Outcome of MRI-guided vacuum-assisted breast biopsy - initial experience at Institute of Oncology Ljubljana, Slovenia

Performance Benchmark Metrics and Clinicopathologic Outcomes of MRI-Guided Breast Biopsies: A Systematic Review and Meta-Analysis

Objective

To determine key performance metrics of magnetic resonance imaging (MRI)-guided breast biopsies (MRGB) to help identify reference benchmarks.

Materials and Methods

We identified studies reporting MRGB results up to 04.01.2021 in the Embase database, Ovid Medline (R) Process, Other Non-Indexed Citations, Ovid Medline (R) and completed a PRISMA checklist and sources of bias (QUADAS-2). The inclusion criteria were English language, available histopathological outcomes, or at least one imaging follow-up after biopsy. A random intercept logistic regression model was used to pool rates. Between-study heterogeneity was quantified by the I2 statistic.

Results

A total of 11,215 lesions in 50 articles were analyzed. The technical success rate was 99.10% [95% confidence interval (CI): 97.89-99.62%]. The MRI indications were staging in 1,496 (28.05%, 95% CI: 26.85-29.28%), screening in 1,427 (26.76%, 95% CI: 25.57-27.97%), surveillance in 1,027 (19.26%, 95% CI: 18.21-20.34%), diagnostic in 1,038 (19.46%, 95% CI: 18.41-20.55%), unknown primary in 74 (1.39%, 95% CI: 1.09-1.74%), and other in 271 (5.08%, 95% CI: 4.51-5.71%). Histopathology was benign in 65.06% (95% CI: 59.15-70.54%), malignant in 29.64% (95% CI: 23.58-36.52%) and high risk in 16.69% (95% CI: 9.96-26.64%). Detection of malignancy was significantly lower in those patients who underwent MRI for screening purposes (odds ratio 0.47, 95% CI: 0.25-0.87; p = 0.02), while mass lesions were more likely to yield malignancy compared to non-mass and foci [27.39% vs 11.36% (non-mass),18.03% (foci); p<0.001]. Surgical upgrade to invasive cancer occurred in 12.24% of ductal carcinoma in situ (95% CI: 7.76-18.77%) and malignancy in 15.14% of high-risk lesions (95% CI: 10.69-21.17%). MRI follow-up was performed in 1,651 (20.92%) patients after benign results [median=25 months (range: 0.4-117)]. Radiology-pathology discordance (2.48%, 95% CI: 1.62-3.77%), false negative after a benign-concordant biopsy (0.75%, 95% CI: 0.34-1.62%) and biopsy complications (2.36%, 95% CI: 2.03-2.72%) were rare.

Conclusion

MRGB is a highly accurate minimally-invasive diagnostic technique with low false-negative and complication rates. MRI indication and lesion type should be considered when evaluating the performance of institutional MRGB programs.

Recent Progress for the Techniques of MRI-Guided Breast Interventions and their applications on Surgical Strategy

With a high sensitivity of breast lesions, MRI can detect suspicious lesions which are occult in traditional breast examination equipment. However, the lower and variable specificity of MRI makes the MRI-guided intervention, including biopsies and localizations, necessary before surgery, especially for patients who need the treatment of breast-conserving surgery (BCS). MRI techniques and patient preparation should be first carefully considered before the intervention to avoid lengthening the procedure time and compromising targeting accuracy. Doctors and radiologists need to reconfirm the target of the lesion and be very familiar with the process approach and equipment techniques involving the computer-aided diagnosis (CAD) tools and the biopsy system and follow a correct way. The basic steps of MRI-guided biopsy and localization are nearly the same regardless of the vendor or platform, and this article systematically introduces detailed methods and techniques of MRI-guided intervention. The two interventions both face different challenging situations during procedures with solutions given in the article. Post-operative statistics show that the complications of MRI-guided intervention are infrequent and mild, and MRI-guided biopsy provides the pathological information for the subsequent surgical decisions and MRI-guided localization fully prepared for follow-up surgical biopsy. New techniques for MRI-guided intervention are also elaborated in the article, which leads to future development. In a word, MRI-guided intervention is a safe, accurate, and effective technique with a low complication rate and successful MRI-guided intervention is truly teamwork with efforts from patients to surgeons, radiologists, MRI technologists, and nurses.

A magnetic resonance image-guided breast needle intervention robot system: overview and design considerations

PURPOSE

We developed an image-guided intervention robot system that can be operated in a magnetic resonance (MR) imaging gantry. The system incorporates a bendable needle intervention robot for breast cancer patients that overcomes the space limitations of the MR gantry.

METHODS

Most breast coil designs for breast MR imaging have side openings to allow manual localization. However, for many intervention procedures, the patient must be removed from the gantry. A robotic manipulation system with integrated image guidance software was developed. Our robotic manipulator was designed to be slim, so as to fit between the patient's side and the MR gantry wall. Only non-magnetic materials were used, and an electromagnetic shield was employed for cables and circuits. The image guidance software was built using open source libraries. In situ feasibility tests were performed in a 3-T MR system. One target point in the breast phantom was chosen by the clinician for each experiment, and our robot moved the needle close to the target point.

RESULTS

Without image-guided feedback control, the needle end could not hit the target point (distance = 5 mm) in the first experiment. Using our robotic system, the needle hits the target lesion of the breast phantom at a distance of 2.3 mm from the same target point using image-guided feedback. The second experiment was performed using other target points, and the distance between the final needle end point and the target point was 0.8 mm.

CONCLUSIONS

We successfully developed an MR-guided needle intervention robot for breast cancer patients. Further research will allow the expansion of these interventions.

MRI vacuum-assisted breast biopsies

The indications, technique, results and limitations of MRI vacuum-assisted breast biopsies are discussed from a review of the literature. This was initially a home-grown technique and its development was slowed down by several factors. As a result of major technical advances, it has become a reliable and very consistent procedure with a low rate of underestimation. It is now an undisputed technique when suspicious MRI enhancement is seen with no corresponding mammography or ultrasound features.