The value of combined MRI, enhanced CT and 18F-FDG PET/CT in the diagnosis of recurrence and metastasis after surgery for ovarian cancer.

OBJECTIVE: The purpose of this article was to investigate the value of combined MRI, enhanced CT and 18F-FDG PET/CT in the diagnosis of recurrence and metastasis after surgery for ovarian cancer. METHODS: Ninety-five ovarian cancer patients were selected as the study subjects, all of them underwent surgical treatment, and MRI, enhanced CT and 18F-FDG PET/CT were performed on all of them in the postoperative follow-up, and the pathological results after the second operation were used as the diagnostic "gold standard". The diagnostic value (sensitivity, specificity, accuracy, negative predictive value and positive predictive value) of the three examination methods alone or in combination for the diagnosis of postoperative recurrence and metastasis of ovarian cancer was compared, and the detection rate was calculated when the lesion was the unit of study, so as to compare the efficacy of the three methods in the diagnosis of postoperative recurrent metastatic lesions of ovarian cancer. RESULTS: The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the combined group were higher than those of MRI and enhanced CT for recurrence and metastasis of ovarian cancer after surgery, and the specificity, accuracy and positive predictive value of the combined group were higher than those of the 18F-FDG PET/CT group, and those of the 18F-FDG PET/CT group were higher than those of the enhanced CT group (all P < 0.05). When the postoperative recurrent metastatic lesions of ovarian cancer were used as the study unit, the detection rate of lesions in the combined group was higher than that of the three examinations detected individually, and the detection rate of lesions in 18F-FDG PET/CT was higher than that of enhanced CT and MRI (P < 0.05). CONCLUSION: The combination of MRI, enhanced CT and 18F-FDG PET/CT can accurately diagnose recurrence and metastasis of ovarian cancer after surgery, detect recurrent metastatic lesions as early as possible, and improve patients' prognosis.

Impact of cannabidiol on brain glucose metabolism of C57Bl/6 male mice previously exposed to cocaine.

Despite evidence of the beneficial effects of cannabidiol (CBD) in animal models of cocaine use disorder (CUD), CBD neuronal mechanisms remain poorly understood. This study investigated the effects of CBD treatment on brain glucose metabolism, in a CUD animal model, using [18F]FDG positron emission tomography (PET). Male C57Bl/6 mice were injected with cocaine (20 mg/kg, i.p.) every other day for 9 days, followed by 8 days of CBD administration (30 mg/kg, i.p.). After 48 h, animals were challenged with cocaine. Control animals received saline/vehicle. [18F]FDG PET was performed at four time points: baseline, last day of sensitization, last day of withdrawal/CBD treatment, and challenge. Subsequently, the animals were euthanized and immunohistochemistry was performed on the hippocampus and amygdala to assess the CB1 receptors, neuronal nuclear protein, microglia (Iba1), and astrocytes (GFAP). Results showed that cocaine administration increased [18F]FDG uptake following sensitization. CBD treatment also increased [18F]FDG uptake in both saline and cocaine groups. However, animals that were sensitized and challenged with cocaine, and those receiving only an acute cocaine injection during the challenge phase, did not exhibit increased [18F]FDG uptake when treated with CBD. Furthermore, CBD induced modifications in the integrated density of NeuN, Iba, GFAP, and CB1R in the hippocampus and amygdala. This is the first study addressing the impact of CBD on brain glucose metabolism in a preclinical model of CUD using PET. Our findings suggest that CBD disrupts cocaine-induced changes in brain energy consumption and activity, which might be correlated with alterations in neuronal and glial function.

Radioprotection in the production of 18F-FDG at Brazilian cyclotron facilities: A comparative study based on dosimetry.

Since the end of the Brazilian state monopoly in 2006, allowing private enterprises to act in producing and commercializing short half-life radiopharmaceuticals, the country observed a growth in the laboratories that use 18F-FDG to PET/CT exams. Considering the radiological protection and safety techniques applied to radioisotope-producing facilities or units, this study assembled the current situation of radiological protection showing the received doses of the professionals of four facilities with cyclotrons for 18F-FDG located in south and southeast Brazil in the years 2020 and 2021. The dose values observed are below the dose limits established by national and international regulatory entities but can still be optimized considering differences between the production units.

Impact of 18F-FDG PET/CT in the management decisions of breast cancer board on early-stage breast cancer.

PURPOSE: Breast cancer is the most common malignancy accounting for 11.7% of all cancer cases, with a rising incidence rate. Various diagnostic methods, including 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT), play a crucial role in breast cancer diagnosis and staging. However, the unnecessary use of advanced imaging techniques such as PET/CT in early-stage breast cancer can have negative effects on both economics and patients. We aimed to investigate the impact of PET/CT on the management decisions of early-stage breast cancer patients by the breast cancer tumor board. METHODS: A retrospective analysis was performed on a cohort of 81 patients with early-stage breast cancer who were evaluated by breast cancer tumor board from January 2015 to December 2020. Demographic, clinical, and radiographic data, along with surgical procedures and treatment options, were documented and analyzed. RESULTS: The results showed that 18F-FDG PET/CT had a moderate impact on treatment decisions of breast cancer tumor board, as only treatment decisions were changed in 14,86% of the patients. The surgical procedure decision of breast cancer tumor board changed in 12.35% of patients, while 87.65% of patients had consistent decisions before and after PET/CT. Pathological assessments revealed invasive ductal carcinoma as the most prevalent tumor type, and molecular subtypes were predominantly luminal B. PET/CT use had limited impact on surgical procedures and did not significantly alter treatment decisions of breast cancer tumor board in this early-stage breast cancer cohort. CONCLUSIONS: In conclusion, this study highlights the importance of adherence to the guidelines and appropriate use of PET/CT in early-stage breast cancer management. PET/CT should be reserved for cases where it is clinically warranted, considering the potential economic burden and minimal impact on treatment decisions of breast cancer tumor board in this patient population.

Detection of Liver Lesions in Colorectal Cancer Patients Using 18F-FDG PET/CT Dual-Time-Point Scan Imaging.

OBJECTIVE: The aim of this study was to evaluate the diagnostic performance of dual-time-point fluorine-18-fluorodeoxyglucose positron emission computed tomography/computed tomography (18F-FDG PET/CT) compared to conventional early imaging for detecting colorectal liver metastases (CRLM) in colorectal cancer (CRC) patients. METHODS: One hundred twenty-four consecutive CRC patients underwent dual-time-point imaging scans on a retrospective basis. Histopathological confirmation and/or clinical follow-up were accepted as the gold standard. Standard uptake values (SUV), signal-to-noise ratio (SNR), retention index (RI), tumor-to-normal liver ratio (TNR), and lesion sizes were measured for early and delayed PET scans. The diagnostic performance of early and delayed images was calculated on a per-patient basis and compared using McNemar's test. RESULTS: Among the 124 patients, 57 (46%) had CRLM, 6 (4.8%) had benign lesions, and 61 (49.2%) had no concerning lesions detected. Smaller CRLM lesions (<5 cm3) showed significantly higher uptake in the delayed scans relative to early imaging (p < 0.001). The SUV and TNR increased significantly in delayed imaging of all metastatic lesions (p < 0.001). The retention index of all CRLM was high (40.8%), especially for small lesions (54.8%). A total of 177 lesions in delayed images and 124 in standard early images were identified. In a per-patient analysis, delayed imaging had significantly higher sensitivity (100% vs. 87.7%) and specificity (91.0% vs. 94.0%) compared to early imaging (p-value = 0.04). CONCLUSIONS: The detection of liver lesions using dual-time-point PET/CT scan improves the sensitivity and specificity for the detection of colorectal liver metastasis.

Semiquantitative analysis of cerebral [18F]FDG-PET uptake in pediatric patients.

BACKGROUND: Glycolytic metabolism in the brain of pediatric patients, imaged with [18F]  fluorodeoxyglucose-positron emission tomography (FDG-PET) is incompletely characterized. OBJECTIVE: The purpose of the current study was to characterize [18F]FDG-PET brain uptake in a large sample of pediatric patients with non-central nervous system diseases as an alternative to healthy subjects to evaluate changes at different pediatric ages. MATERIALS AND METHODS: Seven hundred ninety-five [18F]FDG-PET examinations from children < 18 years of age without central nervous system diseases were included. Each brain image was spatially normalized, and the standardized uptake value (SUV) was obtained. The SUV and the SUV relative to different pseudo-references were explored as a function of age. RESULTS: At all evaluated ages, the occipital lobe showed the highest [18F]FDG uptake (0.27 ± 0.04 SUV/year), while the parietal lobe and brainstem had the lowest uptake (0.17 ± 0.02 SUV/year, for both regions). An increase [18F]FDG uptake was found for all brain regions until 12 years old, while no significant uptake differences were found between ages 13 (SUV = 5.39) to 17 years old (SUV = 5.52) (P < 0.0001 for the whole brain). A sex dependence was found in the SUVmean for the whole brain during adolescence (SUV 5.04-5.25 for males, 5.68-5.74 for females, P = 0.0264). Asymmetries in [18F]FDG uptake were found in the temporal and central regions during infancy. CONCLUSIONS: Brain glycolytic metabolism of [18F]FDG, measured through the SUVmean, increased with age until early adolescence (< 13 years old), showing differences across brain regions. Age, sex, and brain region influence [18F]FDG uptake, with significant hemispheric asymmetries for temporal and central regions.

Repeatability of brown adipose tissue activation measured by [18F]FDG PET after beta3-adrenergic stimuli in a mouse model.

This study aimed to evaluate the repeatability of brown adipose tissue (BAT) activation measured by [18F]FDG-PET after beta3-adrenergic stimuli with CL316243 in mice. METHODS: Male C57BL/6 mice underwent [18F]FDG-PET at baseline without stimulation (T0-NS), on three consecutive days after intravenous administration of the selective ß3-adrenergic agonist CL316243 (T1-CL, T2-CL, T3-CL), and without stimuli after 1 and 2 weeks (T7-NS and T14-NS). The standardized uptake value (SUVmax), BAT metabolic volume (BMV), and total BAT glycolysis (TBG) were measured in each scanning session, with statistical groupwise comparisons by ANOVA and post hoc Tukey test. RESULTS: SUVmax, BMV, and TBG values showed no significant differences between the three PET scans without stimuli, but were significantly higher after CL316243 administration (p < 0.0001). The mean coefficient of variation (CoV) of PET within individuals was 49 % at baseline but only 9 % with pharmacological stimulation. CONCLUSIONS: The study demonstrated that administration of the selective ß3-adrenergic receptor agonist CL316243 (CL) in mice leads to consistent metabolic activation of brown adipose tissue (BAT), as measured by [18F]FDG-PET. We also demonstrated metabolic activation by repeated pharmacological challenge, without evidence of hysteresis. Thus, the methods used in the current work should serve for further studies on BAT metabolism in experimental animals, with translational value for clinical research.

Internal occupational dosimetry for the occupational worker exposed to [18F] FDG from the Cyclotron-PET/CT Laboratory of the Universidad de Costa Rica / Dosimetría ocupacional interna para el personal trabajador expuesto a [18F] FDG del ciclotrón-PET/CT en el Laboratorio de la Universidad de Costa Rica

ABSTRACT: The aim of this work is to provide a methodology for evaluating the committed effective dose E(50) due to the incorporation of [18F] FDG in the occupationally exposed worker (OEW) of the Cyclotron-PET/CT Laboratory of the Centro de Investigación en Ciencias Atómicas, Nucleares y Moleculares (CICANUM) at Universidad de Costa Rica using in vivo measurements. The measurement system was calibrated to perform in vivo measurements and defined as the corresponding bioassay function for the radiopharmaceutical used. The conversion factor was assessed with a known activity of 18F in the geometry and measurement time established. Among the most relevant results, the measurement parameters and the calibration procedure were defined. A value of 1.73 x 103 Bq/cps for in vivo brain measurements was obtained as a conversion factor. This study provides a methodology, to evaluate the committed effective dose due to the incorporation of 18F-FDG in a radionuclide production and diagnostic center

[18F]FDG and [11C]PK11195 PET imaging in the evaluation of brown adipose tissue - effects of cold and pharmacological stimuli and their association with crotamine intake in a male mouse model.

This study aimed to evaluate the role of positron emission tomography (PET) with [11C]PK11195 and [18F]FDG in the characterization of brown adipose tissue (BAT). METHODS: Male C57BL/6 mice were studied with the glucose analogue [18F]FDG (n = 21) and the TSPO mitochondrial tracer [11C]PK11195 (n = 28), without stimulus and after cold (6-9 °C) or beta-agonist (CL316243) stimuli. PET studies were performed at baseline and after 21 days of daily treatment with crotamine, which is a peptide described to induce adipocyte tissue browning and to increase BAT metabolism. Tracer uptake (SUVmax) was measured in the interscapular BAT and translocator protein 18 kDa (TSPO) expression was evaluated by immunohistochemistry. RESULTS: The cold stimulus increased [18F]FDG uptake compared to no-stimulus (5.21 ± 1.05 vs. 2.03 ± 0.21, p < 0.0001) and to beta-agonist stimulus (2.65 ± 0.39, p = 0.0003). After 21 days of treatment with crotamine, there was no significant difference in the [18F]FDG uptake compared to the baseline in the no-stimulus group and in the cold-stimulus group, with a significant increase in uptake after CL stimulus (baseline: 2.65 ± 0.39; 21 days crotamine: 4.77 ± 0.81, p = 0.0003). Evaluation of [11C]PK11195 at baseline shows that CL stimulus increases the BAT uptake compared to no-stimulus (4.47 ± 0.66 vs. 3.36 ± 0.68, p = 0.014). After 21 days of treatment with crotamine, there was no significant difference in the [11C]PK11195 uptake compared to the baseline in the no-stimulus group (2.94 ± 0.58, p = 0.7864) and also after CL stimulus (3.55 ± 0.79, p = 0.085). TSPO expression correlated with [11C]PK11195 uptake (r = 0.83, p = 0.018) but not with [18F]FDG uptake (r = 0.40, p = 0.516). CONCLUSIONS: [11C]PK11195 allowed the identification of BAT under thermoneutral conditions or after beta3-adrenergic stimulation in a direct correlation with TSPO expression. The beta-adrenergic stimulus, despite presenting a lower intensity of glycolytic activation compared to cold at baseline, allowed the observation of an increase in BAT uptake of [18F]FDG after 21 days of crotamine administration. Although some limitations were observed for the metabolic changes induced by crotamine, this study reinforced the potential of using [11C]PK11195 and/or [18F]FDG-PET to monitor the activation of BAT.

Examining differences in brain metabolism associated with childhood maltreatment and suicidal attempt in euthymic patients with bipolar disorder: A PET and Machine Learning Study.

OBJECTIVE: Childhood maltreatment (CM) is a significant risk factor for the development and severity of bipolar disorder (BD) with increased risk of suicide attempts (SA). This study evaluated whether a machine learning algorithm could be trained to predict if a patient with BD has a history of CM or previous SA based on brain metabolism measured by positron emission tomography. METHODS: Thirty-six euthymic patients diagnosed with BD type I, with and without a history of CM were assessed using the Childhood Trauma Questionnaire. Suicide attempts were assessed through the Mini International Neuropsychiatric Interview (MINI-Plus) and a semi-structured interview. Resting-state positron emission tomography with 18F-fluorodeoxyglucose was conducted, electing only grey matter voxels through the Statistical Parametric Mapping toolbox. Imaging analysis was performed using a supervised machine learning approach following Gaussian Process Classification. RESULTS: Patients were divided into 18 participants with a history of CM and 18 participants without it, along with 18 individuals with previous SA and 18 individuals without such history. The predictions for CM and SA were not significant (accuracy = 41.67%; p = 0.879). CONCLUSION: Further investigation is needed to improve the accuracy of machine learning, as its predictive qualities could potentially be highly useful in determining histories and possible outcomes of high-risk psychiatric patients.

Examining differences in brain metabolism associated with childhood maltreatment and suicidal attempts in euthymic patients with bipolar disorder: a PET and machine learning study

Objective: Childhood maltreatment (CM) is a significant risk factor for the development and severity of bipolar disorder (BD) with increased risk of suicide attempts (SA). This study evaluated whether a machine learning algorithm could be trained to predict if a patient with BD has a history of CM or previous SA based on brain metabolism measured by positron emission tomography. Methods: Thirty-six euthymic patients diagnosed with BD type I, with and without a history of CM were assessed using the Childhood Trauma Questionnaire. Suicide attempts were assessed through the Mini International Neuropsychiatric Interview (MINI-Plus) and a semi-structured interview. Resting-state positron emission tomography with 18F-fluorodeoxyglucose was conducted, electing only grey matter voxels through the Statistical Parametric Mapping toolbox. Imaging analysis was performed using a supervised machine learning approach following Gaussian Process Classification. Results: Patients were divided into 18 participants with a history of CM and 18 participants without it, along with 18 individuals with previous SA and 18 individuals without such history. The predictions for CM and SA were not significant (accuracy = 41.67%; p = 0.879). Conclusion: Further investigation is needed to improve the accuracy of machine learning, as its predictive qualities could potentially be highly useful in determining histories and possible outcomes of high-risk psychiatric patients.

Anthracycline cardiotoxicity: current methods of diagnosis and possible role of 18F-FDG PET/CT as a new biomarker.

Despite advances in chemotherapy, the drugs used in cancer treatment remain rather harmful to the cardiovascular system, causing structural and functional cardiotoxic changes. Positron-emission tomography associated with computed tomography (PET/CT) has emerged like a promising technique in the early diagnosis of these adverse drug effects as the myocardial tissue uptake of fluorodeoxyglucose labeled with fluorine-18 (18F-FDG), a glucose analog, is increased after their use. Among these drugs, anthracyclines are the most frequently associated with cardiotoxicity because they promote heart damage through DNA breaks, and induction of an oxidative, proinflammatory, and toxic environment. This review aimed to present the scientific evidence available so far regarding the use of 18F-FDG PET/CT as an early biomarker of anthracycline-related cardiotoxicity. Thus, it discusses the physiological basis for its uptake, hypotheses to justify its increase in the myocardium affected by anthracyclines, importance of 18F-FDG PET/CT findings for cardio-oncology, and primary challenges of incorporating this technique in standard clinical oncology practice.

Characterization of the anticonvulsant effect of dapsone on metabolic activity assessed by [18F]FDG -PET after kainic acid-induced status epilepticus in rats.

BACKGROUND: Development of effective drugs for epilepsy are needed, as nearly 30 % of epileptic patients, are resistant to current treatments. This study is aimed to characterize the anticonvulsant effect of dapsone (DDS), in the kainic acid (KA)-induced Status Epilepticus (SE) by recording the brain metabolic activity with an [18F]FDG-PET analysis. METHODS: Wistar rats received KA (10 mg/kg, i.p., single dose) to produce sustained seizures. [18F]FDG-PET and electroencephalographic (EEG) studies were then performed. DDS or vehicle were administered 30 min before KA. [18F]FDG uptake and EEG were evaluated at baseline, 2 and 25 h after KA injection. Likewise, caspase-8, 3 hippocampal activities and Fluoro-Jade B neuronal degeneration and Hematoxylin-eosin staining were measured 25 h after KA. RESULTS: PET data evaluated at 2 h showed hyper-uptake of [18F]FDG in the control group, which was decreased by DDS. At 25 h, hypo-uptake was observed in the control group and higher values due to DDS effect. EEG spectral power was increased 2 h after KA administration in the control group during the generalized tonic-clonic seizures, which was reversed by DDS, correlated with [18F]FDG-PET uptake changes. The values of caspases-8 activity decreased 48 and 43 % vs control group in the groups treated with DDS (12.5 y 25 mg/kg respectively), likewise; caspase-3 activity diminished by 57 and 53 %. Fewer degenerated neurons were observed due to DDS treatments. CONCLUSIONS: This study pinpoints the anticonvulsant therapeutic potential of DDS. Given its safety and effectiveness, DDS may be a viable alternative for patients with drug-resistant epilepsy.

Applicability of [18F]FDG/PET for investigating rosmarinic acid preconditioning efficacy in a global stroke model in mice

ABSTRACT Positron emission tomography (PET) is a non-invasive nuclear imaging technique that uses radiotracers to track cell activity. The radiopharmaceutical 18F-fluoro-2-deoxyglucose ([18F] FDG) is most commonly used in nuclear medicine for the diagnosis of various diseases, including stroke. A stroke is a serious condition with high mortality and morbidity rates. Rosmarinic acid (RA) is a promising therapeutic agent that exerts neuroprotective effects against various neurological diseases. Therefore, this study aimed to evaluate the applicability of [18F]FDG/PET for investigating the neuroprotective effects of RA in case of a global stroke model in mice. The [18F]FDG/PET technique facilitates the observation of ischemia and reperfusion injuries in the brain. Moreover, the recovery of glucose metabolism in three specific brain regions, the striatum, superior colliculus, and inferior colliculus, was observed after preconditioning with RA. It was concluded that the [18F]FDG/PET technique may be useful for stroke diagnosis and the assessment of treatment response. In addition, a long-term longitudinal study using biochemical analysis in conjunction with functional imaging may provide further conclusive results regarding the effect of RA on cerebral ischemia.

Role of molecular imaging in the diagnosis of prosthetic aortic valve endocarditis by Bacillus licheniformis: a case report.

Background: Infective endocarditis is a challenging diagnosis that usually requires cardiovascular image confirmation as part of the approach. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is an imaging technique more sensible for the diagnosis of prosthetic valve endocarditis (PVE) when echocardiography is inconclusive. Case summary: We present the case of a 35-year-old man who had a previous Bentall-De Bono procedure 4 years prior that included biological, national institute of cardiology (INC)-type, locally manufactured aortic valve replacement and woven Dacron tube graft implantation in the ascending aorta. He was admitted because of dyspnoea, oedema, fever, and syncope. A complete auriculoventricular blockade was diagnosed, requiring cardiac pacing. Also, infective endocarditis (IE) was suspected. Blood cultures showed the isolation of Bacillus licheniformis. Transthoracic echocardiography, transoesophageal echocardiography, and CT angiography were inconclusive for IE. Treatment was initiated with intravenous (IV) antibiotic therapy, and an extensive protocol for IE, including molecular imaging modalities, was ordered. 99mTc-Ubiquicidin scintigraphy was acquired without abnormal findings. Images of 18F-FDG-PET/CT revealed abnormally intense heterogeneous uptake in the prosthetic aortic annulus in a classic pattern. Applying the modified 2015 Duke criteria for PET/CT, PVE was confirmed. Discussion: Although the other imaging modalities were negative, the high clinical suspicion made it mandatory to continue the study protocol, remarking on the utility of 18F-FDG-PET/CT on patients categorized as having 'possible' endocarditis, as in our patient.

Tumor glycolytic profiling through 18F-FDG PET/CT predicts immune checkpoint inhibitor efficacy in advanced NSCLC.

Background: A significant proportion of patients with non-small-cell lung cancer (NSCLC) do not respond to immune checkpoint inhibitors (ICIs). Since metabolic reprogramming with increased glycolysis is a hallmark of cancer and is involved in immune evasion, we used 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) to evaluate the baseline glycolytic parameters of patients with advanced NSCLC submitted to ICIs, and assessed their predictive value. Methods: 18F-FDG PET/CT results in the 3 months before ICIs treatment were included. Maximum standardized uptake values, whole metabolic tumor volume (wMTV), and whole-body total lesion glycolysis (wTLG) were evaluated. Cutoff values for high or low glycolytic categories were determined using receiver-operating characteristic curves. Progression-free survival (PFS) and overall survival (OS) were evaluated. Patients with a complete response and a matching group with resistance to ICIs underwent immunohistochemistry analysis. An unsupervised k-means clustering model integrating programmed cell death ligand 1 (PD-L1) expression, glycolytic parameters, and ICIs therapy was performed. Results: In all, 98 patients were included. Lower baseline 18F-FDG PET/CT parameters were associated with responses to ICIs. Patients with low wMTV or wTLG had improved PFS and OS. High wTLG, strong tumor expression of glucose transporter-1, and lack of responses were significantly associated. Patients with low glycolytic parameters benefited from ICIs, regardless of chemotherapy. Conversely, those with high parameters benefited from the addition of chemotherapy. Patients with higher wTLG and lower PD-L1 were associated with progression and worse survival to ICIs monotherapy. Conclusions: Glycolytic metabolic profiles established through baseline 18F-FDG PET/CT are useful biomarkers for evaluating ICI therapy in advanced NSCLC.

Propolis induces cardiac metabolism changes in 6-hydroxydopamine animal model: A dietary intervention as a potential cardioprotective approach in Parkinson's disease.

While there is sustained growth of the older population worldwide, ageing is a consistent risk factor for neurodegenerative diseases, such as Parkinson's-disease (PD). Considered an emblematic movement disorder, PD comprises a miscellany of non-motor symptoms, for which effective management remains an unfulfilled need in clinical practice. Highlighted are the cardiovascular abnormalities, that cause significant burden in PD patients. Evidence suggests that key biological processes underlying PD pathophysiology can be modulated by diet-derived bioactive compounds, such as green propolis, a natural functional food with biological and pharmacological properties. The effects of propolis on cardiac affection associated to PD have received little coverage. In this study, a metabolomics approach and Positron Emission Tomography (PET) imaging were used to assess the metabolic response to diet supplementation with green propolis on heart outcomes of rats with Parkinsonism induced by 6-hydroxydopamine (6-OHDA rats). Untargeted metabolomics approach revealed four cardiac metabolites (2-hydroxybutyric acid, 3-hydroxybutyric acid, monoacylglycerol and alanine) that were significantly modified between animal groups (6-OHDA, 6-OHDA + Propolis and sham). Propolis-induced changes in the level of these cardiac metabolites suggest beneficial effects of diet intervention. From the metabolites affected, functional analysis identified changes in propanoate metabolism (a key carbohydrate metabolism related metabolic pathway), glucose-alanine cycle, protein and fatty acid biosynthesis, energy metabolism, glutathione metabolism and urea cycle. PET imaging detected higher glucose metabolism in the 17 areas of the left ventricle of all rats treated with propolis, substantially contrasting from those rats that did not consume propolis. Our results bring new insights into cardiac metabolic substrates and pathways involved in the mechanisms of the effects of propolis in experimental PD and provide potential novel targets for research in the quest for future therapeutic strategies.

Assessment of Cardiac Sarcoidosis: FDG PET and BMIPP SPECT.

PURPOSE OF REVIEW: Cardiac sarcoidosis (CS) is an inflammatory disease of unknown etiology that can lead to life-threatening arrhythmias, heart failure, and death. Advanced cardiac imaging modalities have improved the clinician's ability to detect this disease. The purpose of this review is to discuss the recent evidence of cardiac metabolic imaging as assessed by [18F]FDG PET and [123I]BMIPP SPECT in the evaluation of CS patients. RECENT FINDINGS: [18F]FDG PET is the gold standard to identify myocardial inflammation. [123I]BMIPP SPECT can uncover early myocardial damage as well as advanced stages of CS when fibrosis prevails. In presence of inflammation, myocardial [18F]FDG uptake is increased, but in contrast, BMIPP myocardial uptake is reduced or even suppressed. Thus, a complementary role of cardiac metabolic imaging by [18F]FDG PET and BMIPP SPECT has been proposed to detect the whole spectrum of CS. [18F]FDG PET is considered an important tool to improve the diagnosis and optimize the management of CS. The role of [123I]BMIPP SPECT in diagnosing CS is still under investigation. Further studies are needed to evaluate the clinical utility of combined cardiac metabolic imaging in the diagnosis, prognosis, and for selecting treatments in CS patients.

Brown fat triglyceride content is associated with cardiovascular risk markers in adults from a tropical region.

Brown adipose tissue (BAT) is regarded as an interesting potential target for the treatment of obesity, diabetes, and cardiovascular diseases, and the detailed characterization of its structural and functional phenotype could enable an advance in these fields. Most studies evaluating BAT structure and function were performed in temperate climate regions, and we are yet to know how these findings apply to the 40% of the world's population living in tropical areas. Here, we used 18F-fluorodeoxyglucose positron emission tomography - magnetic resonance imaging to evaluate BAT in 45 lean, overweight, and obese volunteers living in a tropical area in Southeast Brazil. We aimed at investigating the associations between BAT activity, volume, metabolic activity, and BAT content of triglycerides with adiposity and cardiovascular risk markers in a sample of adults living in a tropical area and we showed that BAT glucose uptake is not correlated with leanness; instead, BAT triglyceride content is correlated with visceral adiposity and markers of cardiovascular risk. This study expands knowledge regarding the structure and function of BAT in people living in tropical areas. In addition, we provide evidence that BAT triglyceride content could be an interesting marker of cardiovascular risk.

Diagnostic impact of 18F-FDG PET/CT imaging on the detection of immune-related adverse events in patients treated with immunotherapy.

INTRODUCTION: Immunotherapy is an effective treatment method for cancer cells with humoral and cellular immune mechanisms of action but triggers an inflammatory response and disrupts standard protective immune tolerance. Early detection of immune-related adverse events (irAEs) on PET/CT is crucial for patient management and subsequent therapy decisions. In this study, we aimed to evaluate the impact of 18F-FDG PET/CT on detecting of irAEs in patients receiving immunotherapy. PATIENTS AND METHODS: Forty-six patients with advanced RCC (n: 32), malign melanoma (n: 9), lung cancer (n: 4), and laryngeal carcinoma (n: 1), who underwent 18F-FDG PET/CT imaging for response assessment after immunotherapy, were enrolled in the study. Newly detected findings associated with irAEs on posttreatment PET/CT images were compared with the pretreatment PET/CT, both qualitatively and semi-quantitatively. RESULTS: Twenty-eight (61%) patients developed irAEs as observed on PET/CT. Enteritis/colitis was the most frequent irAE visualized on PET/CT with 13 patients (28.2%), followed by gastritis (17.3%), thyroiditis (13%), and myositis/arthritis (13%). Hepatitis (6.5%), pneumonitis (6.5%), sarcoid-like reaction (4.3%), and hypophysitis (4.3%) were observed to a lesser extent. The median time between the appearance of irAEs on PET/CT and the initiation of immunotherapy was 4.3 months. There were no significant differences in age, sex, and treatment response status of patients with and without irAEs. CONCLUSION: 18F-FDG PET/CT plays a fundamental role in cancer immunotherapy with the potential to show significant irAEs both in the diagnosis and in follow-up of irAEs. IrAEs were present on PET/CT images of more than half of the patients who received immunotherapy in our study.