William McGahan, Alexa Chadwick, Karen Lindsay, Brook Gulhane, Melissa J Latter, Thomas O’Rourke, Paul A Thomas, David Cavallucci

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 SUVmax 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 SUVmax 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.