68Ga-FAPI PET/CT Prevents Futile Surgery and Demonstrates Tumor Biology in Patients with Pancreatic Ductal Adenocarcinoma

Abstract

PET/CT using ⁶⁸Ga-labeled fibroblast activation protein inhibitor (⁶⁸Ga-FAPI) may detect occult metastases and identify aggressive tumor biology in patients with pancreatic ductal adenocarcinoma (PDAC). We evaluated the impact of ⁶⁸Ga-FAPI PET/CT on surgical treatment in this patient population. Methods: Patients with PDAC who were deemed operative candidates after standard CT underwent pretreatment ⁶⁸Ga-FAPI PET/CT and were followed until confirmation of treatment intent. Lymph node ratio in resected tumors was used as a surrogate marker for tumor biology and correlated with the SUV_max of the primary tumor using linear regression. Results: Of 16 eligible participants, 5 (31%) had metastases that were not visible on CT scans but were detected with ⁶⁸Ga-FAPI PET/CT, and surgery was prevented. No additional investigations were prompted by ⁶⁸Ga-FAPI PET/CT unless they changed treatment intent. Two participants without metastases on ⁶⁸Ga-FAPI PET/CT did not have surgery because of local progression after neoadjuvant therapy. The SUV_max of the primary tumor at 60 min correlated with the lymph node ratio in resected PDAC (P = 0.04). Conclusion: ⁶⁸Ga-FAPI PET/CT may enhance treatment selection in PDAC. Comparative trials are the next step to confirm role in the clinical setting.

Keywords: 68Ga-FAPI PET/CT; lymph node ratio; pancreas; pancreatic ductal adenocarcinoma; tumor biology.