OBJECTIVE: We have studied the use of polymethyl methacrylate (PMMA) as an alternative biopsy marker that is readily detectable with ultrasound Doppler twinkling in cases of in vitro, ex vivo, or limited duration in vivo settings. This study investigates the long-term safety and ultrasound Doppler twinkling detectability of a PMMA breast biopsy marker following local perturbations and different dwell times in a 6-mo animal experiment.
METHODS: This study, which was approved by our Institutional Animal Care and Use Committee, involved three pigs and utilized various markers, including PMMA (Zimmer Biomet), 3D-printed, and Tumark Q markers. Markers were implanted at different times for each pig. Mesh material or ethanol was used to induce a local inflammatory reaction near certain markers. A semiquantitative twinkling score assessed twinkling for actionable localization during monthly ultrasounds. At the primary endpoint, ultrasound-guided localization of lymph nodes with detectable markers was performed. Following surgical resection of the localized nodes, histomorphometric analysis was conducted to evaluate for tissue ingrowth and the formation of a tissue rind around the markers.
RESULTS: No adverse events occurred. Twinkling scores of all markers for all three pigs decreased gradually over time. The Q marker exhibited the highest mean twinkling score followed by the PMMA marker, PMMA with mesh, and Q with ethanol. The 3D-printed marker with mesh and PMMA with ethanol had the lowest scores. All wire-localized lymph nodes were successfully resected. Despite varying percentages of tissue rind around the markers and a significant reduction in overall twinkling (p < 0.001) over time, mean PMMA twinkling scores remained clinically actionable at 6 and 5 mo using a General Electric C1-6 probe and 9L-probe, respectively.
CONCLUSIONS: In this porcine model, the PMMA marker demonstrates an acceptable safety profile. Clinically actionable twinkling aids PMMA marker detection even after 6 mo of dwell time in porcine lymph nodes. The Q marker maintained the greatest twinkling over time compared to all the other markers studied.

BACKGROUND: Breast Screen Australia and Breast Screen Aotearoa guidelines recommend breast biopsy marker (BBM) use in indicated patients. This study aims to evaluate whether BBM cost and availability impacts BBM utilisation.
METHODS: An online survey was disseminated to radiologists who identified \'breast imaging\' as their area of practice in the Royal Australian and New Zealand College of Radiologists (RANZCR) customer relationship management system. Survey questions addressed participant demographics and factors relating to BBM use.
RESULTS: Most (92%, 245/266) participants report that BBMs are routinely available at their place of practice. Those employed in private practice were more likely to report that BBMs are not routinely available. 22% (58/266) of radiologists report that BBM cost influences choice of biopsy type (core biopsy vs fine needle aspirate), this finding was more frequent in those employed in private practice. 47% of respondents report that the cost of BBMs is passed on to the patient, with all these respondents employed in a private or mixed private/public setting. Half the respondents (133/266) reported that their decision to use BBMs would be influenced by the availability of insurance coverage to cover BBM costs.
CONCLUSIONS: Results suggest that BBM cost and availability influences both choice of biopsy type (core biopsy vs FNA) and choice to use a BBM. Radiologists working in private practice or mixed private/public practice report that BBMs are less likely to be available for use, and that BBM cost is more likely passed to the patient; possibly disadvantaging patients who present to private radiology providers with imaging findings or conditions that would indicate BBM insertion under current national guidelines.

BACKGROUND. Targeted axillary lymph node dissection after neoadjuvant systemic therapy (NST) for breast cancer depends on identifying marked metastatic lymph nodes. However, ultrasound visualization of biopsy markers is challenging. OBJECTIVE. The purpose of our study was to identify biopsy markers that show actionable twinkling in cadaveric breast and to assess the association of actionable twinkling with markers\' surface roughness. METHODS. Commercial breast biopsy markers were evaluated for twinkling artifact in various experimental conditions relating to scanning medium (solid gel phantom, ultrasound coupling gel, cadaveric breast), transducer (ML6-15, 9L, C1-6), and embedding material (present vs absent). Markers were assigned twinkling scores from 0 (confident in no twinkling) to 4 (confident in exuberant twinkling); a score of 3 or greater represented actionable twinkling (sufficient confidence to rely solely on twinkling for target localization). Markers were hierarchically advanced to evaluation with increasingly complex media if showing at least minimal twinkling for a given medium. A 3D coherence optical profiler measured marker surface roughness. Mixed-effects proportional odds regression models assessed associations between twinkling scores and transducer and embedding material; Wilcoxon rank sum test evaluated associations between actionable twinkling and surface roughness. RESULTS. Thirty-five markers (21 with embedding material) were evaluated. Ten markers without embedding material advanced to evaluation in cadaveric breast. Higher twinkling scores were associated with presence of embedding material (odds ratio [OR] = 5.05 in solid gel phantom, 9.84 in coupling gel) and transducer (using the C1-6 transducer as reference; 9L transducer: OR = 0.36, 0.83, and 0.04 in solid gel phantom, ultrasound coupling gel, and cadaveric breast; ML6-15 transducer: OR = 0.07, 0.18, and 0.00 respectively; post hoc p between 9L and ML6-15: p < .001, p = .02, and p = .04). In cadaveric breast, three markers (Cork, Professional Q, MRI [Flex]) exhibited actionable twinkling for two or more transducers; surface roughness was significantly higher for markers with than without actionable twinkling for C1-6 (median values: 0.97 vs 0.35, p = .02) and 9L (1.75 vs 0.36; p = .002) transducers. CONCLUSION. Certain breast biopsy markers exhibited actionable twinkling in cadaveric breast. Twinkling was observed with greater confidence for the C1-6 and 9L transducers than the ML6-15 transducer. Actionable twinkling was associated with higher marker surface roughness. CLINICAL IMPACT. Use of twinkling for marker detection could impact preoperative or intraoperative localization after NST.

BACKGROUND: Breast Screen Australia and Breast Screen Aotearoa guidelines recommend breast biopsy marker (BBM) use in indicated patients. This study aims to evaluate breast biopsy practice and BBM utilisation by modality.
METHODS: An online survey was disseminated to radiologists who identified \'breast imaging\' as their area of practice in the Royal Australian and New Zealand College of Radiologists (RANZCR) customer relationship management system. Survey questions addressed participant demographics and factors relating to BBM use.
RESULTS: Most respondents (72%) place between 1 and 4 BBMs per week. Almost all (99%) respondents perform ultrasound-guided biopsy of the breast or axillary nodes, with 85% performing stereotactic or tomosynthesis-guided breast biopsy and 27% performing MRI-guided breast biopsy. BBM utilisation differs by modality, with 97% respondents always placing a BBM post-MRI-guided breast biopsy, 50% always placing a BBM post-stereotactic-guided biopsy and 3% always placing a BBM post-ultrasound-guided breast biopsy.
CONCLUSIONS: Almost all radiologists perform breast biopsy using ultrasound, stereotactic/tomosynthesis or MRI guidance. BBM utilisation varies by modality, with 72% of respondents placing between 1 and 4 clips per week. Reasons for placing or not placing BBM aligned with prior studies. This is the first study to evaluate the number of breast biopsies performed by radiologists on a weekly or monthly basis, providing a useful platform for comparison in the local setting.

OBJECTIVE: 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.
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.

OBJECTIVE: To evaluate the usefulness of the UltraClip® dual trigger breast tissue marker (UltraClip) for sonographic localization, we investigate the sonographic visibility and sonographic appearance of the UltraClip placed in phantoms and patients.
METHODS: Ten UltraClips were placed in the target lesions in the phantoms. After the ultrasound examination of the UltraClip, the ultrasound images were compared to the real appearance of the UltraClip obtained by cutting the phantoms. In the patient, the UltraClip markers were placed after biopsy of a suspicious breast lesion or before or during neoadjuvant chemotherapy. The patients consented to return 1-3 weeks after the procedure for ultrasound imaging of the UltraClip.
RESULTS: The UltraClip placed in the phantom appeared as a hyperechoic structure with a mean maximum diameter of 5.5 mm, which was found to correspond to the metallic clip in 90% (9/10) of the cases, and as a hyperechoic tubular structure with a maximum diameter of 9.0 mm corresponded to the expanded polyvinyl alcohol polymer in the remaining 10% (1/10) of cases. On the other hand, the UltraClip was detected as a hyperechoic structure measuring 3.5 mm in size only in 9 of the 15 (60%) patients. The sonographic visibility of the UltraClip was not affected depending on whether the target lesion or post-biopsy scar was sonographically detectable or not [60% (6/10) vs. 60% (3/5)].
CONCLUSIONS: While sonographic localization by targeting the UltraClip may be useful in 60% of the patients, another localization technique will be needed in the remaining patients.

OBJECTIVE: To develop a breast biopsy marker that resists fast and slow migration and has permanent visibility under commonly used imaging modalities.
METHODS: A polymer-nanoparticle composite film was prepared by embedding superparamagnetic iron oxide nanoparticles and a superelastic Nitinol wire within a flexible polyethylene matrix. MRI, mammography, and ultrasound were used to visualize the marker in agar, ex vivo chicken breast, bovine liver, brisket, and biopsy training phantoms. Fast migration caused by the \"accordion effect\" was quantified after simulated stereotactic, vacuum-assisted core biopsy/marker placement, and centrifugation was used to simulate accelerated long-term (i.e., slow) migration in ex vivo bovine tissue phantoms.
RESULTS: Clear marker visualization under MRI, mammography, and ultrasound was observed. After deployment, the marker partially unfolds to give a geometrically constrained structure preventing fast and slow migration. The marker can be deployed through an 11G introducer without fast migration occurring, and shows substantially less slow migration than conventional markers.
CONCLUSIONS: The polymer-nanoparticle composite biopsy marker is clearly visible on all clinical imaging modalities and does not show substantial migration, which ensures multimodal assessment of the correct spatial information of the biopsy site, allowing for more accurate diagnosis and treatment planning and improved breast cancer patient care.
CONCLUSIONS: Polymer-nanoparticle composite biopsy markers are visualized using ultrasound, MRI, and mammography. Embedded iron oxide nanoparticles provide tuneable contrast for MRI visualization. Permanent ultrasound visibility is achieved with a non-biodegradable polymer having a distinct ultrasound signal. Flexible polymer-based biopsy markers undergo shape change upon deployment to minimize migration. Non-migrating multimodal markers will help improve accuracy of pre/post-treatment planning studies.