Ultrasound-guided surgery for palpable breast cancer is cost-saving: results of a cost-benefit analysis

Intraoperative Ultrasound-Guided Conserving Surgery for Breast Cancer: No More Time for Blind Surgery

BACKGROUND

Breast-conserving surgery (BCS) still remains a blind surgery despite all available tumor localization methods. Intraoperative ultrasound (IOUS) allows real-time visualization during all resection phases.

METHODS

This was a prospective observational cohort study conducted at the Veneto Institute of Oncology between January 2021 and June 2022. Patients with ductal carcinoma in situ, T1-2 invasive cancer, or post-neoadjuvant tumors, suitable for BCS, were recruited. All breast cancer lesion types were included, i.e. solid palpable, solid non-palpable, non-solid non-palpable, and post-neoadjuvant treatment residual lesions. Eligible participants were randomly assigned to either IOUS or traditional surgery (TS) in a 1:1 ratio. The main outcomes were surgical margin involvement, reoperation rate, closest margin width, main specimen and cavity shaving margin volumes, excess healthy tissue removal, and calculated resection ratio (CRR).

RESULTS

Overall, 160 patients were enrolled: 80 patients were allocated to the TS group and 80 to the IOUS group. IOUS significantly reduced specimen volumes (16.8 cm3 [10.5-28.9] vs. 24.3 cm3 [15.0-41.3]; p = 0.015), with wider closest resection margin width (2.0 mm [1.0-4.0] vs. 1.0 mm [0.5-2.0] after TS; p < 0.001). Tumor volume to specimen volume ratio was significantly higher after IOUS (4.7% [2.5-9.1] vs. 2.9% [0.8-5.2]; p < 0.001). IOUS yielded significantly better CRR (84.5% [46-120.8] vs. 114% [81.8-193.2] after TS; p < 0.001), lower involved margin rate (2.5 vs. 15%; p = 0.009) and reduced re-excision rate (2.5 vs. 12.5%; p = 0.032).

CONCLUSIONS

IOUS allows real-time resection margin visualization and continuous control during BCS. It showed clear superiority over TS in both oncological and surgical outcomes for all breast cancer lesion types. These results disfavor the paradigm of blind breast surgery.

Deep Learning in Different Ultrasound Methods for Breast Cancer, from Diagnosis to Prognosis: Current Trends, Challenges, and an Analysis

Breast cancer is the second-leading cause of mortality among women around the world. Ultrasound (US) is one of the noninvasive imaging modalities used to diagnose breast lesions and monitor the prognosis of cancer patients. It has the highest sensitivity for diagnosing breast masses, but it shows increased false negativity due to its high operator dependency. Underserved areas do not have sufficient US expertise to diagnose breast lesions, resulting in delayed management of breast lesions. Deep learning neural networks may have the potential to facilitate early decision-making by physicians by rapidly yet accurately diagnosing and monitoring their prognosis. This article reviews the recent research trends on neural networks for breast mass ultrasound, including and beyond diagnosis. We discussed original research recently conducted to analyze which modes of ultrasound and which models have been used for which purposes, and where they show the best performance. Our analysis reveals that lesion classification showed the highest performance compared to those used for other purposes. We also found that fewer studies were performed for prognosis than diagnosis. We also discussed the limitations and future directions of ongoing research on neural networks for breast ultrasound.

Intraoperative Ultrasound-Guided Excision of Non-Palpable and Palpable Breast Cancer: Systematic Review and Meta-Analysis

Wire-guided localization (WGL) is the most frequently used localization technique in non-palpable breast cancer (BC). However, low negative margin rates, patient discomfort, and the possibility of wire dislocation have been discussed as potential disadvantages, and re-operation due to positive margins may increase relapse risk. Intraoperative ultrasound (IOUS)-guided excision allows direct visualization of the lesion and the resection volume and reduces positive margins in palpable and non-palpable tumors. We performed a systematic review on IOUS in breast cancer and 2 meta-analyses of randomized clinical trials (RCTs). In non-palpable BC, 3 RCTs have shown higher negative margin rates in the IOUS arm compared to WGL. Meta-analysis confirmed a significant difference between IOUS and WGL in terms of positive margins favoring IOUS (risk ratio 4.34, p < 0.0001, I2 = 0%). 41 cohort studies including 3291 patients were identified, of which most reported higher negative margin and lower re-operation rates if IOUS was used. In palpable BC, IOUS was compared to palpation-guided excision in 3 RCTs. Meta-analysis showed significantly higher rates of positive margins in the palpation arm (risk ratio 2.84, p = 0.0047, I2 = 0%). In 13 cohort studies including 942 patients with palpable BC, negative margin rates were higher if IOUS was used, and tissue volumes were higher in palpation-guided cohorts in most studies. IOUS is a safe noninvasive technique for the localization of sonographically visible tumors that significantly improves margin rates in palpable and non-palpable BC. Surgeons should be encouraged to acquire ultrasound skills and participate in breast ultrasound training.

Implementation of Intraoperative Ultrasound Localization for Breast-Conserving Surgery in a Large, Integrated Health Care System is Feasible and Effective

BACKGROUND

Intraoperative ultrasound (IUS) localization for breast cancer is a noninvasive localization technique. In 2015, an IUS program for breast-conserving surgery (BCS) was initiated in a large, integrated health care system. This study evaluated the clinical results of IUS implementation.

METHODS

The study identified breast cancer patients with BCS from 1 January to 31 October 2015 and from 1 January to 31 October 2019. Clinicopathologic characteristics were collected, and localization types were categorized. Clinical outcomes were analyzed, including localization use, surgeon adoption of IUS, day-of-surgery intervals, and re-excision rates. Multivariate logistic regression analysis was performed to evaluate predictors of re-excision.

RESULTS

The number of BCS procedures increased 23%, from 1815 procedures in 2015 to 2226 procedures in 2019. The IUS rate increased from 4% of lumpectomies (n = 79) in 2015 to 28% of lumpectomies (n = 632) in 2019 (p < 0.001). Surgeons using IUS increased from 6% (5 of 88 surgeons) in 2015 to 70% (42 of 60 surgeons) in 2019. In 2019, 76% of IUS surgeons performed at least 25% of lumpectomies with IUS. The mean time from admission to incision was shorter with IUS or seed localization than with wire localization (202 min with IUS, 201 with seed localization, 262 with wire localization in 2019; p < 0.001). The IUS re-excision rates were lower than for other localization techniques (13.6%, vs 19.6% for seed localization and 24.7% for wire localization in 2019; p = 0.006), and IUS predicted lower re-excision rates in a multivariable model (odds ratio [OR], 0.59).

CONCLUSIONS

In a high-volume integrated health system, IUS was adopted for BCS by a majority of surgeons. The use of IUS decreased the time from admission to incision compared with wire localization, and decreased re-excision rates compared with other localization techniques.

Intraoperative ultrasound-guided lumpectomy versus wire-guided excision for nonpalpable breast cancer

Objective

This study was designed to compare the margin clearance and re-excision rates of ultrasound (US)- and wire-guided excision in a large number of patients with nonpalpable breast cancer.

Methods

In total, 520 women who were histologically diagnosed with nonpalpable breast cancer were recruited in this study. All nonpalpable lesions were visible by US. The patients were randomly divided into two groups: those who underwent wire-guided breast-conserving surgery (BCS) and those who underwent US-guided BCS. Re-excision rates and positive surgical margins were recorded.

Results

A total of 262 patients underwent US-guided excision and 258 patients underwent wire-guided excision. No differences were found in tumor or patient characteristics. The positive margin rate was 4.6% in the US-guided group and 19.4% in the wire-guided group with a significant difference. Age, menopausal status, excision volume, histological grade, and tumor type significantly influenced the positive surgical margin rate. The intraoperative re-excision rate was significantly lower in the US-guided group than wire-guided group (11.1% vs. 24.0%, respectively).

Conclusions

US-guided BCS seems to be more effective than wire-guided BCS for treatment of nonpalpable breast cancers in terms of the margin clearance and re-excision rates. Patients can avoid the discomfort caused by preoperative wire placement.

Optimising patient care in medical radiation services through health economics: an introduction

The role of health economics in optimising patient care in medical radiation clinical settings is of increasing importance in ensuring efficient and effective service delivery. This commentary introduces health economics to medical radiation professionals by outlining the main analysis types utilised, highlighted by examples in the literature. The purpose is to provide an over-arching framework and starting point for incorporating health economics into medical radiation research study protocols.

Attributes, Performance, and Gaps in Current & Emerging Breast Cancer Screening Technologies

Background:

Early detection of breast cancer, combined with effective treatment, can reduce mortality. Millions of women are diagnosed with breast cancer and many die every year globally. Numerous early detection screening tests have been employed. A wide range of current breast cancer screening methods are reviewed based on a series of searchers focused on clinical testing and performance. </P><P> Discussion: The key factors evaluated centre around the trade-offs between accuracy (sensitivity and specificity), operator dependence of results, invasiveness, comfort, time required, and cost. All of these factors affect the quality of the screen, access/eligibility, and/or compliance to screening programs by eligible women. This survey article provides an overview of the working principles, benefits, limitations, performance, and cost of current breast cancer detection techniques. It is based on an extensive literature review focusing on published works reporting the main performance, cost, and comfort/compliance metrics considered.

Conclusion:

Due to limitations and drawbacks of existing breast cancer screening methods there is a need for better screening methods. Emerging, non-invasive methods offer promise to mitigate the issues particularly around comfort/pain and radiation dose, which would improve compliance and enable all ages to be screened regularly. However, these methods must still undergo significant validation testing to prove they can provide realistic screening alternatives to the current accepted standards.

Patient-level costs in margin re-excision for breast-conserving surgery

BACKGROUND

High rates of reoperation following breast-conserving surgery (BCS) for positive margins are associated with costs to healthcare providers. The aim was to assess the quality of evidence on reported re-excision costs and compare the direct patient-level costs between patients undergoing successful BCS versus reoperations after BCS.

METHODS

The study used data from women who had BCS with or without reoperation at a single institution between April 2015 and March 2016. A systematic review of health economic analysis in BCS was conducted and scored using the Quality of Health Economic Studies (QHES) instrument. Financial data were retrieved using the Patient-Level Information and Costing Systems (PLICS) for patients. Exchange rates used were: US $1 = £0·75, £1 = €1·14 and US $1 = €0·85.

RESULTS

The median QHES score was 47 (i.q.r. 32·5-79). Only two of nine studies scored in the upper QHES quartile (score at least 75). Costs of initial lumpectomy and reoperation were in the range US $1234-11786 and $655-9136 respectively. Over a 12-month interval, 153 patients had definitive BCS and 59 patients underwent reoperation. The median cost of reoperations after BCS (59 patients) was £4511 (range 1752-18 019), representing an additional £2136 per patient compared with BCS without reoperation (P < 0·001).

CONCLUSION

The systematic review demonstrated variation in methodological approach to cost estimates and a paucity of high-quality cost estimate studies for reoperations. Extrapolating local PLICS data to a national level suggests that getting BCS right first time could result in substantial savings.

Ultrasound-Guided Breast-Conservative Surgery Decreases the Rate of Reoperations for Palpable Breast Cancer

The purpose of this study is to verify whether the performance of ultrasound-guided quadrantectomy (USGQ) versus palpation-guided quadrantectomy (PGQ) can reduce the incidence of positive margins and if it can change the attitude of the surgeon. A retrospective study was conducted on 842 patients underwent quadrantectomy for breast cancer, 332 of them underwent USGQ, whereas 550 underwent PGQ. The histological type of the tumors and the margin status obtained with the histological examination were compared. The histological examination of the surgical specimen showed involvement of the margins in 24/842 patients (2.85%), 22 (2.61%) of them belonged to the PGQ group, and two to the USGQ group (P = 0.0011). The highest rate of microscopically positive margins was, statistically significant, for carcinoma in situ, when compared with patients with invasive carcinoma (0.0001). USGQ technique showed several advantages compared with PGQ. In fact, the former notes a lower positive margin rate and, consequently, a lower rate of reintervention. In addition, it may change the surgeon's attitude by causing him to remove another slice of margin to ensure more histological negativity. It should be the gold standard technique for breast-conservative surgery of palpable tumors.

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.

Reoperation costs in attempted breast-conserving surgery: a decision analysis

BACKGROUND

Breast-conserving surgery (bcs) is the preferred surgical approach for most patients with early-stage breast cancer. Frequently, concerns arise about the pathologic margin status, resulting in an average reoperation rate of 23% in Canada. No consensus has been reached about the ideal reoperation rate, although 10% has been suggested as a target. Upon undergoing reoperation, many patients choose mastectomy and breast reconstruction, which add to the morbidity and cost of patient care. We attempted to identify the cost of reoperation after bcs, and the effect that a reduction in the reoperation rate could have on the B.C. health care system.

METHODS

A decision tree was constructed to estimate the average cost per patient undergoing initial bcs with two reoperation frequency scenarios: 23% and 10%. The model included the direct medical costs from the perspective of the B.C. health care system for the most common surgical treatment options, including breast reconstruction and postoperative radiation therapy.

RESULTS

Costs ranged from a low of $8,225 per patient with definitive bcs [95% confidence interval (ci): $8,061 to $8,383] to a high of $26,026 for reoperation with mastectomy and delayed reconstruction (95% ci: $23,991 to $28,122). If the reoperation rate could be reduced to 10%, the average saving would be $1,055 per patient undergoing attempted bcs (95% ci: $959 to $1,156). If the lower rate were to be achieved in British Columbia, it would translate into a savings of $1.9 million annually.

SUMMARY

The implementation of initiatives to reduce reoperation after bcs could result in significant savings to the health care system, while potentially improving the quality of patient care.

Intraoperative Ultrasound Guidance in Breast-Conserving Surgery Improves Cosmetic Outcomes and Patient Satisfaction: Results of a Multicenter Randomized Controlled Trial (COBALT)

Background

Ultrasound-guided breast-conserving surgery (USS) results in a significant reduction in both margin involvement and excision volumes (COBALT trial).

Objective

The aim of the present study was to determine whether USS also leads to improvements in cosmetic outcome and patient satisfaction when compared with standard palpation-guided surgery (PGS).

Methods

A total of 134 patients with T1–T2 invasive breast cancer were included in the COBALT trial (NTR2579) and randomized to either USS (65 patients) or PGS (69 patients). Cosmetic outcomes were assessed by a three-member panel using computerized software Breast Cancer Conservative Treatment cosmetic results (BCCT.core) and by patient self-evaluation, including patient satisfaction. Time points for follow-up were 3, 6, and 12 months after surgery. Overall cosmetic outcome and patient satisfaction were scored on a 4-point Likert scale (excellent, good, fair, or poor), and outcomes were analyzed using a multilevel, mixed effect, proportional odds model for ordinal responses.

Results

Ultrasound-guided breast-conserving surgery achieved better cosmetic outcomes, with 20 % excellence overall and only 6 % rated as poor, whereas 14 % of PGS outcomes were rated excellent and 13 % as poor. USS also had consistently lower odds for worse cosmetic outcomes (odds ratio 0.55, p = 0.067) than PGS. The chance of having a worse outcome was significantly increased by a larger lumpectomy volume (p_trend = 0.002); a volume >40 cc showed odds 2.78-fold higher for a worse outcome than a volume ≤40 cc. USS resulted in higher patient satisfaction compared with PGS.

Conclusion

Ultrasound-guided breast-conserving surgery achieved better overall cosmetic outcomes and patient satisfaction than PGS. Lumpectomy volumes >40 cc resulted in significantly worse cosmetic outcomes.

Current status of ultrasound-guided surgery in the treatment of breast cancer

The primary goal of breast-conserving surgery (BCS) is to obtain tumour-free resection margins. Margins positive or focally positive for tumour cells are associated with a high risk of local recurrence, and in the case of tumour-positive margins, re-excision or even mastectomy are sometimes needed to achieve definite clear margins. Unfortunately, tumour-involved margins and re-excisions after lumpectomy are still reported in up to 40% of patients and additionally, unnecessary large excision volumes are described. A secondary goal of BCS is the cosmetic outcome and one of the main determinants of worse cosmetic outcome is a large excision volume. Up to 30% of unsatisfied cosmetic outcome is reported. Therefore, the search for better surgical techniques to improve margin status, excision volume and consequently, cosmetic outcome has continued. Nowadays, the most commonly used localization methods for BCS of non-palpable breast cancers are wire-guided localization (WGL) and radio-guided localization (RGL). WGL and RGL are invasive procedures that need to be performed pre-operatively with technical and scheduling difficulties. For palpable breast cancer, tumour excision is usually guided by tactile skills of the surgeon performing “blind” surgery. One of the surgical techniques pursuing the aims of radicality and small excision volumes includes intra-operative ultrasound (IOUS). The best evidence available demonstrates benefits of IOUS with a significantly high proportion of negative margins compared with other localization techniques in palpable and non-palpable breast cancer. Additionally, IOUS is non-invasive, easy to learn and can centralize the tumour in the excised specimen with low amount of healthy breast tissue being excised. This could lead to better cosmetic results of BCS. Despite the advantages of IOUS, only a small amount of surgeons are performing this technique. This review aims to highlight the position of ultrasound-guided surgery for malignant breast tumours in the search for better oncological and cosmetic outcomes.

Tumour-adapted Reduction Mammoplasty - a New (Old) Breast Conserving Strategy: Review

Today over 70 % of patients treated for primary breast carcinoma in certified breast centres are managed with breast conserving surgery. The classical semicircular incision directly above the tumour, though in many cases easily carried out and associated with good cosmetic results, does have limitations. Unsatisfactory aesthetic results often occur when tumour location is unfavourable or when there is unfavourable tumour size relative to breast size. Distortion of the nipple, changes to breast shape and retraction of skin overlying surgical defects can occur. Tumour-adapted reduction mammoplasty/mastopexy or the "modified B technique" offer excellent chances of combining the oncological demands of breast surgery with satisfactory symmetrical cosmetic results. This article reviews a traditional, old operative technique that has been re-embraced in various new forms.

A nationwide pathology study on surgical margins and excision volumes after breast-conserving surgery: There is still much to be gained

AIM OF THE STUDY

The current study aims to assess margin status in relation to amount of healthy breast tissue resected in breast-conserving surgery (BCS) on a nationwide scale.

METHODS

Using PALGA (a nationwide network and registry of histology and cytopathology in the Netherlands), all patients who underwent BCS for primary invasive carcinoma in 2012-13 were selected (10,058 excerpts). 9276 pathology excerpts were analyzed for a range of criteria including oncological margin status and distance to closest margin, specimen weight/volume, greatest tumor diameter, and with or without localization method. Calculated resection ratios (CRR) were assessed to determine excess healthy breast tissue resection.

RESULTS

Margins for invasive carcinoma and in situ carcinoma combined were tumor-involved in 498 (5.4%) and focally involved in 1021 cases (11.0%) of cases. Unsatisfactory resections including (focally) involved margins and margins ≤ 1 mm were reported in 33.8% of patients. The median lumpectomy volume was 46 cc (range 1-807 cc; SD 49.18) and median CRR 2.32 (range 0.10-104.17; SD 3.23), indicating the excision of 2.3 the optimal resection volume.

CONCLUSION

The unacceptable rate of tumor-involved margins as well as margins ≤ 1 mm in one third of all patients is also achieved at the expense of healthy breast tissue resection, which may carry the drawback of high rates of cosmetic failure. These data clearly suggest the need for improvement in current breast conserving surgical procedures to decrease tumor-involved margin rates while reducing the amount of healthy breast tissue resected.

Ultrasound-Guided Versus Wire-Guided Breast-Conserving Surgery for Nonpalpable Breast Cancer

PURPOSE

To determine the efficacy of ultrasound (US)-guided excision of nonpalpable breast cancer and compare it to standard wire-guided breast-conserving surgery (BCS).

METHODS

One hundred fifty-eight women with nonpalpable breast cancer who underwent BCS were retrospectively studied. Positive surgical margins and reexcision rates were investigated.

RESULTS

Of the total cohort, 68 patients were treated with wire-guided and 90 with US-guided tumor excision. The tumor and patient characteristics were similar in the 2 groups; 13.2% and 12.2% of patients in the wire-guided and US-guided groups, respectively, had positive margins. Patient age, menopausal status, tumor size, histologic type, and histologic grade were associated with increased risk of positive margins. The shave margins were reexcised at the time of original operation more often by wire-guided localization (26.5%) than in the US-guided group (10.0%) (P = .010). The surgeon was able to identify correctly the problematic margin in 100% via intraoperative US and in only 27.8% when the wire-guided surgery was used (P < .001). The reexcision rate by a second operation was similar in 2 groups (P = .798). Eight (11.8%) of 68 patients in the wire-guided group and 9 (10.0%) of 90 patients in the US-guided underwent a second operation.

CONCLUSION

US-guided BCS is as effective and safe as standard wire-guided excision of nonpalpable breast tumors.

Ultrasound-guided surgery for palpable breast cancer: a historical perspective

SUMMARY 

Breast cancer surgery has changed dramatically from the en bloc removal of the breast to the less invasive breast-conserving surgery. The recent COBALT trial comparing ultrasound-guided surgery with palpation-guided surgery for palpable breast cancer showed less margin involvement and decreased excision volumes with ultrasonography, which resulted in less additional therapy and possibly improved cosmetic outcome. Other surgical techniques pursuing these same aims have been developed over the past two decades and are referred to as oncoplastic surgery. Unfortunately oncoplastic surgery lacks sufficient evidence to corroborate its widespread implementation and should thereby solely be applied to selected cases. This review aims to highlight the position of ultrasound-guided surgery from a perspective of breast-conserving surgery in the search for better oncological and cosmetic outcomes.

Endoscopy-assisted breast-conserving surgery for breast cancer patients

Breast-conserving surgery (BCS) combined with postoperative radiotherapy is a standard therapy for early-stage breast cancer patients. In addition, recent developments in oncoplastic surgery have improved cosmetic outcomes and patient satisfaction. Therefore, a breast surgeon's current role in BCS is not only to perform a curative resection of cancerous lesions with adequate surgical margins, but also to preserve the shape and appearance of the treated breast. Endoscopy-assisted breast-conserving surgery (EBCS), which has the advantage of a less noticeable scar, was developed more than ten years ago. Recently, some clinical studies have reported the feasibility, oncological outcomes, aesthetic outcomes, and patient satisfaction of EBCS. Herein, we will review the EBCS clinical studies that have been conducted so far and discuss current issues regarding this operative method.

Intra-operative ultrasound versus wire-guided localization in the surgical management of non-palpable breast cancers: systematic review and meta-analysis

INTRODUCTION

The current standard of treatment for non-palpable breast cancers is wire-guided localization (WGL). WGL has its drawbacks and alternatives such as radio-guided surgery (RGL) and intra-operative ultrasound (IOUS) have been developed. The clinical effectiveness of all forms of RGL has been assessed against WGL in previous systematic reviews and meta-analyses. We performed the first systematic review and meta-analysis of IOUS in the management of non-palpable breast cancers.

METHODS

Studies were considered eligible for inclusion in this systematic review if they (1) assessed the role of surgeon-performed IOUS for the treatment of non-palpable breast cancers and ductal carcinoma in situ (DCIS) and (2) specified surgical margin excision status. Those studies, which were randomized controlled trials (RCTs) or cohort studies with comparison WGL groups were included in the meta-analysis. For those studies included in the meta-analysis, pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated using fixed-effects analyses and random-effects analyses in case of statistically significant heterogeneity (p < 0.05).

RESULTS

Eighteen studies reported data on IOUS in 1,328 patients with non-palpable breast cancer and DCIS. Nine cohort studies with control WGL groups and one RCT were included in the meta-analysis. Successful localization rates varied between 95 and 100 % in all studies and there was a statistically significant difference in the rates of involved surgical margins in favour of IOUS with pooled OR 0.52 (95 % CI 0.38-0.71).

CONCLUSION

Compared with WGL, IOUS reduces involved surgical margin rates. Adequately powered RCTs are required to validate these findings.