Can the organic coating of breast tissue markers be identified in vacuum-assisted biopsies as an indicator of representativity? A proof-of-concept evaluation in a turkey breast model

INTRODUCTION: An accurate response assessment after neoadjuvant chemotherapy is essential for tailored surgical treatment. The use of coated clip markers may be considered to better assess the representativeness of the biopsy. This preclinical study investigated whether the organic coating of two breast tissue clip markers (HydroMARK and UltraClip) can be detected in an ultrasound-guided vacuum-assisted biopsy (VAB). METHODS: Ten clip markers of each type were inserted into four turkey breasts. VAB was performed, aiming to sample the organic coating while leaving the clip marker in situ. The procedure was repeated to remove also the metal core of the clip markers. Gross inspection, specimen radiography and histopathological examination of the biopsy samples were performed to detect fragments of the coating material and the metal core. RESULTS: A selective biopsy of the organic coating was achieved in one HydroMARK case. In all other HydroMARK and UltraClip cases, VAB removed the entire clip marker. Fragments of the HydroMARK coating material were visible macroscopically in eight out of ten biopsy specimens and microscopically in ten out of ten specimens. The coating material of the UltraClip was detectable only histologically in three out of ten samples. CONCLUSION: Selective VAB of only the organic coating of the markers was not feasible for either clip. Within the limitations of this preclinical feasibility study, HydroMARK showed more favorable results than UltraClip regarding coating detectability. IMPLICATIONS FOR PRACTICE: This study shows that clip markers with an organic coating can have additional benefits compared to standard clip markers. The detection of clip marker components can be a potential indicator of the biopsy's representativeness. If confirmed in larger studies, this could improve the reliability of the response assessment after neoadjuvant chemotherapy.