Intraoperative margin assessment and re-excision rate in breast conserving surgery

Current Trends and Beyond Conventional Approaches: Advancements in Breast Cancer Surgery through Three-Dimensional Imaging, Virtual Reality, Augmented Reality, and the Emerging Metaverse

Breast cancer stands as the most prevalent cancer globally, necessitating comprehensive care. A multidisciplinary approach proves crucial for precise diagnosis and treatment, ultimately leading to effective disease management. While surgical interventions continue to evolve and remain integral for curative treatment, imaging assumes a fundamental role in breast cancer detection. Advanced imaging techniques not only facilitate improved diagnosis but also contribute significantly to the overall enhancement of breast cancer management. This review article aims to provide an overview of innovative technologies such as virtual reality, augmented reality, and three-dimensional imaging, utilized in the medical field to elevate the diagnosis and treatment of breast cancer. Additionally, the article delves into an emerging technology known as the metaverse, still under development. Through the analysis of impactful research and comparison of their findings, this study offers valuable insights into the advantages of each innovative technique. The goal is to provide physicians, surgeons, and radiologists with information on how to enhance breast cancer management.

Magnetic seed versus skin tattoo localization of non-palpable breast lesions: a single institution cohort study

OBJECTIVE

The objective of this retrospective study was to investigate the accuracy and feasibility of magnetic seed compared to skin tattoo in preoperative localization of impalpable breast lesions in terms of accuracy of placement, re-excision and positive margins rates, and breast/surgical specimen volume ratio.

METHODS

We retrospectively analyzed 77 patients who underwent breast conservative surgery in our center from November 2020 to November 2021, with previous localization with skin tattoo or magnetic seed.

RESULTS

Thirty-seven magnetic seeds were placed in 36 patients (48.6%) and 40 skin tattoos were performed in the remaining cases (51.4%). The seeds were placed correctly at the two-view mammogram acquired after the insertion in 97.6% (36/37) of cases. With both methods, 100% of the index lesions were completely removed and found in the surgical specimen. The reported re-excision rate was 0% for both groups. A significant difference was observed in the volume of breast parenchyma removed between the two groups, inferior in the seed group (p = 0.046), especially in case of voluminous breasts (p = 0.003) and small lesions (dimension < 8 mm, p = 0.019).

CONCLUSIONS

Magnetic seed is a non-radioactive localization technique, feasible to place, recommended in case of non-palpable breast lesions, saving the breast parenchyma removed compared with skin tattoo, without reducing the accuracy.

CLINICAL RELEVANCE STATEMENT

Our findings contribute to the current evidence on preoperative localization techniques for non-palpable breast lesions, highlighting the efficacy of magnetic seed localization for deep and small lesions.

KEY POINTS

• Magnetic seed is a non-radioactive technique for the preoperative localization of non-palpable breast lesions studied in comparison with skin tattoo. • Magnetic seed is feasible to place in terms of post-placement migration and distance from the target lesion. • Magnetic seed is recommended in case of non-palpable breast lesions, saving the breast parenchyma removed without reducing the accuracy.

Ultraviolet metasurface-assisted photoacoustic microscopy with great enhancement in DOF for fast histology imaging

Pathology interpretations of tissue rely on the gold standard of histology imaging, potentially hampering timely access to critical information for diagnosis and management of neoplasms because of tedious sample preparations. Slide-free capture of cell nuclei in unprocessed specimens without staining is preferable; however, inevitable irregular surfaces in fresh tissues results in limitations. An ultraviolet metasurface with the ability to generate an ultraviolet optical focus maintaining < 1.1-µm in lateral resolution and ∼290 µm in depth of field (DOF) is proposed for fast, high resolution, label-free photoacoustic histological imaging of unprocessed tissues with uneven surfaces. Microanatomical characteristics of the cell nuclei can be observed, as demonstrated by the mouse brain samples that were cut by hand and a ∼3 × 3-mm2 field of view was imaged in ∼27 min. Therefore, ultraviolet metasurface-assisted photoacoustic microscopy is anticipated to benefit intraoperative pathological assessments and basic scientific research by alleviating laborious tissue preparations.

Wide-field optical coherence tomography for microstructural analysis of key tissue types: a proof-of-concept evaluation

Introduction: The presence of positive margins following tumor resection is a frequent cause of re-excision surgery. Nondestructive, real-time intraoperative histopathological imaging methods may improve margin status assessment at the time of surgery; optical coherence tomography (OCT) has been identified as a potential solution but has not been tested with the most common tissue types in surgical oncology using a single, standardized platform. Methods: This was a proof-of-concept evaluation of a novel device that employs wide-field OCT (WF-OCT; OTIS 2.0 System) to image tissue specimens. Various cadaveric tissues were obtained from a single autopsy and were imaged with WF-OCT then processed for permanent histology. The quality and resolution of the WF-OCT images were evaluated and compared to histology and with images in previous literature. Results: A total of 30 specimens were collected and tissue-specific microarchitecture consistent with previous literature were identified on both WF-OCT images and histology slides for all specimens, and corresponding sections were correlated. Application of vacuum pressure during scanning did not affect specimen integrity. On average, specimens were scanned at a speed of 10.3 s/cm² with approximately three features observed per tissue type. Conclusion: The WF-OCT images captured in this study displayed the key features of the most common human tissue types encountered in surgical oncology with utility comparable to histology, confirming the utility of an FDA-cleared imaging platform. With further study, WF-OCT may have the potential to bridge the gap between the immediate information needs of the operating room and the longer timeline inherent to histology workflow.

Adjuvant Therapy in Breast Cancer Patients With Microscopic Residual Disease

INTRODUCTION

Surgical resection is the gold standard for early-stage breast cancer. Positive surgical margins are associated with poor outcome. Endocrine therapy (ET) is recommended as primary systemic treatment for hormone receptor positive (HR+) breast cancer after surgery. We hypothesized that chemoenocrine therapy (CET) would not be associated with improved survival relative to ET for patients with positive margins.

MATERIALS AND METHODS

The National Cancer Database was queried for pathologic stage I HR + HER2-breast cancer patients treated with partial mastectomy and adjuvant whole-breast irradiation between 2004 and 2017. The adjuvant treatment approaches to positive surgical margins were investigated and compared. Overall survival was compared between systemic treatment groups using multivariable cox proportional hazards regression.

RESULTS

Among 228,453 patients, a positive surgical margin (microscopic residual disease, R1) was identified in 3561 (1.6%) patients. Compared with complete resections, positive margin was associated with inferior overall survival (hazard ratio [HR] = 1.276, P = 0.003). Among the R1 patients, 78.7% received ET only, 11.7% received CET, 1.2% received chemotherapy only, and 8.5% received no systemic therapy. After controlling for patient, facility, and tumor characteristics, ET provided greatest survival benefit (relative to no therapy, HR = 0.378, P < 0.001) followed by CET (HR = 0.446, P = 0.020). Compared with ET alone, CET is not associated with additional overall survival benefit (HR = 1.179, P = 0.595).

CONCLUSIONS

CET appeared not to be associated with an improved overall survival in early stage HR + HER2-breast cancer with microscopic residual disease relative to ET. Positive surgical margins therefore are probably not a relevant clinical factor for adjuvant chemotherapy decision-making.

In situ Raman spectroscopy and machine learning unveil biomolecular alterations in invasive breast cancer

SIGNIFICANCE

As many as 60% of patients with early stage breast cancer undergo breast-conserving surgery. Of those, 20% to 35% need a second surgery because of incomplete resection of the lesions. A technology allowing in situ detection of cancer could reduce re-excision procedure rates and improve patient survival.

AIM

Raman spectroscopy was used to measure the spectral fingerprint of normal breast and cancer tissue ex-vivo. The aim was to build a machine learning model and to identify the biomolecular bands that allow one to detect invasive breast cancer.

APPROACH

The system was used to interrogate specimens from 20 patients undergoing lumpectomy, mastectomy, or breast reduction surgery. This resulted in 238 ex-vivo measurements spatially registered with standard histology classifying tissue as cancer, normal, or fat. A technique based on support vector machines led to the development of predictive models, and their performance was quantified using a receiver-operating-characteristic analysis.

RESULTS

Raman spectroscopy combined with machine learning detected normal breast from ductal or lobular invasive cancer with a sensitivity of 93% and a specificity of 95%. This was achieved using a model based on only two spectral bands, including the peaks associated with C-C stretching of proteins around 940    cm - 1 and the symmetric ring breathing at 1004    cm - 1 associated with phenylalanine.

CONCLUSIONS

Detection of cancer on the margins of surgically resected breast specimen is feasible with Raman spectroscopy.

Metabolic characteristics of the various incision margins for breast cancer conservation surgery

Background

Breast cancer (BC) has recently become the most prevalent malignancy in women. There are many alternative treatments for BC, and for aesthetic and postoperative quality of life concerns, breast-conserving surgery and corresponding adjuvant therapy have become the predominant treatment for early invasive BC. Currently, the main method used to assess the margins for breast-conserving surgery is intraoperative pathological diagnosis. However, the designation of surgical margins is controversial, and metabolomics may be a novel approach to evaluate surgical margins.

Methods

We collected specimens from 10 breast cancer patients and samples from its surrounding tissues and divided them into cancerous tissue and 1 mm, 2 mm, 3 mm, 5 mm and 10 mm cutting edge tissues, with a total of 60 samples. The samples were analyzed by mass spectrometry on an ultra-performance liquid chromatography-quadrupole/Orbitrap high resolution platform. The data were then statistically analyzed to detect metabolic changes in the different cutting edges and to identify possible surgical cutting edges with statistically significant findings. Abnormal metabolic pathways were identified by Kyoto Encyclopedia of Genes and Genomes (KEGG), which elucidated potential markers.

Results

Statistical analysis indicated that there were substantial differences between the 1 mm margin tissue and the cancer tissue, while there were no statistically significant differences between the 1 mm tissue and tissues from the other margins. The levels of 6 metabolites in the 1 mm tissue were significantly different from those in the cancer tissue and were not significantly different from those in the 2 mm tissue. The six metabolites were pyruvate, N-acetyl-L-aspartate, glutamic acid, γ-aminobutyric acid, fumaric acid, and citric acid. Metabolic pathways such as amino acid metabolism and amino t-RNA synthesis in the margin tissue were significantly distinct from those in cancer tissues based on KEGG analysis.

Conclusion

There was a significant difference between the 1 mm margin tissue and the cancerous tissue. Based on metabolomic analysis, the 1 mm negative margin is sufficient for surgery, and the six metabolites that we identified as abnormal, including pyruvic acid, N-acetyl-L-aspartic acid, glutamic acid, gamma-aminobutyric acid, fumaric acid and citric acid, may serve as biomarkers for a negative margin and help surgeons select an appropriate surgical margin.

Efficacy and Accuracy of Using Magnetic Seed for Preoperative Non-Palpable Breast Lesions Localization: Our Experience with Magseed

In this retrospective study we share our single-center experience using a magnetic seed for the preoperative localization of non-palpable breast lesions. Patients who underwent a preoperative localization with Magseed^® (Endomagnetics, Cambridge, UK) placement between 2020 and 2022 were enrolled. Indications to Magseed placement have been established during multidisciplinary meetings prior to surgery and all patients underwent breast-conserving surgery (BCS). 45 patients were included. Magnetic seeds have been introduced under ultrasound guidance in 40 patients (88.9%) and under stereotactic guidance in 5 patients (11.1%). We registered a highly successful placement rate (97.8%), with only one case of migration (2.2%). After BCS, all the magnetic seeds were recovered (100% retrieval rate). The re-excision rate for positive margins was 0%. Our experience, with a highly successful placement and retrieval rate and a re-excision rate equal to 0%, is consistent with the encouraging literature published on Magseed so far, suggesting this technique to be extremely effective. Moreover, our single case of seed migration supports the existing data stating that Magseed migration is rare. In conclusion, despite acknowledging Magseed limitations, we highly value the advantages linked to this technique, and we, therefore, uphold its use.

Rapid slide-free and non-destructive histological imaging using wide-field optical-sectioning microscopy

Histopathology based on formalin-fixed and paraffin-embedded tissues has long been the gold standard for surgical margin assessment (SMA). However, routine pathological practice is lengthy and laborious, failing to guide surgeons intraoperatively. In this report, we propose a practical and low-cost histological imaging method with wide-field optical-sectioning microscopy (i.e., High-and-Low-frequency (HiLo) microscopy). HiLo can achieve rapid and non-destructive imaging of freshly-excised tissues at an extremely high acquisition speed of 5 cm²/min with a spatial resolution of 1.3 µm (lateral) and 5.8 µm (axial), showing great potential as an SMA tool that can provide immediate feedback to surgeons and pathologists for intraoperative decision-making. We demonstrate that HiLo enables rapid extraction of diagnostic features for different subtypes of human lung adenocarcinoma and hepatocellular carcinoma, producing surface images of rough specimens with large field-of-views and cellular features that are comparable to the clinical standard. Our results show promising clinical translations of HiLo microscopy to improve the current standard of care.

High-Throughput, Label-Free and Slide-Free Histological Imaging by Computational Microscopy and Unsupervised Learning

Rapid and high-resolution histological imaging with minimal tissue preparation has long been a challenging and yet captivating medical pursuit. Here, the authors propose a promising and transformative histological imaging method, termed computational high-throughput autofluorescence microscopy by pattern illumination (CHAMP). With the assistance of computational microscopy, CHAMP enables high-throughput and label-free imaging of thick and unprocessed tissues with large surface irregularity at an acquisition speed of 10 mm2 /10 s with 1.1-µm lateral resolution. Moreover, the CHAMP image can be transformed into a virtually stained histological image (Deep-CHAMP) through unsupervised learning within 15 s, where significant cellular features are quantitatively extracted with high accuracy. The versatility of CHAMP is experimentally demonstrated using mouse brain/kidney and human lung tissues prepared with various clinical protocols, which enables a rapid and accurate intraoperative/postoperative pathological examination without tissue processing or staining, demonstrating its great potential as an assistive imaging platform for surgeons and pathologists to provide optimal adjuvant treatment.

Optical scatter imaging of resected breast tumor structures matches the patterns of micro-computed tomography

In patients undergoing breast-conserving surgery (BCS), the rate of re-excision procedures to remove residual tumor left behind after initial resection can be high. Projection radiography, and recently, volumetric x-ray imaging are used to assess margin adequacy, but x-ray imaging lacks contrast between healthy, abnormal benign, and malignant fibrous tissues important for surgical decision making. The purpose of this study was to compare micro-CT and optical scatter imagery of surgical breast specimens and to demonstrate enhanced contrast-to intra-tumoral morphologies and tumor boundary features revealed by optical scatter imaging. A total of 57 breast tumor slices from 57 patients were imagedex vivoby spatially co-registered micro-CT and optical scatter scanning. Optical scatter exhibited greater similarity with micro-CT in 89% (51/57) of specimens versus diffuse white light (DWL) luminance using mutual information (mean ± standard deviation of 0.48 ± 0.21 versus 0.24 ± 0.12;p < 0.001) and in 81% (46/57) of specimens using the Sørensen-Dice coefficient (0.48 ± 0.21 versus 0.33 ± 0.18;p < 0.001). The coefficient of variation (CV) quantified the feature content in each image. Optical scatter exhibited the highest CV in every specimen (optical scatter: 0.70 ± 0.17; diffuse luminance: 0.24 ± 01; micro-CT: 0.15 ± 0.03 for micro-CT;p < 0.001). Optical scatter also exhibited the highest contrast ratios across representative tumor boundaries with adjacent healthy/benign fibrous tissues (1.5-3.7 for optical scatter; 1.0-1.1 for diffuse luminance; 1.0-1.1 for micro-CT). The two main findings from this study were: first, optical scatter contrast was in general similar to the radiological view of the tissue relative to DWL imaging; and second, optical scatter revealed additional features associated with fibrous tissue structures of similar radiodensity that may be relevant to diagnosis. The value of micro-CT lies in its rapid three-dimensional scanning of specimen morphology, and combined with optical scatter imaging with sensitivity to fibrous surface tissues, may be an attractive solution for margin assessment during BCS.

Assessment of breast cancer surgical margins with multimodal optical microscopy: A feasibility clinical study

Providing surgical margin information during breast cancer surgery is crucial for the success of the procedure. The margin is defined as the distance from the tumor to the cut surface of the resection specimen. The consensus among surgeons and radiation oncologists is that there should be no tumor left within 1 to maximum 2 mm from the surface of the surgical specimen. If a positive margin remains, there is substantial risk for tumor recurrence, which may also result in potentially reduced cosmesis and eventual need for mastectomy. In this paper we report a novel multimodal optical imaging instrument based on combined high-resolution confocal microscopy-optical coherence tomography imaging for assessing the presence of potential positive margins on surgical specimens. Since rapid specimen analysis is critical during surgery, this instrument also includes a fluorescence imaging channel to enable rapid identification of the areas of the specimen that have potential positive margins. This is possible by specimen incubation with a cancer specific agent prior to imaging. In this study we used a quenched contrast agent, which is activated by cancer specific enzymes, such as urokinase plasminogen activators (uPA). Using this agent or a similar one, one may limit the use of high-resolution optical imaging to only fluorescence-highlighted areas for visualizing tissue morphology at the sub-cellular scale and confirming or ruling out cancer presence. Preliminary evaluation of this technology was performed on 20 surgical specimens and testing of the optical imaging findings was performed against histopathology. The combination of the three imaging modes allowed for high correlation between optical image analysis and histological ground-truth. The initial results are encouraging, showing instrument capability to assess margins on clinical specimens with a positive predictive value of 1.0 and a negative predictive value of 0.83.

Development of near-infrared imaging agents for detection of junction adhesion molecule-A protein

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Anti-junctional adhesion molecule-A (JAM-A) monoclonal antibodies (mAb) conjugated with near infra-red fluorescent dye, IR700 – as a JAM-A mAb/IR700 agent was developed.

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An in vivo JAM-A mAb/IR700-specific near infra-red imaging of human-derived prostate and breast cancer xenograft is presented.

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A single injection of the agent is diminished number of mitotic cells in cancerous tissue of mice bearing heterotopic tumors.

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Since, our agent depicts the specific accumulation within the targeted tumors, this agent may be adapted to solid tumor targeted photoimmunotherapy.

Introduction

Prostate and breast cancer are the most prevalent primary malignant human tumors globally. Prostatectomy and breast conservative surgery remain the most common definitive treatment option for the >500,000 men and women newly diagnosed with localized prostate and breast cancer each year only in the US. Morphological examination is the mainstay of diagnosis but margin under-sampling of the excised cancer tissue may lead to local recurrence. In despite of the progress of non-invasive optical imaging, there is still a clinical need for targeted optical imaging probes that could rapidly and globally visualize cancerous tissues.

Methods

Elevated expression of junctional adhesion molecule-A (JAM-A) on tumor cells and its multiple pro-tumorigenic activity make the JAM-A a candidate for molecular imaging. Near-infrared imaging probe, which employed anti-JAM-A monoclonal antibody (mAb) phthalocyanine dye IR700 conjugates (JAM-A mAb/IR700), was synthesized and used to identify and visualize heterotopic human prostate and breast tumor mouse xenografts in vivo.

Results

The intravenously injected JAM-A mAb/IR700 conjugates enabled the non-invasive detection of prostate and breast cancerous tissue by fluorescence imaging. A single dose of JAM-A mAb/IR700 reduced number of mitotic cancer cells in vivo, indicating theranostic ability of this imaging agent. The JAM-A mAb/IR700 conjugates allowed us to image a specific receptor expression in prostate and breast tumors without post-image processing.

Conclusion

This agent demonstrates promise as a method to image the extent of prostate and breast cancer in vivo and could assist with real-time visualization of extracapsular extension of cancerous tissue.

Accuracy of gross intraoperative margin assessment for breast cancer: experience since the SSO-ASTRO margin consensus guidelines

Gross intraoperative assessment can be used to ensure negative margins at the time of surgery. Previous studies of this technique were conducted before the introduction of consensus guidelines defining a “positive” margin. We performed a retrospective study examining the accuracy of this technique since these guidelines were published. We identified all specimens that were grossly examined at the time of breast conserving surgery from January 2014 to July 2020. Gross and final microscopic diagnoses were compared and the performance of intraoperative examination was assessed in terms of false positive and false negative rates. Logistic regression models were used to examine the effect of clinicopathologic covariates on discordance. 327 cases were reviewed. Gross exam prompted re-excision in 166 cases (61%). The rate of false negative discordance was 8.6%. In multivariate analysis, multifocality on final pathology was associated with discordance. We consider the false negative rate acceptable for routine clinical use; however, there is an ongoing need for more accurate methods for the intraoperative assessment of margins.

Does Gross Margin Examination Reduce Re-excision Rate in Breast Conservation for Invasive Carcinoma? CALLER Review

Objective

Determine if Gross Margin Examination reduces margin re-excision rate. Our institutional practice is to perform Gross Margin Examination (GME) with Real-time re-excision (RRE) for all breast conservation specimens with Invasive Carcinoma.

Materials and Methods

Chart review was done to determine if this practice is helpful. 51 CALLER charts were reviewed from December 2016 to December 2017.

Results

Thirty-three underwent margin RRE based on the GME. 11 had cancer in the re-resected margin, 6 of which were cleared with the RRE. The other 5 were reoperated on to clear the margin because on final pathology a margin other than the re-resected margin was positive for malignancy. GME was helpful in preventing reoperation in 55%. None of the remaining 22 patients receiving were found to have a positive margin on final pathology, with 1.6 margins on average re-resected. 13/18 patients did not have RRE and had a final clear margin, but of the other 5, final margin was positive for DCIS in 2 and Invasive Cancer in 3. GME missed invasive disease at the margin in 3 of these 18 patients.

Conclusion

GME was helpful in preventing reoperation in 6 of 11 patients who would have had a positive margin. However, this resulted in the unnecessary removal of additional normal breast tissue in 22 patients. 3 patients' positive margins were missed with GME and required reoperation. 13 patients were able to avoid re-excision and 11 were able to clear their margin in real-time, improving outcomes 24/51 patients. GME therefore does appear useful.

Ultrasound Guided Optoacoustic Tomography in Assessment of Tumor Margins for Lumpectomies

PURPOSE: To determine the accuracy of a handheld ultrasound-guided optoacoustic tomography (US-OT) probe developed for human deep-tissue imaging in ex vivo assessment of tumor margins postlumpectomy. METHODS: A custom-built two-dimensional (2D) US-OT–handheld probe was used to scan 15 lumpectomy breast specimens. Optoacoustic signals acquired at multiple wavelengths between 700 and 1100 nm were reconstructed using model linear algorithm, followed by spectral unmixing for lipid and deoxyhemoglobin (Hb). Distribution maps of lipid and Hb on the anterior, posterior, superior, inferior, medial, and lateral margins of the specimens were inspected for margin involvement, and results were correlated with histopathologic findings. The agreement in tumor margin assessment between US-OT and histopathology was determined using the Bland–Altman plot. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of margin assessment using US-OT were calculated. RESULTS: Ninety margins (6 × 15 specimens) were assessed. The US-OT probe resolved blood vessels and lipid up to a depth of 6 mm. Negative and positive margins were discriminated by marked differences in the distribution patterns of lipid and Hb. US-OT assessments were concordant with histopathologic findings in 87 of 89 margins assessed (one margin was uninterpretable and excluded), with diagnostic accuracy of 97.9% (kappa = 0.79). The sensitivity, specificity, PPV, and NPV were 100% (4/4), 97.6% (83/85), 66.7% (4/6), and 100% (83/83), respectively. CONCLUSION: US-OT was capable of providing distribution maps of lipid and Hb in lumpectomy specimens that predicted tumor margins with high sensitivity and specificity, making it a potential tool for intraoperative tumor margin assessment.

Clinical outcomes of an intraoperative surgical margin assessment using the fresh frozen section method in patients with invasive breast cancer undergoing breast-conserving surgery - a single center analysis

Breast conserving treatment (BCT) is a safe standard therapeutic method in patients with early invasive breast cancer. However, it is associated with an increased risk of residual neoplastic tissues in surgical margins. The aim of this study was to assess the outcome of the use of the intraoperative pathologic analysis by the frozen section (FS) method for evaluation of the extent of the primary lumpectomy. The study concerns a retrospective analysis of a group of 1102 patients who underwent BCT between Jan 2015 and Dec 2016. The assessment focused on the frequency of the intraoperative pathologic analysis of the primary lumpectomy extent (fresh frozen section method). The influence of the BCT specimen analysis method on the free margins width, as well as the rate and the cause of reoperation were evaluated. The intraoperative lumpectomy evaluation was performed in 45.8% (505/1102) of patients (Group I), while in the remaining 54.2% of the cases it was decided to abandon this procedure (Group II). Although in 72 (14.3%) patients the intraoperative analysis gave negative results, the margins contained residual tumor tissue (vs. 16.9% in Group II). In Group I, conversion from the previously planned BCT to mastectomy was necessary in 5.9% (30/505) patients (vs. 9.7% in Group II). The duration of surgery was 48.9 ± 17.3 minutes (Group I) and 42.9 ± 13.6 minutes (Group II). In patients undergoing BCT, the use of the intraoperative pathologic analysis by the FS method resulted in a reduction of the total number of reoperations performed due to residual tumor found in the margins following the primary lumpectomy. However, it statistically significantly extended the duration of the surgery.

Structured light imaging for breast-conserving surgery, part II: texture analysis and classification

Subdiffuse spatial frequency domain imaging (sd-SFDI) data of 42 freshly excised, bread-loafed tumor resections from breast-conserving surgery (BCS) were evaluated using texture analysis and a machine learning framework for tissue classification. Resections contained 56 regions of interest (RoIs) determined by expert histopathological analysis. RoIs were coregistered with sd-SFDI data and sampled into ∼4  ×  4  mm2 subimage samples of confirmed and homogeneous histological categories. Sd-SFDI reflectance textures were analyzed using gray-level co-occurrence matrix pixel statistics, image primitives, and power spectral density curve parameters. Texture metrics exhibited statistical significance (p-value  <  0.05) between three benign and three malignant tissue subtypes. Pairs of benign and malignant subtypes underwent texture-based, binary classification with correlation-based feature selection. Classification performance was evaluated using fivefold cross-validation and feature grid searching. Classification using subdiffuse, monochromatic reflectance (illumination spatial frequency of fx  =  1.37  mm  −  1, optical wavelength of λ  =  490  nm) achieved accuracies ranging from 0.55 (95% CI: 0.41 to 0.69) to 0.95 (95% CI: 0.90 to 1.00) depending on the benign–malignant diagnosis pair. Texture analysis of sd-SFDI data maintains the spatial context within images, is free of light transport model assumptions, and may provide an alternative, computationally efficient approach for wide field-of-view (cm2) BCS tumor margin assessment relative to pixel-based optical scatter or color properties alone.

Structured light imaging for breast-conserving surgery, part I: optical scatter and color analysis

Structured light imaging (SLI) with high spatial frequency (HSF) illumination provides a method to amplify native tissue scatter contrast and better differentiate superficial tissues. This was investigated for margin analysis in breast-conserving surgery (BCS) and imaging gross clinical tissues from 70 BCS patients, and the SLI distinguishability was examined for six malignancy subtypes relative to three benign/normal breast tissue subtypes. Optical scattering images recovered were analyzed with five different color space representations of multispectral demodulated reflectance. Excluding rare combinations of invasive lobular carcinoma and fibrocystic disease, SLI was able to classify all subtypes of breast malignancy from surrounding benign tissues (p-value  <  0.05) based on scatter and color parameters. For color analysis, HSF illumination of the sample generated more statistically significant discrimination than regular uniform illumination. Pathological information about lesion subtype from a presurgical biopsy can inform the search for malignancy on the surfaces of specimens during BCS, motivating the focus on pairwise classification analysis. This SLI modality is of particular interest for its potential to differentiate tissue classes across a wide field-of-view (∼100  cm2) and for its ability to acquire images of macroscopic tissues rapidly but with microscopic-level sensitivity to structural and morphological tissue constituents.

Surgical clips vs. iodine-125 (125I) seeds for marking the location of nonpalpable malignant breast lesions: preliminary results

OBJECTIVES

To assess the usefulness of iodine-125 (125I) seeds as an alternative to surgical clips for marking the location of nonpalpable malignant breast lesions for surgery.

MATERIAL AND METHODS

We included patients with histologically confirmed nonpalpable malignant lesions treated by surgery in 2015 or 2016. Patients were randomly assigned to presurgical marking with metallic clips (Group A) or with 125I seeds (Group B). In both groups, marking was guided by ultrasound and/or mammography depending on the radiologic characteristics of the lesion. During surgery, a gamma probe was used and afterward the presence of seeds in the surgical specimen was checked radiologically. In the histological analysis, the absence of tumor in the stain was considered free margins. We analyzed the following variables: age, lesion characteristics (laterality, mean size on MRI and in the surgical specimen, radiological type), and presence/absence of free margins.

RESULTS

In Group A (n=53), the most common histologic subtypes were infiltrating ductal carcinoma (IDC, 84.9%) and luminal A (LA, 49.1%); the mean size of the lesions was 1.8cm. In Group B (n=45), the most common histologic subtypes were IDC (82.2%) and LA (46.5%); the mean size of the lesions was 1.5cm. In Group A, 13.2% had involved margins and 13.2% underwent a second surgical intervention. In Group, B 11.4% had involved margins and 7.5% underwent a second surgical intervention. The differences between groups were not significant (p=0.7 for involved margins and p=0.5 for reintervention). The volume of the surgical specimens was significantly lower in Group B than in Group A (128.68cm3 vs. 189.37cm3; p<0.05).

CONCLUSIONS

Using 125I seeds was feasible and enabled significantly smaller surgical specimens than using metallic clips.

High-speed Intraoperative Assessment of Breast Tumor Margins by Multimodal Ultrasound and Photoacoustic Tomography

Conventional methods for breast tumor margins assessment need a long turnaround time, which may lead to re-operation for patients undergoing lumpectomy surgeries. Photoacoustic tomography (PAT) has been shown to visualize adipose tissue in small animals and human breast. Here, we demonstrate a customized multimodal ultrasound and PAT system for intraoperative breast tumor margins assessment using fresh lumpectomy specimens from 66 patients. The system provides the margin status of the entire excised tissue within 10 minutes. By subjective reading of three researchers, the results show 85.7% [95% confidence interval (CI), 42.0% - 99.2%] sensitivity and 84.6% (95% CI, 53.7% - 97.3%) specificity, 71.4% (95% CI, 30.3% - 94.9%) sensitivity and 92.3% (95% CI, 62.1% - 99.6%) specificity, and 100% (95% CI, 56.1% - 100%) sensitivity and 53.9% (95% CI, 26.1% - 79.6%) specificity respectively when cross-correlated with post-operational histology. Furthermore, a machine learning-based algorithm is deployed for margin assessment in the challenging ductal carcinoma in situ tissues, and achieved 85.5% (95% CI, 75.2% - 92.2%) sensitivity and 90% (95% CI, 79.9% - 95.5%) specificity. Such results present the potential of using mutlimodal ultrasound and PAT as a high-speed and accurate method for intraoperative breast tumor margins evaluation.

Review of methods for intraoperative margin detection for breast conserving surgery

Breast conserving surgery (BCS) is an effective treatment for early-stage cancers as long as the margins of the resected tissue are free of disease according to consensus guidelines for patient management. However, 15% to 35% of patients undergo a second surgery since malignant cells are found close to or at the margins of the original resection specimen. This review highlights imaging approaches being investigated to reduce the rate of positive margins, and they are reviewed with the assumption that a new system would need high sensitivity near 95% and specificity near 85%. The problem appears to be twofold. The first is for complete, fast surface scanning for cellular, structural, and/or molecular features of cancer, in a lumpectomy volume, which is variable in size, but can be large, irregular, and amorphous. A second is for full, volumetric imaging of the specimen at high spatial resolution, to better guide internal radiologic decision-making about the spiculations and duct tracks, which may inform that surfaces are involved. These two demands are not easily solved by a single tool. Optical methods that scan large surfaces quickly are needed with cellular/molecular sensitivity to solve the first problem, but volumetric imaging with high spatial resolution for soft tissues is largely outside of the optical realm and requires x-ray, micro-CT, or magnetic resonance imaging if they can be achieved efficiently. In summary, it appears that a combination of systems into hybrid platforms may be the optimal solution for these two very different problems. This concept must be cost-effective, image specimens within minutes and be coupled to decision-making tools that help a surgeon without adding to the procedure. The potential for optical systems to be involved in this problem is emerging and clinical trials are underway in several of these technologies to see if they could reduce positive margin rates in BCS.

Precision biopsy of breast microcalcifications: An improvement in surgical excision

The aim of the present study was to improve the conventional wire-guided localization biopsy (WGLB) of breast microcalcifications to overcome disadvantages associated with the procedure, including inaccurate localization and large specimen volume. The novel approach described in the present study was termed double wire-guided localization and rotary cutting biopsy (DWGLB). Prior to surgery, the precise localization of the lesions was assessed using two wires under the assistance of mammography X-ray and ultrasound, followed by complete excision of the lesions using a novel rotary cutting tool. The cylindrical specimen was placed on a scaled specimen holder for pathological examination. DWGLB was performed in 108 patients with the classification of as Breast Imaging Reporting and Data System score 4A. Percutaneous localization of the lesions guided by a mammography X-ray and ultrasound were successful in all 108 lesions (100%) with one puncture attempt. The lesions were precisely excised in all of 108 patients, and included 13 malignant lesions (DCIS of breast in 7 cases, DCIS with focal invasive carcinoma in 3 cases and invasive ductal carcinoma in 3 cases). The average distance of the BARD Dualok to the lesion was 4.1 mm; the average weight of specimens was 8.5 g. Compared with WGLB, DWGLB offers several advantages, including more accurate localization of lesions, a more standardized biopsy method and a smaller specimen volume. DWGLB can also provide the precise position of lesions in the specimen for further pathological examination.

Surgeon Variability and Factors Predicting for Reoperation Following Breast-Conserving Surgery

BACKGROUND

Reoperation after breast-conserving surgery (BCS) is common and has been partially associated with the lack of consensus on margin definition. We sought to investigate factors associated with reoperations and variation in reoperation rates across breast surgeons at our cancer center.

METHODS

Retrospective analyses of patients with clinical stage I-II breast cancer who underwent BCS between January and December 2014 were conducted prior to the recommendation of 'no ink on tumor' margin. Patient demographics and tumor and surgical data were extracted from medical records. A multivariate regression model was used to identify factors associated with reoperation.

RESULTS

Overall, 490 patients with stage I (n  = 408) and stage II (n  = 89) breast cancer underwent BCS; seven patients had bilateral breast cancer and underwent bilateral BCS procedures. Median invasive tumor size was 1.1 cm, reoperation rate was 22.9% (n  = 114) and varied among surgeons (range 15-40%), and, in 100 (88%) patients, the second procedure was re-excision, followed by unilateral mastectomy (n  = 7, 6%) and bilateral mastectomy (n  = 7, 6%). Intraoperative margin techniques (global cavity or targeted shaves) were utilized in 50.1% of cases, while no specific margin technique was utilized in 49.9% of cases. Median total specimen size was 65.8 cm³ (range 24.5-156.0). In the adjusted model, patients with multifocal disease were more likely to undergo reoperation [odds ratio (OR) 5.78, 95% confidence interval (CI) 2.17-15.42]. In addition, two surgeons were found to have significantly higher reoperation rates (OR 6.41, 95% CI 1.94-21.22; OR 3.41, 95% CI 1.07-10.85).

CONCLUSIONS

Examination of BCS demonstrated variability in reoperation rates and margin practices among our breast surgeons. Future trials should look at surgeon-specific factors that may predict for reoperations.

Predicting initial margin status in breast cancer patients during breast-conserving surgery

Background

We sought to develop and validate a model for prediction of initial margin status during breast-conserving surgery (BCS).

Methods

We included eligible breast cancer patients receiving BCS in Sun Yat-sen Memorial Hospital from January 2003 to December 2014. All patients received intraoperative frozen-section analysis for initial margin assessment. We used univariate and multivariate logistic regression analyses to screen for predictors. A nomogram was developed in the training cohort (n=1,193) from the south branch of the hospital and externally validated in the validation cohort (n=499) from the north branch. We used the area under the receiver-operating characteristic curve and Hosmer–Lemeshow tests to assess the discrimination and accuracy of the nomogram.

Results

The initial margin-positivity rates were 19.5% and 25.2% in the training and validation cohorts, respectively. Preoperative tumor size, preoperative lymph-node status, suspicion of multifocality, hormone-receptor status, and HER2 status were significantly associated with margin status. The model included these five variables. The discrimination and calibration of the model were considered acceptable in both cohorts.

Conclusion

The nomogram can predict the likelihood of having positive initial margins during BCS and may be useful for clinical decision-making in the surgical treatment of breast cancer patients.

Multiscale nonlinear microscopy and widefield white light imaging enables rapid histological imaging of surgical specimen margins

The ability to histologically assess surgical specimens in real-time is a long-standing challenge in cancer surgery, including applications such as breast conserving therapy (BCT). Up to 40% of women treated with BCT for breast cancer require a repeat surgery due to postoperative histological findings of close or positive surgical margins using conventional formalin fixed paraffin embedded histology. Imaging technologies such as nonlinear microscopy (NLM), combined with exogenous fluorophores can rapidly provide virtual H&E imaging of surgical specimens without requiring microtome sectioning, facilitating intraoperative assessment of margin status. However, the large volume of typical surgical excisions combined with the need for rapid assessment, make comprehensive cellular resolution margin assessment during surgery challenging. To address this limitation, we developed a multiscale, real-time microscope with variable magnification NLM and real-time, co-registered position display using a widefield white light imaging system. Margin assessment can be performed rapidly under operator guidance to image specific regions of interest located using widefield imaging. Using simulated surgical margins dissected from human breast excisions, we demonstrate that multi-centimeter margins can be comprehensively imaged at cellular resolution, enabling intraoperative margin assessment. These methods are consistent with pathology assessment performed using frozen section analysis (FSA), however NLM enables faster and more comprehensive assessment of surgical specimens because imaging can be performed without freezing and cryo-sectioning. Therefore, NLM methods have the potential to be applied to a wide range of intra-operative applications.

Innovations in image-guided preoperative breast lesion localization

Screening mammography increases detection of non-palpable breast lesions requiring image-guided localization prior to surgery. Accurate preoperative localization is crucial for successful surgical outcomes. Wire-guided localization is currently the most widely used localization method for non-palpable breast lesions; however, this technique has multiple disadvantages including patient discomfort, possible wire transection and migration, suboptimal surgical incision placement due to wire location and limited scheduling flexibility decreasing operating room efficiency. As a result, promising new techniques including radioactive seed localization, non-radioactive radar localization and magnetic seed localization have been developed as alternatives. In this article, we provide an overview of these techniques and discuss their advantages, drawbacks and currently available outcome data.

A fiber optoacoustic guide with augmented reality for precision breast-conserving surgery

Lumpectomy, also called breast-conserving surgery, has become the standard surgical treatment for early-stage breast cancer. However, accurately locating the tumor during a lumpectomy, especially when the lesion is small and nonpalpable, is a challenge. Such difficulty can lead to either incomplete tumor removal or prolonged surgical time, which result in high re-operation rates (~25%) and increased surgical costs. Here, we report a fiber optoacoustic guide (FOG) with augmented reality (AR) for sub-millimeter tumor localization and intuitive surgical guidance with minimal interference. The FOG is preoperatively implanted in the tumor. Under external pulsed light excitation, the FOG omnidirectionally broadcasts acoustic waves through the optoacoustic effect by a specially designed nano-composite layer at its tip. By capturing the acoustic wave, three ultrasound sensors on the breast skin triangulate the FOG tip's position with 0.25-mm accuracy. An AR system with a tablet measures the coordinates of the ultrasound sensors and transforms the FOG tip's position into visual feedback with <1-mm accuracy, thus aiding surgeons in directly visualizing the tumor location and performing fast and accurate tumor removal. We further show the use of a head-mounted display to visualize the same information in the surgeons' first-person view and achieve hands-free guidance. Towards clinical application, a surgeon successfully deployed the FOG to excise a "pseudo tumor" in a female human cadaver. With the high-accuracy tumor localization by FOG and the intuitive surgical guidance by AR, the surgeon performed accurate and fast tumor removal, which will significantly reduce re-operation rates and shorten the surgery time.

Rapid virtual hematoxylin and eosin histology of breast tissue specimens using a compact fluorescence nonlinear microscope

Up to 40% of patients undergoing breast conserving surgery for breast cancer require repeat surgeries due to close to or positive margins. The lengthy processing required for evaluating surgical margins by standard paraffin-embedded histology precludes its use during surgery and therefore, technologies for rapid evaluation of surgical pathology could improve the treatment of breast cancer by reducing the number of surgeries required. We demonstrate real-time histological evaluation of breast cancer surgical specimens by staining specimens with acridine orange (AO) and sulforhodamine 101 (SR101) analogously to hematoxylin and eosin (H&E) and then imaging the specimens with fluorescence nonlinear microscopy (NLM) using a compact femtosecond fiber laser. A video-rate computational light absorption model was used to produce realistic virtual H&E images of tissue in real time and in three dimensions. NLM imaging could be performed to depths of 100 μm below the tissue surface, which is important since many surgical specimens require subsurface evaluation due to contamination artifacts on the tissue surface from electrocautery, surgical ink, or debris from specimen handling. We validate this method by expert review of NLM images compared to formalin-fixed, paraffin-embedded (FFPE) H&E histology. Diagnostically important features such as normal terminal ductal lobular units, fibrous and adipose stromal parenchyma, inflammation, invasive carcinoma, and in situ lobular and ductal carcinoma were present in NLM images associated with pathologies identified on standard FFPE H&E histology. We demonstrate that AO and SR101 were extracted to undetectable levels after FFPE processing and fluorescence in situ hybridization (FISH) HER2 amplification status was unaffected by the NLM imaging protocol. This method potentially enables cost-effective, real-time histological guidance of surgical resections.

Radioactive seed localization compared with wire-guided localization of non-palpable breast carcinoma in breast conservation surgery- the first experience in the United Kingdom

OBJECTIVE

In the UK, guidewires have traditionally been used for localization of non-palpable breast lesions in patients undergoing breast conservation surgery (BCS). Radioactive seed localization (RSL) using Iodine-125 seeds is an alternative localization method and involves inserting a titanium capsule, containing radioactive Iodine-125, into the breast lesion. We aim to demonstrate feasibility of RSL compared with guidewire-localization (GWL) for BCS in the UK.

METHODS

Data were collected on 100 patients with non-palpable unifocal invasive carcinoma of the breast undergoing GWL WLE prior to the introduction of RSL and the first 100 patients treated with RSL WLE. Statistical comparisons were made using Χ²-squared analysis or unpaired two-sample t-test. Significance was determined to be at p ≤ 0.05.

RESULTS

Mean total tumour size was 19.44 mm (range: 5-55) in the GWL group and 18.61 mm (range: 3.8-59) in the RSL group (p = 0.548), while mean total specimen excision weight was significantly lower in the RSL group; 31.55 g (range: 4.5-112) vs 37.42 g (range: 7.8-157.1) (p = 0.018). Although 15 patients had inadequate surgical resection margins in the GWL group compared the 13 in the RSL group (15 vs 13%, respectively, p = 0.684), 10 of the patients in the GWL group had invasive carcinoma present resulting in at least one positive margin compared with only 3 patients in the RSL group (10 vs 3%, respectively, p = 0.045).

CONCLUSION

In this study, RSL is shown to be non-inferior to the use of GWL for non-palpable carcinoma in patients undergoing BCS and we suggest that it could be introduced successfully in other breast units. Advances in knowledge: Here we have demonstrated the use of RSL localization results in significant lower weight resection specimens of breast carcinoma when compared with a matched group using GWL, without any significant differences in oncological outcome between the groups.

Comparative Evaluation of Iodine-125 Radioactive Seed Localization and Wire Localization for Resection of Breast Lesions

Purpose

Radioactive seed localization (RSL) uses a titanium seed labeled with iodine-125 energy for surgery of nonpalpable breast lesions. RSL facilitates radiology–surgery scheduling and allows for improved oncoplasty compared with wire localization (WL). The purpose of this work was to compare the 2 techniques.

Methods

We performed a retrospective study of all breast lesions operated with RSL between February 2013 and March 2015 at our university institution, and compared with an equivalent number of surgeries performed with a single WL. Imaging and pathology reports were reviewed for information on guidance mode, accuracy of targeting, nature of excised lesion, size and volume of surgical specimen, status of margins, and reinterventions.

Results

A total of 254 lesions (247 women) were excised with RSL and compared with 257 lesions (244 women) whose surgery was guided by WL. Both groups were comparable in lesion pathology, guidance mode for RSL or WL positioning, and accuracy of targeting (98% correct). Mean delay between biopsy and surgery was 84 days for RSL versus 103 after WL ( P = .04). No differences were noted after RSL or WL for surgical specimen mean weight, largest diameter, and volume excised. For malignancies, the rate of positive margins was comparable (2.8%-3%), with 5 of 10 women in the RSL group who underwent a second surgery displaying residual malignancy compared with 3 of 9 women in the WL group.

Conclusions

RSL is safe and accurate, and has comparable surgical endpoints to WL. Because RSL offers flexible scheduling and facilitated oncoplasty, RSL may replace WL for resection of nonpalpable single breast lesions.

Intraoperative Margin Management in Breast-Conserving Surgery: A Systematic Review of the Literature

BACKGROUND

Breast surgeons have a wide variety of intraoperative techniques available to help achieve low rates for positive margins of excision, with variable levels of evidence.

METHODS

A systematic review of the medical literature from 1995 to July 2016 was conducted, with 434 abstracts identified and evaluated. The analysis included 106 papers focused on intraoperative management of breast cancer margins and contained actionable data.

RESULTS

Ultrasound-guided lumpectomy for palpable tumors, as an alternative to palpation guidance, can lower positive margin rates, but the effect when used as an alternative to wire localization (WL) for nonpalpable tumors is less certain. Localization techniques such as radioactive seed localization and radioguided occult lesion localization were found potentially to lower positive margin rates as alternatives to WL depending on baseline positive margin rates. Intraoperative pathologic methods including gross histology, frozen section analysis, and imprint cytology all have the potential to lower the rates of positive margins. Cavity-shave margins and the Marginprobe device both lower rates of positive margins, with some potential for negative cosmetic effects. Specimen radiography and multiple miscellaneous techniques did not affect positive margin rates or provided too little evidence for formation of a conclusion.

CONCLUSIONS

A systematic review of the literature showed evidence that several intraoperative techniques and actions can lower the rates of positive margins. These results are presented together with graded recommendations.

Direct comparison between confocal and multiphoton microscopy for rapid histopathological evaluation of unfixed human breast tissue

Rapid histopathological examination of surgical specimen margins using fluorescence microscopy during breast conservation therapy has the potential to reduce the rate of positive margins on postoperative histopathology and the need for repeat surgeries. To assess the suitability of imaging modalities, we perform a direct comparison between confocal fluorescence microscopy and multiphoton microscopy for imaging unfixed tissue and compare to paraffin-embedded histology. An imaging protocol including dual channel detection of two contrast agents to implement virtual hematoxylin and eosin images is introduced that provides high quality imaging under both one and two photon excitation. Corresponding images of unfixed human breast tissue show that both confocal and multiphoton microscopy can reproduce the appearance of conventional histology without the need for physical sectioning. We further compare normal breast tissue and invasive cancer specimens imaged at multiple magnifications, and assess the effects of photobleaching for both modalities using the staining protocol. The results demonstrate that confocal fluorescence microscopy is a promising and cost-effective alternative to multiphoton microscopy for rapid histopathological evaluation of ex vivo breast tissue.

A Wearable Goggle Navigation System for Dual-Mode Optical and Ultrasound Localization of Suspicious Lesions: Validation Studies Using Tissue-Simulating Phantoms and an Ex Vivo Human Breast Tissue Model

Surgical resection remains the primary curative treatment for many early-stage cancers, including breast cancer. The development of intraoperative guidance systems for identifying all sites of disease and improving the likelihood of complete surgical resection is an area of active ongoing research, as this can lead to a decrease in the need of subsequent additional surgical procedures. We develop a wearable goggle navigation system for dual-mode optical and ultrasound imaging of suspicious lesions. The system consists of a light source module, a monochromatic CCD camera, an ultrasound system, a Google Glass, and a host computer. It is tested in tissue-simulating phantoms and an ex vivo human breast tissue model. Our experiments demonstrate that the surgical navigation system provides useful guidance for localization and core needle biopsy of simulated tumor within the tissue-simulating phantom, as well as a core needle biopsy and subsequent excision of Indocyanine Green (ICG)—fluorescing sentinel lymph nodes. Our experiments support the contention that this wearable goggle navigation system can be potentially very useful and fully integrated by the surgeon for optimizing many aspects of oncologic surgery. Further engineering optimization and additional in vivo clinical validation work is necessary before such a surgical navigation system can be fully realized in the everyday clinical setting.

The Role of Intraoperative Pathologic Assessment in the Surgical Management of Ductal Carcinoma In Situ

BACKGROUND

Re-excision surgeries for the treatment of ductal carcinoma in situ (DCIS) put a strain on patients and healthcare resources; however, intraoperative pathologic assessment of DCIS may lead to a reduction in these additional surgeries. This study examined the relationship between intraoperative pathologic assessment and subsequent operations in patients with a diagnosis of DCIS.

METHODS

Surveillance, Epidemiology, and End Results-Medicare patients diagnosed with DCIS from 1999 to 2007 who initially underwent partial mastectomy, without axillary surgery, were included in this study. Use of intraoperative frozen section or touch preparation during the initial surgery was assessed. Multivariable logistic regression was used to describe the relationship between the use of intraoperative pathologic assessment and any subsequent mastectomy or partial mastectomy within 90 days of the initial partial mastectomy.

RESULTS

Of 8259 DCIS patients, 3509 (43 %) required a second surgery, and intraoperative pathologic assessment was performed for 2186 (26 %). Intraoperative pathologic assessment had no statistically significant effect on whether or not a subsequent breast surgery occurred (adjusted odds ratio 1.07, 95 % confidence interval 0.95-1.21; p = 0.293). Patient residence in a rural area, tumor size ≥2 cm, and poorly differentiated tumor grade were associated with a greater likelihood of subsequent surgery, while age 80 years and older was associated with a lower likelihood of subsequent surgery.

CONCLUSIONS

The use of intraoperative frozen section or touch preparation during partial mastectomy from 1999 to 2007 was not associated with a reduction in subsequent breast operations in women with DCIS. These results highlight the need to identify cost-effective tools and strategies to reduce the need for additional surgery in patients with DCIS.

Bond-selective photoacoustic imaging by converting molecular vibration into acoustic waves

The quantized vibration of chemical bonds provides a way of detecting specific molecules in a complex tissue environment. Unlike pure optical methods, for which imaging depth is limited to a few hundred micrometers by significant optical scattering, photoacoustic detection of vibrational absorption breaks through the optical diffusion limit by taking advantage of diffused photons and weak acoustic scattering. Key features of this method include both high scalability of imaging depth from a few millimeters to a few centimeters and chemical bond selectivity as a novel contrast mechanism for photoacoustic imaging. Its biomedical applications spans detection of white matter loss and regeneration, assessment of breast tumor margins, and diagnosis of vulnerable atherosclerotic plaques. This review provides an overview of the recent advances made in vibration-based photoacoustic imaging and various biomedical applications enabled by this new technology.

Rapid imaging of surgical breast excisions using direct temporal sampling two photon fluorescent lifetime imaging

Two photon fluorescent lifetime imaging is a modality that enables depth-sectioned, molecularly-specific imaging of cells and tissue using intrinsic contrast. However, clinical applications have not been well explored due to low imaging speed and limited field of view, which make evaluating large pathology samples extremely challenging. To address these limitations, we have developed direct temporal sampling two photon fluorescent lifetime imaging (DTS-FLIM), a method which enables a several order of magnitude increase in imaging speed by capturing an entire lifetime decay in a single fluorescent excitation. We use this greatly increased speed to perform a preliminary study using gigapixel-scale imaging of human breast pathology surgical specimens.

Standardized processing of native tissue in breast pathology

In breast surgery, replacement of intraoperative frozen section by core needle and vacuum biopsies hampers collections of unfixed breast specimens. We practice immediate intraoperative macroscopic analysis of resection margins and vacuum-cooling of breast specimens to enable native tissue asservation for assessment of biological markers and tissue banking of tumor tissue. In addition, slicing of native tissue before formalin fixation guarantees a standardized and uniform fixation. Starting in 2013, more than 350 breast specimens were processed as native specimens in the Institute of Pathology of Hannover Medical School. Breast specimens with an invasive carcinoma and request of an intraoperative resection margin assessment were processed with an immediate intraoperative pathological analysis. All other breast specimens without assessment of an intraoperative resection margin were vacuum-fixed processed. In all cases, native tissue for biomarker analyses and tumor banking could be preserved.

Assessing breast tumor margin by multispectral photoacoustic tomography

An unmet need exists in high-speed and highly-sensitive intraoperative assessment of breast cancer margin during conservation surgical procedures. Here, we demonstrate a multispectral photoacoustic tomography system for breast tumor margin assessment using fat and hemoglobin as contrasts. This system provides ~3 mm tissue depth and ~125 μm axial resolution. The results agreed with the histological findings. A high sensitivity in margin assessment was accomplished, which opens a compelling way to intraoperative margin assessment.

Is intraoperative frozen section analysis of reexcision specimens of value in preventing reoperation in breast-conserving therapy?

OBJECTIVES

A prior study at our institution showed a marked reduction in reoperation for margin reexcision following the development of an intraoperative frozen section evaluation of margins (FSM) practice on lumpectomy specimens from patients undergoing breast-conserving therapy (BCT). This study aimed to examine the frequency of FSM utilization, FSM pathology performance, and outcomes for BCT patients undergoing margin reexcision only.

METHODS

Consecutive reexcision-only specimens were reviewed from a 40-month period following the development of the FSM practice. Clinicopathologic features and patient outcomes were assessed.

RESULTS

FSM was performed in 46 (30.7%) of 150 reexcision-only operations. Of the 46 operations with FSM, there were 28 (60.9%) true-negative, 12 (26.1%) true-positive, six (13.0%) false-negative, and no false-positive cases. There was no difference in further reexcision, total operations, or conversion to mastectomy among patients with and without FSM. Need for further reexcision was significantly associated with tumor multifocality (P = .008).

CONCLUSIONS

Despite overall good pathology performance for FSM in reexcision-only specimens, use of FSM did not affect patient outcome. Rather, underlying disease biology appeared most significant in predicting whether adequate surgical margins could be attained.

Application of desorption electrospray ionization mass spectrometry imaging in breast cancer margin analysis

Distinguishing tumor from normal glandular breast tissue is an important step in breast-conserving surgery. Because this distinction can be challenging in the operative setting, up to 40% of patients require an additional operation when traditional approaches are used. Here, we present a proof-of-concept study to determine the feasibility of using desorption electrospray ionization mass spectrometry imaging (DESI-MSI) for identifying and differentiating tumor from normal breast tissue. We show that tumor margins can be identified using the spatial distributions and varying intensities of different lipids. Several fatty acids, including oleic acid, were more abundant in the cancerous tissue than in normal tissues. The cancer margins delineated by the molecular images from DESI-MSI were consistent with those margins obtained from histological staining. Our findings prove the feasibility of classifying cancerous and normal breast tissues using ambient ionization MSI. The results suggest that an MS-based method could be developed for the rapid intraoperative detection of residual cancer tissue during breast-conserving surgery.

Perioperative measures to optimize margin clearance in breast conserving surgery

Margin status is one of the most important determinants of local recurrence following breast conserving surgery. The fact that up to 60% of patients undergoing breast conserving surgery require re-excision highlights the importance of optimizing margin clearance. In this review we summarize the following perioperative measures that aim to enhance margin clearance: (1) patient risk stratification, specifically risk factors and nomograms, (2) preoperative imaging, (3) intraoperative techniques including wire-guided localization, radioguided surgery, intraoperative ultrasound-guided resection, intraoperative specimen radiography, standardized cavity shaving, and ink-directed focal re-excision; (4) and intraoperative pathology assessment techniques, namely frozen section analysis and imprint cytology. Novel surgical techniques as well as emerging technologies are also reviewed. Effective treatment requires accurate preoperative planning, developing and implementing a consistent definition of margin clearance, and using tools that provide detailed real-time intraoperative information on margin status.

Intraoperative assessment of margins in breast conserving therapy: a systematic review

Approximately one quarter of patients undergoing breast conserving therapy for breast cancer will require a second operation to achieve adequate clearance of the margins. A number of techniques to assess margins intraoperatively have been reported. This systematic review examines current intraoperative methods for assessing margin status. The final pathology status, statistical measures including accuracy of tumour margin assessment, average time impact on the procedure and second operation rate, were used as criteria for comparison between studies. Although pathological methods, such as frozen section and imprint cytology performed well, they added on average 20-30 min to operation times. An ultrasound probe allows accurate examination of the margins and delivers results in a timely manner, yet it has a limited role with DCIS where calcification is present and in multifocal cancer. Further research is required in other intraoperative margin assessment techniques, such as mammography, radiofrequency spectroscopy and optical coherence tomography.