Objectives: Diagnosing ampullary and duodenal papillary carcinomas (ADPCs) is challenging. In the present study, we investigated the application value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the preoperative evaluation of these tumours.
Methods: 18F-FDG PET/CT images of 58 patients with ADPC and 28 patients with benign disease were retrospectively analysed. Preoperative 18F-FDG PET/CT was compared to contrast-enhanced (CE) CT and magnetic resonance imaging (MRI) in terms of diagnostic efficacy, certainty, staging and impact on treatment decisions.
Results: 18F-FDG PET/CT showed a high sensitivity (93.1%) and a medium specificity (78.6%) for diagnosing ADPC. Compared to CE CT/MRI, 18F-FDG PET/CT had a higher diagnostic specificity (78.6 vs. 35.7%, p = 0.001) but a similar sensitivity (93.1 vs. 89.6%, p = 0.508). 18F-FDG PET/CT provided a much higher diagnostic certainty than CE CT/MRI (definite reports, 88.4 vs. 50.0%, χ2 = 29.698, p < 0.001), especially for small tumours ≤ 1.5 cm, and found distant metastases in five patients. The 18F-FDG PET/CT findings affected the treatment plans of 11 patients and improved the confidence in the diagnoses of 28 patients.
Conclusions: The present study demonstrated that 18F-FDG PET/CT can supplement CE CT/MRI to provide a more accurate diagnosis for ADPC, and thus, plays an important role in the decision-making process before complicated pancreaticoduodenectomy procedures.
Key points: • It is a challenge for CT and MRI to diagnose ampullary carcinoma, especially at their early stage. • Our study demonstrated that the benefit of PET/CT was improving the diagnostic confidence for ampullary and duodenal papillary carcinomas. • 18F-FDG PET/CT can change the treatment decision for ampullary and duodenal papillary carcinomas.
Keywords: Ampulla of Vater; Carcinomas; Diagnosis; Magnetic resonance imaging; Positron emission tomography.