Post-neoadjuvant treatment pancreatic cancer resectability and outcome prediction using CT, 18F-FDG PET/MRI and CA 19–9

Abstract

Background CT prediction of resectability and prognosis following neoadjuvant treatment (NAT) in patients with pancreatic ductal adenocarcinoma (PDAC) remains challenging. This study aims to determine whether addition of 18F-fluorodeoxyglucose (FDG) postiron emission tomography (PET)/MRI and carbohydrate antigen (CA) 19–9 to contrast-enhanced CT (CECT) can improve accuracy of predicting resectability compared to CECT alone and predict prognosis in PDAC patients after NAT. Methods In this retrospective study, 120 PDAC patients (65 women; mean age, 66.7 years [standard deviation, 8.4]) underwent CECT, PET/MRI, and CA 19–9 examinations after NAT between January 2013 and June 2021. Three board-certified radiologists independently rated the overall resectability on a 5-point scale (score 5, definitely resectable) in three sessions (session 1, CECT; 2, CECT plus PET/MRI─no FDG avidity and no diffusion restriction at tumor-vessel contact indicated modification of CECT scores to ≥ 3; 3, CECT plus PET plus CA 19–9─no FDG avidity at tumor-vessel contact and normalized CA 19–9 indicated modification of CECT scores to ≥ 3). Jackknife free-response receiver operating characteristic method and generalized estimating equations were used to compare pooled area under the curve (AUC), sensitivity, and specificity of three sessions. Predictors for recurrence-free survival (RFS) were assessed using Cox regression analyses. Results Each session showed different pooled AUC (session 1 vs. 2 vs. 3, 0.853 vs. 0.873 vs. 0.874, p = 0.026), sensitivity (66.2% [137/207] vs. 86.0% [178/207] vs. 84.5% [175/207], p < 0.001) and specificity (67.3% [103/153] vs. 58.8% [90/153] vs. 60.1% [92/153], p = 0.048). According to pairwise comparison, specificity of CECT plus PET/MRI was lower than that of CECT alone (adjusted p = 0.042), while there was no significant difference in specificity between CECT alone and CECT plus PET plus CA 19–9 (adjusted p = 0.081). Twenty-eight of 69 patients (40.6%) with R0 resection experienced tumor recurrence (mean follow-up, 18.0 months). FDG avidity at tumor-vessel contact on post-NAT PET (HR = 4.37, p = 0.033) and pathologically confirmed vascular invasion (HR = 5.36, p = 0.004) predicted RFS. Conclusion Combination of CECT, PET and CA 19–9 increased area under the curve and sensitivity for determining resectability, compared to CECT alone, without compromising the specificity. Furthermore, 18F-FDG avidity at tumor-vessel contact on post-NAT PET predicted RFS.

Imaging of pancreatic ductal adenocarcinoma – An update for all stages of patient management

“…Both CT and MRI FDG-PET’s metabolic response has been reported to be associated with pathologic response, being superior than CA19–9 for this purpose [119] , [120] . FDG-PET MRI added to contrast-enhanced CT showed improved accuracy for determining resectability status when compared with contras-enhanced CT alone, in a retrospective study [121] . A recent systematic review reported FDG-PET’s potential for predicting and assessing response to neoadjuvant therapy; however, the small numbers of patients enrolled in each study and methodological heterogeneity prompt the need for well-designed prospective trials [122] .…”

Computed tomography and guidelines‐based human–machine fusion model for predicting resectability of the pancreatic cancer

“…Guggenberger et al assessed the role of current imaging-based resectability criteria in multi-center, openlabel, randomized phase 2 trial 10 ; Yoo et al validated that addition of F-18-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging, and carbohydrate antigen 19-9 to contrast-enhanced CT (CECT) can improve accuracy of predicting resectability compared with CECT alone. 11 Quero, et al reported how multidisciplinary tumor board (MDTB) may influence PC diagnosis and treatment, with particular focus on PC resectability assessment and the correspondence between MDTB definition of resectability and intraoperative findings. 12 However, these studies all relied on clinical trial studies and did not involve quantitative prediction.…”

Editorial: Reviews in radiation oncology

“…In addition, FDG-avid lesions potentially could be dose-escalated simultaneously, allowing greater dose delivery while minimizing dose to the surrounding critical structures such as the duodenum. PET/MRI imaging is also being evaluated in other such as prostate and head and neck for target delineation, initial staging, and treatment response assessment (3)(4)(5). We await to see whether PET/MRI could be incorporated into routine radiation oncology practice.…”