Evaluation of the dislocation and long-term sonographic detectability of a hydrogel-based breast biopsy site marker

Purpose To evaluate the usefulness of the HydroMARK, a hydrogel-based breast biopsy site marker for ultrasound localization of breast lesions, we investigated the tendency for dislocation and sonographic detectability of the marker placed in patients. Materials and methods The marker was placed in lesions that were expected to become obscured after biopsy for a suspicious breast lesion or after neoadjuvant chemotherapy for breast cancer. The patients consented to return for a repeat ultrasound ± mammography examination, and the degree of displacement of the marker was measured as the marker-to-residual lesion distance. Results The marker was placed after stereotactic biopsy, ultrasound-guided biopsy, and before/during neoadjuvant chemotherapy, in 11, 22, and 7 lesions, respectively. Surgical resection was performed for 22 of the 40 lesions, while remaining 18 benign lesions were followed. The marker was sonographically detectable in 89.7% (35/39), 100% (35/35), and 100% (18/18) of the cases, respectively, at a median of 8 days, 13 weeks, and 11 months after the deployment. The degree of displacement was lower in the ultrasound-guided placement group than in the stereotactic placement group (median displacement: 0 vs. 4.3 mm; p = 0.001), it was also lower in the core-needle biopsy and neoadjuvent therapy cases than in the vacuum-assisted biopsy cases ( p = 0.003). At a median interval of 2.5 months after deployment, the marker remained unchanged in location in all cases ( n = 18, p = NS). Conclusions The HydroMARK appears to be a safe and effective marker with the advantageous characteristics of a low tendency for dislocation with time and long-term sonographic detectability.