The aim of this study was to assess the diagnostic performance of simultaneous whole-body 68Ga-DOTANOC PET/MRI compared with 68Ga-DOTANOC PET/CT for detection of distant metastatic disease in patients with well-differentiated neuroendocrine tumors (NETs). Patients with histologically proven, well-differentiated NET (G1 or G2) were included in this prospective, institutional review board–approved study. Patients underwent 68Ga-DOTANOC PET/CT and subsequent 68Ga-DOTANOC PET/MRI after a single tracer injection on the same day for staging or restaging purposes. Images were evaluated for the presence of NET lesions by 2 rater teams, each consisting of a nuclear medicine physician and a radiologist, in an observer-blinded fashion. Overall agreement, accuracy, sensitivity, and specificity, relative to a composite reference standard (consensus review including follow-up data), were calculated. Between July 2014 and June 2016, 28 patients were enrolled. Overall agreement and accuracy between the 2 rater teams were 91.7% (95% confidence interval [CI], 87.5%–95.9%) and 97% (95% CI, 94.4%–99.6%) for PET/MRI and 92.3% (95% CI, 88.3%–96.3%) and 94.6% (95% CI, 91.2%–98.1%) for PET/CT, respectively (P = 1.00). Overall, PET/MRI reached 89.8% sensitivity (95% CI, 77.8%–96.6%) and 100% specificity (95% CI, 97%–100%); PET/CT showed 81.6% sensitivity (95% CI, 68%–91.2%) and 100% specificity (95% CI, 97%–100%) for the detection of metastatic disease in NETs. Whole-body 68Ga-DOTANOC PET/MRI appears to be comparable to 68Ga-DOTANOC PET/CT for lesion detection in patients with well-differentiated NETs. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal.

The response evaluation criteria in lymphoma (RECIL) classification for lymphoma treatment response assessment was introduced in 2017, but it has not yet been compared to the established Lugano classification. Also, the value of the provisional “minor response” (MiR) category of RECIL is unclear. In 54 patients with FDG-avid non-Hodgkin lymphomas (41 diffuse large B-cell lymphomas (DLBCL) and 13 follicular lymphomas), [¹⁸F]FDG-PET/CT-based response according to RECIL and Lugano was determined at interim and end-of-treatment (EOT) restaging. Rates of agreement and Cohen’s kappa (κ) coefficients were calculated. The relationship between RECIL and Lugano responses and 2-year complete remission (CR) status of DLBCL patients was determined. At interim restaging, MiR was observed in 14.8%, and at EOT, in 5.6% of patients. When MiR was recoded as partial remission, agreement between RECIL and Lugano was 83.3% at interim restaging (κ = 0.69), and 90.7% at EOT (κ = 0.79). 85.4%, of DLBCL patients with responding disease at interim restaging according to both RECIL and Lugano achieved 2-year CR status; whereas, at EOT, 82.9% of patients with responding disease according to Lugano, and 85.4% of patients with responding disease according to RECIL, achieved 2-year CR status. Thus, RECIL and Lugano classifications show comparable performance for treatment response assessment, and a similar association with 2-year CR status in FDG-avid lymphomas.

Aim of present study was to determine whether the currently recommended 13-cm cranio-caudal diameter cut-off on CT for assessment of splenic involvement in lymphoma offers adequate sensitivity and specificity. Patients with histologically proven lymphoma who had undergone [18F]FDG-PET/CT before therapy were included. Cranio-caudal diameters of the spleen were measured on the CT component of PET/CT, and ROC analyses with calculation of respective areas under the curve (AUC) were used to determine cut-off values of cranio-caudal measurements with their respective sensitivities and specificities, using [18F]FDG-PET as the reference standard. In 93 patients, we found a sensitivity of 74.1% and a specificity of 47% for the 13-cm splenic diameter cut-off. Our results show reasonable, though far from perfect sensitivities and specificities for the currently recommend 13-cm splenic diameter cut-off.