Added value of digital FDG-PET/CT in disease staging and restaging in patients with resectable or borderline resectable pancreatic cancer

• Published in: Surgical oncology Vol. 47; p. 101909
• Main Authors: de Jong, Tonke L., Koopman, Daniëlle, van der Worp, Corné A.J., Stevens, Henk, Vuijk, Floris A., Vahrmeijer, Alexander L., Mieog, J. Sven D., de Groot, Jan-Willem B., Meijssen, Maarten A.C., Nieuwenhuijs, Vincent B., de Geus-Oei, Lioe-Fee, Jager, Pieter L., Patijn, Gijs A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.04.2023
• Subjects: CA-19-9 Antigen - therapeutic use; Chemoradiotherapy; Digital FDG-PET/CT; Disease staging; Fluorodeoxyglucose F18; FOLFIRINOX; Humans; LAPC; Neo-adjuvant therapy; Neoplasm Staging; Nuclear medicine; Pancreatectomy; Pancreatic cancer; Pancreatic Neoplasms; Pancreatic Neoplasms - diagnostic imaging; Pancreatic Neoplasms - drug therapy; Pancreatic Neoplasms - surgery; Pancreatic surgery; Pancreaticoduodenectomy; PDAC; Positron Emission Tomography Computed Tomography - methods; Positron-Emission Tomography - methods; Prospective Studies; Radiopharmaceuticals - therapeutic use; Retrospective Studies; Tumor response evaluation; Digital FDG-PET/CT; Nuclear medicine; FOLFIRINOX; Pancreatectomy; Pancreaticoduodenectomy; LAPC; Chemoradiotherapy; PDAC; Disease staging; Pancreatic cancer; Tumor response evaluation; Neo-adjuvant therapy; Pancreatic surgery
• ISSN: 0960-7404; 1879-3320; 1879-3320
• DOI: 10.1016/j.suronc.2023.101909

We studied the added value of digital FDG-PET/CT in disease staging and restaging compared to the standard work-up with contrast enhanced CT (ceCT) and CA19-9 in patients with resectable or borderline resectable pancreatic cancer who received neo-adjuvant therapy. Primary endpoints were tumor response compared to ceCT and CA19.9 as well as the ability to detect distant metastatic disease. 35 patients were included in this dual-center prospective study. FDG-PET using digital photon counting technology combined with CT scans were acquired before (T1) and after neo-adjuvant therapy (T2). Patients were staged and restaged based on standard protocol with ceCT and CA 19.9, while all PET/CT scans were stored securely and not included in clinical decision making. After the pancreatic resection, an expert team retrospectively assessed the CT tumor diameter, CA19-9, tumor FDG-uptake, and appearance of metastatic disease of all patients for both time points. CA19-9 levels, CT tumor diameter, and tumor FDG-uptake on PET significantly decreased from T1 to T2 (p = 0.017, p = 0.001, and p < 0.0001). The change in FDG-uptake values showed a strong positive correlation with the change in CT tumor diameter and change in CA19-9 (R = 0.75 and R = 0.73, respectively). In addition, small-volume liver lesions were detected on digital PET/CT in 5/35 patients (14%), 4 of which were pathology confirmed at laparotomy. Only one of these five cases was detected on baseline staging ceCT (3%). We found that adding digital PET/CT strengthens restaging after neo-adjuvant therapy based on the observed strong correlation with ceCT tumor diameter and Ca19.9. Also, digital PET/CT was found to detect occult metastatic disease not visualized on ceCT, that would have resulted in altered disease staging and therapeutic strategy in a substantial proportion of patients. •Neoadjuvant therapy is playing an increasing role in the treatment of pancreatic cancer.•Traditional ceCT/MRI are ineffective as restaging modalities for neoadjuvant therapy response evaluation.•Emerging evidence is showing promise for PET/CT as improved restaging modality, in adjunct to CA 19–9.•In this prospective study we investigated the added value of a new generation digital PET-CT with improved accuracy as compared to analog PET/CT.•We found that adding digital PET/CT strengthens restaging after neo-adjuvant therapy.•In addition, digital PET/CT was found to detect occult metastases not visualized on ceCT in 11% of patients.