Diagnostic Performance of 68Ga-SSTR PET/CT and Contrast-Enhanced CT for Preoperative Lymph Node Staging in Duodenal and Pancreatic Neuroendocrine Neoplasms (DP-NENs): A Pathology-Validated Analysis

BACKGROUND: Accurate preoperative lymph node (LN) staging is critical for determining optimal surgical strategies in duodenal and pancreatic neuroendocrine neoplasms (DP-NENs). While both gallium-68-labeled somatostatin receptor (SSTR) PET/CT and contrast-enhanced CT (ceCT) offer distinct advantages for LN assessment, their comparative diagnostic accuracy remains undefined. We aimed to systematically evaluate and directly compare the diagnostic performance of 68Ga-SSTR PET/CT and ceCT against pathological gold standards in DP-NENs. RESULTS: We retrospectively analyzed 521 LNs from 136 regional stations in 42 DP-NEN patients who underwent preoperative 68Ga-SSTR PET/CT and ceCT followed by surgical LN dissection at two medical centers. Pathological validation revealed comparable detection rates for 68Ga-SSTR PET/CT and ceCT at the patient and regional levels. However, at the individual lesion level, 68Ga-SSTR PET/CT demonstrated significantly higher sensitivity (67.6% vs. 26.4%, P=0.008) and accuracy (96.5% vs. 94.0%). In patients with small DP-NENs (≤2 cm), 68Ga-SSTR PET/CT also exhibited superior lesion-level sensitivity (52.6% vs. 26.3%, P=0.004) and accuracy (94.0% vs. 93.5%). The size of the metastatic deposit within LNs significantly influenced 68Ga-SSTR PET/CT detection (P=0.036), whereas the overall LN size was associated with ceCT performance (P=0.048). CONCLUSIONS: 68Ga-SSTR PET/CT provided superior detection of lymph node metastases (LNM) compared to ceCT. Preoperative integration of 68Ga-SSTR PET/CT, particularly in conjunction with ceCT, might enhance staging accuracy, guiding less aggressive surgical approaches and avoiding non-targeted lymphadenectomy, especially in patients with small DP-NENs.