Added value of digital FDG-PET/CT in disease staging and restaging in patients with resectable or borderline resectable pancreatic cancer. (April 2023)

• Record Type: Journal Article
• 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.; Lioe-Fee, de Geus-Oei; Jager, Pieter L.; Patijn, Gijs A.
• Is Part Of: Surgical oncology. Volume 47(2023)
• Publication Date: 2023-04
• Subjects: Nuclear medicine -- Pancreatic cancer -- Digital FDG-PET/CT -- Neo-adjuvant therapy -- Tumor response evaluation -- Disease staging -- Pancreatic surgery -- Pancreaticoduodenectomy -- Pancreatectomy -- FOLFIRINOX -- Chemoradiotherapy -- LAPC -- PDAC; Cancer -- Surgery -- Periodicals; Neoplasms -- surgery -- Periodicals; Cancer -- Chirurgie -- Périodiques; Electronic journals; 616.994059
• DOI: 10.1016/j.suronc.2023.101909
• Languages: English
• ISSNs: 0960-7404

Abstract

Abstract: Background: 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. Methods: 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. Results: 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%). Conclusion: 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. Highlights: 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.