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Purpose: The emergence of chimeric antigen receptor (CAR) T-cell therapy fundamentally changed the management of individuals with relapsed and refractory large B-cell lymphoma (LBCL). However, real-world data have shown divergent outcomes for the approved products. The present study therefore set out to evaluate potential risk factors in a larger cohort. Methods: Our analysis set included 88 patients, treated in four German university hospitals and one Italian center, who had undergone 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (PET) before CAR T-cell therapy with tisagenlecleucel or axicabtagene ciloleucel. We first determined the predictive value of conventional risk factors, treatment lines, and response to bridging therapy for progression-free survival (PFS) through forward selection based on Cox regression. In a second step, the additive potential of two common PET parameters was assessed. Their optimal dichotomizing thresholds were calculated individually for each CAR T-cell product. Results: Extra-nodal involvement emerged as the most relevant of the conventional tumor and patient characteristics. Moreover, we found that inclusion of metabolic tumor volume (MTV) further improves outcome prediction. The hazard ratio for a PFS event was 1.68 per unit increase of our proposed risk score (95% confidence interval [1.20, 2.35], P = 0.003), which comprised both extra-nodal disease and lymphoma burden. While the most suitable MTV cut-off among patients receiving tisagenlecleucel was 11 mL, a markedly higher threshold of 259 mL showed optimal predictive performance in those undergoing axicabtagene ciloleucel treatment. Conclusion: Our analysis demonstrates that the presence of more than one extra-nodal lesion and higher MTV in LBCL are associated with inferior outcome after CAR T-cell treatment. Based on an assessment tool including these two factors, patients can be assigned to one of three risk groups. Importantly, as shown by our study, metabolic tumor burden might facilitate CAR T-cell product selection and reflect the individual need for bridging therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: The total number of PSMA-PET-CT examinations for the staging of prostate cancer patients has increased in recent years, following its superior imaging properties. Fluorinated PSMA ligands can be produced in larger amounts, facilitating higher patient throughput compared to the initially developed gallium labelled PSMA-tracers; allowing PET in only a few patients per synthesis. This results in a longer time after, typically early morning, radiochemical synthesis (TaS) of [18]F-PSMA when the PSMA-PET scan is performed. Moreover, novel fluorinated-PSMA compounds are injected around two hours before PET-CT and the time after injection (TaI) might show significant deviation. [18F]-PSMA PET offers improved detection rates in the proximity of the urinary tract; however, it has the disadvantage of more unspecific uptake, e.g., in the skeleton. This article focusses on the question whether TaS or TaI have an influence on uptake patterns in malignant lesions and healthy tissue. PET imaging using PSMA ligands is increasingly used for staging in prostate cancer patients in different clinical indications. Unlike [68Ga]Ga-labeled PSMA ligands, fluorinated compounds can be produced in large amounts; thus, they can be used for a higher number of patients. One concern is that in patients studied a long time after synthesis (TaS) or time after injection (TaI), the specific activity may decline; thus, the signal may be lower in these patients. In this study, we investigated a potential effect of TaS and TaI on image quality. In total, 134 consecutive patients were included in this retrospective analysis on the effect of TaS and TaI on uptake in prostate cancer lesions. All the patients underwent [18F]F-PSMA-1007 PET-CT from 99 min up to 549 min after tracer quality control. TaS and TaI were compared to the quantitative tumoral uptake parameters SUVmax and SUVpeak. In a second exploratory part of the analysis, TaS and TaI were correlated to a physiological tracer uptake in different organs. TaS and TaI did not affect the SUVmax and SUVpeak in tumor lesions in [18F]F-PSMA-1007 PET. The physiological uptake in salivary glands, lacrimal glands and the ganglia, spleen and urine was not significantly correlated to TaS or TaI; in contrast to the mean liver uptake, showing a weak, but significant correlation to TaS. The [18F]F-PSMA-1007 uptake in prostate cancer lesions is not significantly dependent on the TaS and TaI. These results are extremely reassuring when performing [18F]F-PSMA-1007 PET a considerable time after synthesis. [ABSTRACT FROM AUTHOR]

Recently introduced fluorine‑18 prostate‑specific membrane antigen‑1007 ( 18F‑PSMA‑1007) for imaging prostate cancer has an intense physiologic liver uptake and biliary excretion. The aim of the present study was to evaluate the effect of different dietary conditions on this physiological uptake. Forty consecutive prostate cancer patients were scanned with 18F‑PSMA‑1007 positron emission tomography/computed tomography at different dietary conditions. In addition to a blinded read scoring, tracer uptake intensities (standardized uptake values [SUVs]) were measured in the liver and small bowel. There was no significant difference in liver and small‑bowel uptake between different patient groups. Wilcoxon signed‑rank tests revealed no significant difference of the median mean SUV of the liver or maximum SUV of the horizontal part of the duodenum between different dietary conditions groups. A dietary preparation of patients by fasting or the attempt to clear liver activity by high caloric drinks does not have a significant effect on tracer uptake in the liver or in the small bowel. [ABSTRACT FROM AUTHOR]

Purpose: Dual-time point PET/CT scanning with [68Ga]Ga-PSMA-11 in the diagnosis of prostate cancer (PC) has been advanced as a method to increase detection of PC lesions, particularly at early stages of biochemical recurrence and as a potential means to aid the discrimination between benign and pathological prostate-specific membrane antigen (PSMA) uptake. However, the assumption that all PC lesions uniformly exhibit increasing tracer uptake at delayed imaging has not yet been investigated, which this present study aims to address. Methods: One hundred consecutive patients with biochemically recurrent PC who received standard and late [68Ga]Ga-PSMA-11 PET/CT (by local protocol at 1.5 h "standard" and 2.5 h p.i. "late") underwent retrospective evaluation. All lesions with a tracer uptake above local background were analysed with regard to their maximum standardised uptake values at standard and late images (SUVmax) and characterised according to their morphological characteristics. Results: Seventy-nine of 100 patients had PSMA-positive scans, in whom a total of 185 individual PSMA-positive lesions were identified. These were morphologically characterised as bone lesions (n = 48), solid organ lesions (n = 3), lymph node (LN) lesions (n = 78) and locally recurrent lesions in the prostatic fossa or seminal vesicles (n = 56). The relative uptake between standard and late imaging was considered; all lesions classified as local recurrence presented with increasing (86%) or stable patterns of tracer uptake (14%). In contrast, only 58% of bone lesions exhibited increasing tracer uptake, with 21% exhibiting a stable pattern and 21% exhibiting a decreasing tracer uptake at late imaging. Conclusion: A heterogeneous pattern of dynamic tracer uptake was observed, with a largely increasing pattern observed for locally recurrent lesions and lymph nodes and a significant proportion of bone lesions exhibiting decreasing tracer uptake. The results are of significance not only in the imaging and identification of PC lesions, but they also have implications for PSMA-directed ligand therapy. [ABSTRACT FROM AUTHOR]

The noninvasive characterization of cardiac tumors is of clinical importance for surgical resection planning. Conventional radiological examinations like cardiac computed tomography (CT) or magnetic resonance imaging (MRI) may be misleading as benign cardiac lesions can present features suspicious for malignancy. Moreover, the low prevalence of cardiac tumors may additionally hamper a sound diagnosis. However, fluorodeoxyglucose-positron emission tomography (FDG-PET) has proven to be a reliable tool for cardiac tumor characterization. Here, FDG-PET/CT imaging of a 50-year-old man suffering from a cardiac tumor is presented. Despite CT and MRI signs of malignancy, FDG-PET characterized the tumor as benign. Histology confirmed the FDG-PET prediction and revealed a pericardial capillary hemangioma. Thereby, it seems important to integrate FDG-PET in the diagnostic workup of cardiac tumors. [ABSTRACT FROM AUTHOR]

Purpose: PSMA-targeted PET in patients with prostate cancer (PCa) has a significant impact on treatment decisions. By far the most frequently used PSMA ligand is 68Ga-labelled PSMA-11. However, due to the availability of larger amounts of activity, 18F-labelled PSMA ligands are of major interest. The aim of the present study was to evaluate the biodistribution and performance of the novel 18F-labelled ligand PSMA-1007 at two different time points.Methods: This retrospective analysis included 40 consecutive patients (mean age 68.7 ± 8.1 years) referred for PSMA PET/CT. 18F-PSMA-1007 PET/CT was performed for localization of biochemical relapse, primary staging or therapy follow-up. Circular regions of interest were placed on representative slices of the liver, spleen, kidney, abdominal aortic blood pool, bone marrow (fourth lumbar vertebral body), urinary bladder and gluteus muscle at 60 and 120 min after injection. In malignant lesions the maximum standardized uptake (SUVmax) was measured within volumes of interest at both time points. All SUVs at 60 min were compared with those at 120 min after injection.Results: The activity in the blood pool, urinary bladder and gluteus muscle was very low and decreased significantly over time (P < 0.001). Uptake in the liver, spleen and kidney showed a significant increase over time and uptake in the bone marrow remained stable. Overall, 135 PCa lesions were detected at 60 min and 136 lesions at 120 min after injection. The median SUVmax increased significantly (P < 0.001) from 10.98 to 15.51 between 60 and 120 min.Conclusion: PCa lesions show a significant increase in 18F-PSMA-1007 uptake at 120 min compared with 60 min after injection. In addition, accumulation of the tracer in the urinary bladder was very low leading to improved contrast of adjacent PCa lesions. Increasing accumulation in the liver may limit the sensitivity of the tracer in detecting liver metastases. [ABSTRACT FROM AUTHOR]

Systemic cancer is the second most common cause of death in developed countries and metastatic brain tumour the most common tumour of the central nervous system (CNS). As the incidence of brain metastases appears to be rising, more accurate non-invasive imaging modalities for diagnosis, prognosis, prediction and follow-up of treatment are requisites for efficient patient management. Positron emission tomography (PET) imaging has the ability to evaluate different aspects of tumour microenvironment on the molecular and cellular level and impact the workup of patients with brain metastasis. This article reviews the current application of PET imaging in patients with metastatic brain disease. [ABSTRACT FROM AUTHOR]

The authors discuss the discrepancy between glucose metabolism and sympathetic nerve terminals in a 20-year-old man with an aggressive abdominal paraganglioma. They highlight the value of fludeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as an additional test for accurate detection and localization of metastases for malignant tumors of the sympathetic nervous system. They also state that a precise staging of these heterogeneous tumors is needed for adequate treatment.

Surgical resection is the therapy of choice in head and neck paraganglioma but is associated with considerable morbidity. For treatment of inoperable or progressive disease, less aggressive adjuvant options are warranted. This study assessed effectiveness and safety of peptide receptor radionuclide therapy (PRRT) with lutetium-177–DOTATATE for head and neck paraganglioma with emphasis on response assessment. A retrospective analysis of 7 patients with head and neck paraganglioma treated with PPRT between May 2014 and October 2016 was performed. Three patients had jugulotympanic paraganglioma, 3 patients had carotid body tumors, and 1 patient had a combination of both. Patients underwent PRRT after discussion in the local tumor board regarding progressive disease, inoperability, or lack of other adjuvant options. All patients underwent 3–5 cycles of PRRT. Treatment response was evaluated by gallium-68–DOTATATE positron emission tomography/computed tomography and contrast-enhanced computed tomography or magnetic resonance imaging. Outcome measures were two-dimensional tumor diameters and total tumor volumes. Median patient age was 60 years (interquartile range: 14–84 years). All patients had stable disease at posttherapy assessment. Decreasing tumor volumes were found in 4 patients. Clinical symptoms improved in 2 patients. No progression or adverse events occurred during a median follow-up of 39 months (interquartile range: 35–47 months). Somatostatin receptor–targeted therapy using lutetium-177-DOTATATE shows promising effectiveness with a high safety profile. Patients in whom surgical morbidity outweighs oncologic benefit should be informed about PRRT as a treatment option. [ABSTRACT FROM AUTHOR]