Automated assessment of breast margins in deep ultraviolet fluorescence images using texture analysis

Microscopy with ultraviolet surface excitation (MUSE) is increasingly studied for intraoperative assessment of tumor margins during breast-conserving surgery to reduce the re-excision rate. Here we report a two-step classification approach using texture analysis of MUSE images to automate the margin detection. A study dataset consisting of MUSE images from 66 human breast tissues was constructed for model training and validation. Features extracted using six texture analysis methods were investigated for tissue characterization, and a support vector machine was trained for binary classification of image patches within a full image based on selected feature subsets. A weighted majority voting strategy classified a sample as tumor or normal. Using the eight most predictive features ranked by the maximum relevance minimum redundancy and Laplacian scores methods has achieved a sample classification accuracy of 92.4% and 93.0%, respectively. Local binary pattern alone has achieved an accuracy of 90.3%.

"No Ink on Tumor" in Breast-Conserving Surgery after Neoadjuvant Chemotherapy

Background/Aim: Patients with Stage I-II breast cancer undergoing breast-conserving surgery after neoadjuvant chemotherapy (BCS-NAC) were retrospectively assessed in order to evaluate the extent of a safe excision margin. Materials and Methods: Between 2003 and 2020, 151 patients underwent risk-adapted BCS-NAC; margin involvement was always assessed at definitive histology. Patients with complete pathological response (pCR) were classified as the RX group, whereas those with residual disease and negative margins were stratified as R0 < 1 mm (margin < 1 mm) and R0 > 1 mm (margin > 1 mm). Results: Totals of 29 (19.2%), 64 (42.4%), and 58 patients (38.4%) were included in the R0 < 1 mm, R0 > 1 mm, and RX groups, respectively, and 2 patients with margin involvement had a mastectomy. Ten instances of local recurrence (6.6%) occurred, with no statistically significant difference in local recurrence-free survival (LRFS) between the three groups. A statistically significant advantage of disease-free survival (p = 0.002) and overall survival (p = 0.010) was observed in patients with pCR. Conclusions: BCS-NAC was increased, especially in HER-2-positive and triple-negative tumors; risk-adapted BCS should be preferably pursued to highlight the cosmetic benefit of NAC. The similar rate of LRFS in the three groups of patients suggests a shift toward the “no ink on tumor” paradigm for patients undergoing BCS-NAC.

Low-Field NMR Relaxometry for Intraoperative Tumour Margin Assessment in Breast-Conserving Surgery

Simple Summary

Breast cancer is the most diagnosed cancer for women, and clear surgical margins in breast-conserving surgery (BCS) are essential for preventing recurrence. In this study, the potential of fast field-cycling ¹H-NMR relaxometry as a new tool for intraoperative margin assessment was evaluated. The technique allows the determination of the tissue proton relaxation rates as a function of the applied magnetic field on small tissue samples excised from surgical specimens, at the margins of tumour resection, prior to histopathological analysis. It was found that a good accuracy in margin assessment, i.e., a sensitivity of 92% and a specificity of 85%, can be achieved. The discriminating ability shown by the relaxometric assay relies mainly on the difference of fat/water content between healthy and tumour cells. The information obtained has the potential to support the surgeon in real-time margin assessment during BCS.

Abstract

As conserving surgery is routinely applied for the treatment of early-stage breast cancer, the need for new technology to improve intraoperative margin assessment has become increasingly important. In this study, the potential of fast field-cycling ¹H-NMR relaxometry as a new diagnostic tool was evaluated. The technique allows the determination of the tissue proton relaxation rates (R₁), as a function of the applied magnetic field, which are affected by the changes in the composition of the mammary gland tissue occurring during the development of neoplasia. The study involved 104 small tissue samples obtained from surgical specimens destined for histopathology. It was found that a good accuracy in margin assessment, i.e., a sensitivity of 92% and a specificity of 85%, can be achieved by using two quantifiers, namely (i) the slope of the line joining the R₁ values measured at 0.02 and 1 MHz and (ii) the sum of the R₁ values measured at 0.39 and 1 MHz. The method is fast, and it does not rely on the expertise of a pathologist or cytologist. The obtained results suggest that a simplified, low-cost, automated instrument might compete well with the currently available tools in margin assessment.

Adjuvant Trastuzumab Emtansine (T-DM1) and Concurrent Radiotherapy for Residual Invasive HER2-positive Breast Cancer: Single-center Preliminary Results

OBJECTIVES

The treatment of nonmetastatic HER2-positive breast cancer with residual invasive disease using concurrent Trastuzumab emtansine (T-DM1) and radiotherapy appears to be an effective option. Our aim was to evaluate the acute side effects of this treatment regime.

METHODS

Fourteen patients were treated between March 2019 and April 2020 concurrent T-DM1 and radiotherapy. Left ventricular ejection fraction was assessed at baseline, before and after radiotherapy. All toxicities were evaluated using Common Terminology Criteria of Adverse Events (CTCAE) version 3.0.

RESULTS

The median age was 55 years (range 36 to 72). All patients received total dose of 50 Gy for the breast/ chest wall, 10 patients got lymph node irradiation, 4 patients received an additional tumor bed boost. The most common side effect was grade 1 radiodermatitis. A reversible grade 2 left ventricular ejection fraction decrease occurred in 2 patients. During our examination 3 patients showed alanine aminotransferases increase after the cycle 4 of T-DM1, 1 patient had grade 1, 1 patient grade 2, and 1 patient grade 3 alanine aminotransferase increases.

CONCLUSIONS

The acute toxicity rate especially focusing on skin and cardiac toxicity were assumed acceptable in our cohort. To safely administer this concomitant treatment, further examination and prospective data are needed.

Impact of SSO-ASTRO "No Ink on Tumor" Guidelines on Reexcision Rates among Older Breast Cancer Patients

BACKGROUND

The SSO-ASTRO consensus guideline on invasive breast cancer defined negative margin as no ink on tumor, obviating the need for reexcision in some patients. We evaluated the impact of these recommendations on the rates of reexcision in older breast cancer patients undergoing breast-conserving surgery (BCS).

PATIENTS AND METHODS

Women age ≥ 66 years with stage I-II breast cancer who underwent BCS and radiation were identified in the SEER-Medicare linked database (2012-2015). We divided patients into three cohorts: pre-guideline (January 2012 to September 2013), peri-guideline (October 2013 to March 2014), and post-guideline (April 2014 to September 2016). Descriptive statistics were used, and the relative change in reexcision rate between the pre- and post-guideline periods was calculated. Multivariable logistic regression was used to evaluate factors associated with risk of reexcision.

RESULTS

A total of 11,639 patients were included (pre-guideline, N = 5211; peri-guideline, N = 1366; post-guideline, N = 5062); overall, 21.7% of patients underwent reexcision. The reexcision rates decreased after the guideline was published (23.5% vs. 19.3%, p < 0.001). In the multivariable model, BCS during the post-guideline period was associated with a statistically significant decreased risk of reexcision (RR = 0.84; 95% CI 0.78-0.90). Lobular histology was associated with a higher risk of reexcision (RR = 1.32; 95% CI 1.19-1.46), and greater surgeon volume was associated with lower risk of reexcision (RR = 0.92; 95% CI 0.85-1.0).

CONCLUSIONS

Among older breast cancer patients undergoing BCS for invasive cancer, reexcision rates decreased with the dissemination of the SSO-ASTRO consensus guideline. Identifying factors associated with higher rates of reexcision could improve guideline compliance and reduce the frequency of unnecessary interventions in older patients.

Rapid assessment of breast tumor margins using deep ultraviolet fluorescence scanning microscopy

SIGNIFICANCE

Re-excision rates for women with invasive breast cancer undergoing breast conserving surgery (or lumpectomy) have decreased in the past decade but remain substantial. This is mainly due to the inability to assess the entire surface of an excised lumpectomy specimen efficiently and accurately during surgery.

AIM

The goal of this study was to develop a deep-ultraviolet scanning fluorescence microscope (DUV-FSM) that can be used to accurately and rapidly detect cancer cells on the surface of excised breast tissue.

APPROACH

A DUV-FSM was used to image the surfaces of 47 (31 malignant and 16 normal/benign) fresh breast tissue samples stained in propidium iodide and eosin Y solutions. A set of fluorescence images were obtained from each sample using low magnification (4  ×  ) and fully automated scanning. The images were stitched to form a color image. Three nonmedical evaluators were trained to interpret and assess the fluorescence images. Nuclear-cytoplasm ratio (N/C) was calculated and used for tissue classification.

RESULTS

DUV-FSM images a breast sample with subcellular resolution at a speed of 1.0  min  /  cm2. Fluorescence images show excellent visual contrast in color, tissue texture, cell density, and shape between invasive carcinomas and their normal counterparts. Visual interpretation of fluorescence images by nonmedical evaluators was able to distinguish invasive carcinoma from normal samples with high sensitivity (97.62%) and specificity (92.86%). Using N/C alone was able to differentiate patch-level invasive carcinoma from normal breast tissues with reasonable sensitivity (81.5%) and specificity (78.5%).

CONCLUSIONS

DUV-FSM achieved a good balance between imaging speed and spatial resolution with excellent contrast, which allows either visual or quantitative detection of invasive cancer cells on the surfaces of a breast surgical specimen.

A comparative study of perioperative techniques to attain negative margins and spare healthy breast tissue in breast conserving surgery

BACKGROUND AND AIM

Traditionally lumpectomy as a part of breast-conserving surgery (BCS) is performed by palpation-guided method leading to positive margins and large excision volumes. There is no evidence suggesting that wide margin excisions decrease intra-breast tumour recurrence. Various perioperative techniques are used for margin assessment. We aimed to compare three commonly used techniques, i.e., ultrasound-guided surgery, palpation-guided surgery and cavity shaving for attaining negative margins and estimating the extent of healthy breast tissue resection.

METHOD

A prospective comparative study was performed on 90 patients who underwent breast conservation surgery for early breast cancer between August 2018 and June 2019. Tumour excision with a minimum of 1 cm margin was done either using ultrasound, palpation or cavity shaving. Histopathological evaluation was done to assess the margin status and excess amount of resected normal breast tissue. Calculated resection ratio (CRR) defining the excess amount of the resected breast tissue was achieved by dividing the total resection volume (TRV) by optimal resection volume (ORV). The time taken for excision was also recorded.

RESULTS

Histopathology of all 90 patients (30 in each group) revealed a negative resection margin in 93.3% of 30 patients in palpation-guided surgery group and 100% in both ultrasound-guided surgery and cavity shaving groups. Two patients (6.7%) from the cavity shaving group had positive margins on initial lumpectomy but shave margins were negative. TRV was significantly less in the ultrasound-guided surgery group compared to the palpation-guided surgery group and cavity shaving group (76.9 cm3, 94.7 cm3 and 126.3 cm3 respectively; p < 0.0051). CRR was 1.2 in ultrasound group compared to 1.9 in palpation group and 2.1 in cavity shave group which was also statistically significant (p < 0.0001).Excision time was significantly less (p < 0.001) in palpation-guided surgery group (13.8 min) compared to cavity shaving group (15.1 min) and ultrasound-guided group (19.4 min).

CONCLUSION

Ultrasound-guided surgery is more accurate in attaining negative margins with the removal of least amount of healthy breast tissue compared to palpation-guided surgery and cavity shaving.

Update of the American Society of Breast Surgeons Toolbox to address the lumpectomy reoperation epidemic

In 2015, the American Society of Breast Surgeons (ASBrS) convened a multidisciplinary consensus conference, the Collaborative Attempt to Lower Lumpectomy Reoperation Rates (CALLER). The CALLER conference endorsed a "toolbox" of multiple processes of care for which there was evidence that they were associated with fewer reoperations. We present an update of the toolbox taking into consideration the latest advances in decreasing re excision rates. In this review, we performed a comprehensive review of the literature from 2015-2018 using search terms for each tool. The original ten tools were updated with the latest evidence from the literature and our strength of recommendation. We added an additional section looking at new tools and techniques that may provide more accurate intraoperative assessment of margins. The updates on the CALLER Toolbox for lumpectomy will help guide surgeons to various resources to aid in the removal of breast cancer, while being aware of cosmesis and decreasing re excision rates.

American Society of Breast Surgeons' Practice Patterns After Publication of the SSO-ASTRO-ASCO DCIS Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation

BACKGROUND

The SSO-ASTRO-ASCO consensus guideline on margins for breast-conserving surgery with whole breast irradiation in ductal carcinoma in situ (DCIS) recommended a 2-mm margin. We sought to determine the impact of guideline publication on clinician practice.

METHODS

A total of 3081 members of the American Society of Breast Surgeons (ASBrS) received a survey. Respondents' clinical practice type and duration, guideline familiarity, and margin width preferences before and after publication were assessed. Clinical practice pattern differences before and after publication were investigated using McNemar's test.

RESULTS

A total of 767 (24.9%) of those surveyed responded. Most (92.4%) indicated guideline familiarity. Of those familiar, re-excision preference for DCIS and a positive margin remained the same before (94.4%) and after (94.3%) publication (McNemar's test p = 1.0). Following publication, surgeons were more likely to avoid re-excision to achieve margins wider than 2-mm (82.3% pre versus 87.5% post, p = 0.002). More surgeons performed re-excision for a close margin with pure DCIS (25.9% pre versus 36.5% post, p < 0.001) and with DCIS with microinvasion (DCIS-M) (40.7% pre versus 52.3% post, p < 0.001). For patients with invasive disease with extensive intraductal component (EIC) and a close margin, preference to avoid re-excision was similar (51.2% per versus 55.2% post, p = 0.071).

CONCLUSION

Since guideline publication, surgeons are less likely to perform re-excision to obtain a margin greater than 2-mm and more likely to perform re-excision to obtain a 2-mm margin for both pure DCIS and DCIS-M. Preference to avoid re-excision with a close margin and EIC was similar before and after publication.

Factors influencing reoperation following breast-conserving surgery

BACKGROUND

Reoperation rates after breast-conserving surgery are highly variable and the best techniques for optimizing margin clearance are being evaluated. The aim was to identify the reoperation rate at our centre and identify influential factors, including a change in guidelines on margin recommendations and the introduction of in-theatre specimen X-ray.

METHODS

A retrospective review of medical records was undertaken to identify 562 patients who underwent breast conservation at The Royal Melbourne Hospital and Royal Women's Hospital between 2013 and 2015. All cases that underwent subsequent re-excision or total mastectomy were captured and factors influencing margin excision recorded.

RESULTS

Reoperation was undertaken in 19.5% of patients (110; 86 re-excisions and 24 total mastectomies). There was a reduction in reoperation rate from 25% to 17% (P = 0.01) with adoption of the margin guidelines in 2014, but no significant reduction with the introduction of in-theatre specimen X-ray in 2015 (21% versus 16%, P = 0.14). On multivariate analysis, factors that significantly influenced reoperation rates were the presence of multifocality on mammogram (odds ratio (OR): 5.3, 95% confidence interval (CI): 1.6-16.7, P < 0.01); lesion size on mammogram (OR: 2.2 per 10 mm, 95% CI: 1.4-3.6, P < 0.01); smaller excision specimen weight (OR: 0.5 per 25 g of resection, 95% CI: 0.3-0.8, P < 0.01); and pure ductal carcinoma in situ on final pathology (OR: 5.9, 95% CI: 1.9-16.7, P < 0.01).

CONCLUSION

Optimizing reoperation rates following breast-conserving surgery remains a surgical challenge, particularly in patients with in situ or multifocal disease. Adoption of international margin guidelines reduced reoperation rates at our centre; however, introduction of intraoperative specimen X-ray had no influence.

Changes in margin re-excision rates: Experience incorporating the "no ink on tumor" guideline into practice

INTRODUCTION

Prior to the "no ink on tumor" SSO/ASTRO consensus guideline, approximately 20% of women with stage I/II breast cancers undergoing breast conservation surgery at our institution underwent margin re-excision. On May 20, 2013, our institution changed the definition of negative margins from 2 mm to "no ink on tumor."

METHODS

A retrospective review was conducted of patients who had surgery at our institution with clinical stage I/II breast cancers between June 1, 2011 and May 1, 2015. In the pre-guideline cohort (pre) and post-guideline cohort (post), negative margins were 2 mm and "no ink on tumor," respectively.

RESULTS

Implementation of the guideline resulted in a significant decrease in the positive/close margin rate (29.6% pre vs 10.1% post; P < 0.001) and numerical decrease in re-excision rate (20.4% pre vs 16.3% post; P = 0.104). No significant difference was found in local recurrence between the cohorts with limited follow-up (1.2% pre vs 1.5% post; P = 0.787).

CONCLUSION

The implementation of the "no ink on tumor" guideline at our institution has resulted in a significant decrease in positive margin rates and a numerical decrease in margin re-excisions. In addition to margin status, surgeons continue to use individual patient and histologic factors to decide for or against margin re-excision.

Cost Implications of an Evidence-Based Approach to Radiation Treatment After Lumpectomy for Early-Stage Breast Cancer

INTRODUCTION

Breast cancer treatment costs are rising, and identification of high-value oncology treatment strategies is increasingly needed. We sought to determine the potential cost savings associated with an evidence-based radiation treatment (RT) approach among women with early-stage breast cancer treated in the United States.

PATIENTS AND METHODS

Using the National Cancer Database, we identified women with T1-T2 N0 invasive breast cancers treated with lumpectomy during 2011. Adjuvant RT regimens were categorized as conventionally fractionated whole-breast irradiation, hypofractionated whole-breast irradiation, and omission of RT. National RT patterns were determined, and RT costs were estimated using the Medicare Physician Fee Schedule.

RESULTS

Within the 43,247 patient cohort, 64% (n = 27,697) received conventional RT, 13.3% (n = 5,724) received hypofractionated RT, 1.1% (n = 477) received accelerated partial-breast irradiation, and 21.6% (n = 9,349) received no RT. Among patients who were eligible for shorter RT or omission of RT, 57% underwent treatment with longer, more costly regimens. Estimated RT expenditures of the national cohort approximated $420.2 million during 2011, compared with $256.2 million had women been treated with the least expensive regimens for which they were safely eligible. This demonstrated a potential annual savings of $164.0 million, a 39% reduction in associated treatment costs.

CONCLUSION

Among women with early-stage breast cancer after lumpectomy, use of an evidence-based approach illustrates an example of high-value care within oncology. Identification of high-value cancer treatment strategies is critically important to maintaining excellence in cancer care while reducing health care expenditures.

Trends in Treatment Patterns and Outcomes for Ductal Carcinoma In Situ

BACKGROUND

Impact of contemporary treatment of pre-invasive breast cancer (ductal carcinoma in situ [DCIS]) on long-term outcomes remains poorly defined. We aimed to evaluate national treatment trends for DCIS and to determine their impact on disease-specific (DSS) and overall survival (OS).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) registry was queried for patients diagnosed with DCIS from 1991 to 2010. Treatment pattern trends were analyzed using Cochran-Armitage trend test. Survival analyses were performed using inverse probability weights (IPW)-adjusted competing risk analyses for DSS and Cox proportional hazard regression for OS. All tests performed were two-sided.

RESULTS

One hundred twenty-one thousand and eighty DCIS patients were identified. The greatest proportion of patients was treated with lumpectomy and radiation therapy (43.0%), followed by lumpectomy alone (26.5%) and unilateral (23.8%) or bilateral mastectomy (4.5%) with significant shifts over time. The rate of sentinel lymph node biopsy increased from 9.7% to 67.1% for mastectomy and from 1.4% to 17.8% for lumpectomy. Compared with mastectomy, OS was higher for lumpectomy with radiation (hazard ratio [HR] = 0.79, 95% confidence interval [CI] = 0.76 to 0.83, P < .001) and lower for lumpectomy alone (HR = 1.17, 95% CI = 1.13 to 1.23, P < .001). IPW-adjusted ten-year DSS was highest in lumpectomy with XRT (98.9%), followed by mastectomy (98.5%), and lumpectomy alone (98.4%).

CONCLUSIONS

We identified substantial shifts in treatment patterns for DCIS from 1991 to 2010. When outcomes between locoregional treatment options were compared, we observed greater differences in OS than DSS, likely reflecting both a prevailing patient selection bias as well as clinically negligible differences in breast cancer outcomes between groups.

Rethinking the Local Therapy of Breast Cancer: Integration of Biology and Anatomy

Local control has traditionally been considered a function of disease burden. Local control is now known to differ among biologic subtypes of breast cancer and is greatly improved with the use of systemic therapy. This offers opportunities for decreasing the morbidity of treatment and individualizing local therapy. The use of smaller margins in breast-conserving surgery and elimination of axillary dissection for some node-positive breast cancer patients are current examples of leveraging the benefits of systemic therapy to reduce surgery. Emerging evidence indicates that molecular profiling can identify patients at high and low risk for locoregional recurrence after surgery in a more accurate way than tumor burden, potentially allowing individualization of the use of postmastectomy and comprehensive node field irradiation. Future clinical trials should incorporate both disease burden and molecular profiling when examining treatment strategies.

Assessment of Practice Patterns Following Publication of the SSO-ASTRO Consensus Guideline on Margins for Breast-Conserving Therapy in Stage I and II Invasive Breast Cancer

BACKGROUND

The recently published SSO-ASTRO consensus guideline on margins concluded "no ink on tumor" is the standard for an adequate margin. This study was conducted to determine how this guideline is aligned with current clinical practice.

METHODS

A survey was sent to 3057 members of the American Society of Breast Surgeons. Questions assessed respondents' clinical practice type and duration, familiarity with the guideline, and preferences for margin re-excision.

RESULTS

Of those surveyed, 777 (25%) responded. Most (92%) indicated familiarity with the guideline. Of these respondents, the majority (n = 678, or 94.7%) would re-excise all or most of the time when tumor extended to the inked margin. Very few (n = 9, or 1.3%) would re-excise all or most of the time when tumor was within 2 mm of the margin. Over 12 % (n = 90) would re-excise all or most of the time for a triple-negative tumor within 1 mm of the margin, whereas 353 (49.6%) would re-excise all or most of the time when imaging and pathology were discordant, and tumor was within 1 mm of multiple margins. Finally, 330 (45.8%) would re-excise all or most of the time when multiple foci of ductal carcinoma in situ extended to within 1 mm of multiple inked margins.

CONCLUSIONS

Surgeons are in agreement to re-excise margins when tumor touches ink and generally not to perform re-excisions when tumor is close to (but not touching) the inked margin. For more complex scenarios, surgeons are utilizing their individual clinical judgment to determine the need for re-excision.