First Reported Use of the Faxitron LOCalizer™ Radiofrequency Identification (RFID) System in Europe - A Feasibility Trial, Surgical Guide and Review for Non-palpable Breast Lesions

A Radiological Clip Design Using Ultrasound Identification to Improve Localization

OBJECTIVE

We demonstrate the use of ultrasound to receive an acoustic signal transmitted from a radiological clip designed from a custom circuit. This signal encodes an identification number and is localized and identified wirelessly by the ultrasound imaging system.

METHODS

We designed and constructed the test platform with a Teensy 4.0 microcontroller core to detect ultrasonic imaging pulses received by a transducer embedded in a phantom, which acted as the radiological clip. Ultrasound identification (USID) signals were generated and transmitted as a result. The phantom and clip were imaged using an ultrasonic array (Philips L7-4) connected to a Verasonics™ Vantage 128 system operating in pulse inversion (PI) mode. Cross-correlations were performed to localize and identify the code sequences in the PI images.

RESULTS

USID signals were detected and visualized on B-mode images of the phantoms with up to sub-millimeter localization accuracy. The average detection rate across 30,400 frames of ultrasound data was 98.1%.

CONCLUSION

The USID clip produced identifiable, distinguishable, and localizable signals when imaged.

SIGNIFICANCE

Radiological clips are used to mark breast cancer being treated by neoadjuvant chemotherapy (NAC) via implant in or near treated lesions. As NAC progresses, available marking clips can lose visibility in ultrasound, the imaging modality of choice for monitoring NAC-treated lesions. By transmitting an active signal, more accurate and reliable ultrasound localization of these clips could be achieved and multiple clips with different ID values could be imaged in the same field of view.

Evolution of localization methods for non-palpable breast lesions: a literature review from a translational medicine perspective

Background and Objective

With an increasing number of non-palpable breast lesions detected due to improved screening, accurate localization of these lesions for surgery is crucial. This literature review explores the evolution of localization methods for non-palpable breast lesions, highlighting the translational journey from concept to clinical practice.

Methods

A comprehensive search of PubMed, Embase, and Scopus databases until September 2023 was conducted.

Key Content and Findings

Multiple methods have been developed throughout the past few decades. (I) Wire-guided localization (WGL) introduced in 1966, has become a reliable method for localization. Its simplicity and cost-effectiveness are its key advantages, but challenges include logistical constraints, patient discomfort, and potential wire migration. (II) Intraoperative ultrasound localization (IOUS) has shown promise in ensuring complete lesion removal with higher negative margin rates. However, its utility is limited to lesions visible on ultrasound (US) imaging. (III) Breast biopsy marker localization: the use of markers has improved the precision of localization without the need for wire. However, marker visibility remains a challenge despite improvements in their design. (IV) Radioactive techniques: radio-guided occult lesion localization (ROLL) and radioactive seed localization (RSL) offer flexibility in scheduling and improved patient comfort. However, they require close multidisciplinary collaboration and specific equipment due to radioactive concerns. (V) Other wireless non-radioactive techniques: wireless non-radioactive techniques have been developed in recent three decades to provide flexible and patient-friendly alternatives. It includes magnetic seed localization, radar techniques, and radiofrequency techniques. Their usage has been gaining popularity due to their safety profile and allowance of more flexible scheduling. However, their high cost and need for additional training remain a barrier to a wider adoption.

Conclusions

The evolution of breast lesion localization methods has progressed to more patient-friendly techniques, each with its unique advantages and limitations. Future research on patient-reported outcomes, cosmetic outcomes, breast biopsy markers and integration of augmented reality with breast lesion localization are needed.

Wire- and radiofrequency identification tag-guided localization of impalpable breast lesions: iBRA-NET localization study

A national cohort ideal stage 2a/2b study comparing the safety and effectiveness of Wire- and RFID -guided localisation for impalpable breast lesions.

Radiofrequency localization of nonpalpable breast cancer in a multicentre prospective cohort study: feasibility, clinical acceptability, and safety

PURPOSE

In breast conserving surgery, accurate lesion localization is essential for obtaining adequate surgical margins. Preoperative wire localization (WL) and radioactive seed localization (RSL) are widely accepted methods to guide surgical excision of nonpalpable breast lesions but are limited by logistical challenges, migration issues, and legislative complexities. Radiofrequency identification (RFID) technology may offer a viable alternative. The purpose of this study was to evaluate the feasibility, clinical acceptability, and safety of RFID surgical guidance for localization of nonpalpable breast cancer.

METHODS

In a prospective multicentre cohort study, the first 100 RFID localization procedures were included. The primary outcome was the percentage of clear resection margins and re-excision rate. Secondary outcomes included procedure details, user experience, learningcurve, and adverse events.

RESULTS

Between April 2019 and May 2021, 100 women underwent RFID guided breast conserving surgery. Clear resection margins were obtained in 89 out of 96 included patients (92.7%), re-excision was indicated in three patients (3.1%). Radiologists reported difficulties with the placement of the RFID tag, partially related to the relatively large needle-applicator (12-gauge). This led to the premature termination of the study in the hospital using RSL as regular care. The radiologist experience was improved after a manufacturer modification of the needle-applicator. Surgical localization involved a low learning curve. Adverse events (n = 33) included dislocation of the marker during insertion (8%) and hematomas (9%). The majority of adverse events (85%) occurred using the first-generation needle-applicator.

CONCLUSION

RFID technology is a potential alternative for non-radioactive and non-wire localization of nonpalpable breast lesions.

Clinical experience of the Magseed® magnetic marker to localize non-palpable breast lesions: a cohort study of 100 consecutive cases

Background

The aim of this study was to report on a cohort of 100 patients where the Magseed® paramagnetic marker was used to localize non-palpable breast lesions.

Methods

Data were collected from a cohort of 100 patients with non-palpable breast lesions, who underwent localization using the Magseed® marker. This marker consists of a paramagnetic seed that can be seen on mammography or ultrasound and intraoperatively detected with the use of the Sentimag® probe. The data were collected over a period of 23 months (May 2019 to April 2021).

Results

All 111 seeds were successfully placed in the breasts of 100 patients under ultrasound or via stereotactic guidance. Eighty-nine seeds were inserted in single lesions or small microcalcification clusters in a single breast, 12 seeds were deployed to a bracket microcalcification clusters and 10 to help localize two tumors within the same breast. Most Magseed® markers (88.3%) were placed in the center of the lesion (≤1 mm). The re-excision rate was 5%. All Magseed® markers were successfully retrieved and no surgical complications were observed.

Conclusions

This study reports our experience in a Belgian breast unit using the Magseed® magnetic marker and it highlights the many advantages of the Magseed® marker system. With this system, we successfully identified subclinical breast lesions and extended microcalcification clusters, targeting multiple sites within the same breast.

Radiofrequency Identification—RFID using LOCalizer-Tag in Non-palpable Breast Lump

For many years, wire-guided localization represented the gold standard method for the detection of non-palpable breast lesions, despite the acknowledged limitations. LOCalizer™ is the most recent and promising radiofrequency identification system, characterized by the capability of measuring the distance from the tagged lesion in millimeters and the association of each marker with a unique code. A 45-year-old woman with two lesions suspected of cancer in the same breast was referred to our department. She underwent double localization with LOCalizer™ (Hologic, Santa Carla, CA, USA) of the lumps into opposite quadrants. We performed a mini-invasive and oncologically safe surgical excision through a tunneling approach after a peri-areolar incision. The surgical technique realized with Localizer™ could be an effective method for locating multiple non-palpable breast lesions and is able to offer excellent oncological and cosmetic results, as also confirmed by several reports in the literature.

Intraoperative Margin Trials in Breast Cancer

Purpose of Review

Obtaining negative margins in breast conservation surgery continues to be a challenge. Re-excisions are difficult for patients and expensive for the health systems. This paper reviews the literature on current strategies and intraoperative clinical trials to reduce positive margin rates.

Recent Findings

The best available data demonstrate that intraoperative imaging with ultrasound, intraoperative pathologic assessment such as frozen section, and cavity margins have been the most successful intraoperative strategies to reduce positive margins. Emerging technologies such as optical coherence tomography and fluorescent imaging need further study but may be important adjuncts.

Summary

There are several proven strategies to reduce positive margin rates to < 10%. Surgeons should utilize best available resources within their institutions to produce the best outcomes for their patients.

A multicenter prospective cohort study to evaluate feasibility of radio-frequency identification surgical guidance for nonpalpable breast lesions: design and rationale of the RFID Localizer 1 Trial

BACKGROUND

Breast cancer screening and improving imaging techniques have led to an increase in the detection rate of early, nonpalpable breast cancers. For early breast cancer, breast conserving surgery is an effective and safe treatment. Accurate intraoperative lesion localization during breast conserving surgery is essential for adequate surgical margins while sparing surrounding healthy tissue to achieve optimal cosmesis. Preoperative wire localization and radioactive seed localization are accepted standard methods to guide surgical excision of nonpalpable breast lesions. However, these techniques present significant limitations. Radiofrequency identification (RFID) technology offers a new, nonradioactive method for localizing nonpalpable breast lesions in patients undergoing breast conserving surgery. This study aims to evaluate the feasibility of RFID surgical guidance for nonpalpable breast lesions.

METHODS

This multicenter prospective cohort study was approved by the Institutional Review Board of the University Medical Center Utrecht. Written informed consent is obtained from all participants. Women with nonpalpable, histologically proven in situ or invasive breast cancer, who can undergo breast conserving surgery with RFID localization are considered eligible for participation. An RFID tag is placed under ultrasound guidance, up to 30 days preoperatively. The surgeon localizes the RFID tag with a radiofrequency reader that provides audible and visual real-time surgical guidance. The primary study outcome is the percentage of irradical excisions and reexcision rate, which will be compared to standards of the National Breast Cancer Organisation Netherlands (NABON)(≤ 15% irradical excisions of invasive carcinomas). Secondary outcomes include user acceptability/experiences, learning curve, duration and ease of the placement- and surgical procedure and adverse events.

DISCUSSION

This study evaluates the feasibility of RFID surgical guidance for nonpalpable breast lesions. Results may have implications for the future localization techniques in women with nonpalpable breast cancer undergoing breast conserving surgery.

TRIAL REGISTRATION

Netherlands National Trial Register, NL8019 , registered on September 12^th 2019.

The Evolving Role of Radiofrequency Guided Localisation in Breast Surgery: A Systematic Review

Wire-guided localisation (WGL) has been the gold-standard for localising non-palpable breast lesions before excision. Due to its drawbacks, various wireless alternatives have been developed, including LOCalizer™, which is based on radio-frequency identification (RFID) technology. In this systematic review, we consulted EMBASE, Medline and PubMed databases using appropriate search terms regarding the use of RFID technology in the localisation of occult breast lesions. Retrospective and prospective studies were included if they quoted the number of patients, rate of successful placement, retrieval rate, margin positivity rate and the re-excision rate. In addition, studies comparing RFID to WGL were also included and analysed separately. Seven studies were included in this systematic review spanning 1151 patients and 1344 tags. The pooled deployment rate was 99.1% and retrieval rate was 100%. Re-excision rate was 13.9%. One complication was identified. Two studies compared RFID with WGL (128 vs. 282 patients respectively). For both techniques the re-excision rate was 15.6% (20/128 vs. 44/282 respectively, p value is 0.995). Based on our review, LOCalizer™ is safe and non-inferior to WGL in terms of successful localisation and re-excision rates. However, further research is required to assess the cost effectiveness of this approach and its impact on the aesthetic outcome compared with WGL and other wire free technologies to better inform decision making in service planning and provision.

Image-guided Localization Techniques for Nonpalpable Breast Lesions: An Opportunity for Multidisciplinary Patient-centered Care

Selection of a localization method for nonpalpable breast lesions offers an opportunity for institutions to seek multidisciplinary input to promote value-based, patient-centered care. The diverse range of nonpalpable breast and axillary pathologies identified through increased utilization of screening mammography often necessitates image-guided preoperative localization for accurate lesion identification and excision. Preoperative localization techniques for breast and axillary lesions have evolved to include both wire and nonwire methods, the latter of which include radioactive seeds, radar reflectors, magnetic seeds, and radiofrequency identification tag localizers. There are no statistically significant differences in surgical outcomes when comparing wire and nonwire localization devices. Factors to consider during selection and adoption of image-guided localization systems include physician preference and ease of use, workflow efficiency, and patient satisfaction.

Biopsy marker localization with thermo-acoustic ultrasound for lumpectomy guidance

PURPOSE

Almost one in four lumpectomies fails to fully remove cancerous tissue from the breast, requiring reoperation. This high failure rate suggests that existing lumpectomy guidance methods are inadequate for allowing surgeons to consistently identify the proper volume of tissue for excision. Current guidance techniques either provide little information about the tumor position or require surgeons to frequently switch between making incisions and manually probing for a marker placed at the lesion site. This article explores the feasibility of thermo-acoustic ultrasound (TAUS) to enable hands-free localization of metallic biopsy markers throughout surgery, which would allow for continuous visualization of the lesion site in the breast without the interruption of surgery. In a TAUS-based localization system, microwave excitations would be transmitted into the breast, and the amplification in microwave absorption around the metallic markers would generate acoustic signals from the marker sites through the thermo-acoustic effect. Detection and ranging of these signals by multiple acoustic receivers on the breast could then enable marker localization through acoustic multilateration.

METHODS

Physics simulations were used to characterize the TAUS signals generated from different markers by microwave excitations. First, electromagnetic simulations determined the spatial pattern of the amplification in microwave absorption around the markers. Then, acoustic simulations characterized the acoustic fields generated from these markers at various acoustic frequencies. TAUS-based one-dimensional (1D) ranging of two metallic markers-including a biopsy marker that is FDA-approved for clinical use-immersed in saline was also performed using a bench-top setup. To perform TAUS acquisitions, a microwave applicator was driven by 2.66 GHz microwave signals that were amplitude-modulated by chirps at the desired acoustic excitation frequencies, and the resulting TAUS signal from the markers was detected by an ultrasonic transducer.

RESULTS

The simulation results show that the geometry of the marker strongly impacts the quantity and spatial pattern of both the microwave absorption around the marker and the resulting TAUS signal generated from the marker. The simulated TAUS signal maps and acoustic frequency responses also make clear that the marker geometry plays an important role in determining the overall system response. Using the bench-top setup, TAUS detection and 1D localization of the markers were successfully demonstrated for multiple different combinations of microwave applicator and metallic marker. These initial results indicate that TAUS-based localization of biopsy markers is feasible.

CONCLUSIONS

Through microwave excitations and acoustic detection, TAUS can be used to localize metallic biopsy markers. With further development, TAUS opens new avenues to enable a more intuitive lumpectomy guidance system that could help to achieve better lumpectomy outcomes.

Combined LOCalizer™ and Intraoperative Ultrasound Localization: First Experience in Localization of Non-palpable Breast Cancer

BACKGROUND

Wire-guided localization is the gold-standard for the detection of non-palpable breast lesions, although with acknowledged limitations. The aim of this study was to evaluate the combined use of LOCalizerr™ (Hologic, Santa Carla, CA, USA), and intraoperative ultrasound (IOUS) for localization and surgery of non-palpable breast cancer.

PATIENTS AND METHODS

Patients with non-palpable breast lesions underwent localization procedure with LOCalizer™ and IOUS. After the placement of the marker, eight measures were made to guide the excision. LOCalizerr™ Pencil and IOUS were performed to obtain the distance between the dissection plane and the margins of lesions.

RESULTS

The procedure was feasible in the five enrolled patients and associated with clear oncological margins in all cases. Moreover, a high satisfaction according to Likert scale for surgeons, radiologists and patients, performing limited and tailored resections, was reported.

CONCLUSION

Combining LOCalizerr™ and IOUS is an effective method for locating non-palpable breast cancer, guarantying excellent oncological and cosmetic results.

Reflector-Guided Localisation of Non-Palpable Breast Lesions: A Prospective Evaluation of the SAVI SCOUT® System

Simple Summary

Marking impalpable areas of breast cancer prior to surgery is an important part of the modern treatment of breast cancer. Traditionally, the target lesion would be marked by a wire just before surgery under image guidance and would help the surgeon locate the tumour during surgery. However, this method has some drawbacks, such as patient discomfort, the risk of migration and dislodgement, and the need to couple surgical and radiological schedules. Therefore, there has been a growing interest in this system, thus supporting its potential. In this study, we have evaluated one such system, SAVI SCOUT^®, in 63 consecutive patients. Our experience with this system supported its potential role in modern breast surgery.

Abstract

Wire-guided localisation (WGL) has been the mainstay for localising non-palpable breast lesions before excision. Due to its limitations, various wireless alternatives have been developed. In this prospective study, we evaluate the role of radiation-free wireless localisation using the SAVI SCOUT^® system at the London Breast Institute. A total of 72 reflectors were deployed in 67 consecutive patients undergoing breast conserving surgery for non-palpable breast lesions. The mean interval between deployment and surgery for the therapeutic cases was 18.8 days (range: 0–210). The median deployment duration was 5 min (range: 1–15 min). The mean distance from the lesion was 1.1 mm (median distance: 0; range: 0–20 mm). The rate of surgical localisation and retrieval of the reflector was 98.6% and 100%, respectively. The median operating time was 28 min (range: 15–55 min) for the therapeutic excision of malignancy and 17 min (range: 15–24) for diagnostic excision. The incidence of reflector migration was 0%. Radial margin positivity in malignant cases was 7%. The median weight for malignant lesions was 19.6 g (range: 3.5–70 g). Radiologists and surgeons rated the system higher than WGL (93.7% and 98.6%, respectively; 60/64 and 70/71). The patient mean satisfaction score was 9.7/10 (n = 47, median = 10; range: 7–10). One instance of signal failure was reported. In patients who had breast MRI after the deployment of the reflector, the MRI void signal was <5 mm (n = 6). There was no specific technique-related surgical complication. Our study demonstrates that wire-free localisation using SAVI SCOUT^® is an effective and time-efficient alternative to WGL with excellent physician and patient acceptance.

First Reported Use of Radiofrequency Identification (RFID) Technique for Targeted Excision of Suspicious Axillary Lymph Nodes in Early Stage Breast Cancer - Evaluation of Feasibility and Review of Current Recommendations

BACKGROUND/AIM

The purpose of this study was to evaluate, whether radio frequency identification (RFID) labeling of axillary lymph nodes (LNs) for the use of targeted resection is feasible in primary breast cancer patients with suspicious LNs.

PATIENTS AND METHODS

We analyzed 10 consecutive patients where RFID technique was used for intraoperative detection of suspicious LNs without preceding neoadjuvant chemotherapy (NACT). We compared the specifics of these procedures to 10 consecutive sentinel lymph node biopsies (SLNB) in the cN0 situation.

RESULTS

Intraoperative detection rate (DR) for the RFID-labeled target lymph node (TLN) was 100%. Perioperative complications were infrequent and comparable to SLNB. Average time for location of the RFID labeled TLN was quicker than for the SLN. In 71.4% the chip bearing TLN equaled a SLN.

CONCLUSION

The use of the RFID technique for intraoperative localization of axillary LNs for targeted excision seems feasible. RFID technique for targeted axillary dissection (TAD) following NACT should be investigated in a prospective manner.

Retrospective Review of Preoperative Radiofrequency Tag Localization of Breast Lesions in 848 Patients

BACKGROUND. Advantages of radiofrequency tags for preoperative breast lesion localization include decoupling of tag placement from surgical schedules and improved patient comfort. OBJECTIVE. The purpose of this study was to evaluate the feasibility of a preoperative localization radiofrequency tag system for breast lesions requiring surgical excision. METHODS. The cohort for this retrospective study included consecutive patients who underwent image-guided needle localization with radiofrequency tags before surgical excision from July 12, 2018, to July 31, 2019. Images and medical records were reviewed to evaluate the pathologic diagnoses serving as indications for tag placement, imaging guidance for tag placement, number of tags placed, and target lesion type. Tag placement technical accuracy rate (defined as deployment of the tag within 1 cm of the edge of the target), success (defined as technical accuracy without complication), and surgical margin and reexcision status were evaluated. RESULTS. A total of 1013 tags were placed under imaging guidance in 848 patients (mean age, 60 years; range, 23-96 years) and 847 subsequently underwent surgical excision. Tags were most commonly placed for invasive carcinoma (537/1013, 53.0%), ductal carcinoma in situ (138/1013, 13.6%), and high-risk lesions (289/1013, 28.5%). A total of 673 (66.4%) tags were deployed under mammographic guidance, whereas 340 (33.6%) were placed under sonographic guidance. Two or more tags were placed in 149 of 848 patients (17.6%). Targeted lesion types primarily included masses (448/1013, 44.2%), biopsy clip markers (331/1013, 32.7%), and calcifications (155/1013, 15.3%). Technical accuracy of placement was achieved in 1004 (99.1%) tags. Of the nine inaccurate tag placements, seven (77.8%) required an additional tag or wire placement. Seven (0.7%) biopsy clip markers were displaced within the breast or removed by the tag device during placement. No complications were reported intraoperatively. Therefore, success was achieved in 997 (98.4%) tags. Tags were successfully retrieved in all 847 patients who underwent surgery. Of the 568 patients with a preoperative diagnosis of carcinoma, 86 (15.1%) had positive or close surgical margins requiring surgical reexcision. CONCLUSION. Preoperative image-guided localization with radiofrequency tags is a safe and feasible technique for breast lesions requiring surgery. CLINICAL IMPACT. Radiofrequency tag localization is an acceptable alternative to needle or wire localization, offering the potential for improved patient workflow and experience.

Platelet-Rich Plasma (PRP) in Breast Cancer Patients: An Application Analysis of 163 Sentinel Lymph Node Biopsies

Introduction

Literature shows platelet-rich plasma (PRP) to improve overall outcomes in orthopedics, dermatology, ophthalmology, gynecology, and plastic surgery. Data on oncological patients is very limited. Only one publication is available on PRP in breast cancer patients. This work evaluated PRP in sentinel node biopsy procedures for breast cancer patients in terms of complication rates and oncological short-term follow-up.

Methods

The evaluated PRP was ACP®, i.e., autologous conditioned plasma by Arthrex®. Between 2015 and 2018, 163 patients were offered to receive an ACP®/PRP injection in their lymph node biopsy site. Recruitment resulted in an approximate one-to-one ratio for analysis. Endpoints were major (revision) and minor (seroma, hematoma, and infection) complications rates as well as distant metastases, local recurrence, and overall survival. Median follow-up was 30 months.

Results

Complication rates and oncological follow-up showed PRP to be applicable to use in a sentinel node biopsy scenario in breast cancer patients. There were 0 revisions in the ACP®/PRP group and 1.2% revisions in the control group (not significant). Oncological follow-up showed zero (0) distant metastases and local recurrences as well as a 100% 30-month overall survival.

Conclusions

This is the first analysis of ACP®/PRP used in breast cancer patients in a sentinel node biopsy setting worldwide. PRP does not seem to increase rates of local recurrence within this 30-month follow-up time frame. Also, trend towards decreasing complication rates could be shown.

The LOCalizer Radiofrequency Identification System: An Effective New Technology for Localizing Non-Palpable Breast Lesions for Surgery

Background. Breast screening has decreased morbidity and mortality due to detection of early, non-palpable breast cancers. One of the challenges of performing breast-conserving surgery on non-palpable breast tumours is accurate localization of the cancer. We aimed to perform a feasibility study to examine the outcomes associated with the introduction of a novel radiofrequency identification system (RFID) called LOCalizer as an alternative to traditional wire-guided localization. Methods. Data were prospectively collected on all patients undergoing breast-conserving surgery using the LOCalizer RFID system in a regional cancer centre between July 2019 and March 2020. Patients had a RFID tag placed preoperatively and underwent surgical removal of the tag with the index lesion guided by a handheld LOCalizer probe. The primary aim was successful placement and retrieval of the RFID tag. Re-excision rates, specimen size, specimen weight, cancer subtype and complication rate were all recorded. Results. Sixty-nine patients aged between 50 and 69 years had a LOCalizer tag inserted between July 2019 and March 2020. Of these, 6 (8.7%) were diagnostic and 63 (91.3%) were therapeutic. There was no migration of RFID tags, and all tags were retrieved with the index lesion. The overall re-excision of margin rate was 17.4% (12/69). All re-excision of margins was due to positive radial margins. The overall complication rate was 1.4% with one grade 1 Clavien-Dindo morbidity. Conclusion. The LOCalizer RFID is an effective and safe wire-free localization method for non-palpable breast lesions.

Wireless Breast Localization Using Radio-frequency Identification Tags: The First Reported European Experience in Breast Cancer

BACKGROUND/AIM

Wire-guided localisation (WGL) has been the mainstay for localisation of clinically occult breast lesions before excision. However, it has restrictive scheduling requirements, and causes patient discomfort. This has prompted the development of various wireless alternatives. In this prospective study we shall evaluate the role of radiation-free wireless localisation using a radiofrequency identification (RFID) tag and a hand-held reader (LOCalizer™) in the management of occult breast lesions.

PATIENTS AND METHODS

This technique was evaluated in a prospective cohort of 10 patients. The evaluation focused on: i) successful deployment, ii) identification and retrieval, iii) the status of surgical margins and need for re-operation, iv) resected specimen weight, v) marker migration rates (>5mm), and vi) acceptance by patients, radiologists and surgeons.

RESULTS

RFID tags (n=11) were deployed under ultrasound guidance pre-operatively to localise occult breast lesions in 10 patients. The mean time for deployment of the RFID tag was 5.4 min (range=2-20). The mean distance from the lesion was 0.45 mm (range=0-3). The mean duration for retrieval was 10.2 min (range=6-20). Mean specimen weight was 19.6 g for malignant lesions (range=4.5-42). All tags were identified, and none had migrated. There were no positive margins, re-operations, nor complications. Patient feedback was highly positive. Both radiologists and surgeons rated the LOCalizer™ technique as better than WGL.

CONCLUSION

Our study demonstrates that wireless localisation using RFID is an effective and time-efficient alternative to WGL, with low margin positivity and re-operation rates, and high patient, radiologist and surgeon acceptance.

A comparison of two non-radioactive alternatives to wire for the localization of non-palpable breast cancers

PURPOSE

Multiple wire-free technologies for localization of non-palpable breast cancers have emerged as satisfactory alternatives to wire. However, no study has compared two non-radioactive wire-free approaches to one another. The purpose of this study was to compare outcomes among LOCalizer™ radiofrequency identification (RFID), SAVI Scout® (SAVI), and wire localization (WL).

METHODS

This was a retrospective, cross-sectional cohort study of patients undergoing lumpectomy for non-palpable breast cancer at a single institution between August 2017 and February 2019. Patients were divided into three cohorts based on localization technique: RFID, SAVI or WL. Operative times and average tumor volumes were compared using one-way analysis of variance. Positive margin and re-excision rates were compared with Fisher's exact test.

RESULTS

Among 104 patients who underwent lumpectomy for non-palpable breast cancer, 33 patients (31.7%) had RFID, 21 (20.2%) had SAVI, and 50 (48.0%) had WL. Operative times were 79 min for RFID, 81 min for SAVI, and 78 min for WL (p = 0.91). Volume of tissue resected was 36.3 cm³, 31.7 cm³, and 35.3 cm³ for RFID, SAVI, and WL, respectively (p = 0.84). Positive margin rates (RFID 3.0% vs SAVI 9.5% vs WL 8.0%, p = 0.67) and re-excision rates (RFID 6.1% vs SAVI 9.5% vs WL 10.0%, p = 0.82) were similar across groups.

CONCLUSIONS

Wire-free localization technologies have been compared to WL demonstrating similar efficacy. Our study suggests that RFID and SAVI Scout also perform similarly to one another. Physicians and institutions may consider more nuanced features of each localization system rather than performance alone when choosing a wire-free alternative.