Search

Abstract Background Correct classification of estrogen receptor (ER) status is essential for prognosis and treatment planning in patients with breast cancer (BC). Therefore, it is recommended to sample tumor tissue from an accessible metastasis. However, ER expression can show intra- and intertumoral heterogeneity. 16α-[18F]fluoroestradiol ([18F]FES) Positron Emission Tomography/Computed Tomography (PET/CT) allows noninvasive whole-body (WB) identification of ER distribution and is usually performed as a single static image 60 min after radiotracer injection. Using dynamic whole-body (D-WB) PET imaging, we examine [18F]FES kinetics and explore whether Patlak parametric images ( $${K}_{i}$$ K i ) are quantitative and improve lesion visibility. Results This prospective study included eight patients with metastatic ER-positive BC scanned using a D-WB PET acquisition protocol. The kinetics of [18F]FES were best characterized by the irreversible two-tissue compartment model in tumor lesions and in the majority of organ tissues. $${K}_{i}$$ K i values from Patlak parametric images correlated with $${K}_{i}$$ K i values from the full kinetic analysis, r2 = 0.77, and with the semiquantitative mean standardized uptake value (SUVmean), r2 = 0.91. Furthermore, parametric $${K}_{i}$$ K i images had the highest target-to-background ratio (TBR) in 162/164 metastatic lesions and the highest contrast-to-noise ratio (CNR) in 99/164 lesions compared to conventional SUV images. TBR was 2.45 (95% confidence interval (CI): 2.25–2.68) and CNR 1.17 (95% CI: 1.08–1.26) times higher in $${K}_{i}$$ K i images compared to SUV images. These quantitative differences were seen as reduced background activity in the $${K}_{i}$$ K i images. Conclusion [18F]FES uptake is best described by an irreversible two-tissue compartment model. D-WB [18F]FES PET/CT scans can be used for direct reconstruction of parametric $${K}_{i}$$ K i images, with superior lesion visibility and $${K}_{i}$$ K i values comparable to $${K}_{i}$$ K i values found from full kinetic analyses. This may aid correct ER classification and treatment decisions. Trial registration ClinicalTrials.gov: NCT04150731, https://clinicaltrials.gov/study/NCT04150731

Background: Anesthesia can significantly impact positron emission tomography (PET) neuroimaging in preclinical studies. Therefore, understanding these effects is crucial for accurate interpretation of the results. In this experiment, we investigate the effect of [18F]-labeled glucose analog fluorodeoxyglucose ([18F]FDG) uptake in the brains of rats anesthetized with two commonly used anesthetics for rodents: isoflurane, an inhalation anesthetic, and Hypnorm–Dormicum, a combination injection anesthetic. Materials and Methods: Female adult Sprague Dawley rats were randomly assigned to one of two anesthesia groups: isoflurane or Hypnorm–Dormicum. The rats were submitted to dynamic [18F]FDG PET scan. The whole brain [18F]FDG standard uptake value (SUV) and the brain voxel-based analysis were performed. Results: The dynamic [18F]FDG data revealed that the brain SUV was 38% lower in the isoflurane group after 40 min of image (2.085 ± 0.3563 vs. 3.369 ± 0.5577, p = 0.0008). In voxel-based analysis between groups, the maps collaborate with SUV data, revealing a reduction in [18F]FDG uptake in the isoflurane group, primarily in the cortical regions, with additional small increases observed in the midbrain and cerebellum. Discussion and Conclusions: The observed differences in [18F]FDG uptake in the brain may be attributed to variations in metabolic activity. These results underscore the necessity for careful consideration of anesthetic choice and its impact on neuroimaging outcomes in future research.

Background. Nonmotor symptoms, including constipation and dysphagia, are very common in Parkinson’s disease (PD) and Lewy pathology is widespread in the gastrointestinal tract, particularly in the lower esophagus. Constipation and REM sleep behavior disorder (RBD) may present prior to clinical diagnosis. Yet, little is known about esophageal dysfunction and its connection to constipation in early PD. Objective. This study aimed to investigate esophageal and colonic transit in early moderate PD and to study correlations between symptoms and objective measures. Methods. Thirty early moderate PD patients and 28 healthy controls (HC) were included in this cross-sectional study. Esophageal transit times were determined by esophageal scintigraphy and colonic transit times by CT after radio-opaque marker ingestion. Olfaction tests, clinical evaluation, and nonmotor questionnaires were also performed. Results. Distal esophageal transit times and colonic transit times were both significantly prolonged in the PD group compared to HC (p

Dopaminergic medication for motor symptoms in Parkinson’s disease recently has been linked with impulse control disorders, including pathological gambling, which affects up to 8% of patients. Pathological gambling often is considered a behavioral addiction associated with disinhibition, risky decision-making, and altered striatal dopaminergic neurotransmission. Using [11C]raclopride with positron emission tomography, we assessed dopaminergic neurotransmission during Iowa Gambling Task performance. Here we present data from a single patient with Parkinson’s disease and concomitant pathological gambling. We noted a marked decrease in [11C]raclopride binding in the left ventral striatum upon gambling, indicating a gambling-induced dopamine release. The results imply that pathological gambling in Parkinson’s disease is associated with a high dose of dopaminergic medication, pronounced motor symptomatology, young age at disease onset, high propensity for sensation seeking, and risky decision-making. Overall, the findings are consistent with the hypothesis of medication-related pathological gambling in Parkinson’s disease and underscore the importance of taking clinical variables, such as age and personality, into account when patients with Parkinson’s disease are medicated, to reduce the risk of pathological gambling.