Abstract P1-09-08: A new modified technique "Modus Spirdonov 1" in fine-needle aspiration biopsy

Abstract Introduction: The most fundamental problem in the assessment of benign and malignant neoplasms is the exact preoperative diagnosis. Fine-needle aspiration biopsy (FNAB) is one of the most used techniques for obtaining cytological material for further evaluation. Insufficient biopsy material is reported as a major drawback, which often requires repeated interventions (25.3% published in the literature for the standard technique). The authors have developed a modified technique “Modus Spirdonov 1” in order to obtain a larger amount of cytological material and verify the results with quantitative analysis in an experimental model. Material and methods: For the purpose of the experiment porcine liver and longissimus dorsi muscle were selected as target tissues sampled by standard method with direct grip (n = 60), by using CAMECO Syringe Pistol (n = 60) and by applying the technique “Modus Spirdonov 1” (n = 60). The measurements were performed by an authorized specialist in the only specialized and certified laboratory for standards of the Bulgarian Institute of Metrology. For comparison with the standard methods, in FNAB "Modus Spirdonov 1" after achieving a vacuum, rotational movements are performed along the longitudinal axis in two opposite directions without displacing the needle from the target center. This maneuver provides more efficient tissue cutting with the edge of the needle. A comparative analysis of the weight of the sample obtained by the three methods was performed. Results: The analysis shows that there is a statistically significant difference when comparing the results from the different techniques. The modified method “Modus Spirdonov 1” significantly exceeds the other two techniques (p<0,001) according to the quantity of the obtained material. According to the results of our study in experienced hands we achieved a sensitivity of the method of 98.5%, a false negative rate of 1% and a false positive rate of 0.5% in 1100 biopsies performed in clinical practice with 0% repeated biopsies. In addition, the gathered material is visually significantly richer, including ductal epithelial complexes, abundance of stromal cells, calcifications, detritis and a giant cell, macrophages filling the entire field of view microscopically. Conclusion: The authors believe that the described modified technique is a viable alternative to the currently used FNAB and could increase the diagnostic value of the preoperative biopsy in a number of diseases. Citation Format:Slavyana Usheva, Yordan Spirdonov, Georgi Varbanov, Ivan Terziev, Theophil Sedloev. A new modified technique "Modus Spirdonov 1" in fine-needle aspiration biopsy [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P1-09-08.