PET/CT for Pancreatic Malignancy: Potential and Pitfalls

Initial staging PET/CT in a 65-y-old man with known pancreatic adenocarcinoma. (A) Axial noncontrast CT demonstrates enlarged mesenteric lymph nodes (circle). (B) Corresponding PET/CT fusion image demonstrates intense ¹⁸F-FDG uptake within nodes suggestive of metastatic involvement. Physiologic uptake is present within small bowel.

Initial staging PET/CT in a 63-y-old woman with pancreatic adenocarcinoma. (A) Noncontrast axial CT images demonstrates ill-defined peritoneal masses within pelvic cul-de-sac (arrow). This is another difficult location to evaluate with CT alone. (B) Corresponding PET/CT image demonstrates these masses to be intensely hypermetabolic (arrow), helpful in diagnosing peritoneal/mesenteric metastases. Incidental note is made of fat density mass (circle) within left adnexa, which does not demonstrate any ¹⁸F-FDG uptake consistent with dermoid/mature cystic teratoma.

PET/CT performed for evaluating response to chemotherapy in a 69-y-old man with pancreatic adenocarcinoma. (A) Noncontrast CT shows small pleural-based mass adjacent to left lung apex (arrow). (B) Corresponding PET/CT demonstrates its hypermetabolic nature, suggestive of pleural metastasis. This was previously not identified on CECT, and presence of ¹⁸F-FDG uptake led to improved identification and, hence, more accurate staging assessment with PET/CT.

Restaging PET/CT in a 71-y-old woman with pancreatic adenocarcinoma. Hypermetabolic focus at right lung base (arrow) (A) without corresponding nodule on CT component of examination (B) represents misregistration of hepatic activity mimicking a lung nodule.