Evaluation of Parotid Salivary Gland Echo Texture by Ultrasound Examinations and Correlation With Whole-Body Scintigraphy After Radioiodine Therapy in Patients With Differentiated Thyroid Carcinoma.

OBJECTIVES: This study aimed to evaluate the echo texture of the parotid salivary glands before and after radioiodine therapy (RIT) using ultrasound (US) images in patients with differentiated thyroid cancer and to evaluate the correlations between post-RIT whole-body scintigraphy (WBS) images and US image patterns in salivary and cervical areas. METHODS: A retrospective study was performed with data on demographic and clinical information, US examinations, and WBS images collected through medical recordings. RESULTS: Comparing the US features before and after RIT, significant echo texture heterogeneity was found in 31.3% of all patients evaluated. When evaluated according to the level of iodine 131 (I-131) radioactivity (<5.6, 5.6-<9.3, and ≥9.3 GBq), echo texture heterogeneity was significantly associated with the 5.6-GBq I-131 radioactivity group (P < .001). No association was found for any level of I-131 post-RIT WBS uptake intensity and changes in US feature patterns. CONCLUSIONS: Ultrasound may be a useful tool for evaluating chronic sialadenitis after RIT, and the I-131 uptake intensity using a routine post-RIT WBS is not associated with US echo texture changes.

Effects of ketamine/xylazine and isoflurane on rat brain glucose metabolism measured by 18 F-fluorodeoxyglucose-positron emission tomography.

The aim of the present study was to investigate changes in glucose metabolism in male Wistar rats induced by the anesthetics isoflurane and ketamine combined with xylazine via 18 F-fluorodeoxyglucose-positron emission tomography. We analyzed the differential effects of the anesthetics on 18 F-fluorodeoxyglucose uptake and pharmacokinetics in 33 rats using quantification methods: (a) the standardized uptake value, (b) voxel-based analyses, and (c) kinetic analysis. Both anesthetics reduced glucose uptake in the entire brain. The voxel-based analyses detected smaller uptake reductions in the bilateral primary somatosensory system cortex and part of the limbic system in the ketamine-xylazine (KX) group and in the vestibular nucleus in the isoflurane group. Through kinetic analysis, we found that the volume of distribution and the membrane transport rate K1 were reduced in the KX group. Through various methods of 18 F-fluorodeoxyglucose-positron emission tomography quantification, the present study found that anesthesia with the ketamine-xylazine combination induced a global reduction of glucose metabolism compared with isoflurane; this reduction of metabolism was relatively lower in the primary somatosensory cortex and part of the limbic system. The volume of distribution of 18 F-fluorodeoxyglucose and its Glut1-mediated transport across the brain membranes (K1 ) were decreased in the KX group.

Efficacy and safety of creatine supplementation in juvenile dermatomyositis: A randomized, double-blind, placebo-controlled crossover trial.

INTRODUCTION: It has been suggested that creatine supplementation is safe and effective for treating idiopathic inflammatory myopathies, but no pediatric study has been conducted to date. The objective of this study was to examine the efficacy and safety of creatine supplementation in juvenile dermatomyositis (JDM) patients. METHODS: In this study, JDM patients received placebo or creatine supplementation (0.1 g/kg/day) in a randomized, crossover, double-blind design. Subjects were assessed at baseline and after 12 weeks. The primary outcome was muscle function. Secondary outcomes included body composition, aerobic conditioning, health-related quality of life, and muscle phosphocreatine (PCr) content. Safety was assessed by laboratory parameters and kidney function measurements. RESULTS: Creatine supplementation did not affect muscle function, intramuscular PCr content, or any other secondary outcome. Kidney function was not affected, and no side effects were reported. CONCLUSIONS: Twelve weeks of creatine supplementation in JDM patients were well-tolerated and free of adverse effects, but treatment did not affect muscle function, intramuscular PCr, or any other parameter.

Evaluation of MDRD4, CKD-EPI, BIS-1, and modified Cockcroft-Gault equations to estimate glomerular filtration rate in the elderly renal-transplanted recipients.

Equations to estimate glomerular filtration rate (eGFR) were developed in patients using the variables age, body weight, and serum creatinine, which may be different in the elderly. Elderly renal transplant patients (EG; n=70; mean age 65 ± 4 y) who measured plasma 51 Cr-EDTA-Clearance (mGFR) had mGFR compared to eGFR obtained by the Cockcroft-Gault corrected by body surface area (CG-BSA), the modification of diet in renal disease (MDRD-4), the Berlin Initiative Study (BIS-1), and the chronic kidney disease epidemiology collaboration (CKD-EPI). Results were validated using a cohort of 43, of the 70 elderly recipients, who performed a second 51 Cr-EDTA-Clearance. Mean mGFR was 47 ± 16 mL/min/1.73 m2 and statistically lower than eGFR by MDRD (52 ± 19, P=.001) and BIS-1 (51 ± 13, P=.007) but not different from the CG-BSA (47 ± 15) and CKD-EPI (49 ± 18). The CKD-EPI and CG-BSA presented the lowest bias but only CKD-EPI also showed the highest 30% and 10% accuracy. The same findings were repeated in the validation set. For a cohort of elderly recipients ≥65 years (n=35, 68 ± 3y), the CKD-EPI performed better with the lowest bias (0 ± 12 mL/min/1.73 m2 ) and best 30% and 10% accuracy. The CKD-EPI equation is a valuable tool to monitor GFR in the elderly RTx recipients.

Correlation of 18F-sodium fluoride uptake and radiodensity in extraosseous metastases of medullary thyroid carcinoma.

Objective: Although 18F-sodium fluoride (18F-NaF) uptake is frequently observed in extraosseous metastases of medullary thyroid carcinoma (MTC) with calcification, itcan also occur in metastatic sites without visible calcium deposition, leading to the hypothesis that visually undetectable calcium accumulation may be responsible for this uptake. The aim of this study was to indirectly support this hypothesis by analyzing the correlation between the degree of 18F-NaF uptake and radiodensity in extraosseous MTC metastases, since calcium deposition can increase attenuation even when not visually detectable. Subjects and methods: Extraosseous metastatic lesions of 15 patients with MTC were evaluated using 18F-NaF positron-emission tomography (PET)/computed tomography (CT)and segmented by levels of standardized uptake value (SUV). The correlation between mean SUV and mean Hounsfield unit (HU) values was assessed for the entire group of segments and for two subgroups with different mean HU values. Results: Very high correlations were observed between mean SUV and mean HU values for both the entire group of segments and the subgroup with a mean HU value greater than 130 (p = 0.92 and p = 0.95, respectively; p < 0.01). High correlation (p = 0.71) was also observed in the subgroup with mean HU values ranging from 20 to 130 (p < 0.01). Conclusion: The findings of the present study suggest that there is an association between 18F-NaF uptake and calcium deposition in extraosseous metastasesof MTC, supporting the hypothesis that visually undetectable calcium accumulation may be responsible for 18F-NaF uptake in regions without visible calcium deposition.

Validation of automated image co-registration integrated into in-house software for voxel-based internal dosimetry on single-photon emission computed tomography images.

Objective: To develop an automated co-registration system and test its performance, with and without a fiducial marker, on single-photon emission computed tomography (SPECT) images. Materials and Methods: Three SPECT/CT scans were acquired for each rotation of a Jaszczak phantom (to 0°, 5°, and 10° in relation to the bed axis), with and without a fiducial marker. Two rigid co-registration software packages-SPM12 and NMDose-coreg-were employed, and the percent root mean square error (%RMSE) was calculated in order to assess the quality of the co-registrations. Uniformity, contrast, and resolution were measured before and after co-registration. The NMDose-coreg software was employed to calculate the renal doses in 12 patients treated with 177Lu-DOTATATE, and we compared those with the values obtained with the Organ Level INternal Dose Assessment for EXponential Modeling (OLINDA/EXM) software. Results: The use of a fiducial marker had no significant effect on the quality of co-registration on SPECT images, as measured by %RMSE (p = 0.40). After co-registration, uniformity, contrast, and resolution did not differ between the images acquired with fiducial markers and those acquired without. Preliminary clinical application showed mean total processing times of 9 ± 3 min/patient for NMDose-coreg and 64 ± 10 min/patient for OLINDA/EXM, with a strong correlation between the two, despite the lower renal doses obtained with NMDose-coreg. Conclusion: The use of NMDose-coreg allows fast co-registration of SPECT images, with no loss of uniformity, contrast, or resolution. The use of a fiducial marker does not appear to increase the accuracy of co-registration on phantoms.

Objetivo: Desenvolver corregistro automático e testar seu desempenho com ou sem marcador fiducial em imagens de tomografia computadorizada de emissão de fóton único (SPECT). Materiais e Métodos: Três SPECT/CTs foram adquiridas para cada rotação de um simulador de Jaszczak em relação ao eixo da maca (0°, 5° e 10°), com e sem fiducial. Dois métodos de corregistro inelástico foram aplicados - SPM12 e NMDose-coreg -, e a porcentagem do erro quadrático médio (%RMSE) foi usada para analisar a qualidade do corregistro. Uniformidade, contraste e resolução foram medidos antes e após o corregistro. NMDose com corregistro automático foi usado para calcular a dose renal de 12 pacientes tratados com 177Lu-DOTATATE e comparado com OLINDA/EXM. Resultados: A marcação fiducial não modificou a qualidade do corregistro das imagens SPECT, medida pela %RMSE (p = 0,40). Não houve impacto na uniformidade, contraste e resolução após o corregistro de imagens adquiridas com ou sem fiduciais. Aplicação clínica preliminar mostrou tempo total de processamento de 9 ± 3 min/paciente para NMDose e 64 ± 10 min/paciente para OLINDA/EXM, com alta correlação entre ambos, apesar de menor dose renal em NMDose. Conclusão: NMDose-coreg permite o corregistro rápido de imagens SPECT, sem perda de uniformidade, contraste ou resolução. O uso da marcação fiducial não aumentou a precisão do corregistro em fantomas.

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.

Comparison of Oral and IV 18 F-NaF PET/CT Administration in the Assessment of Bone Metastases in Patients With Breast or Prostate Cancers.

PURPOSE: The aim of this study was to compare oral and IV administrations of 18 F-NaF PET/CT for detection of suspicious bone metastatic lesions of breast and prostate cancers. PATIENTS AND METHODS: Thirty-six patients with breast (n = 23) or prostate (n = 13) cancers and high risk for bone metastases were prospectively evaluated. All patients underwent 2 PET/CT studies after IV and oral 18 F-NaF administration within a 2 to 23 days interval between them. The maximum SUVs from the same suspicious lesions (≤5 index lesions per patient) in both studies were measured. The target-to-background ratio (TBR), defined as the relation between the lesion maximum SUV and the whole skeletal mean SUV, was calculated for each lesion. The TBRs in the same lesion calculated using the 2 administration routes were compared. The agreements between 2 physicians in the definition of the number of lesions in both studies were also assessed using weighted κ. RESULTS: One hundred thirty-four pairs of lesions were analyzed. There was no significant statistical difference between the median TBRs ( P = 0.212) for IV (10.33) and oral (10.85). Excellent intraobserver agreement was observed between IV and oral routes: weighted κ of 1.0 (95% confidence interval, 0.92-1.0) and 0.92 (95% confidence interval, 0.81-0.99) for physicians 1 and 2, respectively. The interobserver coefficients were 0.82 and 0.87 for "oral versus oral" and "IV versus IV," respectively. CONCLUSIONS: 18 F-NaF PET/CT studies using oral and IV routes present comparable performance; thus, it is possible to use oral route in patients with difficult venous access.

Radiation safety measures in diagnostic nuclear medicine, based on the potential radiation dose emitted by radioactive patients.

Objective: To measure the potential radiation dose emitted by patients who have recently undergone diagnostic nuclear medicine procedures, in order to establish optimal radiation safety measures for such procedures. Materials and Methods: We evaluated the radiation doses emitted by 175 adult patients in whom technetium-99m, iodine-131, and fluorine-18 radionuclides were administered for bone, kidney, heart, brain, and whole-body scans, as measured with a radiation detector. Those values served as the basis for evaluating whole-body radiopharmaceutical clearance, as well as the risk for the exposure of others to radiation, depending on the time elapsed since administration of the radiopharmaceutical. Results: The mean time to clearance of the radiopharmaceuticals administered, expressed as the effective half-life, ranged from 1.18 ± 0.30 h to 11.41 ± 0.02 h, and the mean maximum cumulative radiation dose at 1.0 m from the patients was 149.74 ± 56.72 µSv. Even at a distance of 0.5 m, the cumulative dose was found to be only half and one tenth of the limits established for exposure of the general public and family members/caregivers (1.0 mSv and 5.0 mSv per episode, respectively). Conclusion: Cumulative radiation doses emitted by patients immediately after diagnostic nuclear medicine procedures are considerably lower than the limits established by the International Commission on Radiological Protection and the International Atomic Energy Agency, and precautionary measures to avoid radiation exposure are therefore not required after such procedures.

Objetivo: O objetivo deste trabalho foi levantar o potencial de dose de radiação emitida por pacientes em procedimentos diagnósticos, visando a estabelecer cuidados de radioproteção mais otimizados. Materiais e Métodos: Taxas de dose de radiação emitidas por 175 pacientes administrados com os radionuclídeos 99mTc, 131I e 18F para cintilografias óssea, renal, cardíaca, cerebral e corpo inteiro, foram mensuradas com um detector de radiação, servindo para avaliar o clareamento do radiofármaco no organismo e risco de exposição após administração dos radiofármacos. Resultados: O clareamento, representado pela meia-vida efetiva, variou de 1,18 ± 0,30 h até 11,41 ± 0,02 h e a dose de radiação máxima acumulada oferecida pelos pacientes a 1,0 m foi de 149,74 ± 56,72 µSv. Mesmo para distâncias de 0,5 m, as doses estimadas foram, respectivamente, duas e dez vezes inferiores ao nível de restrição para o público geral (1,0 mSv) e exposição médica (5,0 mSv/episódio). Conclusão: Doses de radiação oferecidas por pacientes em procedimentos diagnósticos são inferiores aos níveis de restrição recomendados pela International Commission on Radiological Protection e International Atomic Energy Agency, e assim, cuidados de radioproteção são geralmente desnecessários.

[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.

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.

Potential of [11C](R)-PK11195 PET Imaging for Evaluating Tumor Inflammation: A Murine Mammary Tumor Model.

BACKGROUND: Breast tumor inflammation is an immunological process that occurs mainly by mediation of Tumor-Associated Macrophages (TAM). Aiming for a specific measurement of tumor inflammation, the current study evaluated the potential of Positron Emission Tomography (PET) imaging with [11C](R)-PK11195 to evaluate tumor inflammation in a mammary tumor animal model. METHODS: Female Balb/C mice were inoculated with 4T1 cells. The PET imaging with [11C](R)-PK11195 and [18F]FDG was acquired 3 days, 1 week, and 2 weeks after cell inoculation. RESULTS: The [11C](R)-PK11195 tumor uptake increased from 3 days to 1 week, and decreased at 2 weeks after cell inoculation, as opposed to the [18F]FDG uptake, which showed a slight decrease in uptake at 1 week and increased uptake at 2 weeks. In the control group, no significant differences occurred in tracer uptake over time. Tumor uptake of both radiopharmaceuticals is more expressed in tumor edge regions, with greater intensity at 2 weeks, as demonstrated by [11C](R)-PK11195 autoradiography and immunofluorescence with TSPO antibodies and CD86 pro-inflammatory phenotype. CONCLUSION: The [11C](R)-PK11195 was able to identify heterogeneous tumor inflammation in a murine model of breast cancer and the uptake varied according to tumor size. Together with the glycolytic marker [18F]FDG, molecular imaging with [11C](R)-PK11195 may provide a better characterization of inflammatory responses in cancer.

In-depth cardiovascular and pulmonary assessments in children with multisystem inflammatory syndrome after SARS-CoV-2 infection: A case series study.

We assessed PET-CT myocardial blood flow (MBF) using N-13 ammonia, brachial flow-mediated dilation, and cardiopulmonary exercise test in five post-discarged MIS-C survivors. None of the patients (median age: 9, range: 7-18 years; 3 females; 2 males) had preexisting pediatric chronic conditions. At the follow-up visit, two patients exhibited severe perfusion defect developed in the left ventricular cavity, suggesting extensive myocardial ischemia (MBF <2.0) and one patient showed persistent mild pericardial effusion. Others two patients demonstrated endothelial dysfunction. Nevertheless, all patients had lower predicted values in the VO2peak , VO2VAT , OUES, and O2 Pulse (range: 35.2%-64.5%; 15.6%-38.2%; 1.0-1.3 L/min; 4-7 ml/beat), respectively. Our d suggested that previously health MIS-C patients had impaired MBF, endothelial dysfunction and lower cardiopulmonary capacity at follow-up analysis. Multidisciplinary further investigations should be conducted to reinforce these findings.

Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial.

Creatine supplementation may have a therapeutic role in diabetes, but it is uncertain whether this supplement is safe for kidney function. The aim of this study was to investigate the effects of creatine supplementation on kidney function in type 2 diabetic patients. A randomized, double-blind, placebo-controlled trial was performed. The patients were randomly allocated to receive either creatine or placebo for 12 weeks. All the patients underwent exercise training throughout the trial. Subjects were assessed at baseline and after the intervention. Blood samples and 24-h urine samples were obtained for kidney function assessments. Additionally, (51)Cr-EDTA clearance was performed. To ensure the compliance with creatine intake, we also assessed muscle phosphorylcreatine content. The creatine group presented higher muscle phosphorylcreatine content when compared to placebo group (CR Pre 44 ± 10, Post 70 ± 18 mmol/kg/wt; PL Pre 52 ± 13, Post 46 ± 13 mmol/kg/wt; p = 0.03; estimated difference between means 23.6; 95% confidence interval 1.42-45.8). No significant differences were observed for (51)Cr-EDTA clearance (CR Pre 90.4 ± 16.9, Post 96.1 ± 15.0 mL/min/1.73 m(2); PL Pre 97.9 ± 21.6, Post 96.4 ± 26.8 mL/min/1.73 m(2); p = 0.58; estimated difference between means -0.3; 95% confidence interval -24.9 to 24.2). Creatinine clearance, serum and urinary urea, electrolytes, proteinuria, and albuminuria were unchanged. CR supplementation does not affect kidney function in type 2 diabetic patients, opening a window of opportunities to explore its promising therapeutic role in this population. ClinicalTrials.gov registration number: NCT00992043.

68Ga-PSMA PET/CT: effect of external cooling on salivary gland uptake.

OBJECTIVE: To evaluate the effect that external cooling of the salivary glands (ECSG) has on the uptake of gallium-68-labeled prostate-specific membrane antigen (68Ga-PSMA), as an indirect assessment of the capacity of ECSG to reduce the local dose in lutetium-177-PSMA-617 radioligand therapy. MATERIALS AND METHODS: Ten patients with prostate cancer were submitted to 68Ga-PSMA positron emission tomography/computed tomography with unilateral ECSG. The ECSG was started at 30 min before the injection of the radiotracer and maintained until the end of image acquisition (1 h after injection). Each salivary gland was assessed by determining the maximum, mean, and peak standardized uptake values (SUVmax, SUVmean, and SUVpeak, respectively). The volume of each gland was determined in a volume of interest delineated by a threshold SUVmax of 10%. Paired Student's t-tests were used in order to compare the results. RESULTS: In terms of the SUV parameters, there were no statistically significant differences between the cooled and contralateral salivary glands. However, the mean volume was 27% lower in the cooled parotid glands than in the contralateral parotid glands (p = 0.004). CONCLUSION: The use of ECSG does not appear to reduce 68Ga-PSMA uptake by the salivary glands. In addition, there is yet no evidence that ECSG is effective in preventing salivary gland toxicity.

OBJETIVO: Avaliar o impacto do resfriamento externo de glândulas salivares (REGS) na captação de 68Ga-PSMA como marcador indireto dessa intervenção para redução da dose local na terapia com 177Lu-PSMA. MATERIAIS E MÉTODOS: Dez pacientes com câncer de próstata foram submetidos a PET/CT com 68Ga-PSMA com REGS unilateral. O resfriamento se iniciou 30 minutos antes da injeção do radiofármaco até o fim da aquisição de imagem, 1 hora após a injeção. Cada glândula foi avaliada para os valores de captação padronizados máximo, médio e pico (SUVmáx, SUVmédio e SUVpico, respectivamente). O volume foi definido por um isocontorno usando 10% do SUVmáx. Os resultados foram comparados com o teste t de Student. RESULTADOS: Não houve diferença estatisticamente significante entre os valores de SUV das glândulas resfriadas e seus controles. Houve 27% de redução volumétrica (p = 0,004) nas parótidas resfriadas em comparação ao controle. CONCLUSÃO: Não houve redução da captação de 68Ga-PSMA nas glândulas salivares ao REGS. Atualmente não há evidências que suportem essa prática clínica.

68Ga-Prostate-Specific Membrane Antigen PET/CT Uptake in Intraventricular Meningioma in the Choroid Plexus.

A 68-year-old man in whom a prostate cancer biochemical recurrence was being investigated was referred for a full-body Ga-prostate-specific membrane antigen PET/CT. Focal uptake in a lesion on the choroid plexus projection was detected. Patient had no neurological complaints. A previous MRI performed 4 years ago showed the same lesion. According to the location and radiological and clinical characteristics, the diagnosis of meningioma was defined. The interpretation of prostate-specific membrane antigen PET/CT must take into account the low frequency of metastases in sites such as the central nervous system, and the possibility of intense uptake in lesions unrelated to prostate cancer.

Whole Skeletal Mean SUV Measured on 18F-NaF PET/CT Studies as a Prognostic Indicator in Patients with Bone Metastatic Breast Cancer.

In this work we assessed the association between the whole skeletal mean standardized uptake value (SUV) measured on 18F-NaF PET/CT studies and the overall survival (OS) of bone metastatic breast cancer patients. Methods: We retrospectively analyzed 176 patients with breast cancer and bone metastatic disease who performed 18F-NaF PET/CT studies. The outcomes of the patients (dead or alive) were established based on the last information available on their files. The mean and maximum SUVs were measured in a whole skeletal volume of interest (wsVOI). The wsVOI was defined based on the CT component of the PET/CT study using Hounsfield Units thresholds. The wsVOI was then applied on the 18F-NaF PET image. Univariate analyses were performed to assess the association of the SUVs with OS. We also analyzed the association of the age of the patients, the presence of visceral metastatic disease, histological subtypes, presence of hormone receptors, human epidermal growth factor receptor 2 expression and the creatinine, CA15-3 and alkaline phosphatase (ALP) levels with OS. The variables statistically significant in the univariate analyses were included in a multivariate cox regression survival analysis. Results: In the univariate analyses there were associations of the mean and maximum whole skeletal SUVs, estrogen receptor status and the CA15-3 and ALP levels with OS. In the multivariate analysis, all the variables that were statistically significant in the univariate analysis but the CA15-3 were associated with OS. Conclusion: In patients with bone metastatic breast cancer, the whole skeletal mean SUV is an independent predictor of overall survival.

Short Dietary Intervention with Olive Oil Increases Brown Adipose Tissue Activity in Lean but not Overweight Subjects.

BACKGROUND: The brown adipose tissue (BAT) is a potential target for the treatment of obesity and metabolic disorders. Its activation by cold exposure or adrenergic drugs can increase systemic insulin sensitivity and improve lipid metabolism; however, little is known about the effects of specific dietary components on BAT activity. OBJECTIVES: We asked if a short-term (4 weeks) dietary intervention with olive oil could modify BAT activity in lean and overweight/obese volunteers. DESIGN: This was a 4-week open clinical trial in which all participants underwent a dietary intervention with extra-virgin olive oil supplementation. As the initial intake of olive oil was controlled all the participants were controls of themselves. RESULTS: The intervention resulted in significant increase in blood monounsaturated fatty acid levels, which was accompanied by increased BAT activity in lean but not in overweight/obese volunteers. In the lean group, an increase in leptin was detected after the intervention, and low leptin values at the beginning of the study were predictive of greater BAT activity after intervention. In addition, increase in leptin concentration was associated with increased BAT activity. Three known endogenous mediators of BAT activity, secretin, fibroblast growth factor 21 (FGF21), and 12,13-dihydroxy-9Z-octadecenoic acid (12,13-diHOME) were increased by intervention in lean, whereas only secretin and FGF21 were increased in subjects with excessive weight. CONCLUSION: This study provides clinical evidence for the impact of monounsaturated fatty acids on BAT activity and an advance in the understanding of the beneficial health effects of olive oil.