This retrospective study shows a correlation between F-FDOPA uptake, especially using TL uptake, urinary MNs, and a PHEO biochemical phenotype. This illustrates that beyond its localization value,F-FDOPA PET further enables PHEO characterization at a specific metabolic level.

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Background: After stereotactic body radiation therapy (SBRT) for lung tumors, follow-up CT scans remain a pitfall. The early detection of local relapse is essential to propose a new treatment. We aim to create a local recurrence predictive score using pre- and post-therapeutic imaging criteria and test it on a validation cohort. Methods: Between February 2011 and July 2016, lung tumors treated by SBRT with available pretreatment fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) and follow-up CT scans were retrospectively analyzed. The risk factors associated with relapse were identified by univariate logistic regression on a train cohort. The score was created using these factors, merging clinical and imaging criteria associated with local relapse, and then tested on an independent validation cohort. Overall and local relapse-free survival at 1 and 3 years were recorded. Results: Twenty-eight patients were included in the train cohort and ten in the derivation cohort (male 74%, median age 70 ± 12 years). Five variables significantly associated with local recurrence (female gender; sequential enlargement; craniocaudal growing; bulging margins; standardized uptake value (SUVmax > 5.5)) were combined to create the score on five points. With the threshold >2.5/5, the sensitivity and specificity of the score on the validation cohort were 100% and 88%, respectively. Overall survival and local relapse-free survival at 1 and 3 years were 89% and 42%, and 89% and 63%, respectively. Conclusion: The local recurrence risk score created has high sensitivity (100%) and specificity (88%), upon independent validation cohort, to detect local relapse. This score is easy to use in daily clinical practice.

Background and objectives 18F-FDG PET/CT has recently been added as a major criterion in the ESC 2015 infective endocarditis (IE) guidelines. We and others have demonstrated that18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) / computed tomography (CT) was useful in patients with suspected prosthetic valve and cardiac device IE. However, the sensitivity and specificity of ESC classification is unknown in patients with native valve endocarditis (NVE) as well as the clinical impact of PET findings. Purposes 1. Primary objective: To assess the value of the new ESC criteria including 18F-FDG PET/CT in native valve infective endocarditis (NVIE). 2. Secondary objectives: – to determine the usefulness of PET/CT concerning embolic or neoplastic detection. – to describe a new PET/CT feature, i.e. the diffuse splenic uptake. Methods Between 2012 and 2017, 75 patients with suspected NVIE were prospectively included, after exclusion of patients with uninterpretable or not feasible PET/CT. Using the expert consensus of the Endocarditis Team after a 3-month follow-up as gold standard, 63 IE were confirmed and 12 were rejected. Patients follow-up was scheduled at one and three months after hospitalization. Results Significant cardiac uptake by PET/CT (major criterion) was observed in 11 among 63 patients with definite NVIE and no patients with rejected IE (sensitivity 18%, specificity 100%). Among the 63 patients with a final diagnosis of NVE, a peripheral embolism or mycotic aneurysm was observed in 20 cases (32%). Considering this, the ESC 2015 classification increased the sensitivity of Duke criteria from 64 to 70% (p<0.001) without no change on specificity (p<0.001). Twenty-four patients (38%) were diagnosed with secondary infectious sites or infectious portal of entry. A diffuse splenic uptake was observed in 39 (52%) patients, including 37 (59%) of patients with a final diagnosis of NVE (specificity 83%). Conclusion 1. The value of 18F-FDG PET/CT in NVE diagnosis is poor (18% sensitivity) 2. Usefulness of PET/CT remains high when concerning embolic or neoplastic detection. 3. Our study describes for the first time in NVE a new potential endocarditis criterion, i.e. the presence of a diffuse splenic uptake on 18F-FDG PET/CT Diffuse splenic uptake Funding Acknowledgement Type of funding source: None

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BackgroundIn FDG-PET, SUV images are hampered by large potential biases. Our aim was to develop an alternative method (ParaPET) to generate 3D kinetic parametric FDG-PET images easy to perform in clinical oncology.MethodsThe key points of our method are the use of a new error model of PET measurement extracted from a late dynamic PET acquisition of 15 min, centered over the lesion and an image-derived input function (IDIF). The 15-min acquisition is reconstructed to obtain five images of FDG mean activity concentration and images of its variance to model errors of PET measurement. Our approach is carried out on each voxel to derive 3D kinetic parameter images. ParaPET was evaluated and compared to Patlak analysis as a reference. Hunter and Barbolosi methods (Barbolosi-Bl: with blood samples or Barbolosi-Im: with IDIF) were also investigated and compared to Patlak. Our evaluation was carried on Ki index, the net influx rate and its maximum value in the lesion (Ki,max).ResultsThis parameter was obtained from 41 non-small cell lung cancer lesions associated with 4 to 5 blood samples per patient, required for the Patlak analysis. Compare to Patlak, the median relative difference and associated range (median; [min;max]) in Ki,max estimates were not statistically significant (Wilcoxon test) for ParaPET (− 3.0%; [− 31.9%; 47.3%]; p = 0.08) but statistically significant for Barbolosi-Bl (− 8.0%; [− 30.8%; 53.7%]; p = 0.001), Barbolosi-Im (− 7.9%; [− 38.4%; 30.6%]; p = 0.007) or Hunter (32.8%; [− 14.6%; 132.2%]; p < 10− 5). In the Bland-Altman plots, the ratios between the four methods and Patlak are not dependent of the Ki magnitude, except for Hunter. The 95% limits of agreement are comparable for ParaPET (34.7%), Barbolosi-Bl (30.1%) and Barbolosi-Im (30.8%), lower to Hunter (81.1%). In the 25 lesions imaged before and during the radio-chemotherapy, the decrease in the FDG uptake (ΔSUVmax or ΔKi,max) is statistically more important (p < 0.02, Wilcoxon one-tailed test) when estimated from the Ki images than from the SUV images (additional median variation of − 2.3% [− 52.6%; + 19.1%] for ΔKi,max compared to ΔSUVmax).ConclusionNone of the four methodologies is yet ready to replace the Patlak approach, and further improvements are still required. Nevertheless, ParaPET remains a promising approach, offering a non-invasive alternative to methods based on multiple blood samples and only requiring a late PET acquisition. It allows deriving Ki values, highly correlated and presenting the lowest relative bias with Patlak estimates, in comparison to the other methods we evaluated. Moreover, ParaPET gives access to quantitative information at the pixel level, which needs to be evaluated in the perspective of radiomic and tumour response.Trial registrationNCT 02821936; May 2016.