Evaluation of transabdominal ultrasound-guided percutaneus core needle biopsy and endoscopic ultrasound-guided aspiration biopsy results in biopsy applications of pancreatic lesions

Purpose: The aim of our study was to compare the diagnostic performance of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) using a 22-gauge needle and transabdominal ultrasound-guided core needle biopsy (US-CNB) using an 18-gauge needle for the diagnosis of pancreatic lesions. From this point of view, it is aimed to contribute to the selection of the method in which pancreatic lesion biopsies will be performed. Materials and Methods: The data of patients who underwent US-CNB and EUS-FNA for pancreatic lesions in our clinic between January 2019 and December 2022 were evaluated retrospectively. The method of operation, the types of needles used were specified. Pathology and cytology reports in the archive were evaluated. Biopsy results were divided into 3 groups as benign, malignant and inadequate. Out of a total of 229 patients included in the study, 89 had EUS-guided fine needle aspiration (EUS-FNA) and 140 had US-guided core needle biopsy (US-CNB). In 102 of the 229 patients included in the study, the diagnostic accuracy was proven by pathological evaluation of surgical results, biopsy results from metastatic lesions, and follow-up findings. Confirmed results were grouped into true positives and true negatives. All procedures in the study were performed on human participants in accordance with national research committee standards and the 1964 Helsinki Declaration ethical guidelines. Approval was obtained by the local ethics committee (decision no: 2023/4376). Permission was obtained from the institutions for the retrospective analysis of the records. The procedures were performed by experienced endoscopists and interventional radiologists. Results: Biopsy was performed in 229 patients (US-CNB, n = 140; EUS-FNA, n = 89). While the mean age of the patients was 66 (56-74) years, 54.6% were male. While 16.6% of the lesions from which the samples were obtained were smaller than 2 cm, 56.8% were between 2-4 cm and the remaining 26.6% were larger than 4 cm. 59.0% of the lesions were in the head-uncinate process of the pancreas, 24.5% were in the body, and 16.6% were in the tail. 76.9% of the lesions were solid, 15.3% cystic, and 7.9% complex. Biliary dilatation was present in 55.5% of the samples examined, and vascular invasion was present in 44.5%. Metastases were present in 25.8% of the samples, 22.3% to the liver, 6.6% to the peritoneum and 3.5% to the lung. 86.5% of the samples examined were sufficient for pathological examination. Of the pathological results of the samples, 62.0% were malignant, 24.5% were benign, and 13.5% were insufficient samples. Biopsy was successfully obtained in 198 of the samples (US-CNB, n = 135; EUS-FNA, n = 63). Inadequate sampling was achieved in 31 of the procedures (US-CNB, n = 5; EUS-FNA, n = 26). While the accuracy, adequacy ratio, and sensitivity (92.7%, 96.4%, and 90.7%, respectively) of US-CNB were higher than that of EUS-FNA (83.0%, 70.8%, and 74.2%), their specificities were equal (100%). The diagnostic yield (sampling success) and diagnostic accuracy of both modalities were compared. Diagnostic yield was found to be superior in US-CNB than EUS-FNA among methods (96.4%, respectively, and 70.8% P<0.001 in EUS-FNA). In addition, comparisons were made after they were divided into groups according to the size, location and nature of the lesion. In patients with lesion size <2 cm and 2-4 cm, head-uncinate, trunk localization, and those with solid and cystic nature, the US-CNB method had higher diagnostic yield than EUS-FNA. In this respect, there was no statistical difference in lesions >4 cm in size, located in the tail, and complex in nature. When it comes to diagnostic accuracy, the accuracy of US-CNB was more successful than EUS-FNA (92.7% vs. 83%). Conclusion: The diagnostic yield and diagnostic accuracy of US-CNB for pancreatic lesions was superior to that of EUS-FNA. Key Words: Pancreas; endoscopic ultrasound-guided fine needle aspiration; image guided biopsy; core needle biopsy; ultrasonography; endoscopic ultrasonography