumors and patients, focusing on individuality is fundamental. In this context, 3D printing (3DP) and 4D printing (4DP) techniques allow for a patient-centered approach. At present, 3DP applications against breast cancer are focused on three main aspects: treatment, tissue regeneration, and recovery of the physical appearance. Scaffolds, drug-loaded implants, and prosthetics have been successfully manufactured; however, some challenges must be overcome to shift to clinical practice. The introduction of the fourth dimension has led to an increase in the degree of complexity and customization possibilities. However, 4DP is still in the early stages; thus, research is needed to prove its feasibility in healthcare applications. This review article provides an overview of current approaches for breast cancer management, including standard treatments and breast reconstruction strategies. The benefits and limitations of 3DP and 4DP technologies are discussed, as well as their application in the fight against breast cancer. Future perspectives and challenges are outlined to encourage and promote AM technologies in real-world practice.

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.

Prediction of Implant Size Based on Breast Volume Using Mammography with Fully Automated Measurements and Breast MRI

BACKGROUND

Determination of implant size is crucial for patients with breast cancer undergoing one-stage breast reconstruction. The purpose of this study is to predict the implant size based on the breast volume measured by mammography (MG) with a fully automated method, and by breast magnetic resonance imaging (MRI) with a semi-automated method, in breast cancer patients with direct-to-implant reconstruction.

PATIENTS AND METHODS

This retrospective study included 84 patients with breast cancer who underwent direct-to-implant reconstruction after nipple-sparing or skin-sparing mastectomy and preoperative MG and MRI between April 2015 and April 2019. Breast volume was measured using (a) MG with a fully automated commercial software and (b) MRI with an in-house semi-automated software program. Multivariable regression analyses including breast volume and patient weight (P < 0.05 in univariable analysis) were conducted to predict implant size.

RESULTS

MG and MRI breast volume was highly correlated with both implant size (correlation coefficient 0.862 and 0.867, respectively; P values < 0.001) and specimen weight (correlation coefficient 0.802 and 0.852, respectively; P values < 0.001). Mean absolute difference between the MR breast volume and implant size was 160 cc, which was significantly higher than that between the MG breast volume and implant size of 118 cc (P < 0.001). On multivariable analyses, only breast volume measured by both MG and MRI was significantly associated with implant size in any implant type (all P values < 0.001).

CONCLUSION

Breast volume measured by MG and MRI can be used to predict appropriate implant size in breast cancer patients undergoing direct-to-implant reconstruction in an efficient and objective manner.

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.

Three-Dimensional Printed Anatomic Models Derived From Magnetic Resonance Imaging Data: Current State and Image Acquisition Recommendations for Appropriate Clinical Scenarios

Three-dimensional (3D) printing technologies have been increasingly utilized in medicine over the past several years and can greatly facilitate surgical planning thereby improving patient outcomes. Although still much less utilized compared to computed tomography (CT), magnetic resonance imaging (MRI) is gaining traction in medical 3D printing. The purpose of this study was two-fold: 1) to determine the prevalence in the existing literature of using MRI to create 3D printed anatomic models for surgical planning and 2) to provide image acquisition recommendations for appropriate clinical scenarios where MRI is the most suitable imaging modality. The workflow for creating 3D printed anatomic models from medical imaging data is complex and involves image segmentation of the regions of interest and conversion of that data into 3D surface meshes, which are compatible with printing technologies. CT is most commonly used to create 3D printed anatomic models due to the high image quality and relative ease of performing image segmentation from CT data. As compared to CT datasets, 3D printing using MRI data offers advantages since it provides exquisite soft tissue contrast needed for accurate organ segmentation and it does not expose patients to unnecessary ionizing radiation. MRI, however, often requires complicated imaging techniques and time-consuming postprocessing procedures to generate high-resolution 3D anatomic models needed for 3D printing. Despite these challenges, 3D modeling and printing from MRI data holds great clinical promises thanks to emerging innovations in both advanced MRI imaging and postprocessing techniques. EVIDENCE LEVEL: 2 TECHNICAL EFFICATCY: 5.

A Novel Method of Outcome Assessment in Breast Reconstruction Surgery: Comparison of Autologous and Alloplastic Techniques Using Three-Dimensional Surface Imaging

BACKGROUND

Breast reconstruction is an important coping tool for patients undergoing a mastectomy. There are numerous surgical techniques in breast reconstruction surgery (BRS). Regardless of the technique used, creating a symmetric outcome is crucial for patients and plastic surgeons. Three-dimensional surface imaging enables surgeons and patients to assess the outcome's symmetry in BRS. To discriminate between autologous and alloplastic techniques, we analyzed both techniques using objective optical computerized symmetry analysis. Software was developed that enables clinicians to assess optical breast symmetry using three-dimensional surface imaging.

METHODS

Twenty-seven patients who had undergone autologous (n = 12) or alloplastic (n = 15) BRS received three-dimensional surface imaging. Anthropomorphic data were collected digitally using semiautomatic measurements and automatic measurements. Automatic measurements were taken using the newly developed software. To quantify symmetry, a Symmetry Index is proposed.

RESULTS

Statistical analysis revealed that there is no difference in the outcome symmetry between the two groups (t test for independent samples; p = 0.48, two-tailed).

CONCLUSION

This study's findings provide a foundation for qualitative symmetry assessment in BRS using automatized digital anthropometry. In the present trial, no difference in the outcomes' optical symmetry was detected between autologous and alloplastic approaches. Level of evidence Level IV.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Review of Plastic Surgery Biomaterials and Current Progress in Their 3D Manufacturing Technology

Plastic surgery is a broad field, including maxillofacial surgery, skin flaps and grafts, liposuction and body contouring, breast surgery, and facial cosmetic procedures. Due to the requirements of plastic surgery for the biological safety of materials, biomaterials are widely used because of its superior biocompatibility and biodegradability. Currently, there are many kinds of biomaterials clinically used in plastic surgery and their applications are diverse. Moreover, with the rise of three-dimensional printing technology in recent years, the macroscopically more precise and personalized bio-scaffolding materials with microporous structure have made good progress, which is thought to bring new development to biomaterials. Therefore, in this paper, we reviewed the plastic surgery biomaterials and current progress in their 3D manufacturing technology.