Prospective randomized study comparing cryo-assisted and needle-wire localization of ultrasound-visible breast tumors

Optimal localization strategies for non-palpable breast cancers –A network meta-analysis of randomized controlled trials

Purpose

Mammographic screening programmes have increased detection rates of non-palpable breast cancers. In these cases, wire-guided localization (WGL) is the most common approach used to guide breast conserving surgery (BCS). Several RCTs have compared WGL to a range of novel localization techniques. We aimed to perform a network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing methods of non-palpable breast cancer localization.

Methods

A NMA was performed according to PRISMA-NMA guidelines. Analysis was performed using R packages and Shiny.

Results

24 RCTs assessing 9 tumour localization methods in 4236 breasts were included. Margin positivity and reoperation rates were 16.9% (714/4236) and 14.3% (409/2870) respectively. Cryo-assisted localization had the highest margin positivity (28.2%, 58/206) and reoperation (18.9%, 39/206) rates. Compared to WGL (n = 2045 from 24 RCTs) only ultrasound guided localization (USGL) (n = 316 from 3 RCTs) significantly lowered margin positivity (odds ratio (OR): 0.192, 95% confidence interval (CI): 0.079–0.450) and reoperation rates (OR: 0.182, 95%CI: 0.069–0.434). Anchor-guided localization (n = 52, 1 RCT) significantly lowered margin positivity (OR: 0.229, 95%CI: 0.050–0.938) and magnetic-marker localization improved patient satisfaction (OR: 0.021, 95%CI: 0.001–0.548). There was no difference in operation duration, overall complications, haematoma, seroma, surgical site infection rates, or specimen size/vol/wt between methods.

Conclusion

USGL and AGL are non-inferior to WGL for the localization of non-palpable breast cancers. The reported data suggests that these techniques confer reduced margin positivity rates and requirement for re-operation. However, caution when interpreting results relating to RCTs with small sample sizes and further validation is required in larger prospective, randomized studies.

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Ultrasound-guided (USGL) and anchor-guided (AGL) localization had optimal outcomes.

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These methods significantly lowered margin positivity (odds ratio: 0.192 & 0.229).

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However, small sample sizes in trials evaluating USGL and AGL limit these results.

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Operation duration, complications, or specimen data were comparable for all methods.

Comparative effectiveness of different localization techniques for non-palpable breast cancer. A systematic review and network meta-analysis

BACKGROUND

Several localization techniques are in use for localization of non palpable breast cancer but data on comparative effectiveness of these techniques are sparse. Our aim was to provide the first comparative effectiveness data on the topic.

METHODS

PubMed, Ovid, Scopus and Cochrane library were searched for randomized controlled trials. Pairwise meta-analysis was performed when more than 2 studies reported on the same head-to-head comparison. Network meta-analysis was performed in Stata.

RESULTS

Eighteen studies with 3112 patients were identified. A star shaped network was formed for every outcome as all studies had as common comparator the wire localization technique (WGL). Ultrasound guided surgery (UGS) had decreased positive margin both in the pairwise [OR = 0.19(0.11, 0.35); P < 0.01] and network meta-analysis OR = 0.19 (0.11,0.60). There was also a statistically significant reduction in re-operation rate [OR = 0.19 (0.11, 0.36); P < 0.01] and operative time [MD = -4.24(-7.85,-0.63); P = 0.02] as compared to WGL in pairwise meta-analysis. Re-operation rate and operative time did not hold there statistical significance in network meta-analysis. On network meta-analysis UGS had a statistically significant reduction in positive margin as compared to radio-guided occult lesion localization (ROLL) OR = 0.19 (0.11,0.6) and radioactive seed localization (RSL) OR = 0.26(0.13, 0.52). UGS had a 54.6% of being the best technique for positive margin. All techniques were equivalent for successful excision, localization complications, operative time and overall complications.

CONCLUSIONS

UGS has potential benefits in reduction of positive surgical margin, the rest of the techniques seem to have equivalent efficacy. Further randomized trials are required to verify these results.

Rapid Assessment of Resection Margins During Breast Conserving Surgery Using Intraoperative Flow Cytometry

BACKGROUND

Positive margins are the most important factor for recurrence of the disease after breast-conserving surgery. Several methods have been developed throughout the years to evaluate the margin status during surgery in an attempt to assist the surgeon in excising the whole tumor at once, a goal that has not yet been accomplished.

PATIENTS AND METHODS

In our study, we compared intraoperative flow cytometry (iFC) with cytology and pathology in order to evaluate 606 samples of margins and tumors corresponding to 99 patients with invasive ductal carcinoma of no special type and invasive lobular carcinoma obtained from breast-conserving surgeries.

RESULTS

Using the pathology as the gold standard, flow cytometry had 93.3% sensitivity, 92.4% specificity, and 92.5% accuracy. Cytology had 82.3% sensitivity, 94.6% specificity, and 94.2% accuracy.

CONCLUSIONS

Our data support the suggestion that iFC is a novel, reliable technique that allows rapid evaluation of the excision margins of lumpectomies, thus improving the precision of breast-conserving surgery. Among the advantages of iFC are that it does not rely on the expertise of a pathologist or cytologist, it is low cost, and it has no additional psychological effect on patients, because no re-operation is needed.

Development of a mechatronic guidance system for targeted ultrasound-guided biopsy under high-resolution positron emission mammography localization

PURPOSE

Image-guided needle biopsy of small, detectable lesions is crucial for early-stage diagnosis, treatment planning, and management of breast cancer. High-resolution positron emission mammography (PEM) is a dedicated functional imaging modality that can detect breast cancer independent of breast tissue density, but anatomical context and real-time needle visualization are not yet available to guide biopsy. We propose a mechatronic guidance system integrating an ultrasound (US)-guided core-needle biopsy (CNB) with high-resolution PEM localization to improve the spatial sampling of breast lesions. This paper presents the benchtop testing and phantom studies to evaluate the accuracy of the system and its constituent components for targeted PEM-US-guided biopsy under simulated high-resolution PEM localization.

METHODS

A mechatronic guidance system was developed to operate with the Radialis PEM system and a conventional US system. The system includes a user-operated guidance arm and end-effector biopsy device, integrating a US transducer and CNB gun, with its needle focused on a remote center of motion (RCM). Custom software modules were developed to track, display, and guide the end-effector biopsy device. Registration of the mechatronic guidance system to a simulated PEM detector plate was performed using a landmark-based method. Testing was performed with fiducials positioned in the peripheral and central regions of the simulated detector plate and registration error was quantified. Breast phantom experiments were performed under ideal detection and localization to evaluate for bias in the end-effector biopsy device. The accuracy of the complete mechatronic guidance system to perform targeted breast biopsy was assessed using breast phantoms with simulated lesions. Three-dimensional positioning error was quantified, and principal component analysis assessed for directional trends in 3D space within 95% prediction intervals. Targeted breast biopsies with test phantoms were performed and an overall in-plane needle targeting error was quantified.

RESULTS

The mean registration errors were 0.63 mm (N = 44) and 0.73 mm (N = 72) in the peripheral and central regions of the simulated PEM detector plate, respectively. A 3D 95% prediction ellipsoid shows an error volume <2.0 mm in diameter, centered on the mean registration error. Under ideal detection and localization, targets <1.0 mm in diameter can be sampled with 95% confidence. The complete mechatronic guidance system was able to successfully spatially sample simulated breast lesions, 4 mm and 6 mm in diameter and height (N = 20) in known 3D positions in the PEM image coordinate space. The 3D positioning error was 0.85 mm (N = 20) with 0.64 mm in-plane and 0.44 mm cross-plane component errors. Targeted breast biopsies resulted in a mean in-plane needle targeting error of 1.08 mm (N = 15) allowing for targets 1.32 mm in radius to be sampled with 95% confidence.

CONCLUSIONS

We demonstrated the utility of our mechatronic guidance system for targeted breast biopsy under high-resolution PEM localization. Breast phantom studies showed the ability to accurately guide, position, and target breast lesions with the accuracy to spatially sample targets <3.0 mm in diameter with 95% confidence. Future work will integrate the developed system with the Radialis PEM system toward combined PEM-US-guided breast biopsy.

Novel wire-free techniques for localization of impalpable breast lesions-A review of current options

Localization methods for breast lesions including cancers have changed and advanced since their inception. Currently, the most widely used technique in the United Kingdom is the image-guided hook wire localizer developed in the 1970s. It remains as the gold standard for localization of impalpable breast tumors. Besides its advantages, there are some disadvantages associated with this technique. In recent years, novel wire-free techniques (eg, Magseed^® , SCOUT^® , and LOCalizer™) have been developed to not only localize impalpable breast lesions but also negate the disadvantages of wire localization. This article reviews the variety of techniques from their origins to the most recent advancements that are used to localize breast lesions. The future is heading toward non-wire technology and wire localization may then be reserved for special cases.

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.

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.

Localization techniques for guided surgical excision of non-palpable breast lesions

BACKGROUND

Breast cancer is the most common form of cancer and the second leading cause of death amongst women in Europe. Amongst five invasive cancers per 1000 women detected in screening, 2.7 were < 15 mm in diameter; and others reported that over one third of excised breast lesions were clinically occult. The challenge is to accurately locate small non-palpable lesions intraoperatively for optimal therapeutic outcome. A secondary important goal is to remove the smallest amount possible of healthy glandular tissue for optimal cosmesis. Currently the most widely adopted approach (80% in one survey) in guided breast-conserving surgery for excising non-palpable breast lesions is wire-guided localization (WGL). With the clinical setting shifting towards earlier non-palpable breast lesions being detected through screening, we investigated whether the current standard in assisting surgical excision of these lesions, WGL, yields the best therapeutic outcome for women with breast cancer.

OBJECTIVES

To assess the therapeutic outcomes of any new form of guided surgical intervention for non-palpable breast lesions against wire-guided localization, the current gold standard.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group's (CBCG) Specialized Register, MEDLINE (via PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal from the earliest available date up to 30 March 2015. We also handsearched recent conference proceedings and sought information from experts in the field.

SELECTION CRITERIA

Two review authors, BC and RJ, independently screened by title and abstract the studies we had identified through the search strategy; when this was inconclusive, they examined the full-text article for inclusion. We resolved any discrepancies regarding eligibility by discussion with a third review author, RA.

DATA COLLECTION AND ANALYSIS

Three review authors, BC, JW, and RJ, independently extracted data using a standardized data sheet. We performed all analyses using Review Manager (RevMan) or the R meta package, and in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. We reported results via a graphical assessment using forest plots showing the study estimates. We considered and discussed additional subgroup and sensitivity analyses.

MAIN RESULTS

We identified 11 randomized controlled trials (RCTs) that met the inclusion criteria of this Cochrane review and included eight trials in the meta-analyses. Six RCTs compared radioguided occult lesion localization (ROLL) versus WGL, and two RCTs compared radioactive iodine ((125)I) seed localization (RSL) versus WGL. Of the three remaining trials, one RCT compared cryo-assisted techniques (CAL) versus WGL, one compared intraoperative ultrasound-guided lumpectomy (IOUS) versus WGL, and one compared modified ROLL technique in combination with methylene dye (RCML) versus WGL. Of the trials we included in the meta-analysis, there were a total of 1273 participants with non-palpable breast lesions (627 participants (WGL); 443 participants (ROLL); and 203 participants (RSL)). The participant population varied considerably between included trials, which included participants with both non-palpable benign and malignant lesions, and varied in defining clear margins. The included trials did not report any long-term outcomes.In general, the outcomes of WGL, ROLL and RSL were comparable.ROLL demonstrated favourable results in successful localization (risk ratio (RR) 0.60, 95% confidence interval (CI) 0.16 to 2.28; 869 participants; six trials), positive excision margins (RR 0.74, 95% CI 0.42 to 1.29; 517 participants; five trials), and re-operation rates (RR 0.51, 95% CI 0.21 to 1.23; 583 participants; four trials) versus WGL, but none were statistically significant. WGL was significantly superior to RSL in successfully localizing non-palpable lesions (RR 3.85, 95% CI 1.21 to 12.19; 402 participants; two trials). However, for successful excision, ROLL and RSL have comparable outcomes versus WGL (ROLL versus WGL: RR 1.00, 95% CI 0.99 to 1.01; 871 participants; six trials; RSL versus WGL: RR 1.00, 95% CI 0.99 to 1.01; 402 participants; two trials). These findings were similar in that RSL demonstrated favourable results over WGL in positive tumour margins (RR 0.67, 95% CI 0.43 to 1.06; 366 participants; two trials), and re-operation rates (RR 0.80, 95% CI 0.48 to 1.32; 305 participants; one trial) but neither reached statistical significance. In contrast, WGL had fewer postoperative complications to both ROLL (RR 1.18, 95% CI 0.71 to 1.98; 642 participants; four trials) and RSL (RR 1.51, 95% CI 0.75 to 3.03; 305 participants; one trial), although this was also not statistically significant.The overall quality of evidence was good. The main risk of bias amongst included studies consisted of incomplete data sets, selective reporting, and allocation concealment. Interpretation and applicability of this meta-analysis was hindered by the mixed indication of diagnostic versus therapeutic purposes when undertaking WGL, ROLL, or RSL, leading to a high level of mixed pathology in numerous trials. Other limitations include underpowered studies, lack of data in standardized format for meta-analysis, lack of complete data amongst the trials, and absence of long-term data.

AUTHORS' CONCLUSIONS

Owing to a lack of trials in certain localization techniques, we could only draw conclusions about ROLL and RSL versus WGL. There is no clear evidence to support one guided technique for surgically excising a non-palpable breast lesion over another. Results from this Cochrane review support the continued use of WGL as a safe and tested technique that allows for flexibility in selected cases when faced with extensive microcalcification. ROLL and RSL could be offered to patients as a comparable replacement for WGL as they are equally reliable. Other techniques such as IOUS, RCML, and CAL are of academic interest, but recommendation for routine use in the clinical environment and oncological outcomes require further validation. The results of this Cochrane review also stress the need for more fully powered RCTs to evaluate the best technique according to the comprehensive criteria described, with a more consistent and standardized approach in outcome reporting.

Surgical treatment of nonpalpable primary invasive and in situ breast cancer

Breast cancer is the most-common cancer among women worldwide, and over one-third of all cases diagnosed annually are nonpalpable at diagnosis. The increasingly widespread implementation of breast-screening programmes, combined with the use of advanced imaging modalities, such as magnetic resonance imaging (MRI), will further increase the numbers of patients diagnosed with this disease. The current standard management for nonpalpable breast cancer is localized surgical excision combined with axillary staging, using sentinel-lymph-node biopsy in the clinically and radiologically normal axilla. Wire-guided localization (WGL) during mammography is a method that was developed over 40 years ago to enable lesion localization preoperatively; this technique became the standard of care in the absence of a better alternative. Over the past 20 years, however, other technologies have been developed as alternatives to WGL in order to overcome the technical and outcome-related limitations of this technique. This Review discusses the techniques available for the surgical management of nonpalpable breast cancer; we describe their advantages and disadvantages, and highlight future directions for the development of new technologies.

A Pilot Study of Ultrasound-Guided Cryoablation of Invasive Ductal Carcinomas up to 15 mm With MRI Follow-Up and Subsequent Surgical Resection

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of ultrasound-guided cryoablation in treating small invasive ductal carcinoma and to assess the role of contrast-enhanced (CE) MRI in determining the outcome of cryoablation.

SUBJECTS AND METHODS

Twenty consecutive participants with invasive ductal carcinomas up to 15 mm, with limited or no ductal carcinoma in situ (DCIS), underwent ultrasound-guided cryoablation. Preablation mammography, ultrasound, and CE-MRI were performed to assess eligibility. Clinical status was evaluated at 1 day, 7-10 days, and 2 weeks after ablation. CE-MRI was performed 25-40 days after ablation, followed by surgical resection within 5 days.

RESULTS

Ultrasound-guided cryoablation was uniformly technically successful, and postablation clinical status was good to excellent in all participants. Cryoablation was not clinically successful in 15% (three of 20 patients). Three participants had residual cancer at the periphery of the cryoablation site. Two participants had viable nonmalignant tissue within the central zone of cryoablation-induced necrosis. Postablation CE-MRI had a sensitivity of 0% (0/3) and specificity of 88% (15/17). The predictive value of negative findings on CE-MRI was 83% (15/18). Correlations between cancer characteristics, cryoablation procedural variables, postablation CE-MRI findings, and surgical specimen features were not statistically significant. There were also no significant differences in participants with or without residual cancer.

CONCLUSION

In our pilot experience, ultrasound-guided cryoablation of invasive ductal carcinomas up to 15 mm has a clinical failure rate of 15% but is technically feasible and well tolerated by patients. The majority of cryoablation failures are manifest as DCIS outside the cryoablation field. Postablation CE-MRI does not reliably predict cryoablation outcome.

Realization of a biomechanical model-assisted image guidance system for breast cancer surgery using supine MRI

PURPOSE

Unfortunately, the current re-excision rates for breast conserving surgeries due to positive margins average 20-40 %. The high re-excision rates arise from difficulty in localizing tumor boundaries intraoperatively and lack of real-time information on the presence of residual disease. The work presented here introduces the use of supine magnetic resonance (MR) images, digitization technology, and biomechanical models to investigate the capability of using an image guidance system to localize tumors intraoperatively.

METHODS

Preoperative supine MR images were used to create patient-specific biomechanical models of the breast tissue, chest wall, and tumor. In a mock intraoperative setup, a laser range scanner was used to digitize the breast surface and tracked ultrasound was used to digitize the chest wall and tumor. Rigid registration combined with a novel nonrigid registration routine was used to align the preoperative and intraoperative patient breast and tumor. The registration framework is driven by breast surface data (laser range scan of visible surface), ultrasound chest wall surface, and MR-visible fiducials. Tumor localizations by tracked ultrasound were only used to evaluate the fidelity of aligning preoperative MR tumor contours to physical patient space. The use of tracked ultrasound to digitize subsurface features to constrain our nonrigid registration approach and to assess the fidelity of our framework makes this work unique. Two patient subjects were analyzed as a preliminary investigation toward the realization of this supine image-guided approach.

RESULTS

An initial rigid registration was performed using adhesive MR-visible fiducial markers for two patients scheduled for a lumpectomy. For patient 1, the rigid registration resulted in a root-mean-square fiducial registration error (FRE) of 7.5 mm and the difference between the intraoperative tumor centroid as visualized with tracked ultrasound imaging and the registered preoperative MR counterpart was 6.5 mm. Nonrigid correction resulted in a decrease in FRE to 2.9 mm and tumor centroid difference to 5.5 mm. For patient 2, rigid registration resulted in a FRE of 8.8 mm and a 3D tumor centroid difference of 12.5 mm. Following nonrigid correction for patient 2, the FRE was reduced to 7.4 mm and the 3D tumor centroid difference was reduced to 5.3 mm.

CONCLUSION

Using our prototype image-guided surgery platform, we were able to align intraoperative data with preoperative patient-specific models with clinically relevant accuracy; i.e., tumor centroid localizations of approximately 5.3-5.5 mm.

The Use of Second Harmonic Generation to Image the Extracellular Matrix During Tumor Progression

Metastasis is the leading cause of cancer mortality, resulting from changes in the tumor microenvironment which increases tumor cell migration, dispersal to distant organs, and subsequent survival. This is accompanied by changes in tumor collagen which may allow cells to travel more efficiently away from a primary tumor and invade the surrounding tissue. Second Harmonic generation (SHG) is an intrinsic optical signal that has expanded our understanding of collagen evolution throughout tumor progression. This article addresses current research into tumor progression using SHG, as well as the future prospects of using SHG to advance our understanding of the tumor microenvironment.

Image-guided ablation in breast cancer treatment

In the past 2 decades, new and improved imaging technologies and the use of breast cancer screening have led to the detection of smaller and earlier-stage breast cancers. Furthermore, there has been a trend toward less aggressive treatment of small breast cancers, which has led to the development of less invasive alternatives than surgery with promising effectiveness, and less morbidity. Many patients are not satisfied with the cosmetic outcome after breast-conservation therapy. Better cosmesis can be achieved with less invasive techniques. Moreover, less aggressive treatment options would be very useful in patients older than 70 years with comorbidities that make surgery a difficult and sometimes life-threatening treatment. Minimally invasive ablation techniques have been studied in early-stage small tumors with the goal of attaining efficacy similar to that of breast-conservation therapy. These techniques would have less scarring and pain, lower costs, better preservation of breast tissue, superior cosmesis, and faster recovery time. Breast lesions can be destroyed by thermal methods, that is, by heating or freezing the tissue. There are 5 types of thermal ablations that have been or currently are in research clinical trials: cryoablation, radiofrequency, laser, microwave, and high-intensity focused ultrasound ablation. The first 4 methods destroy cancers using percutaneous image-guided probe placement. High-intensity focused ultrasound is noninvasive, performed without any skin opening.

Intra-operative guidance: methods for achieving negative margins in breast conserving surgery

The increasing incidence of breast cancer and advances in detection of small, impalpable cancers presents increasing challenges for the modern breast surgeon. Accurate localization and excision with adequate oncological margins to reduce loco-regional recurrence rates whilst minimizing volume deficit and maximizing aesthetics remains the "gold standard." We review the current techniques available and the developments within this field.

Cryosurgery in the treatment of women with breast cancer-a review

Cryoablation could be an alternative to surgical excision of breast cancer. The cytotoxic potential of cryosurgery has been shown in both animal models and studies conducted on humans. There are several advantages to be gained from ablation performed at very low temperatures and these include the method's simplicity, lack of pain, low morbidity, cost-effectiveness, and potential for positive cryo-immunologic effects. This manuscript reviews data concerning the use of cryoablation in the treatment of breast cancer.

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.

Radioactive seed localization for non-palpable breast cancer

BACKGROUND

Radioactive seed localization (RSL) is an alternative to wire localization for guiding surgical excision of non-palpable breast cancer. This review provides an overview of the available evidence on the accuracy of RSL in patients undergoing breast-conserving surgery.

METHODS

PubMed, Embase and the Cochrane Library were searched systematically in January 2012 for studies that addressed localization of non-palpable breast cancer using an iodine-125-labelled seed. Studies were deemed eligible if they reported on the proportion of patients with tumour-positive margins after RSL, the proportion of patients needing re-excision after RSL, and procedural complications.

RESULTS

Six studies reported data on RSL in 1611 patients with non-palpable breast lesions. Overall complete resection rates ranged from 73 to 96.7 per cent. Three studies included over 300 patients, and complete resection rates in these studies varied between 89.5 and 96.7 per cent. The risk of seed migration and failure of seed placement ranged from 0 to 0.6 per cent and 0 to 7.2 per cent respectively.

CONCLUSION

Available scientific evidence suggests that RSL is a safe and accurate technique for localization of non-palpable breast lesions.

Rapid Stereomicroscopic Imaging of HER2 Overexpression in Ex Vivo Breast Tissue Using Topically Applied Silica-Based Gold Nanoshells

Tumor margin detection for patients undergoing breast conservation surgery primarily occurs postoperatively. Previously, we demonstrated that gold nanoshells rapidly enhance contrast of HER2 overexpression in ex vivo tissue sections. Our ultimate objective, however, is to discern HER2 overexpressing tissue from normal tissue in whole, nonsectioned, specimens to facilitate rapid diagnoses. Here, we use targeted nanoshells to quickly and effectively visualize HER2 receptor expression in intact ex vivo human breast tissue specimens. Punch biopsies of human breast tissue were analyzed after a brief 5-minute incubation with and without HER2-targeted silica-gold nanoshells using two-photon microscopy and stereomicroscopy. Labeling was subsequently verified using reflectance confocal microscopy, darkfield hyperspectral imaging, and immunohistochemistry to confirm levels of HER2 expression. Our results suggest that anti-HER2 nanoshells used in tandem with a near-infrared reflectance confocal microscope and a standard stereomicroscope may potentially be used to discern HER2-overexpressing cancerous tissue from normal tissue in near real time and offer a rapid supplement to current diagnostic techniques.

Intraoperative ultrasound guidance for excision of non-palpable invasive breast cancer: a hospital-based series and an overview of the literature

Intraoperative ultrasound (IOUS) can be used in the operation theatre for localization of non-palpable breast cancers. In this prospective cohort study, we compared the yield of IOUS to guidewire localization (GWL). A total of 258 consecutive patients with non-palpable invasive breast cancer underwent breast conserving surgery between 1999 and 2010. GWL was performed in 138 (54 %) and IOUS in 120 (46 %) patients. Tumor dimensions, resection volume, margin status and re-excision rates were compared by means of multivariate regression analysis. The groups were similar in terms of age, histological subtype and presence of DCIS. Lesions in the IOUS group were larger (1.24 vs. 0.98 cm, P < 0.001), while microcalcifications were more common in the GWL group (19 vs. 3 %, P < 0.001). Even after stratification for tumor diameter, presence of DCIS and findings on mammography, resection volumes were similar in both groups. Tumor-free resection margins were obtained in >93 % of patients (93.5 % with GWL vs. 93.3 % with IOUS, P = 0.958) and re-excision was performed in 11 % of patients undergoing GWL and 12.5 % of patients undergoing IOUS (P = 0.684). For localization of non-palpable breast cancer, IOUS is a reliable alternative to GWL, as it achieves similar results in terms of complete tumor removal, re-excision rate and excised volume.

Toward MR-guided high intensity focused ultrasound for presurgical localization: focused ultrasound lesions in cadaveric breast tissue

PURPOSE

To investigate magnetic resonance image-guided high intensity focused ultrasound (MR-HIFU) as a surgical guide for nonpalpable breast tumors by assessing the palpability of MR-HIFU-created lesions in ex vivo cadaveric breast tissue.

MATERIALS AND METHODS

MR-HIFU ablations spaced 5 mm apart were made in 18 locations using the ExAblate2000 system. Ablations formed a square perimeter in mixed adipose and fibroglandular tissue. Ablation was monitored using T1-weighted fast spin echo images. MR-acoustic radiation force impulse (MR-ARFI) was used to remotely palpate each ablation location, measuring tissue displacement before and after thermal sonications. Displacement profiles centered at each ablation spot were plotted for comparison. The cadaveric breast was manually palpated to assess stiffness of ablated lesions and dissected for gross examination. This study was repeated on three cadaveric breasts.

RESULTS

MR-ARFI showed a collective postablation reduction in peak displacement of 54.8% ([4.41 ± 1.48] μm pre, [1.99 ± 0.82] μm post), and shear wave velocity increase of 65.5% ([10.69 ± 1.60] mm pre, [16.33 ± 3.10] mm post), suggesting tissue became stiffer after the ablation. Manual palpation and dissection of the breast showed increased palpability, a darkening of ablation perimeter, and individual ablations were visible in mixed adipose/fibroglandular tissue.

CONCLUSION

The results of this preliminary study show MR-HIFU has the ability to create palpable lesions in ex vivo cadaveric breast tissue, and may potentially be used to preoperatively localize nonpalpable breast tumors.

Ablative therapies of the breast

Minimally invasive ablative therapy techniques are being used in research protocols to treat benign and malignant tumors of the breast in select patient populations. These techniques offer the advantages of an outpatient setting, decreased pain, and improved cosmesis. These therapies, including radiofrequency ablation, cryotherapy, interstitial laser therapy, high-intensity focused ultrasonography, and focused microwave thermotherapy, are reviewed in this article.

Positron emission mammography in breast cancer presurgical planning: comparisons with magnetic resonance imaging

PURPOSE

The objective of this study was to compare the performance characteristics of (18)F-fluorodeoxyglucose (FDG) positron emission mammography (PEM) with breast magnetic resonance imaging (MRI) as a presurgical imaging and planning option for index and ipsilateral lesions in patients with newly diagnosed, biopsy-proven breast cancer.

METHODS

Two hundred and eight women >25 years of age (median age = 59.7 ± 14.1 years) with biopsy-proven primary breast cancer enrolled in this prospective, single-site study. MRI, PEM, and whole-body positron emission tomography (WBPET) were conducted on each patient within 7 business days. PEM and WBPET images were acquired on the same day after intravenous administration of 370 MBq of FDG (median = 432.9 MBq). PEM and MRI images were blindly evaluated, compared with final surgical histopathology, and the sensitivity determined. Substudy analysis compared the sensitivity of PEM versus MRI in patients with different menopausal status, breast density, and use of hormone replacement therapy (HRT) as well as determination of performance characteristics for additional ipsilateral lesion detection.

RESULTS

Two hundred and eight patients enrolled in the study of which 87% (182/208) were analyzable. Of these analyzable patients, 26.4% (48/182), 7.1% (13/182), and 64.2% (120/182) were pre-, peri-, and postmenopausal, respectively, and 48.4% (88/182) had extremely or heterogeneously dense breast tissue, while 33.5% (61/182) had a history of HRT use. Ninety-two percent (167/182) underwent core biopsy for index lesion diagnosis. Invasive cancer was found in 77.5% (141/182), while ductal carcinoma in situ (DCIS) and/or Paget's disease were found in 22.5% (41/182) of patients. Both PEM and MRI had index lesion depiction sensitivity of 92.8% and both were significantly better than WBPET (67.9%, p < 0.001, McNemar's test). For index lesions, PEM and MRI had equivalent sensitivity of various tumors, categorized by tumor stage as well as similar invasive tumor size predictions with Spearman's correlation coefficient of 0.61 for both PEM and MRI compared to surgical pathology. Menopausal status, breast density, and HRT did not influence the sensitivity of PEM or MRI. For 67 additional unsuspected ipsilateral lesions or multifocal lesions, PEM had sensitivity of 85% (34/40) and specificity of 74%, (20/27) compared to MRI's sensitivity of 98% (39/40) and specificity of 48% (13/27) [p = 0.074, for sensitivity; p = 0.096 for specificity]

CONCLUSION

PEM is a good alternative to MRI as a presurgical breast imaging option and its performance characteristics are not affected by patient menopausal/hormonal status or breast density.

Surgical outcome of patients with core-biopsy-proven nonpalpable breast carcinoma: a large cohort follow-up study

BACKGROUND

Breast-conserving surgery (BCS) is the preferred treatment for nonpalpable breast carcinoma. The outcome, however, may be disappointing. In this study surgical outcome in a large cohort of patients diagnosed with nonpalpable breast carcinoma is evaluated.

METHODS

In 833 patients with 841 nonpalpable breast carcinomas the number of re-excisions and type of surgical procedures was calculated and summed per patient. Subsequently, the number of conversions to mastectomy and the number of days until complete tumor removal were analyzed. In a subgroup analysis the patients with an in situ carcinoma were compared with the patients with an invasive carcinoma.

RESULTS

The initial surgery consisted of BCS for 589 tumors (70%) and of mastectomy for 242 tumors (29%). For ten tumors (1%) the initial surgery was unknown. After BCS, 158/589 tumors (27%) required a re-excision: 116/337 (34%) for the in situ carcinomas and 63/504 (13%) for the invasive carcinomas (p = 0.0001). The number of conversions from BCS to mastectomy was 106/589 (18%): 66/241 (28%) in patients diagnosed with an in situ carcinoma versus 40/348 (11%) in patients with an invasive carcinoma (p = 0.0001). The median number of days until complete tumor removal was 28, being 38 days for the in situ carcinomas and 25 days for the invasive carcinomas (p = 0.0001).

CONCLUSIONS

There is room for improvement in the surgical treatment of nonpalpable breast carcinoma, especially the relatively favorable in situ carcinoma, as it requires significantly more excisions, mastectomies, conversions to mastectomy, and days for complete removal.

Obtaining adequate surgical margins in breast-conserving therapy for patients with early-stage breast cancer: current modalities and future directions

Inadequate surgical margins represent a high risk for adverse clinical outcome in breast-conserving therapy (BCT) for early-stage breast cancer. The majority of studies report positive resection margins in 20% to 40% of the patients who underwent BCT. This may result in an increased local recurrence (LR) rate or additional surgery and, consequently, adverse affects on cosmesis, psychological distress, and health costs. In the literature, various risk factors are reported to be associated with positive margin status after lumpectomy, which may allow the surgeon to distinguish those patients with a higher a priori risk for re-excision. However, most risk factors are related to tumor biology and patient characteristics, which cannot be modified as such. Therefore, efforts to reduce the number of positive margins should focus on optimizing the surgical procedure itself, because the surgeon lacks real-time intraoperative information on the presence of positive resection margins during breast-conserving surgery. This review presents the status of pre- and intraoperative modalities currently used in BCT. Furthermore, innovative intraoperative approaches, such as positron emission tomography, radioguided occult lesion localization, and near-infrared fluorescence optical imaging, are addressed, which have to prove their potential value in improving surgical outcome and reducing the need for re-excision in BCT.

Diagnostic performance of a novel device for real-time margin assessment in lumpectomy specimens

BACKGROUND

Margin status in breast lumpectomy procedures is a prognostic factor for local recurrence and the need to obtain clear margins is often a cause for repeated surgical procedures. A recently developed device for real-time intraoperative margin assessment (MarginProbe; Dune Medical Devices, Caesarea, Israel), was clinically tested. The work presented here looks at the diagnostic performance of the device.

METHODS

The device was applied to freshly excised lumpectomy and mastectomy specimens at specific tissue measurement sites. These measurement sites were accurately marked, cut out, and sent for histopathologic analysis. Device readings (positive or negative) were compared with histology findings (namely malignant, containing any microscopically detected tumor, or nonmalignant) on a per measurement site basis. The sensitivity and specificity of the device was computed for the full dataset and for additional relevant subgroups.

RESULTS

A total of 869 tissue measurement sites were obtained from 76 patients, 753 were analyzed, of which 165 were cancerous and 588 were nonmalignant. Device performance on relatively homogeneous sites was: sensitivity 1.00 (95% CI: 0.85-1), specificity 0.87 (95% CI: 0.83-0.90). Performance for the full dataset was: sensitivity 0.70 (95% CI: 0.63-0.77), specificity 0.70 (95% CI: 0.67-0.74). Device sensitivity was estimated to change from 56% to 97% as the cancer feature size increased from 0.7 mm to 6.6 mm. Detection rate of samples containing pure DCIS clusters was not different from rates of samples containing IDC.

CONCLUSIONS

The device has high sensitivity and specificity in distinguishing between normal and cancer tissue even down to small cancer features.

Intraoperative ultrasound versus mammographic needle localization for ductal carcinoma in situ

BACKGROUND

Ductal carcinoma in situ (DCIS) often requires some method of localization to achieve breast-conserving therapy. The purpose of this study was to compare the efficacy of intraoperative ultrasound versus mammographic needle localization (MNL) for partial mastectomy in DCIS.

MATERIALS AND METHODS

Data were collected from a Breast Cancer Surgery Database. All DCIS cases undergoing partial mastectomy (PM) were identified. Margin status, re-excision rates, and cost were determined for both groups.

RESULTS

A total of 155 patients undergoing PM for DCIS were identified from the database. In the 96 patients undergoing ultrasound-guided PM (Group 1), the positive margin rate was 10.4%, and close margins (<1 mm) were observed in 22.9% after initial surgery. There were 59 patients who underwent MNL (Group 2); the positive margin rate was 11.9%, and close margins were observed in 27.1%. The difference between positive and close margins in Group 1 versus Group 2 was not statistically significant. The rate of re-excision was 20.8% for Group 1 and 30.5% for Group 2, resulting in 1.23 and 1.37 operations per patient, respectively. The average cost of an intraoperative ultrasound at our institution was $933 and $1858 for MNL (excluding cost of radiologic interpretation), a difference of $925 per case.

CONCLUSION

Our study showed equivalent rates of positive margins and re-excision between intraoperative ultrasound and MNL when performing PM for nonpalpable DCIS. Considering the more invasive nature and increased cost of MNL, we consider surgeon-performed intraoperative ultrasound, when possible, the more cost-effective and practical procedure for patients with DCIS.

Towards oncological application of Raman spectroscopy

As the possibilities in the treatment of cancer continue to evolve, its early detection and correct diagnosis are becoming increasingly important. From the early detection of cancer to the guidance of oncosurgical procedures new sensitive in vivo diagnostic tools are much needed. Many studies report the Raman spectroscopic detection of malignant and premalignant tissues in different sites of the body with high sensitivities. The great appeal of this technique lies in its potential for in vivo clinical implementation. We present an overview of the in vitro and in vivo work on the oncological application of Raman spectroscopy and discuss its potential as a new tool in the clinico-oncological practice. Opportunities for integration of Raman spectroscopy in oncological cure and care as a real-time guidance tool during diagnostic (i.e. biopsy) and therapeutic (surgical resection) modalities as well as technical shortcomings are discussed from a clinician's point of view.

A prospective, randomized, controlled, multicenter study of a real-time, intraoperative probe for positive margin detection in breast-conserving surgery

BACKGROUND

This randomized, double-arm trial was designed to study the benefit of a novel device (MarginProbe, Dune Medical Devices, Caesarea, Israel) in intraoperative margin assessment for breast-conserving surgery (BCS) and the associated reduction in reoperations.

METHODS

In the device group, the probe was applied to the lumpectomy specimen and additional tissue was excised according to device readings. Study arms were compared by reoperation rates and by correct surgical reaction confirmed by histology.

RESULTS

Three hundred patients were enrolled. Device use was associated with improved correct surgical reaction, defined as additional re-excision in all histologically detected positive margins, with tumor within 1 mm of inked margin. The repeat lumpectomy rate was significantly reduced by 56% in the device arm: 5.6% versus 12.7% in the control arm. There were no differences in excised tissue volume or cosmetic outcome.

CONCLUSIONS

Intraoperative use of the MarginProbe for positive margin detection is safe and effective in BCS and decreases the rate of repeat operations.

A device for real-time, intraoperative margin assessment in breast-conservation surgery

BACKGROUND

This trial was designed to study performance of a novel handheld probe (Dune Medical Devices, Caesarea, Israel) in intraoperative detection of positive margins and its potential benefit toward minimizing the positive margin rate.

METHODS

The probe was intraoperatively applied to 57 lumpectomy specimens. Surgeons were blinded to device output, and surgical decisions were not affected by probe data. Probe readings were compared with histological analysis per margin and per patient.

RESULTS

Nineteen of 22 (86%) pathology-positive patients were intraoperatively detected with device use. Per-margin sensitivity was .71, and specificity was .68, maintained within a range of positive margin definitions (0-.4 cm).

CONCLUSIONS

The device is an effective tool for intraoperative detection of positive margins with the potential for significant positive margin rate reduction.

Pathologic evaluation of cryoprobe-assisted lumpectomy for breast cancer

Cryoprobe-assisted lumpectomy is a relatively new technique that converts nonpalpable carcinomas into well-defined, palpable ones by creating an ice ball under ultrasonographic guidance, thus eliminating the need for preoperative needle localization. We evaluated the effect of cryoprobe-induced freezing on tumor tissue, peritumoral tissue, and margin status in 6 cases of cryoprobe-assisted lumpectomy performed for infiltrating ductal carcinoma. Immunohistochemical stains for estrogen and progesterone receptors and the proliferation marker Ki-67 were performed on 4 cases and results compared with those of the pretreatment biopsy specimens. Although it was possible to recognize the tumor as infiltrating carcinoma in all cases, the alteration in tumor morphology interfered with tumor grading, distinguishing in situ and invasive components, and assessment of mitoses and lymphovascular invasion. The expression of estrogen and progesterone receptors was greatly reduced, whereas the Ki-67 staining was not significantly different when compared with pretreatment biopsy specimens. The "cryoprobe effect" did not interfere with evaluation of the margins and surrounding breast tissue.