Optimal Design of Bionic Flexible Fixation System for MRI-Guided Breast Biopsy

In Magnetic Resonance Imaging(MRI)guided intervention procedures,the flexibility and reliability of the mammary gland fixation device are important indicators for cnsuring the quality of surgery.This paper presents a bionic flexible fixation system for MRI-guided breast biopsy,and establishes a mathematical model of the palm-type curved plate and a breast compression model.The bending angle,eccentricity,and tightening stroke of the palm-type curved plate are considered the main influencing factors.The bending angle and eccentricity of the bionic palm-type curved plate and flexible fingers are optimized,and a prototype of the breast fixation system is developed.The experimental results show that when the external force is 10 N,the average repetitive accuracy of four lesion points is 0.71 mm,0.60 mm,0.63 mm,and 0.68 mm,respectively.When the pressures are 8 N,10 N,and 12 N,the thickness of the compressed tissue is 76.27 mm,72.8 mm and 68.73 mm,respectively.It has good repetitive accuracy and is compatible with the concept of flexible fixation that reduces the uncomfortable feeling of the human body.We propose that by optimizing the flexible tightening mechanism,it is feasible to properly control the external compression force to effectively reduce the compression pain for patients while guaranteeing the tightening reliability in breast biopsy.

Staging the axilla in women with breast cancer: the utility of preoperative ultrasound-guided needle biopsy

Preoperative staging of the axilla in women with invasive breast cancer using ultrasound-guided needle biopsy(UNB) identifies approximately 50% of patients with axillary nodal metastases prior to surgical intervention. Although moderately sensitive, it is a highly specific staging strategy that is rarely falsely-positive, hence a positive UNB allows patients to be triaged to axillary lymph-node dissection(ALND) avoiding potentially unnecessary sentinel node biopsy(SNB). In this review, we extend our previous work through an updated literature search, focusing on studies that report data on UNB utility. Based on data for 10,934 breast cancer patients, sourced from 35 studies, a positive UNB allowed triage of 1,745 cases(simple proportion 16%) to axillary surgical treatment: the utility of UNB was a median 19.8% [interquartile range(IQR) 11.6%-26.7%] across these studies. We also modelled data from a subgroup of studies, and estimated that amongst patients with metastases to axillary nodes, the odds ratio(OR) for high nodal disease burden for a positive UNB versus a negative UNB was 4.38 [95% confidence interval(95% CI): 3.13, 6.13], P<0.001. From this model, the estimated proportion with high nodal disease burden was 58.9%(95% CI: 50.2%, 67.0%) for a positive UNB, whereas the estimated proportion with high nodal disease burden was 24.6%(95% CI: 17.7%, 33.2%) if UNB was negative. Overall, axillary UNB has good clinical utility and a positive UNB can effectively triage to ALND. However, the evolving landscape of axillary surgical treatment means that UNB will have relatively less utility where surgeons have modified their practice to omission of ALND for minimal nodal metastatic disease.

The promise of liquid biopsy in cancer:a clinical perspective

The clinical utility of liquid biopsy in cancer treatment will increase as circulating tumor cells （CTCs） analysis move from the enumeration to the real-time measurement of tumor characteristics. Intratumor heterogeneity is becoming increasingly recognized as a major drawback to the shift to personalized medicine. Spatial and temporal heterogeneity might be reflected by the serial assessment of CTCs. Indeed, the developing technologies for CTCs analysis now allow digital genomic and next- generation sequencing approaches, able to differentiate molecular subtypes of the disease and to monitor genetic variation over time. The liquid biopsy of cancer might offer a real-time assessment of tumor biology, providing the opportunity to serially evaluate patients most likely to benefit from targeted drugs based on a dynamic characterization of the disease at the molecular level. Mthough hurdles remain before liquid biopsy is seen in routine clinical practice, the information derived from CTCs may facilitate the real-time identification of actionable mutations in cancer leading the way toward personalized medicine.

Specimen Radiography for MRI-Guided Biopsies

Background: Specimen radiography is important for the biopsy of breast microcalcifications, and MRI is limited in the detection of microcalcifications. It is unknown whether or not the presence of microcalcifications on MRI-guided biopsies is significant. Purpose: To determine whether specimen radiography of MRI-guided biopsy samples provides any added benefits in tissue assessment. Materials and Methods: This is an IRB-approved, HIPPA-compliant retrospective review of MRI-guided biopsy reports whose tissue underwent specimen radiography from 2010 to 2017. Pathology reports were queried to compare samples with and without calcium and reviewed to determine if calcifications correlated with the lesion of interest. If there was a correlation, the original MRI was reviewed. Final pathology reports were also reviewed if excision was performed. Results: A total of 889 patients ages 22 - 85 were included with 140 (15.7%, 140/889) containing calcifications. Of 140 specimens, 119 (85.0%, 119/140) cases separated the calcifications. A total of 41 (34.5%, 41/119) were malignant or high-risk lesions/atypia of which 15 (36.6%, 15/41) showed a higher-grade lesion in the specimen containing calcium. Out of these 15, 4 (26.7%, 4/15) were pathologically associated with calcium;however, pathologic diagnosis was not dependent on the presence of calcifications. All 4 were high-risk lesions and none were malignancies. MRI in these cases showed three enhancing masses and one non-mass enhancement. None were upgraded at excision. Conclusion: The presence of microcalcifications on MRI-guided biopsies does not aid in tissue assessment and does not impact pathologic diagnosis. Specimen radiography provides no added benefits in the setting of MRI-guided biopsies.