328 - Role of Percutaneous Image-guided Biopsy in the Era of Endoscopic Biopsy of Pancreatic Lesions

Purpose: Endoscopic ultrasound–guided fine-needle aspiration/biopsy (EUS-FNA/FNB) has become widely used for sampling pancreatic lesions, but image-guided percutaneous needle biopsy (PNB) remains important when endoscopic access is limited or contraindicated. We evaluated the diagnostic accuracy of image-guided PNB for pancreatic lesions at a tertiary cancer centre and examined technical and clinical factors influencing diagnostic yield.

Materials and Methods: A retrospective analysis was conducted of 181 image-guided percutaneous pancreatic biopsies performed between 2015 and 2021 at a tertiary cancer centre. Post-biopsy histopathology reports were reviewed and categorized as malignant, benign, infective, or non-diagnostic (insufficient, non-representative, inflammatory, or haemorrhagic). Diagnostic performance of PNB was evaluated by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy. The reference standard was postoperative surgical histopathology when available; for non-operated patients, clinical and imaging follow-up for at least one year was used.

Results: Among 181 pancreatic biopsies, image-guided PNB demonstrated a diagnostic accuracy of 91.7%, with sensitivity 90.9%, specificity 100%, PPV 100%, and NPV 51.6%. The major complication rate was 1.1%. Statistically significant predictors of successful diagnostic yield included precise technical targeting of the lesion (p < 0.001), concurrent fine-needle aspiration cytology (FNAC) with on-site evaluation (p < 0.001), and elevated serum CA 19-9 levels (p = 0.01). Imaging modality (CT vs. USG), lesion size, and biopsy approach were not significantly associated with diagnostic yield.

Conclusion: Image-guided percutaneous needle biopsy is a highly accurate and safe method for diagnosing pancreatic lesions. However, its low negative predictive value underscores the need for cautious interpretation of negative results and diligent follow-up. Diagnostic yield is maximized by precise technical targeting and the use of concurrent on-site cytopathology, supporting the continued role of PNB as a complementary tool in the era of endoscopic biopsy.