Predictive Factors for Positive Margin and the Surgical Learning Curve in Non-Palpable Breast Cancer After Wire-Guided Localization – Prospective Study of 214 Consecutive Patients

Radiofrequency as a method of localizing impalpable breast lesions

BACKGROUND

The incidence of early stage breast cancer has risen as a result of increased detection of non-palpable tumors through the implementation of screening programs and greater public awareness. Performing breast-conserving surgery can be challenging due to the need for accurate localization of non-palpable breast lesions, particularly given the logistical difficulties associated with wire localization. After implementing a new technique for localizing non-palpable breast lesions (LOCalizerTM Radiofrequency identification TAG-Hologic®), a radiofrequency identification tag localization device manufactured by Hologic, Inc. in Marlborough, MA, was launched in 2017, our objective was to investigate its impact on surgical outcomes, whether there was an increase in re-excision rates for positive margins and whether the attainment of clear margins was dependent on the exact positioning of the RFID device.

METHOD

A single-center single-arm interventional study, data were gathered both in a forward-looking manner for 1 year (prospectively) and by looking back at past records for 1 year (retrospectively) for a total period of two years. Individuals who were diagnosed with non-palpable breast lesions, as confirmed by histological analysis, or invasive breast cancer and who were scheduled to undergo breast-conserving surgery were eligible for inclusion in the study. The RFID (Radiofrequency Identification) method was used to localize the lesions prior to surgery. Either with a mammogram or ultrasound scan position of the Tag was recorded, including the distance of the lesion from the center of the lesion and the lesion depth from the skin in millimeters. The rate of re-excision was documented and examined in relation to the parameters mentioned above.

RESULTS

Two hundred and twenty RFID Tags were inserted in two hundred and seventeen (three patient had bilateral tags insertion), patients aged between 30 and 85 had a localizer Tag inserted between Oct 2020 and Oct 2022. Three patients had non-palpable breast lesions in both breasts. Fourteen were inserted under stereotactic guidance and two hundred and six under ultrasound guidance. Ten patients subsequently had wire insertion also due to Tag position. Of 210 procedures, RFIF Tags within the lesion was seen in hundred and sixty patients (76.19 %). An additional 50 procedures were performed using the RFID Tag system, which were not directly related to the lesion but were deemed appropriate to proceed with. Out of a total of 220 procedures, positive margins were observed in 38 cases (17.27 %). Among these cases, eleven (28.94 %) involved the use of the RFID Tag system, not within the lesion but adjacent to it (within 15 mm surrounding the lesion).

CONCLUSION

RFID is a good alternative to wire localization of non-palpable breast lesions. Re-excision rates are higher in patients with Tag outside the lesion compared to those with Tag within the lesion.

A Randomized Controlled Trial for Doing vs. Omitting Intraoperative Frozen Section Biopsy for Resection Margin Status in Selected Patients Undergoing Breast-Conserving Surgery (OFF-MAP Trial)

Purpose

Intraoperative frozen section biopsy is used to reduce the margin positive rate and re-excision rate and has been reported to have high diagnostic accuracy. A majority of breast surgeons in the Republic of Korea routinely perform frozen section biopsy to assess margins intraoperatively, despite its long turnaround time and high resource requirements. This study aims to determine whether omitting frozen section biopsy for intraoperative margin evaluation in selected patients is non-inferior to performing frozen section biopsy in terms of resection margin positivity rate.

Methods

This study is a phase III, randomized controlled, parallel-group, multicenter non-inferiority clinical trial. Patients meeting the inclusion criteria and providing written informed consent will be randomized to the “frozen section biopsy” or “frozen section biopsy omission” group after lumpectomy. Patients with clinical stage T1–T3 disease who are diagnosed with invasive breast cancer by core-needle biopsy and plan to undergo breast-conserving surgery will be included in this study. If a daughter nodule, non-mass enhancement, or microcalcification is identified on preoperative imaging, these features must be within 1 cm of the main mass for inclusion in the trial. The target sample size is 646 patients per arm. The primary endpoint will be the resection margin positive rate, and the secondary endpoints include the reoperation rate, operating time, residual cancer after reoperation, residual cancer after re-excision according to the frozen section biopsy result, resection volume, patient quality of life, and cost-effectiveness.

Discussion

This is the first randomized clinical trial utilizing frozen section biopsy for intraoperative margin evaluation and aims to determine the non-inferiority of omitting frozen section biopsy in selected patients compared to performing frozen section biopsy. We expect that this trial will help surgeons perform the procedure more efficiently while ensuring patient safety.

Trial Registration

ClinicalTrials.gov Identifier: NCT03975179; Clinical Research Information Service Identifier: KCT0004606

Sentinel node occult lesion localization technique for impalpable breast cancer

BACKGROUND

Mammographic screening has enabled earlier detection of breast cancer, with 25-35% of malignancies being non-palpable at diagnosis. Accurate removal and sentinel node biopsy for staging these lesions are crucial to successful management. Both these aspects are achieved by peritumoural localization with radioisotope and lymphoscintigraphy for sentinel lymph node (SN) mapping using the sentinel node and occult lesion localization (SNOLL) technique. This study reports SNOLL outcomes in a large cohort of women with non-palpable breast cancers to assess its performance and promote its logistic advantages.

METHODS

This retrospective cohort study used data from BreastSurgANZ Quality Audit supplemented with private case notes. Inclusion criteria were females >18 years, with invasive breast cancer that was asymptomatic and non-palpable at presentation, who underwent SNOLL (n = 450). Primary outcomes were proportion of successful lesion localization, proportion of patients requiring re-excision and volume of tissue excised. Secondary outcomes focused on lymphoscintigraphy success rate in detecting sentinel nodes and SN positivity rates.

RESULTS

Tumours were successfully removed with the initial SNOLL procedure in 449 cases (99.8%). The re-excision rate was 15.1% (n = 68). The mean total excision volume was 54.69 cm3 (95% CI 51.49-57.88 cm3 ; range 2.75-195.33 cm3 ), with a mean closest circumferential margin of 7.05 mm (95% CI 6.60-7.49 mm; range 0 to ≥10 mm). Lymphoscintigraphy was successful in 96.9% (n = 436) of cases. Sentinel nodes were successfully identified and removed in 99.6% (n = 448) of cases. SN positivity rate was 18.4%.

CONCLUSION

SNOLL is an efficient and effective technique for localizing non-palpable invasive breast lesions while simultaneously identifying sentinel nodes.

Surgery Tutor for Computational Assessment of Technical Proficiency in Soft-Tissue Tumor Resection in a Simulated Setting

BACKGROUND

In competency-based medical education, progression between milestones requires reliable and valid methods of assessment. Surgery Tutor is an open-source motion tracking platform developed to objectively assess technical proficiency during open soft-tissue tumor resections in a simulated setting. The objective of our study was to provide evidence in support of construct validity of the scores obtained by Surgery Tutor. We hypothesized that Surgery Tutor would discriminate between novice, intermediate, and experienced operators.

METHODS

Thirty participants were assigned to novice, intermediate, or experienced groups, based on the number of prior soft-tissue resections performed. Each participant resected 2 palpable and 2 nonpalpable lesions from a soft-tissue phantom. Surgery Tutor was used to track hand and instrument motions, number of tumor breaches, and time to perform each resection. Mass of excised specimens and margin status were also recorded.

RESULTS

Surgery Tutor scores demonstrated "moderate" to "good" internal structure (test-retest reliability) for novice, intermediate, and experienced groups (interclass correlation coefficient = 0.596, 0.569, 0.737; p < 0.001). Evidence in support of construct validity (consequences) was demonstrated by comparing scores of novice, intermediate, and experienced participantsfor number of hand and instrument motions (690 ± 190, 597 ± 169, 469 ± 110; p < 0.001), number of tumor breaches (29 ± 34, 16 ± 11, 9 ± 6; p < 0.001), time per resection (677 ± 331 seconds, 561 ± 210 seconds, 449 ± 148 seconds; p < 0.001), mass of completely excised specimens (22 ± 7g, 21 ± 11g, 17 ± 6 g; p = 0.035), and rate of positive margin (68%, 50%, 28%; p < 0.001). There was "strong" and "moderate" relationships between motion scores and Objective Structured Assessment of Technical Skill scores, and time per resection and Objective Structured Assessment of Technical Skill scores respectively (r = -0.60, p < 0.001; r = -0.54, p < 0.001).

CONCLUSION

Surgery Tutor scores demonstrate evidenceof construct validity with regards to good internal structure, consequences, and relationship to other variables in the assessment of technical proficiency duringopen soft-tissue tumor resections in a simulated setting. Utilization of Surgery Tutor can provide formative feedback and objective assessment of surgical proficiency in a simulated setting.

Ultrasound-guided preoperative localization of breast lesions: a good choice

PURPOSE

The aim of the study was to verify whether ultrasound (US)-guided preoperative localization of breast lesions is an adequate technique for correct and safe surgical resection and to contribute positively and effectively to this topic in the literature with our results.

METHODS

From June 2016 to November 2016, 155 patients with both benign and malignant breast lesions were selected from our institute to undergo US localization before surgery. The lesions included were: sonographically visible and nonpalpable lesions; palpable lesions for which a surgeon had requested US localization to better evaluate the site and extension; sonographically visible, multifocal breast lesions, both palpable and nonpalpable. US localization was performed using standard linear transducers (Siemens 18 L6, 5.5-8 MHz, 5.6 cm, ACUSON S2000 System, Siemens Medical Solutions). The radiologist used a skin pen to mark the site of the lesion, and the reported lesion's depth and distance from the nipple and pectoral muscle were recorded. The lesions were completely excised by a team of breast surgeons, and the surgical specimens were sent to the Radiology Department for radiological evaluation and to the Pathology Department for histological assessment.

RESULTS

In 155 patients who underwent to preoperative US localization, 188 lesions were found, and the location of each lesion was marked with a skin pen. A total of 181 lesions were confirmed by the final histopathologic exam (96.28%); 132 of them (72.92%) were malignant, and 124 of these (93.93%) showed free margins.

CONCLUSIONS

US-guided preoperative localization of sonographically visible breast lesions is a simple and nontraumatic procedure with high specificity and is a useful tool for obtaining accurate surgical margins.

Radioactive seed localization for breast conservation surgery: Low positive margin rate with no learning curve

BACKGROUND

Radioactive seed localization (RSL) is an alternative to wire localization. We compared the rate of positive margins for evidence of a learning curve in implementing RSL.

METHODS

A retrospective review of RSL by three surgeons at a single institution from 2002 to 2016. Positive margins were defined as ink on tumor.

RESULTS

Surgeon experience with RSL for ranged from 142 to >500 cases. The positive margin rate among the first 100 of each surgeons' experience (n = 300) was 2.3% and the rate during the most recent up to 100 cases after experience with at least 100 RSL procedures (n = 242) was 4.1% (p = 0.32). Individual surgeon's positive margin rates ranged from 2 to 5% in the early experience and 2-7% in the later experience (p = NS).

CONCLUSIONS

RSL for breast conservation surgery has a low rate of positive margins even early in a surgeon's experience. Implementation of RSL can be done with no evidence of a learning curve.