Fine Needle Aspiration Improvements Team Members: Janie Goldsworthy, Kristi Hinner, Nick Kortan, Crystal Marshek Client: Dr. Elizabeth Burnside, Assistant Professor, Chief, Breast Imaging Advisor: Professor John Webster December 12, 2002 Abstract The following document presents our final design to modify the current fine needle aspiration (FNA) procedure used to diagnose abnormal cells in breast tissue. FNA is one of four commonly performed techniques used to remove tissue or cells during a breast biopsy. Often a sample taken using FNA is declared insufficient by the cytologist doing the analysis. This can be due to either lack of cells or the cells obtained remain in a clump, which makes analysis difficult. It is for this reason that there is an attempt being made to modify the needle used to perform the FNA in the hopes that the modifications will increase the amount of material exhumed from the site in the breast as well as to break up the cells that are removed. An increase in material would allow the cytologist to diagnose the cells or tissue with only one FNA attempt. Currently, multiple attempts need to be made before adequate material is removed. The needle design chosen is a microdrill bit insert, which has been tested on fixed tissue samples to allow for evaluation of the technique’s success. Results were promising after two series of tests. ___________________________________________________________________________2 Table of Contents Page Number Client Statement 3 Background information Techniques 3-4 FNA Biopsy Procedure 5-6 Other Needle Manufacturers 6 Design Constraints 6 Alternative Design Solutions 6-8 Final Design Solution 8-10 Future Plans 10-12 Conclusion 12 Appendix PDS 13-15 Mammography 16 Ultrasound 17 Testing Procedure 18 References 193 Figure 1: Fine needle aspiration, http://www.imaginis.com/breasthealth/biopsy/fine Client Statement Dr. Elizabeth Burnside, assistant professor and chief of breast imaging, performs between one and four breast biopsies each day. Two biopsy methods often used by Dr. Burnside are core biopsy and fine needle aspiration (FNA). While core biopsy almost always obtains sufficient samples, it poses many disadvantages. One disadvantage is that it is a more invasive procedure [4]. Second, a loud noise occurs during the procedure, which can scare the patient, and third if the mass is found near the ribs there may be a risk of internal injury to the ribs due to this procedure. FNA is the least invasive method for breast biopsies and is most comfortable and affordable for the patient (given that the first sample is sufficient). However, FNA is often unsuccessful due to the difficulty of retrieving a sufficient sample through a small needle (approximately 20-gauge). When an insufficient sample is obtained, either the FNA procedure is repeated or a more invasive biopsy method, such as core biopsy or vacuum-assisted biopsy is performed. The waiting involved with repetition of the FNA procedure often adds to a patient’s already heightened anxiety. As a result of the insufficient samples associated with FNA, many physicians are straying away from this minimally invasive technique. Dr. Burnside would like us to modify the current FNA needle (Inrad Aspiration Biopsy Needle), by developing a small needle with a unique tip or insert that would maximize the tissue obtained and increase the diagnostic yield of this very valuable procedure. Background Information Techniques: There are approximately four needle aspiration procedures performed to remove tissue or cells. Each procedure differs in how it is performed, the equipment used, and the type and amount of tissue it removes. The four procedures are fine needle aspiration, core needle biopsy, vacuum-assisted biopsy and large core biopsy. The fine needle aspiration (Figure 1) procedure is fast, minimally painful, and involves no incision. The surgeon uses a fine hollow needle that is sometimes attached to a syringe to extract fluid from a cyst or cells from a solid lesion. Once the needle is removed the sample is delivered to a cytologist, who immediately analyzes the sample. Often the cytologist declares the sample as insufficient (lacking a large enough number of cells in question), in which case the physician either repeats the FNA procedure or uses the core biopsy procedure to obtain a larger sample [4]. In the case that the sample is sufficient, the cytologist will declare the sample as cancer or fibrinoma (non-cancerous). Often the patient will be informed of the test results before leaving.4 Figure 3: Vacuum-assisted Biopsy, http://www.imaginis.com/breasthealth/biopsy/fine Figure 2: Core needle biopsy, http://www.imaginis.com/breasthealth/biopsy/fine Figure 4: Large Core Biopsy (ABBI), http://www.imaginis.com/breasthealth/biopsy/fine Core needle biopsy (Figure 2) is similar to fine needle aspiration, but the needle is larger, enabling a larger sample to be obtained. It is performed under local anesthesia and ultrasound (Appendix C) or mammography (Appendix B) is used if the lump cannot be felt. Three to six needle insertions are needed to obtain an adequate sample of tissue [13]. A loud clicking sound may be heard as the samples are being taken and the patient may feel some pressure, but should not feel pain. The procedure takes a few minutes and no stitches are required. Core needle biopsy may provide a more accurate analysis and diagnosis than fine needle aspiration because tissue is removed, rather than just cells. This procedure is not accurate in patients with very small or hard lumps [3, 13]. Vacuum-assisted biopsy (Figure 3) utilizes a vacuum-like device to remove breast tissue. Local anesthesia is used and no incision is made. Mammography is used to guide a breast probe to the lesion. Computers pinpoint the mass and suction draws out the breast tissue. The needle is inserted once to obtain multiple samples. In some cases, the entire lesion may be removed. Vacuum-assisted biopsy is safe, reliable, and valuable for patients who are not candidates for other minimally invasive biopsy techniques and those who wish to avoid surgical biopsy [9, 13]. Large core biopsy, also called advanced breast