Achieving clear margins. Directed shaving using MarginProbe, as compared to a full cavity shave approach

Reducing re-excision rates in breast conserving surgery with Margin Probe: systematic review

INTRODUCTION

Different intraoperative techniques with varying levels of evidence are available to decrease positive surgical margins during breast conserving surgery. The aim of this review is to assess the effectiveness of the MarginProbe® device as an intraoperative adjunct tool in reducing positive surgical margins, and subsequently exploring the effect on patient re-excision rates.

METHODOLOGY

A systematic review of the available medical literature was conducted from 2007 to March 2022. A literature search of Cochrane, PubMed and Embase by two independent reviewers reviwers was performed to identify eligible articles looking at the primary outcome of percentage reduction in patient re-excision rates using MarginProbe®. Secondary outcomes analysed were comparison of tissue volume removed, absolute and relative reduction in re-excision rate, cosmetic outcome, as well as MarginProbe® sensitivity and specificity.

RESULTS

A total of 12 full text articles were identified. An independent samples t-test using a total of 2680 patients found a 54.68 per cent reduction in re-excision rate with the use of MarginProbe®, which was statistically significant with a large effect size (P < 0.001; d = 1.826). Secondary outcomes showed a relatively higher sensitivity of the MarginProbe® device, at the expense of decreased specificity, and no significant impact on cosmesis and volume of breast tissue excised.

CONCLUSION

MarginProbe® is an effective intraoperative adjunct in breast-conservation surgery that reduces patient re-excision rates, with no adverse effects relating to breast cosmesis or increase in volume of excised tissue.

Cost minimization in breast conserving surgery: a comparative study of radiofrequency spectroscopy and full cavity shave margins

BACKGROUND

In an effort to minimize positive margins and subsequent re-excision after breast conserving surgery (BCS), many providers and facilities have implemented either a Full Cavity Shave (FCS) approach or adding the MarginProbe Radiofrequency Spectroscopy System.

OBJECTIVE

We sought to create a functioning Pro-Forma for use by facilities and payers to evaluate and compare the cost savings of implementing FCS or MarginProbe based on personalized variable inputs.

METHODS

A decision tree demonstrating three possible surgical pathways, BCS, BCS + FCS, and BCS + MarginProbe was developed with clinical inputs for re-excision rate, mastectomy as 2nd surgery, rate of reconstruction, and rate of 3rd surgery derived by a literature review. A surgical pathway cost formula was created using the decision tree and financial inputs derived by utilizing the nation's largest database of privately billed health insurance claims and Medicare claims data (fairhealth.org). Using the surgical pathway formula and financial inputs, a customizable Pro-Forma was created for immediate cost savings analysis of BCS + FCS and BCS + Marginprobe using variable inputs. Costs are from the perspective of third-party payers.

RESULTS

Utilizing MarginProbe to reduce re-excisions for positive margins can be associated with better cost-savings than FCS due to the increased pathology processing costs by using an FCS approach. The reduction in re-excision provided by both FCS and MarginProbe offset their increased expense to various degrees with cost savings of each method improving as baseline re-excisions rates increase, until ultimately each may become cost-neutral or cost-prohibitive when compared to BCS alone. Our data suggest that in the privately insured population, MarginProbe provides a cost-savings over BCS alone when baseline re-excision rates are over 20% and that FCS becomes cost-saving when baseline re-excision rates are over 29%. For Medicare patients, MarginProbe provides a cost-savings when baseline re-excision rates exceed 34%, and FCS becomes cost-saving for re-excision rates over 52%. Our Pro-Forma allows an individual provider or institution to evaluate the cost savings of the FCS approach and/or utilization of the MarginProbe device such that the additional cost or cost-savings of utilizing one or both of these methods can be quickly calculated based on their facility's volume and baseline re-excision rate.

CONCLUSIONS

Our data suggest that utilizing either an FCS approach or the MarginProbe radiofrequency spectroscopy system may be a cost-saving solution to reducing the rate of re-excisions depending on a facility or practice's surgical volume and baseline re-excision rate. The degree to which each of these interventions provides an added cost or cost-savings to healthcare payers can be evaluated by utilizing the Pro-Forma outlined herein with customizable variable inputs.

The efficiency of MarginProbe in detecting positive resection margins in epithelial breast cancer following breast conserving surgery

INTRODUCTION

Up to 30% of patients undergoing lumpectomy for breast cancer are in need for re-excision due to either close or involved margins. We evaluated the yield of Margin Probe© (MP; Dilon Technologies, USA) in a cohort of patients undergoing lumpectomy for both palpable and non-palpable tumors.

METHODS

Following lumpectomy, margins were evaluated with MP and readings were compared to the lumpectomies' pathological evaluation irrespective of whether additional margins were removed during surgery. Involved margins or the presence of DCIS within 1 mm of the resection margins were considered as positive margins.

RESULTS

48 patients with 51 tumors underwent lumpectomy. Thirteen of the 51 lumpectomies had pathological close or involved margins. MP identified 3 out of the 13 positive margins. False-positive readings were recorded in 97 out of 287 margins. The sensitivity, specificity, positive predictive value and negative predictive value were 23.1% (95%CI 5.0% 53.8%), 66.4% (95%CI 60.7%-71.9%), 3% (95%CI 0.6%-8.5%), and 95.1% (95%CI 91.1%-97.6%) respectively.

CONCLUSIONS

MP cancer detection rate is relatively low while high false-positive rate leads to unnecessary shavings in almost all patients. Evaluation of MP performance should be based on comparing MP read to pathology report.

Minimizing re-excision after breast conserving surgery - a review of radiofrequency spectroscopy for real-time, intraoperative margin assessment

INTRODUCTION

For early-stage breast cancer, breast-conserving surgery (BCS) plus radiation is standard-of-care. Nationwide, >20% of BCS patients require re-excision for positive margins, resulting in delayed adjuvant therapy, increased complications, emotional and financial stress for patients, and additional cost to the healthcare system. Although several methods may be employed to mitigate positive margins, no technique can fully address the need. MarginProbe® is an adjunctive tool for real-time intraoperative margin assessment and is shown to reduce positive margins by >50%.

AREAS COVERED

Discussion of the impact of re-excision following BCS, a review of currently available methods for intraoperative margin management, followed by a technology and literature review of the MarginProbe® Radiofrequency Spectroscopy System.

EXPERT OPINION

Re-excision significantly impacts patients, providers and payers. Limitations in the ability to assess margins at time of surgery warrant more advanced methods of residual disease detection. MarginProbe facilitates the most efficient pathway for breast cancer patients through the surgical phase of treatment. The device is well-suited for adoption as the healthcare focus shifts from volume to value and supports the three pillars of the US Department of Health and Human Services' 'Triple-Aim' strategy: improve population health, improve patient experience of care, and reduce per-capita costs.

Intraoperative fluorescence imaging with aminolevulinic acid detects grossly occult breast cancer: a phase II randomized controlled trial

BACKGROUND

Re-excision due to positive margins following breast-conserving surgery (BCS) negatively affects patient outcomes and healthcare costs. The inability to visualize margin involvement is a significant challenge in BCS. 5-Aminolevulinic acid hydrochloride (5-ALA HCl), a non-fluorescent oral prodrug, causes intracellular accumulation of fluorescent porphyrins in cancer cells. This single-center Phase II randomized controlled trial evaluated the safety, feasibility, and diagnostic accuracy of a prototype handheld fluorescence imaging device plus 5-ALA for intraoperative visualization of invasive breast carcinomas during BCS.

METHODS

Fifty-four patients were enrolled and randomized to receive no 5-ALA or oral 5-ALA HCl (15 or 30 mg/kg). Forty-five patients (n = 15/group) were included in the analysis. Fluorescence imaging of the excised surgical specimen was performed, and biopsies were collected from within and outside the clinically demarcated tumor border of the gross specimen for blinded histopathology.

RESULTS

In the absence of 5-ALA, tissue autofluorescence imaging lacked tumor-specific fluorescent contrast. Both 5-ALA doses caused bright red tumor fluorescence, with improved visualization of tumor contrasted against normal tissue autofluorescence. In the 15 mg/kg 5-ALA group, the positive predictive value (PPV) for detecting breast cancer inside and outside the grossly demarcated tumor border was 100.0% and 55.6%, respectively. In the 30 mg/kg 5-ALA group, the PPV was 100.0% and 50.0% inside and outside the demarcated tumor border, respectively. No adverse events were observed, and clinical feasibility of this imaging device-5-ALA combination approach was confirmed.

CONCLUSIONS

This is the first known clinical report of visualization of 5-ALA-induced fluorescence in invasive breast carcinoma using a real-time handheld intraoperative fluorescence imaging device.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT01837225 . Registered 23 April 2013.

A Single institution's randomized double-armed prospective study of lumpectomy margins with adjunctive use of the MarginProbe in nonpalpable breast cancers

Breast conservation surgery (BCS) aims to excise all cancerous tissue while minimizing the amount of healthy breast tissue removed. Up to 30% of patients undergoing BCS require a second operation for re-excision to obtain negative margins. Previous studies reported a lower re-excision rate with intraoperative use of the MarginProbe device (Dune Medical Devices). This device utilizes radiofrequency spectroscopy to detect differences between cancerous and normal tissue. From July 2009 to January 2010, our institution enrolled 46 patients electing for BCS in a prospective double-arm randomized controlled trial and had a significantly lower re-excision rate than that reported in the multicenter trial. Intraoperatively, after performing conventional lumpectomy with excision of any additional shavings deemed necessary based on palpation and visual inspection alone, patients were then randomized. In the device arm, the surgeon used the MarginProbe to interrogate the lumpectomy specimen, taking additional shavings from the cavity surfaces corresponding to the parts of the specimen read as positive by the device. In the control arm, only standard intraoperative assessments were performed. All specimens were evaluated by pathologists who were blinded to the study arm. In this population, 72% had invasive ductal carcinoma (IDC), 20% had ductal carcinoma in situ (DCIS), and 8% had invasive lobular carcinoma (ILC). Average age was 64 years old. The average size of the specimen was 5.6 cm, the average volume was 37.8 cm³ , and the average weight was 32.7 g. The mean size of DCIS was 1.4 cm. For invasive specimens, 32 were T1 and 7 were T2. Prior to randomization, 43 patients were thought to have positive or close margins and therefore underwent additional shavings. Twenty-three patients were randomized to the device arm and 23 to the control arm. In the device arm, 14 (60%) patients had IDC, 7 (30%) had DCIS, and 2 (8%) had ILC, vs the control arm where 19 (82%) patients had IDC, 2 (8%) had DCIS, and 2 (8%) had ILC. Eight (35%) patients in the control group vs 1 (4%) in the device group underwent re-excision for margin involvement (P < .05). The use of the MarginProbe device at our institution significantly improved the ability of our surgeons to obtain clear margins during initial BCS. Our results show a lower re-excision rate (4%) than those published in the multicenter trial (19.8%). We postulate that in the face of more patients having DCIS in our device group (30%), our surgeons responded by taking thicker shavings when the MarginProbe device reported margin involvement during the initial lumpectomy, resulting in greater success achieving clear final margins on the shaved tissue and a significantly lower re-excision rate than previously reported with the MarginProbe device.

Use of MarginProbe as an adjunct to standard operating procedure does not significantly reduce re-excision rates in breast conserving surgery

PURPOSE

A positive margin after breast conserving surgery has consistently been shown to be a significant predictor for ipsilateral breast tumor recurrence. Currently, there is no standard for intraoperative margin assessment during lumpectomy, and up to 20% of cases result in positive margins. MarginProbe is a device that provides real-time evaluation of lumpectomy margins during surgery. The aim of this study was to evaluate the impact of MarginProbe as an adjunct to standard operating procedure (SOP).

METHODS

Patients diagnosed with breast cancer scheduled for breast conserving surgery were consented for intraoperative use of MarginProbe. Shaved margins were excised based on margin assessment using the surgeon's SOP which included specimen radiography and gross pathologic examination, and feedback from the device. The primary endpoint was re-excision rate. Secondary endpoints included sensitivity, specificity, false-positive and negative rates.

RESULTS

Of the 60 breast cancers, initial histologically close/positive margins were identified in 18 patients (30%). The re-excision rate in the overall cohort was 6.6%, compared to a historical re-excision rate of 8.6% (p < 0.01). Based on 360 measurement sites, MarginProbe demonstrated a sensitivity of 67% and specificity of 60%, with a positive predictive value of 16%, and of negative predictive value of 94%, which was similar to the accuracy of SOP.

CONCLUSIONS

MarginProbe performs equally as well as specimen radiography and gross pathologic examination. In this setting where the baseline re-excision rate was low, the use of MarginProbe as an adjunct to SOP resulted in a small 2% absolute reduction in re-excision rate.

The role of Micro-CT in imaging breast cancer specimens

PURPOSE

The goal of breast cancer surgery is to remove all of the cancer with a minimum of normal tissue, but absence of full 3-dimensional information on the specimen makes this difficult to achieve.

METHOD

Micro-CT is a high resolution, X-ray, 3D imaging method, widely used in industry but rarely in medicine.

RESULTS

We imaged and analyzed 173 partial mastectomies (129 ductal carcinomas, 14 lobular carcinomas, 28 DCIS). Imaging was simple and rapid. The size and shape of the cancers seen on Micro-CT closely matched the size and shape of the cancers seen at specimen dissection. Micro-CT images of multicentric/multifocal cancers revealed multiple non-contiguous masses. Micro-CT revealed cancer touching the specimen edge for 93% of the 114 cases judged margin positive by the pathologist, and 28 of the cases not seen as margin positive on pathological analysis; cancer occupied 1.55% of surface area when both the pathologist and Micro-CT suggested cancer at the edge, but only 0.45% of surface area for the "Micro-CT-Only-Positive Cases". Thus, Micro-CT detects cancers that touch a very small region of the specimen surface, which is likely to be missed on sectioning.

CONCLUSIONS

Micro-CT provides full 3D images of breast cancer specimens, allowing one to identify, in minutes rather than hours, while the patient is in OR, margin-positive cancers together with information on where the cancer touches the edge, in a fashion more accurate than possible from the histology slides alone.

Towards mm-wave spectroscopy for dielectric characterization of breast surgical margins

PURPOSE

The evaluation of the surgical margin in breast conservative surgery is a matter of general interest as such treatments are subject to the critical issue of margin status as positive surgical margins can undermine the effectiveness of the procedure. The relatively unexplored ability of millimeter-wave (mm-wave) spectroscopy to provide insight into the dielectric properties of breast tissues was investigated as a precursor to their possible use in assessment of surgical margins.

METHODS

We assessed the ability of a mm-wave system with a roughly hemispherical sensitive volume of ∼3 mm radius to distinguish malignant breast lesions in prospectively and consecutively collected tumoral and non-tumoral ex-vivo breast tissue samples from 91 patients. We characterized the dielectric properties of 346 sites in these samples, encompassing malignant, fibrocystic disease and normal breast tissues. An expert pathologist subsequently evaluated all measurement sites.

RESULTS

At multivariate analysis, mm-wave dielectric properties were significantly correlated to histologic diagnosis and fat content. Further, using 5-fold cross-validation in a Bayesian logistic mixed model that considered the patient as a random effect, the mm-wave dielectric properties of neoplastic tissues were significantly different from normal breast tissues, but not from fibrocystic tissue.

CONCLUSION

Reliable discrimination of malignant from normal, fat-rich breast tissue to a depth compatible with surgical margin assessment requirements was achieved with mm-wave spectroscopy.

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.