U. Fischer

Quality indicators with tentative reference values.

The proportion of mammographic findings in the BI-RADS categories 4 and 5 with a correlating sonographic finding, which undergo a US-guided core biopsy that satisfies the quality standard specifications: ≥ 70%

The proportion of mammographic findings that contain micro-calcifications, are in the BI-RADS categories 4 and 5, and are without a correlating sonographic finding, which undergo a stereotactic VAB that satisfies the quality standard specifications: ≥ 70%

The proportion of MR-mammographic findings in the BI-RADS categories 4 and 5 that are solely seen on MR mammography, which undergo an MRI-guided VAB that satisfies the quality standard specifications: ≥ 95%

The proportion of mammographic findings in the BI-RADS categories 4 and 5, and/or sonographic findings in the BI-RADS categories 4 and 5, and/or MR-mammographic findings in the BI-RADS categories 4 and 5 that are histologically verified by an appropriate image-guided biopsy: ≥ 70%

The proportion of nonpalpable findings that are histologically verified preoperatively by mammographic-, sonographic-, or MRI-guided CNB or VAB: ≥ 70%

The proportion of palpable and nonpalpable findings that are histologically verified preoperatively by mammographic-, sonographic-, or MRI-guided CNB or VAB: ≥ 90%

The proportion of interventions for mammographic findings with microcalcifications in the BI-RADS categories 4 and 5 that have representative microcalcifications detected in the specimen radiograph: ≥ 95%

The proportion of cases in which surgical excision reveals a malignant finding after image-guided biopsy has yielded a benign finding (B classification 1 or 2) (false-negative): < 10%

Quality indicators with tentative reference values.

The proportion of breast operations after preoperative wire localization in which the wire is placed ≤ 1 cm from the lesion border: ≥ 95%

The proportion of breast operations after preoperative mammographic localization with intraoperative specimen radiography: ≥ 95%

The proportion of breast operations after preoperative US-guided localization with intraoperative specimen US: ≥ 95%

The proportion of excision specimens that are clearly topo-graphically marked by the surgeon: ≥ 95%

Basic Principles

Needle biopsy techniques can be performed:

to verify the presence of a suspected malignancy (before neoadjuvant chemotherapy and for surgical planning)

for minimally invasive histologic work-up of ambiguous and nonpalpable breast findings

The quality assurance of these procedures encompasses the following aspects:

the technique used (targeting the lesion, harvesting specimens)

the processing and assessment of the pathologic/cytologic specimen

the appraisal of pathologic results and the resultant therapy planning

Choice of Method

Guidance. Palpable findings can be percutaneously biopsied with or without sonographic guidance. For the biopsy of non-palpable imaging findings, the imaging method used for needle guidance should be chosen according to which method visualizes the lesion best and is the most reliable. This can be mammography (stereotactic), US, or MRI.

Puncture method. The current standard biopsy methods are the large CNB and the VAB. FNAB is reserved for a very few specific indications. Which puncture method to choose is dependent upon the clinical constellation and the attainable accuracy of each method.

In this regard, the puncture methods have significant differences:

The FNAB cannot be recommended as a standard biopsy method (level of evidence [LOE] 3b–3a). Its application should be limited to special cases (complicated cysts, lymph nodes) where specific cytology results can be expected.

Using a standardized technique (see below), the large CNB reaches a sensitivity of 85 to 98% (LOE 3b–3a).

VAB reaches a sensitivity of over 98% using a standardized technique (LOE 3b–3a).

Quality assurance. The practice guidelines of the American College of Radiology (ACR) first included quality assurance measures for breast interventions in 1997. They currently apply to the equipment specifications and technical standards for diagnostic physics performance monitoring of imaging equipment, indications and contraindications for the performance of image-guided breast interventional procedures, and documentation (including image documentation) of the needle position, pathologic results, problems encountered, and follow-up recommendations. In addition, the ACR practice guidelines also include the minimum qualification requirements of the examiner, and the—albeit relatively small—number of interventions the examiner must perform per year to maintain his or her expertise.

To promote the quality of core biopsy and VAB performance, studies pertaining to the optimal needle diameter and the number of specimens to be harvested have been performed and recommendations based on these studies exist in voluntary practice guidelines. In addition, a quality-assured procedural protocol has been developed specifically for the performance of MRI-guided interventions (VAB, preoperative localization; Breast Diagnostics Working Committee of the German Radiology Association).

Independent of the biopsy method performed, it is always essential that histology be correlated with the diagnostic imaging (EU and ACR guidelines) to recognize biopsies that are not representative. Results that are discordant with the imaging assessment must be discussed in an interdisciplinary conference. A therapeutic recommendation can only be made after a representative biopsy has been ensured. If this is not the case, a repeat intervention or open biopsy must be performed.

Summary

Thorough quality assurance on different levels is necessary for the performance of high-standard percutaneous interventions. High accuracy has been reported for CNB and VAB, but not, however, for FNAB. Quality standards for CNB and VAB have been developed.

Percutaneous Biopsy

Personnel requirements

Physician:

1. Extensive knowledge and experience in breast diagnostic imaging, including the diagnostic image work-up of ambiguous findings, is a prerequisite for the reliable identification and localization of the significant lesion(s) on mammography in two orthogonal planes.

2. For the performance of stereotactic interventions: Performance of at least 30 stereotactic breast biopsy procedures under the supervision of a qualified physician, or performance of at least 10 stereotactic breast biopsy procedures under the supervision of a qualified company representative and at least 20 stereotactic breast biopsy procedures under the supervision of a qualified physician. Extensive knowledge of how to verify calibration (10 independently performed verification procedures) is also necessary.

3. For the performance of US-guided interventions: Extensive knowledge and experience in diagnostic breast US examination and performance of at least 30 US-guided breast biopsy procedures under the supervision of a qualified physician.

4. For the performance of MRI-guided interventions: Extensive knowledge and experience in diagnostic MR mammography and performance of at least 30 MRI-guided breast biopsy procedures under the supervision of a qualified physician.

5. For the maintenance of competence, the performance of at least 50 stereotactic-guided percutaneous biopsies per year, at least 50 US-guided percutaneous biopsies per year, and/or at least 50 MRI-guided VABs per year are recommended.

1. Certification after having successfully completed an advanced academic program encompassing specialized training in breast diagnostics

2. For the performance of stereotactic-guided interventions:

– extensive knowledge pertaining to the mammographic imaging technique, including image quality, breast positioning, radiation protection

– vocational training in how to verify calibration (at least 10 verifications) and performance of at least 10 stereotactic breast biopsy procedures under the supervision of a an experienced radiologist’s assistant, a medical physicist/technologist, or engineer

Technical quality control

Certified radiologist’s assistant: