Wire- and magnetic-seed-guided localization of impalpable breast lesions: iBRA-NET localisation study.

BACKGROUND: Wire localization is historically the most common method for guiding excision of non-palpable breast lesions, but there are limitations to the technique. Newer technologies such as magnetic seeds may allow some of these challenges to be overcome. The aim was to compare safety and effectiveness of wire and magnetic seed localization techniques. METHODS: Women undergoing standard wire or magnetic seed localization for non-palpable lesions between August 2018 and August 2020 were recruited prospectively to this IDEAL stage 2a/2b platform cohort study. The primary outcome was effectiveness defined as accurate localization and removal of the index lesion. Secondary endpoints included safety, specimen weight and reoperation rate for positive margins. RESULTS: Data were accrued from 2300 patients in 35 units; 2116 having unifocal, unilateral breast lesion localization. Identification of the index lesion in magnetic-seed-guided (946 patients) and wire-guided excisions (1170 patients) was 99.8 versus 99.1 per cent (P = 0.048). There was no difference in overall complication rate. For a subset of patients having a single lumpectomy only for lesions less than 50 mm (1746 patients), there was no difference in median closest margin (2 mm versus 2 mm, P = 0.342), re-excision rate (12 versus 13 per cent, P = 0.574) and specimen weight in relation to lesion size (0.15 g/mm2versus 0.138 g/mm2, P = 0.453). CONCLUSION: Magnetic seed localization demonstrated similar safety and effectiveness to those of wire localization. This study has established a robust platform for the comparative evaluation of new localization devices.

Comparison of vacuum-assisted excision (VAE) and breast lesion excision system (BLES) in the treatment of intraductal papillomas.

PURPOSE: This study aims to compare the feasibility of VAE and BLES in the treatment of intraductal papillomas. MATERIAL AND METHODS: Patients with a suspected intraductal papilloma who underwent a BLES or a VAE procedure were included in this retrospective study. The BLES procedures were performed between November 2011 and June 2016 and the VAE procedures between May 2018 and September 2020 at the Department of Radiology of Helsinki University Hospital (HUH). The procedures were performed with an intent of complete removal of the lesions. RESULTS: In total, 72 patients underwent 78 BLES procedures and 95 patients underwent 99 VAE procedures. Altogether 52 (60%) papillomas with or without atypia were completely removed with VAE, whereas 24 (46%) were completely removed with BLES, p = 0.115. The median radiological size of the high-risk lesions completely removed with BLES was 6 mm (4-12 mm), whereas with VAE it was 8 mm (3-22 mm), p = 0.016. Surgery was omitted in 90 (94.7%) non-malignant breast lesions treated with VAE and in 66 (90.4%) treated with BLES, p = 0.368. CONCLUSION: Both VAE and BLES were feasible in the treatment of intraductal papillomas. In most non-malignant lesions surgery was avoided, but VAE was feasible in larger lesions than BLES. However, follow-up ultrasound was needed more often after VAE. The histopathologic assessment is more reliable after BLES, as the lesion is removed as a single sample.

Retrospective Study of Radiotherapy Impact on the Outcome of Material-assisted Implant-based Subpectoral Breast Reconstruction.

BACKGROUND/AIM: Synthetic meshes (SMs) and acellular dermal matrices (ADMs) are used in reconstructive breast surgery. In the absence of prospective comparative studies, the identification of differences relies on retrospective analyses. PATIENTS AND METHODS: Our analysis focused on the impact of pre- and postoperative radiotherapy (RTX) and material-related differences. The analysis included 281 breast cancer patients (362 breasts) after nipple- and skin-sparing mastectomy with subpectoral implant insertion. RESULTS: Overall, the implant loss rate was 23.1% using porcine ADM, 7% using partially resorbable SM (prSM), and 5.6% using non-resorbable SM (nrSM). After RTX, the implant loss rate was 56.3% with ADM, 13% with prSM and 13.2% with nrSM. The ADM group showed a significant effect of RTX on the postoperative seroma rate, wound infections, and implant loss rate. When prSM was used, RTX showed no significant effect. When using the nrSM, RTX significantly influenced complication rates regarding wound infections and implant loss. CONCLUSION: In material-assisted breast reconstructions with pre- or post-operative RTX, there is a significantly higher implant loss rate when using porcine ADM compared to SM.

Patient and clinician satisfaction and clinical outcomes of Magseed compared with wire-guided localisation for impalpable breast lesions.

BACKGROUND: Guide-wire localisation remains the most commonly used technique for localisation of impalpable breast lesions in the UK. One alternative is magnetic seed localisation. We aimed to investigate patient and clinician satisfaction in two consecutive cohorts, describe re-excision and positive margin rates, and explore reasons for positive margins and the implications for localisation techniques. METHODS: A single-institution prospective service evaluation of two cohorts of consecutive cases of wire and then Magseed localisation was carried out. Data were collected on patient and clinician satisfaction, clinico-pathological findings, and causes of involved margins. T tests were used to compare continuous variables and Chi-squared test for satisfaction outcomes. RESULTS: 168 consecutive cases used wire-guided localisation (WGL) and 128 subsequent cases used Magseeds. Patients reported less anxiety between localisation and surgery in the Magseed group, and clinicians reported greater ease of use of Magseeds. There were no differences in lesion size, surgical complexity, or re-excision rate between the groups. In a subset of patients receiving standard wide local excision (i.e., excluding mammoplasties), the impact on margin involvement was investigated. There was no significant difference in radiological under-sizing or accuracy of localisation. However, specimen weight and eccentricity of the lesion were statistically significantly lower in the Magseed group. Despite this, re-excision rates were not significantly different (p = 0.4). CONCLUSIONS: This is the first large study of satisfaction with localisation and showed clinician preference for Magseed and a reduction in patient anxiety. It also demonstrated similar positive margin rates despite smaller specimen weights in the Magseed group. Magnetic seed localisation offers an acceptable clinical alternative to guide wire localisation. The impact on local service provision should also be considered.

Optimization of Wire-guided Technique With Bracketing Reduces Resection Volumes in Breast-conserving Surgery for Early Breast Cancer.

BACKGROUND: Wire-guided localization (WGL) of early breast cancer can be facilitated using multiple wires, which is called bracketing wire-guided localization (BWL). The primary aim of this study is to compare BWL and conventional WGL regarding minimization of resection volumes without compromising margin status. Secondly, BWL is evaluated as an alternative method for intraoperative ultrasound (US) guidance in poorly definable breast tumors on US. PATIENTS AND METHODS: In this retrospective cohort study, patients with preoperatively diagnosed breast cancer undergoing wide local excision between January 2016 and December 2018 were analyzed. Patients with multifocal disease or neoadjuvant treatment were excluded from this study. Optimal resection with minimal healthy breast tissue removal was assessed using the calculated resection ratio (CRR). RESULTS: BWL was performed in 17 (9%) patients, WGL in 44 (22%), and US in 139 (70%). The rate of negative margins was comparable in all 3 groups. The CRR was significantly smaller for BWL (0.6) than WGL (1.3) in tumors larger than 1.5 cm. Additionally, BWL (0.8) led to smaller CRRs than US (1.7). This could be explained by the high number of small tumors (≤ 1.5 cm) in the US group for which greater CRRs are obtained than for large tumors (> 1.5 cm) (1.9 vs. 1.4; P = .005). CONCLUSION: For breast tumors larger than 1.5 cm, BWL achieves more optimal resection volumes without compromising margin status compared with WGL. Moreover, BWL seems a suitable alternative to US in patients with poorly ultrasound-visible breast tumors and patients with a small tumor in a (large) breast.

Reporting and Abstracting Variability in Technical Standards for Breast Cancer Operations.

BACKGROUND: The American College of Surgeons Commission on Cancer has incorporated documentation of critical elements outlined in Operative Standards for Cancer Surgery into revised standards for cancer center accreditation. This study assessed the current documentation of critical elements in partial mastectomy (PM) and sentinel lymph node biopsy (SLNB) operative reports. MATERIALS AND METHODS: Operative reports for PM + SLNB at a single academic institution from 2013 to 2018 were reviewed for compliance and surveyor interobserver reliability with the Oncologic Elements of Operative Record defined in Operative Standards and compared with a nonredundant American Society of Breast Surgeons Mastery of Breast Surgery (MBS) quality measure for specimen orientation. RESULTS: Ten reviewers each evaluated 66 PM + SLNB operative reports for 13 Oncologic Elements and one MBS measure. No operative records reported all critical elements for PM + SLNB or PM alone. Residents completed 36.4% of operative reports: Element documentation was similar for PM but varied significantly for SLNB between resident and attending authorship. Combined reporting performance and interrater reliability varied across all elements and was highest for the use of SLNB tracer (97.1% and κ = 0.95, respectively) and lowest for intraoperative assessment of SLNB (30.6%, κ = 0.43). MBS specimen orientation had both high proportion reported (87.0%) and interrater reliability (κ = 0.84). CONCLUSIONS: Adherence to reporting critical elements for PM and SLNB varied. Whether differential compliance was tied to discrepancies in documentation or reviewer abstraction, clarification of synoptic choices may improve reporting consistency. Evolving techniques or technologies will require continuous appraisal of mandated reporting for breast surgery.

Efficacy of an external volume expansion device and autologous fat grafting for breast reconstruction following breast conserving surgery and total mastectomy: Small improvements in quality of life found in a prospective cohort study.

BACKGROUND: Although autologous fat grafting (AFG) for breast reconstruction is feasible, the best methods have yet to be established. This study aimed to assess the efficacy of fat grafting using an external expansion device for complete breast reconstruction post breast cancer surgery hypothesizing that it would improve quality of life. METHODS: A prospective cohort study was conducted in women who had undergone breast cancer surgery and complete reconstruction using AFG. An external expansion device was used previously (as per Miami protocol) to a single-stage AFG. Quality of life outcomes were determined using the validated BREAST-Q questionnaire, and 3D laser and magnetic resonance imaging scan were used to measure fat graft retention. RESULTS: Twenty-six participants were recruited, with seven withdrawing. The remaining 19 women were compliant with external expander use. The mean volume of AFG was 270.4 mL (98-490 mL) with a mean of 48.8% retained at 12 months following injection. Symmetry improved but did not meet the acceptable symmetry ratio of 0.8. Nine patients (47.3%) noted increased skin elasticity and softening of areas of scarring. Skin irritation occurred in 11 out of 19 patients. Mean BREAST-Q scores improved significantly in the domains of satisfaction with breast (40 vs. 49, p < 0.001), psychosocial well-being (55 vs. 68, p < 0.001), physical well-being abdomen (73 vs. 87, p < 0.001), and sexual well-being (41 vs, 48, p < 0.001). CONCLUSION: Improved quality of life and breast volume increase were achieved following external expansion and AFG. However, breast fat engraftment retention was similar to that reported in previous studies using fat grafting alone.

Long-Term Outcomes of Multiple-Wire Localizations for More Extensive Breast Cancer: Multiple-Wire Excision Does Not Increase Recurrence, Unplanned Imaging, or Biopsies.

BACKGROUND: We previously reported that breast conservation was feasible for women with large or irregularly shaped breast cancers when tumor resection was guided by multiple localizing wires. We now report long-term outcomes of multiple-wire versus single-wire localized lumpectomies for breast cancer. PATIENTS AND METHODS: We retrospectively reviewed wire-localized lumpectomies at our institution from May 2000 to November 2006. Rates of ipsilateral in-breast tumor recurrence, metastasis, and subsequent unplanned diagnostic imaging and biopsy were compared between multiple-wire and single-wire cohorts. RESULTS: We identified 112 multiple-wire and 160 single-wire breast cancer lumpectomies that achieved clear margins. Median age was 64 years in the multiple-wire cohort and 57 years in the single-wire cohort. Mean lumpectomy volume was 75 mL in multiple-wire patients and 49 mL in single-wire patients (P = .003). Invasive tumor size, axillary node status, and use of radiation and systemic therapy were similar, but the multiple-wire group had more patients with ductal carcinoma-in-situ only (38% vs. 28%). At 108 months' median follow-up, there was no significant difference in local or distant recurrence rates between multiple-wire and single-wire cohorts. Six (5%) multiple-wire patients and 6 (4%) single-wire patients had local recurrences and 3 (3%) multiple-wire and 5 (3%) single-wire patients developed metastatic disease. Unplanned diagnostic imaging was required for 53 (47%) multiple-wire and 65 (41%) single-wire patients. Subsequent ipsilateral biopsy occurred in 15 (13%) multiple-wire and 19 (12%) single-wire patients. CONCLUSION: Breast-conserving surgery with multiple localizing wires is a safe alternative to mastectomy for breast cancer patients with large mammographic lesions.

Robot-assisted Nipple-sparing Mastectomy with Immediate Breast Reconstruction: An Initial Experience.

Seeking smaller and indistinct incisions, physicians have attempted endoscopic breast surgery in breast cancer patients. Unfortunately, there are some limitations in the range of movement and visualization of the operation field. Potentially addressing these limitations, we investigated the outcomes of gas and gasless robot-assisted nipple-sparing mastectomy (RANSM) with immediate breast reconstruction (IBR). Ten patients underwent 12 RANSM with IBR between November 2016 and April 2018. Patients with tumors measuring >5 cm in diameter, tumor invasion of the skin or nipple-areolar complex, proven metastatic lymph nodes, or planned radiotherapy were excluded. Age, breast weight, diagnosis, tumor size, hormone receptor status, and operation time were retrospectively collected. Postoperative outcomes including postoperative complications and final margin status of resected were analyzed. The median total operation time and console time were 351 min (267-480 min) and 51 min (18-143 min), respectively. The learning curve presented as a cumulative sum graph showed that the console time decreased and then stabilized at the eighth case. There was no open conversion or major postoperative complication. One patient had self-resolved partial nipple ischemia, and two patients experienced partial skin ischemia. We deemed that RANSM with IBR is safe and feasible for early breast cancer, benign disease of the breast, and BRCA 1/2 mutation carriers. RANSM is an advanced surgical method with a short learning curve.

Rapid Implementation of Intraoperative Ultrasonography to Reduce Wire Localization in The Permanente Medical Group.

CONTEXT: Preoperative wire localization (WL), the most common localization technique for nonpalpable breast lesions, has drawbacks including scheduling constraints, cost, and patient discomfort. OBJECTIVE: To reduce WL use in our health care system, we investigated using hydrogel clips to facilitate intraoperative ultrasonography-guided lumpectomies. DESIGN: We retrospectively reviewed electronic medical records of patients with nonpalpable, ultrasound-visible breast lesions who underwent lumpectomy by 7 surgeons at 4 pilot sites in Kaiser Permanente Northern California between January 2015 and October 2015. Hydrogel clips, used for several years before the study period, were placed routinely during core-needle biopsy in all patients with nonpalpable, ultrasound-visible breast lesions. MAIN OUTCOME MEASURES: Localization method, lesion size, margin positivity, and receipt of neoadjuvant therapy. RESULTS: One hundred forty-three patients underwent hydrogel clip placement and lumpectomy by pilot-site surgeons. Localization consisted of intraoperative ultrasonography alone, preoperative skin marking, or WL. Of the 143 patients, 71.3% did not need WL (60.8% ultrasonography alone and 10.5% skin marking). The non-WL and WL groups had similarly sized lesions, and the positive margin rate was 7.2% overall, with no significant difference between the non-WL and WL groups (5.9% vs 11.5%, p = 0.33). Of the 12 patients who underwent neoadjuvant chemotherapy, 8 (67%) did not require WL. CONCLUSION: A multifacility protocol using intraoperative ultrasonography to visualize hydrogel clips was implemented, which decreased WL procedures and produced no significant difference in margin positivity between the WL and non-WL groups. This technique can be a cost-effective alternative to WL in patients who are candidates for hydrogel clip placement.

Outcomes of single-port gasless laparoscopic breast-conserving surgery for breast cancer: An observational study.

To compare the clinical efficacy and aesthetic perspectives between single-port gasless laparoscopic breast-conserving surgery (SGL-BCS) and traditional breast-conserving surgery (T-BCS) in early-stage breast cancer. A total of 70 patients who were diagnosed with stage I or stage II breast cancer participated in this study, which 35 patients underwent SGL-BCS, while others underwent T-BCS. There were no death or severe intraoperative complications, and none of the patients exhibited regional recurrence, distant metastases, or any critical complications after 2 years follow-up. SGL-BCS is feasible and safe surgery, and has advantages in terms of a single, shorter, hidden incision, high-satisficed aesthetic outcome and less intraoperative blood loss.

Surgical Clips in Breast-conserving Surgery: Do they Represent the Tumour Bed Accurately?

INTRODUCTION: Radiotherapy after Breast-Conserving Surgery (BCS) is a standard treatment for breast cancer. Currently, surgical clips are used to determine the tumour bed before radiotherapy planning. This study aimed to evaluate the migration of these clips on mammograms. METHODS: The study was conducted on 121 females who were treated with radiotherapy after BCS at their first radiologic control examination 6 months after the end of treatment. MLO and CC views of all cases were evaluated regarding the clips. The distance between the surgical scar centre and the centre of the area covered by the clips was measured on both MLO and CC projections and recorded separately. This distance was determined as the clip displacement. A displacement ≤10 mm was recorded as no displacement. RESULTS: The clips were out of the images and were not evaluated in 45 cases (37.2%) on CC and in 9 cases (7.4%) on MLO projections. There were no clip displacements in 37 (30.6%) cases on CC and in 43 (35.5%) cases on MLO views. The amount of displacement ranged from 11 to 56 mm with a mean of 24.38 mm on CC views, while on MLO projections, displacement ranged from 11 to 66 mm with a mean of 24.42 mm. CONCLUSION: A clip displacement of greater than 10 mm was found in 64.5% of cases on MLO views. Therefore, we believe that the reliability of these clips for accurate delineation of the tumour bed in radiotherapy planning is controversial and other methods must be added.

The Impact of Breast Lumpectomy Tray Utilization on Cost Savings.

BACKGROUND: Right-sizing instrument trays reduce processing and replacement costs, physical strain, and turnover times. Historically, a 98-instrument head and neck tray has been used for breast lumpectomy cases at our institution. Observations revealed that many instruments on the tray were not used during the breast cases. With the significant number of surgical breast lumpectomies performed annually, tray downsizing could significantly reduce costs and physical strain. METHODS: Surgical technicians identified instruments needed for a standard breast lumpectomy. Breast surgeons reviewed the list and made final recommendations. Three of 13 existing head and neck trays were converted to breast lumpectomy trays. The number of breast lumpectomies in 2017 was pulled from the institution's health information system. Instrument quantities were verified using instrument management software. Weights were taken on a digital scale, and processing cost was estimated by a consultant. RESULTS: The new breast trays included 51 instruments rather than the standard 98-instrument trays. Reprocessing cost decreased from $49.98 to $26.01. With 449 breast lumpectomies performed at the institution in 2017, the annual reprocessing savings totaled $10,763. The tray weight was reduced from 27 to 16 pounds. Setup time decreased from 7 to 4 min per use (22.5 h saved annually). CONCLUSIONS: Downsizing from a head and neck tray to a specific breast lumpectomy tray demonstrated a reduction in reprocessing cost, tray weight, and setup time. Lighter trays allow for safer handling and transport by surgical personnel. In the current health-care environment, it is important to maximize operating room efficiency and minimize cost.

What a difference a clip makes! Analysis of boost volume definition in radiation therapy for conservative breast surgery.

PURPOSE/OBJECTIVE(S): To evaluate the role of surgical clips placement in the definition of boost treatment volume. MATERIALS/METHODS: Clinical Target Volumes (CTV) were defined as: CTV Breast, CTV Quadrant (based on physical exam and pre-surgical images), CTV Boost, defined by clip plus margin (1 cm for 2 or more clips and 2 cm for 1 clip only) plus radiological changes, CTV NT (normal tissue), defined by CTV Quadrant minus CTV Boost and CTV MISS (CTV that would be outside the treatment volume), defined by CTV Boost minus CTV Quadrant. RESULTS: A total of 247 patients were included. Upper lateral quadrant was the most common clinical location (47.3%). The median number of clips used was three. The mean volumes were: CTV Breast:982.52 cc, CTV Boost:36.59 cc, CTV Quadrant:285.07 cc, CTV NT:210.1 cc and CTV MISS:13.57 cc. Only 50.6% (125) of the patients presented the CTV Boost completely inside the CTV Quadrant and in 47.3% (117), partially inside. Among patients with any CTV MISS, 80.3% (98) had 10% or more of CTV Boost outside the treatment volume. Regarding CTV MISS, there were no statistically significant differences between the groups with 1 clip versus 2 or more clips, nor between patients with or without reconstructive surgery. In average, the CTV Boost was 87% smaller than the CTV Quadrant. The whole quadrant irradiation would lead to unnecessary irradiation of 26% of normal breast tissue. CONCLUSION: Surgical bed clipping is up most important in the definition of the boost volume irradiation to ensure precision minimizing geographical miss and optimizing surrounding normal tissue sparing.

Improvement of consistency in delineating breast lumpectomy cavity using surgical clips.

BACKGROUND: Delineation of lumpectomy cavity for whole breast radiation therapy after breast conserving surgery can be challenging because of poor visualization of the cavity. The use of surgical clips on lumpectomy cavity walls has been suggested as an effective and low-cost method to improve the accuracy and consistency of lumpectomy cavity delineation. MATERIALS AND METHODS: Twenty-three eligible female breast cancer patients who were treated with lumpectomy and adjuvant radiation therapy were recruited for this study. During breast conserving surgery, four surgical clips were placed on the superior, inferior, lateral, and medial walls of the lumpectomy cavity. Patients were imaged prior and during radiation treatment. Software was developed to anonymize the image sets and digitally remove the clips from the computed tomography images. Three radiation oncologists contoured the lumpectomy cavity volume, with and without presence of clips. Contoured image sets were analyzed with regard to cavity volume, dimensions, and concordance index. Statistical analysis was performed using a paired t-test. RESULTS: The presence of clips significantly increased the average lumpectomy cavity volumes from 23.50 cc to 26.42 cc (P < 0.0001). The presence of clips also significantly increased the mean craniocaudal, anteroposterior, and mediolateral dimensions by 6.8, 2.3, and 2.9 mm, respectively (all P < 0.01). In addition, the presence of surgical clips improved the consistency in delineation in CC dimension by significantly decreasing the standard deviation (P < 0.006). CONCLUSIONS: The presence of surgical clips improves the accuracy of lumpectomy cavity delineation. However, consistency is only improved in CC dimension.

Raman-Encoded Molecular Imaging with Topically Applied SERS Nanoparticles for Intraoperative Guidance of Lumpectomy.

Intraoperative identification of carcinoma at lumpectomy margins would enable reduced re-excision rates, which are currently as high as 20% to 50%. Although imaging of disease-associated biomarkers can identify malignancies with high specificity, multiplexed imaging of such biomarkers is necessary to detect molecularly heterogeneous carcinomas with high sensitivity. We have developed a Raman-encoded molecular imaging (REMI) technique in which targeted nanoparticles are topically applied on excised tissues to enable rapid visualization of a multiplexed panel of cell surface biomarkers at surgical margin surfaces. A first-ever clinical study was performed in which 57 fresh specimens were imaged with REMI to simultaneously quantify the expression of four biomarkers HER2, ER, EGFR, and CD44. Combined detection of these biomarkers enabled REMI to achieve 89.3% sensitivity and 92.1% specificity for the detection of breast carcinoma. These results highlight the sensitivity and specificity of REMI to detect biomarkers in freshly resected tissue, which has the potential to reduce the rate of re-excision procedures in cancer patients. Cancer Res; 77(16); 4506-16. ©2017 AACR.

Rapid evaporative ionisation mass spectrometry of electrosurgical vapours for the identification of breast pathology: towards an intelligent knife for breast cancer surgery.

BACKGROUND: Re-operation for positive resection margins following breast-conserving surgery occurs frequently (average = 20-25%), is cost-inefficient, and leads to physical and psychological morbidity. Current margin assessment techniques are slow and labour intensive. Rapid evaporative ionisation mass spectrometry (REIMS) rapidly identifies dissected tissues by determination of tissue structural lipid profiles through on-line chemical analysis of electrosurgical aerosol toward real-time margin assessment. METHODS: Electrosurgical aerosol produced from ex-vivo and in-vivo breast samples was aspirated into a mass spectrometer (MS) using a monopolar hand-piece. Tissue identification results obtained by multivariate statistical analysis of MS data were validated by histopathology. Ex-vivo classification models were constructed from a mass spectral database of normal and tumour breast samples. Univariate and tandem MS analysis of significant peaks was conducted to identify biochemical differences between normal and cancerous tissues. An ex-vivo classification model was used in combination with bespoke recognition software, as an intelligent knife (iKnife), to predict the diagnosis for an ex-vivo validation set. Intraoperative REIMS data were acquired during breast surgery and time-synchronized to operative videos. RESULTS: A classification model using histologically validated spectral data acquired from 932 sampling points in normal tissue and 226 in tumour tissue provided 93.4% sensitivity and 94.9% specificity. Tandem MS identified 63 phospholipids and 6 triglyceride species responsible for 24 spectral differences between tissue types. iKnife recognition accuracy with 260 newly acquired fresh and frozen breast tissue specimens (normal n = 161, tumour n = 99) provided sensitivity of 90.9% and specificity of 98.8%. The ex-vivo and intra-operative method produced visually comparable high intensity spectra. iKnife interpretation of intra-operative electrosurgical vapours, including data acquisition and analysis was possible within a mean of 1.80 seconds (SD ±0.40). CONCLUSIONS: The REIMS method has been optimised for real-time iKnife analysis of heterogeneous breast tissues based on subtle changes in lipid metabolism, and the results suggest spectral analysis is both accurate and rapid. Proof-of-concept data demonstrate the iKnife method is capable of online intraoperative data collection and analysis. Further validation studies are required to determine the accuracy of intra-operative REIMS for oncological margin assessment.

Radioactive seed localization is the preferred technique in nonpalpable breast cancer compared with wire-guided localization and radioguided occult lesion localization.

OBJECTIVES: Three commonly used techniques for localization of nonpalpable breast cancer are radioactive seed localization (RSL), wire-guided localization (WGL) and radioguided occult lesion localization (ROLL). In this study, we analysed the surgical margins of these three techniques. METHODS: Women diagnosed with nonpalpable breast cancer undergoing breast-conserving surgery with one of the above-mentioned techniques were retrospectively included. The primary outcome parameter was tumour-free margin rate. Secondary outcomes were re-excision rate, recurrence of disease and volume of removed tissue. RESULTS: In total, 272 women were included in whom RSL (n=69), WGL (n=76) or ROLL (n=137) was performed. RSL showed a higher tumour-free margin rate [64 (92.8%)] compared with WGL [51 (67.1%)] and ROLL [113 (82.5%)] (P=0.001). In our multivariable analysis, RSL showed a higher tumour-free margin rate as well compared with WGL (P=0.036) and ROLL (P=0.049). Also, fewer re-excisions were encountered using RSL [5 (7.2%)] compared with WGL [13 (17.1%)] and ROLL [15 (10.9%)] (P=0.171). In 11 patients (WGL n=2, ROLL n=9), recurrence of disease occurred, despite a radical excision. The mean resection volumes were comparable within the three groups. CONCLUSION: RSL results in a higher tumour-free margin rate in nonpalpable breast tumours compared with WGL and ROLL. Therefore, we prefer using RSL in nonpalpable breast tumours.