Early reflector localization improves the accuracy of localization and excision of a previously positive axillary lymph node following neoadjuvant chemotherapy in patients with breast cancer

Systematic review of targeted axillary dissection in node-positive breast cancer treated with neoadjuvant systemic therapy: variation in type of marker and timing of placement

BACKGROUND

In node-positive (cN+) breast cancer treated with neoadjuvant systemic therapy, combining sentinel lymph node biopsy and targeted lymph node excision, that is targeted axillary dissection, increases accuracy. Targeted axillary dissection procedures differ in terms of the targeted lymph node excision technique. This systematic review aimed to provide an overview of targeted axillary dissection procedures regarding definitive marker type and timing of placement: before neoadjuvant systemic therapy (1-step procedure) or after neoadjuvant systemic therapy adjacent to a clip placed before the neoadjuvant therapy (2-step procedure).

METHODS

PubMed and Embase were searched, to 4 July 2023, for RCTs, cohort studies, and case-control studies with at least 25 patients. Studies of targeted lymph node excision only (without sentinel lymph node biopsy), or where intraoperative localization of the targeted lymph node was not attempted, were excluded. For qualitative synthesis, studies were grouped by definitive marker and timing of placement. The targeted lymph node identification rate was reported. Study quality was assessed using a National Institutes of Health quality assessment tool.

RESULTS

Of 277 unique records, 51 studies with a total of 4512 patients were included. Six definitive markers were identified: wire, 125I-labelled seed, 99mTc, (electro)magnetic/radiofrequency markers, black ink, and a clip. Fifteen studies evaluated one-step procedures, with the identification rate of the targeted lymph node at surgery varying from 8 of 13 to 47 of 47. Forty-one studies evaluated two-step procedures, with the identification rate of the clipped targeted lymph node on imaging after neoadjuvant systemic therapy varying from 49 to 100%, and the identification rate of the targeted lymph node at surgery from 17 of 24 to 100%. Most studies (40 of 51) were rated as being of fair quality.

CONCLUSION

Various targeted axillary dissection procedures are used in clinical practice. Owing to study heterogeneity, the optimal targeted lymph node excision technique in terms of identification rate and feasibility could not be determined. Two-step procedures are at risk of not identifying the clipped targeted lymph node on imaging after neoadjuvant systemic therapy.

Efficacy of Targeted Axillary Dissection With Radar Reflector Localization Before Neoadjuvant Chemotherapy

INTRODUCTION

For clinically node positive breast cancer patients treated with neoadjuvant chemotherapy (NAC), targeted axillary dissection (TAD) can be used to stage the axilla. TAD removes the sentinel lymph node (SLN) and tagged positive nodes, which can be identified via radar reflector localization (RRL). As it can be challenging to localize a previously positive node after NAC, we evaluated RRL prior to NAC.

METHODS

We performed a retrospective chart review of breast cancer patients with node positive disease treated with NAC who underwent TAD with RRL. We compared retrieval of radar reflector and clip, timing of localization, and, if a node was positive, whether the radar reflector node or SLN was positive.

RESULTS

Seventy-nine patients fulfilled inclusion criteria; 32 were placed pre-NAC (mean 187 d before surgery) and 47 were placed post-NAC (mean 7 d before surgery). For pre-NAC placement, 31 of 32 radar reflectors and 31 of 32 clips were retrieved. For post-NAC placement, 47 of 47 radar reflectors and 46 of 47 clips were retrieved. There was no significant difference in radar reflector or clip retrieval rates between pre-NAC and post-NAC groups (P = 0.41, P = 1, respectively). Thirty of 32 patients with pathologic complete response avoided an axillary lymph node dissection. Of 47 patients with a positive lymph node, 32 were both the SLN and radar reflector node, 11 were radar reflector alone, and four were the SLN.

CONCLUSIONS

RRL systems are an effective way to guide TAD, and RRL makers can be safely placed prior to NAC.

Targeted Axillary Dissection with 125I Seed Placement Before Neoadjuvant Chemotherapy in a Danish Multicenter Cohort

BACKGROUND

Targeted axillary dissection (TAD), with marking of the metastatic lymph node before neoadjuvant chemotherapy (NACT), is increasingly used for breast cancer axillary staging. In the case of axillary pathological complete response (ax-pCR), axillary lymph node clearance can be omitted. Several marking methods exist, most using re-marking before surgery. Feasibility, learning curve, and identification rate (IR) vary. Marking with 125I seed before NACT makes re-marking at surgery redundant, possibly increasing feasibility and IR. Here, TAD with 125I seed placed before NACT is evaluated in a Danish multicenter cohort.

METHODS

Patients staged with 125I TAD in Denmark between 1 January 2016 and 31 August 2021 were included. Patients were identified in radioactivity-emitting implant registries at the radiology departments and from the Danish Breast Cancer Group database. Data were extracted from patients' medical records. Information on patient/tumor characteristics, 125I seed activity, marking period, TAD success, number of sentinel nodes (SNs), the histopathological status of excised nodes, and whether the marked lymph node (MLN) was an SN were registered.

RESULTS

142 patients were included. The IR of the MLN was 99.3%, and the IR of the SLNB was 91.5%. TAD success was 91.5%. Minor challenges in marking or removal of the MLN were noted in three patients. In 72.3% of the patients, the MLN was a sentinel node. Overall, 40.8% had axillary pCR.

CONCLUSION

TAD with 125I seed marking before NACT is feasible without re-marking at surgery and with only minor surgical challenges. The IR is high. Staging with TAD spares 41% of breast cancer patients an axillary dissection.

Comparison of 3 Different Systems for Non-wire Localization of Lesions in Breast Cancer Surgery

PURPOSE

Localizing breast lesions by marking tumors and their detection using probes during surgery is a common part of clinical practice. Various nonwire localization systems were intended to be compared from different perspectives.

METHODS

Various measurement experiments were performed. Localization techniques, including radioactive seed (RSLS), magnetically guided (MGLS), or radar (SLS), were compared in signal propagation in water and tissue environments, signal interference by surgical instruments, and the practical experience of surgeons. Individual experiments were thoroughly prospectively planned.

RESULTS

The RSLS signal was detectable at the largest evaluated distance, ie, 60 mm. The SLS and MGLS signal detection was shorter, up to 25 mm to 45 mm and 30 mm, respectively. The signal intensity and the maximum detection distance in water differed slightly depending on the localization marker orientation to the probe, especially for SLS and MGLS. Signal propagation in the tissue was noted to a depth of 60 mm for RSLS, 50 mm for SLS, and 20 mm for MGLS. Except for the expected signal interferences by approaching surgical instruments from any direction for MGLS, the signal interruption for RSLS and SLS was observed only by inserting instruments directly between the localization marker and probe. Moreover, the SLS signal interference by instrument touch was noted. Based on surgeons' results, individual systems did not differ significantly for most measurement condition settings.

CONCLUSION

Apparent differences noted among localization systems can help experts choose an appropriate system for a specific situation or reveal small nuances that have not yet been observed in clinical practice.

Image-Guided Radar Reflector Localization for Small Soft-Tissue Lesions in the Musculoskeletal System

Preoperative localization of nonpalpable breast lesions using a radar reflector surgical guidance system has become commonplace, but the clinical utility of this emerging technology in the musculoskeletal system has not yet been well established. The system components include a console, a handpiece, an implanted radiofrequency reflector that works as a lesion marker, and an infrared light-emitting probe to guide the surgeon. The reflector can be deployed to localize small nonpalpable nodules within the subcutaneous fat as well as lesions within the deeper soft tissues. It can also be used for lymph nodes and foreign bodies. Localization can be performed both before and after treatment. The objective of this article is to describe the potential applications and our technique and initial experience for radar reflector localization within the musculoskeletal system.

Radio-isotope occult lesion localization (ROLL) techniques to identify the clipped node for targeted axillary dissection (TAD) in breast cancer

BACKGROUND

Breast cancer patients having neoadjuvant systemic therapy (NAST) who have a positive (clipped) lymph node (CN) at presentation must have that CN removed to assess pathologic response at later surgery. Multiple techniques for localizing the CN have been described. We describe a novel ROLL-based approach.

METHODS

Consecutive patients between 2018 and 2021, having NAST with biopsy proven positive lymph node(s), had a clip placed into the most abnormal node(s). At later surgery sentinel node and occult lesion localization (SNOLL) was performed with peritumoral radio-isotope (^99m Tc-Nanoscan) injected under ultrasound guidance. Planar and single photon emission computed tomography (SPECT-CT) images were used to identify sentinel nodes (SN) and the CN. If the CN was not a SN, then additional ^99m Tc-Nanoscan was injected directly into the CN using ultrasound (ROLL). TAD was performed using a gamma probe and intra-operative specimen radiographs to confirm excision of the CN.

RESULTS

Thirty-eight patients underwent TAD. 20/38 CNs were SNs on SPECT-CT. 17/38 CN were localized separately. 1/38 CN was not a SN and could not be identified on ultrasound. The remaining 37/38 (97.4%) of the CNs were removed intra-operatively. Pathological complete response in the axilla was identified in 18/38 cases. The CN was the only positive node in 10/20 cases. In 18/20 cases the CN contained the largest tumour deposit.

CONCLUSION

Combining SNOLL and ROLL techniques to identify the SNs and, if separate, the CN for TAD is very reliable and logistically robust, especially for units already performing peritumoral lymphoscintigraphy.