Authors (including presenting author) :
Wong T(1), WOO SC (1), Li SK(1), Fung WY(1), Chau CM(1), Chan RLS(1), Yung WT(1), Ma KF(1)
Affiliation :
(1)Department of Radiology, Princess Margaret Hospital
Introduction :
Hookwire has been the conventional localisation technique for non-palpable breast lesions. However, it requires same-day placement as the operation and associated with the risk of wire transection and retained fragments. The inflexible scheduling poses a challenge to fulfill the Key Performance Index about the waiting time of breast cancer patients to receive their first treatment. Radioguided occult lesion localisation (ROLL) although is wireless, it still requires same-day injection due to tracer decay and radiation concern. Non-radioactive non-wire technique localization (NRNWL) by using devices such as Magseeds and Savi Scout reflectors has recently emerged and that eliminates many of these disadvantages.
Objectives :
To retrospectively evaluate the performance of NRNWL in terms of successful device placement, successful device retrieval, complications, and specimen margin clearance.
Methodology :
A single institution retrospective review of 44 patients who underwent lesion excision by NRNWL under image guidance from June 2019 to December 2020 was performed. Target-to-device distance was measured with placement success (target-to-device distance < 10mm) evaluated from post-procedural imaging. Specimen radiography was performed to confirm successful device retrieval. Pathologic analysis, specimen margin clearance and complications were reviewed.
Result & Outcome :
By using sonographic (29 of 44; 65.9%) or stereotactic (15 of 44; 34.1%) guidance, 45 devices (23 Magseeds and 22 reflectors) were placed in 44 lesions. One patient had two Magseeds placed for bracketing 4cm-spanned calcifications. Twenty-eight (63.6%) lesions had localisation devices placed 1 or more days (6-135 days) before surgery. Placement success was achieved in 41 devices (91.1%). Three (6.7%) devices (2 Magseeds and 1 reflector) were found migrated from target (>=10mm). All of them were placed under stereotactic guidance with migration due to accordion effect. One (2.2%) device (Savi Scout reflector) was deployed 10mm away from the centre of target under sonographic guidance due to technical difficulty. Salvage hookwires or skin markers were subsequently placed for these four lesions with unsuccessful device placement. All 44 targets and 45 devices (100%) were successfully excised. Two (33.3%) of the six biopsy proven malignancies with therapeutic intent surgery demonstrated margin close (< 2mm) and required further excision. This rate was similar to our prior internal audit about hookwire (34.6%) and ROLL (41.7%). No other complications were identified. To conclude, NRNWL is a feasible and safe alternative for guiding occult breast lesion excision with comparable specimen margin clearance rate, superior scheduling flexibility and operating theatre efficiency.
