Foreign Body Perforating the Descending Colon Incidentally Detected on 18F-FDG PET/CT.

A 78-year-old woman was diagnosed having unresectable tongue cancer 6 months ago, for which she received radiation therapy. She was on enteral nutrition for more than 2 months due to dysphagia and underwent an 18F-FDG PET/CT for restaging. The images showed uptake in a left cervical node.

Comparison of plasma clearance of [Cr]CrEDTA based on three, two and single samples to measure the glomerular filtration rate in patients with solid tumors: a prospective cross-sectional analysis.

Objectives: [Cr]CrEDTA is used to measure the Glomerular Filtration Rate (GFR) in different clinical conditions. However, there is no consensus on the ideal number of blood samples to be taken and at what time points to measure its clearance. This study aimed to compare Slope Intercept (SI) and Single-Sample (SS) methods for measuring GFR in patients with solid tumors, stratified by age, GFR, and Body Mass Index (BMI).

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

Objective: Although F-sodium fluoride (F-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 F-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 F-NaF positron-emission tomography (PET)/computed tomography (CT)and segmented by levels of standardized uptake value (SUV).

Glomerular Filtration Rate Estimation Using β-Microglobulin and β-Trace Protein in Adults With Solid Tumors: A Prospective Cross-Sectional Study.

Rationale & Objective: β-Microglobulin (B2M) and β-trace protein (BTP) are novel endogenous filtration markers that may improve the accuracy of estimated glomerular filtration rate (eGFR) beyond creatinine and cystatin C (eGFR), but they have not been assessed in patients with cancer.

Study Design: Cross-sectional analysis.

Setting & Participants: Prospective cohort of 1,200 patients with active solid tumors recruited between April 2015 and September 2017.

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

Unlabelled: This study aimed to evaluate the repeatability of brown adipose tissue (BAT) activation measured by [F]FDG-PET after beta3-adrenergic stimuli with CL316243 in mice.

Methods: Male C57BL/6 mice underwent [F]FDG-PET at baseline without stimulation (T0-NS), on three consecutive days after intravenous administration of the selective β3-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.

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.

[F]FDG and [C]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.

Unlabelled: This study aimed to evaluate the role of positron emission tomography (PET) with [C]PK11195 and [F]FDG in the characterization of brown adipose tissue (BAT).

Methods: Male C57BL/6 mice were studied with the glucose analogue [F]FDG (n = 21) and the TSPO mitochondrial tracer [C]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.

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.

Optimized Monte Carlo simulations for voxel-based internal dosimetry.

The scientific community has considered internal dosimetry by the Monte Carlo method the gold standard. However, there is a trade-off between simulation processing time and the statistical quality of the results that makes it a challenge to obtain accurate absorbed dose values in some situations, such as dose estimation in organs affected by cross-irradiation or limited computing power. Variance reduction techniques are used to reduce computational processing time without impairing the statistical quality of the results, such as tracking energy cutoff, secondary particle production threshold, and parallelism of different types of emissions from radionuclides.

Influence on voxel-based dosimetry: noise effect on absorbed dose dosimetry at single time-point versus sequential single-photon emission computed tomography.

Objective: The purpose of this study was to evaluate how statistical fluctuation in single-photon emission computed tomography (SPECT) images propagate to absorbed dose maps.

Methods: SPECT/computed tomography (CT) images of iodine-131 filled phantoms, using different acquisition and processing protocols, were evaluated using STRATOS software to assess the absorbed dose distribution at the voxel level. Absorbed dose values and coefficient of variation (COV) were analyzed for dosimetry based on single time-point SPECT images and time-integrated activities of SPECT sequences with low and high counts.

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.

Potential of [C]()-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 [C]()-PK11195 to evaluate tumor inflammation in a mammary tumor animal model.

Methods: Female Balb/C mice were inoculated with 4T1 cells.

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 F-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.

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.

A prospective cross-sectional study estimated glomerular filtration rate from creatinine and cystatin C in adults with solid tumors.

Current guidelines recommend estimating glomerular filtration rate (eGFR) using creatinine (eGFRcr) with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation as the first test for GFR evaluation, but the Cockcroft-Gault (CG) equation is still commonly used in oncology practice and clinical trials despite increasing evidence of its inaccuracy compared to measured GFR (mGFR). Guidelines recommend eGFR using cystatin C (eGFRcys) or both markers (eGFRcr-cys) as a confirmatory test, but neither was carefully evaluated in cancer patients. Therefore, we compared performance of the CKD-EPI equations and others to the CG equation in adults with a variety of solid tumors.

Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital.

Objectives: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19).

Methods: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed.

Results: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.

Whole Skeletal Mean SUV Measured on F-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 F-NaF PET/CT studies and the overall survival (OS) of bone metastatic breast cancer patients. We retrospectively analyzed 176 patients with breast cancer and bone metastatic disease who performed F-NaF PET/CT studies. The outcomes of the patients (dead or alive) were established based on the last information available on their files.

Hot needles can confirm accurate lesion sampling intraoperatively using [F]PSMA-1007 PET/CT-guided biopsy in patients with suspected prostate cancer.

Purpose: Prostate-specific membrane antigen (PSMA)-targeted PET is increasingly used for staging prostate cancer (PCa) with high accuracy to detect significant PCa (sigPCa). [ Ga]PSMA-11 PET/MRI-guided biopsy showed promising results but also persisting limitation of sampling error, due to impaired image fusion. We aimed to assess the possibility of intraoperative quantification of [F]PSMA-1007 PET/CT uptake in core biopsies as an instant confirmation for accurate lesion sampling.

Supplement-based nutritional strategies to tackle frailty: A multifactorial, double-blind, randomized placebo-controlled trial.

Background: Sarcopenia plays a central role in the development of frailty syndrome. Nutrition and exercise are cornerstone strategies to mitigate the transition to frailty; however, there is a paucity of evidence for which dietary and exercise strategies are effective.

Objective: This large, multifactorial trial investigated the efficacy of different dietary strategies to enhance the adaptations to resistance training in pre-frail and frail elderly.

Ga-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 (Ga-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 Ga-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).

General Concepts in Theranostics.

Theranostics describes the pairing of diagnostic biomarkers and therapeutic agents with common specific targets. Nuclear medicine is the greatest theranostics protagonist, relying on radioactive tracers for imaging biologic phenomena and delivering ionizing radiation to the tissues that take up those tracers. The concept has gained importance with the growth of personalized medicine, allowing customized management for diseases, refining patient selection, better predicting responses, reducing toxicity, and estimating prognosis.

Diagnostic performance of Ga-PSMA-11 PET/MRI-guided biopsy in patients with suspected prostate cancer: a prospective single-center study.

Purpose: Ultrasound-guided biopsy (US biopsy) with 10-12 cores has a suboptimal sensitivity for clinically significant prostate cancer (sigPCa). If US biopsy is negative, magnetic resonance imaging (MRI)-guided biopsy is recommended, despite a low specificity for lesions with score 3-5 on Prostate Imaging Reporting and Data System (PIRADS). Screening and biopsy guidance using an imaging modality with high accuracy could reduce the number of unnecessary biopsies, reducing side effects.