A systemic review and meta-analysis were conducted to investigate the diagnostic ability for staging and impact on management of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and PET/magnetic resonance imaging (MRI) in patients with pancreatic ductal adenocarcinoma. A comprehensive search was performed in four databases to retrieve studies of pancreatic ductal adenocarcinoma patients that have reported the diagnostic ability of FDG PET/CT and PET/MRI for detecting metastasis and the proportion of patients whose management was changed by its results. The sensitivity and specificity for detecting metastasis and the proportion of patients with management changes were pooled using a random-effects model. A total of 10 studies were included. The pooled sensitivity and specificity for detecting lymph node metastasis were 0.55 and 0.94, respectively, while the pooled sensitivity and specificity for detecting distant metastasis were 0.80 and 1.00, respectively. The areas under the summarized receiver operating characteristic curves for detecting lymph node and distant metastasis were 0.88 and 0.92, respectively. The pooled proportion of patients with management changes was 19%. FDG PET/CT and PET/MRI showed high diagnostic accuracy for detecting lymph node and distant metastasis in pancreatic ductal adenocarcinoma patients, and the use of these imaging tools led to management changes in a significant portion of these patients.

To assess the prognostic and predictive value of early quantitative ¹⁸F-FDG PET to monitor therapy with an antibody to the insulin-like growth factor 1 receptor (IGF-1R antibody) in patients with Ewing sarcoma family of tumors (ESFT). Methods: ¹⁸F-FDG PET images at baseline and approximately 9 days after initiation of IGF-1R antibody therapy in 115 patients with refractory or relapsed ESFT were prospectively obtained as part of the Sarcoma Alliance for Research through Collaboration trial (SARC-11). Responses were centrally evaluated by PET response criteria in solid tumors (PERCIST) 1.0 in 93 patients. The 9 day PET responses were correlated to overall survival (OS), progression free survival (PFS), and clinical benefit after 6 weeks of therapy based on clinical observation and CT response by WHO anatomic criteria. Results: The median OS was 8.1 months (95% CI, 6.4 to 10.0 months). Using PERCIST, patients with progressive metabolic disease (PMD) showed shorter OS (median 4.7 months) compared to patients without progression (median 10.0 months, P = 0.001). PMD on day 9 PET was associated with a significantly higher risk of death (hazard ratio=2.8; 95% CI, 1.5 to 5.5). Changes in ¹⁸F-FDG uptake after 9 days of therapy had an area under the curve (AUC) of receiver operating characteristic of 0.71 to predict 1 year OS. The AUC was 0.63 to predict progression at 3 months, and was 0.79 to predict clinical benefit after 6 weeks of therapy. Conclusion: Treatment response by quantitative ¹⁸F-FDG PET assessed by PERCIST 1.0 as early as 9 days into IGF-1R antibody therapy in patients with ESFT can predict the OS, PFS, and clinical response to therapy.

F-18-fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is essential for monitoring response to treatment in patients with diffuse large B-cell lymphoma (DLBCL) and qualitative interpretation is commonly applied in clinical practice. We aimed to evaluate the interobserver agreements of qualitative PET/CT response in patients with DLBCL and the predictive value of PET/CT results for clinical outcome.PET/CT images were obtained for patients with DLBCL 3 times: at baseline, after 3 cycles of first-line chemotherapy (interim), and after completion of chemotherapy. Two nuclear medicine physicians (with 3 and 8 years of experience with PET/CT) retrospectively assessed response to chemotherapy blinded to the clinical outcome using International Harmonization Project (IHP) criteria and Deauville 5-point score. The associations between PET/CT results and progression-free survival (PFS) and overall survival (OS) were assessed using Cox regression analysis.A total of 112 PET/CT images were included from 59 patients with DLBCL (36 male, 23 female; mean age 53 ± 14 years). Using the IHP criteria, interobserver agreement was substantial (Cohen κ = 0.76) with absolute agreement consistency of 89%. Using the Deauville score, interobserver agreement was moderate (Cohen weighted κ = 0.54) and absolute consistency was 62%. The most common cause of disagreements was discordant interpretation of residual tumor uptake. With median follow-up period of 60 months, estimated 5-year PFS and OS were 81% and 92%, respectively. Neither interim nor posttreatment PET/CT results by both readers were significantly associated with PFS. Interim PET/CT result by the more experienced reader using Deauville score was a significant factor for OS (P = 0.019).Moderate-to-substantial interobserver agreement was observed for response assessments according to qualitative PET/CT criteria, and interim PET/CT result could predict OS in patients with DLBCL. Further studies are necessary to further standardize the PET/CT-based response criteria for more consistent interpretation.