Preoperative assessment of pancreatic cancer with [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR versus [¹⁸F]-FDG PET/CT plus contrast-enhanced CT: a prospective preliminary study

To assess the diagnostic performance of [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging in the preoperative evaluation of pancreatic cancer and compare it with that of [¹⁸F]-FDG PET/CT plus contrast-enhanced CT (CECT).

Thirty-one patients with pancreatic cancer underwent preoperative [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR, [¹⁸F]-FDG PET/CT, and CECT imaging. Two nuclear medicine physicians independently reviewed two sets of images (set 1, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR; set 2, [¹⁸F]-FDG PET/CT plus CECT) and reached a consensus on tumour resectability, N staging (N0 or N positive) and M staging (M0 or M1). Based on the above indices, the resectability of the tumour was determined according to a five-point scale. Clinical, operative, and pathological findings were used as a reference standard to compare the diagnostic performance of the two imaging sets via the McNemar test.

The diagnostic performance of [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging was not significantly different from that of [¹⁸F]-FDG PET/CT plus CECT imaging in the assessment of tumour resectability (area under the receiver operating characteristic curve: 0.854 vs. 0.775, p = 0.192), N staging [accuracy: 82.4% (14 of 17 patients) vs. 58.8% (10 of 17 patients), p = 0.125] and M staging [accuracy: 100% (31 of 31 patients) vs. 90.3% (28 of 31 patients), p = 0.250]. However, compared with [¹⁸F]-FDG PET/CT plus CECT imaging, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging changed the M stage in three patients by upstaging from M0 to M1 in 2 patients and downstaging from M1 to M0 in 2 patients. In 13 patients with liver metastases, the number of liver metastases detected via [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging was greater than that detected via [¹⁸F]-FDG PET/CT plus CECT imaging (324 vs. 240). In 3 patients with peritoneal metastases, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging detected more peritoneal metastases than did [¹⁸F]-FDG PET/CT plus CECT imaging.

[⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR imaging has diagnostic accuracy comparable to [¹⁸F]-FDG PET/CT plus CECT in terms of preoperative staging and assessment of resectability in pancreatic cancer; additionally, it exhibits superior capability in detecting liver and peritoneal metastases. Consequently, [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/MR has the potential to become a one-stop imaging tool for the preoperative evaluation of pancreatic cancer.