Intratumoral metabolic heterogeneity by 18F-FDG PET/CT to predict prognosis for patients with thymic epithelial tumors.

BACKGROUND: The aim of the present study was to evaluate the impact of intratumoral metabolic heterogeneity and quantitative 18F-FDG PET/CT imaging parameters in predicting patient outcomes in thymic epithelial tumors (TETs). METHODS: This retrospective study included 100 patients diagnosed with TETs who underwent pretreatment 18F-FDG PET/CT. The maximum and mean standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on PET/CT were measured. Heterogeneity index-1 (HI-1; standard deviation [SD] divided by SUVmean) and heterogeneity index-2 (HI-2; linear regression slopes of the MTV according with different SUV thresholds), were evaluated as heterogeneity indices. Associations between these parameters and patient survival outcomes were analyzed. RESULTS: The univariate analysis showed that Masaoka stage, TNM stage, WHO classification, SUVmax, SUVmean, TLG, and HI-1 were significant prognostic factors for progression-free survival (PFS), while MTV, HI-2, age, gender, presence of myasthenia gravis, and maximum tumor diameter were not. Subsequently, multivariate analyses showed that HI-1 (p < 0.001) and TNM stage (p = 0.002) were independent prognostic factors for PFS. For the overall survival analysis, TNM stage, WHO classification, SUVmax, and HI-1 were significant prognostic factors in the univariate analysis, while TNM stage remained an independent prognostic factor in multivariate analyses (p = 0.024). The Kaplan Meier survival analyses showed worse prognoses for patients with TNM stages III and IV and HI-1 ≥ 0.16 compared to those with stages I and II and HI-1 < 0.16 (log-rank p < 0.001). CONCLUSION: HI-1 and TNM stage were independent prognostic factors for progression-free survival in TETs. HI-1 generated from baseline 18F-FDG PET/CT might be promising to identify patients with poor prognosis.

Predictive value of clinical characteristics and baseline 18F-FDG PET/CT quantization parameters in primary adrenal diffuse large B-cell lymphoma: a preliminary study.

Background: Primary adrenal diffuse large B-cell lymphoma (PA-DLBCL) is a rare occurrence, has a very poor prognosis, and is marked by a high risk of relapse. Accurate prediction of patient prognosis before treatment initiation, along with timely adjustment of the treatment plan, holds paramount importance. 2-Deoxy-2-[fluorine-18]-fluoro-D-glucose (18F-FDG) positron emission tomography combined with computed tomography (PET/CT) imaging techniques are conventionally performed prior to treatment initiation in DLBCL patients, offering indispensable functional and metabolic insights into lymphoma lesions. Methods: We conducted a retrospective case-control study using data collected from January 2014 to December 2022, including 24 patients diagnosed with PA-DLBCL. Clinical information of patients was collected based on inpatient medical records, including age, gender, B symptoms, adrenocorticotropic hormone (ATCH), lactate dehydrogenase (LDH), ß2-microglobulin, albumin (Alb), ferritin (Fe), blood calcium, Eastern Cooperative Oncology Group performance status (ECOG-PS), International Prognostic Index, Ann Arbor staging, number of involved organs, and Hans' algorithm. Prior to treatment, all patients underwent baseline 18F-FDG PET/CT, and the metabolic parameters of the tumor were calculated using a threshold of 41% of maximum standardized uptake value (SUVmax), including metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Prognostic analysis of overall survival (OS) was performed using Kaplan-Meier survival analysis, as well as univariate and multifactor Cox proportional hazards regression models. Results: The 24 enrolled patients comprised 16 men and 8 women (median age 65 years, range 51-90 years). The median follow-up period was 17.5 months (range, 1-107 months). In univariate analysis, Ann Arbor stage, ß2-microglobulin, ATCH, number of involved organs, regions of lymph node involvement, treatment, chemotherapy cycles, SUVmax, MTV, and TLG showed association with OS (P<0.1). In multivariate analysis, Ann Arbor stage, ß2-microglobulin, ATCH, number of involved organs, and treatment were shown to be independent prognostic factors for OS. We found that SUVmax, MTV, and TLG correlated with Ann Arbor staging (P<0.05), mean standardized uptake value (SUVmean) and TLG correlated with the number of involved organs (P<0.05). Conclusions: PA-DLBCL is characterized by a low incidence and a poor prognosis. Baseline 18F-FDG PET/CT quantization parameters showed correlations with Ann Arbor staging and number of involved organs. Increasing the sample size or prolonging the follow-up period may reveal the predictive value of PET/CT quantization parameters.

Duodenal-type follicular lymphoma in 18F-FDG PET/CT imaging: a case report.

Follicular lymphoma (FL) is a subtype of non-Hodgkin lymphoma (NHL) that is typically characterized by a slow-growing course. Duodenal-type follicular lymphoma (D-FL) was recently reclassified as a distinct variant. This subtype exhibits unique clinical and biological characteristics, which set it apart from other forms of FL. We report a case of a 36-year-old male patient with multiple, small, gray polypoid lesions in the descending duodenum which were detected by esophagogastroduodenoscopy. The pathological diagnosis was low-grade D-FL. 18F-FDG PET/CT was performed for staging and revealed the pancreas and peripheral lymph nodes were involved by FL, with a clinical IV stage. The patient underwent a bone marrow smear cytology, which revealed no bone marrow abnormalities, and excluded bone marrow involvement. He was treated with six cycles of chemotherapy using the R-CHOP regimen and reached complete remission.

Primary renal myxoid liposarcoma with pancreatic invasion on 18F-FDG PET/CT: first case report and literature review.

Background: Myxoid liposarcoma (MLS) is a rare malignant soft tissue sarcoma that predominantly manifests in the deep soft tissues of the extremities, particularly within the musculature of the thigh. Unlike other types of liposarcoma, MLS demonstrates a propensity for metastasis to atypical sites, including the lung parenchyma, soft tissues, retroperitoneum, mediastinum, breast, liver, thymus, lymph nodes, and bones. The definitive diagnosis primarily relies on histology with HE staining. Imaging modalities such as ultrasound, CT, MRI, and 18F-FDG PET/CT scans serve as valuable tools for tumor identification. Case report: A 57-year-old man presented with symptoms of abdominal distention and vomiting 1 month ago. Contrast-enhancement CT revealed a heterogeneous hypodense mass in the upper-middle part of the left kidney, displaying irregular morphology and protrusion towards the exterior of the kidney, with abundant blood supply and had a maximum dimension of approximately 10.7 cm × 9.0 cm. Additionally, a rounded soft tissue density was identified in the pancreatic body. Multiplanar reconstruction demonstrated a connection between the pancreatic lesion and the kidney mass. 18F-FDG PET/CT was conducted for staging, revealing significant growth of the lesion in the upper-middle part of the left kidney, extending beyond the kidney and infiltrating the pancreatic body. The lesion demonstrated remarkably high 18F-FDG uptake (SUVmax = 10.2, MTV = 136.13 cm3, TLG = 484.62). The postoperative pathological examination confirmed the diagnosis of MLS. On the 10th day post-surgery, the patient presented with tumor recurrence and underwent another surgical resection. Unfortunately, during the operation, the patient experienced a sudden cardiac arrest and died. Conclusion: Renal MLS with invasion into the pancreas is very rare in clinical practice. Due to the limited research on the utilization of 18F-FDG PET/CT in this particular context, given the rarity and low incidence of MLS, its role remains largely unexplored. As PET/CT imaging becomes increasingly prevalent, thorough imaging of disease sites becomes indispensable for the development of treatment protocols and the monitoring of treatment response.

Multimodality imaging of an unusual giant cell tumor of thoracic spine with mediastinal invasion: a case report.

Giant cell tumor (GCT) is a benign yet locally aggressive bone neoplasm typically situated in the juxta-articular metaphysis of long bones. Although spinal involvement is rare, it is predominantly reported in the axial skeleton, with the sacrum being the primary location. Conversely, GCTs are notably uncommon in the thoracic spine. In this report, we present computed tomography (CT), magnetic resonance imaging (MRI), and 2-Deoxy-2-[fluorine-18]-fluoro-D-glucose (18F-FDG) positron emission tomography combined with computed tomography (PET/CT) multimodality imaging findings of a 36-year-old woman diagnosed with a GCT of the thoracic spine. CT scans provide a precise evaluation of cortical thinning and penetration. While MRI lacks specific diagnostic indicators for GCT, it remains invaluable for delineating the extent of soft tissue expansion and the tumor's relationship with intraspinal neural elements - critical information for surgical planning. 18F-FDG PET/CT effectively illustrates the lesion's hypermetabolic and locally aggressive characteristics. It is noteworthy that GCT occasionally exhibits metastatic malignant potential, underscoring the value of FDG PET as a pivotal modality for staging, restaging, or assessing therapy response, and for monitoring the efficacy of radiotherapy. Familiarity with the imaging features of GCT is essential for physicians to avoid misinterpretation. This tumor should be considered in the differential diagnosis of spinal tumors, distinguishing it from bone metastases or neurogenic tumors.

18F-FDG PET/CT and ultrasonogrpahy in differentiated thyroid carcinoma patients with elevated serum levels of antithyroglobulin antibody, negative Tg and whole body 131I scan.

OBJECTIVE: In the follow-up of patients with differentiated thyroid cancer (DTC), several patients had elevated serum levels of antithyroglobulin antibody (TgAb), undetectable serum thyroglobulin (Tg), and negative radioiodine whole body scan (131I-WBS). We describe the use of neck ultrasonography (US) and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging in these patients to investigate this clinically challenging problem and propose treating. SUBJECTS AND METHODS: A total of 49 DTC patients with elevated serum levels of TgAb (>115IU/mL), undetectable Tg and negative 131I-WBS were divided into two groups (positive and negative) according to the neck US findings. Differences in the rate of recurrence between the two groups were investigated. The diagnostic value of 18F-FDG PET/CT in these patients was evaluated. RESULTS: Among the 49 patients, the rate of recurrence of patients with positive neck US was 50%, which was significantly higher than that of patients with negative neck US (17.24%; P=0.014). The sensitivity, specificity, and positive predictive values of 18F-FDG PET/CT imaging in diagnosing the clinical status of these patients were 93.33%, 70.59% and 58.33%, respectively. After the 18F-FDG PET/CT scan, clinical management was changed in 14 patients. Nine patients were operated and five underwent 131I ablation therapy. CONCLUSION: In the 49 DTC patients with elevated serum levels of TgAb but negative findings in serum Tg and in 131I-WBS, neck US and 18F-FDG PET/CT imaging supported the clinical diagnosis and suggested subsequent treatment.

Development of 11C-Labeled ω-sulfhydryl fatty acid tracer for myocardial imaging with PET.

[11C]-S-methyl-16-thiopalmitic acid (a) was developed with excellent heart-to-background uptake ratios and higher retention in heart. Myocardial uptake and metabolism of the tracer is markedly higher CPT I dependent. When compared to [11C]-S-methyl-14-thiomyristic acid (b), [11C]-S-methyl-12-thiododecanoic acid (c) and [11C]-palmitate, a showed an early high uptake and a significantly slower late clearance in heart and a prolonged myocardial elimination half-life (30 min). Analysis of heart tissue and urine samples showed that a was metabolized via beta-oxidation in myocardium. Small animal PET images of the accumulation of a in the rat myocardium were clearly superior to [11C]-palmitate. These initial studies suggest that a could be a potentially useful clinical PET tracer to assess myocardial fatty acid metabolism.

Neural correlates of the popular music phenomenon: evidence from functional MRI and PET imaging.

PURPOSE: Music can induce different emotions. However, its neural mechanism remains unknown. The aim of this study was to use functional magnetic resonance imaging (fMRI) and position emission tomography (PET) imaging for mapping of neural changes under the most popular music in healthy volunteers. METHODS: Blood-oxygen-level-dependent (BOLD) fMRI and monoamine receptor PET imaging with 11C-N-methylspiperone (11C-NMSP) were conducted under the popular music Gangnam Style and light music A Comme Amour in healthy subjects. PET and fMRI images were analyzed by using the Statistical Parametric Mapping software (SPM). RESULTS: Significantly increased fMRI BOLD signals were found in the bilateral superior temporal cortices, left cerebellum, left putamen and right thalamus cortex. Monoamine receptor availability was increased significantly in the left superior temporal gyrus and left putamen, but decreased in the bilateral superior occipital cortices under the Gangnam Style compared with the light music condition. Significant positive correlation was found between 11C-NMSP binding and fMRI BOLD signals in the left temporal cortex. Furthermore, increased 11C-NMSP binding in the left putamen was positively correlated with the mood arousal level score under the Gangnam Style condition. CONCLUSION: Popular music Gangnam Style can arouse pleasure experience and strong emotional response. The left putamen is positively correlated with the mood arousal level score under the Gangnam Style condition. Our results revealed characteristic patterns of brain activity associated with Gangnam Style, and may also provide more general insights into the music-induced emotional processing.

PET imaging reveals brain functional changes in internet gaming disorder.

BACKGROUND: Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D2 (D2)/Serotonin 2A (5-HT2A) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D2 receptor and glucose metabolism. METHODS: Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and (11)C-N-methylspiperone ((11)C-NMSP) to assess the availability of D2/5-HT2A receptors and with (18)F-fluoro-D-glucose ((18)F-FDG) to assess regional brain glucose metabolism, a marker of brain function. (11)C-NMSP and (18)F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. RESULTS: In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. CONCLUSIONS: For the first time, we report the evidence that D2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D2/5-HT2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects.

Multimodality molecular imaging of stem cells therapy for stroke.

Stem cells have been proposed as a promising therapy for treating stroke. While several studies have demonstrated the therapeutic benefits of stem cells, the exact mechanism remains elusive. Molecular imaging provides the possibility of the visual representation of biological processes at the cellular and molecular level. In order to facilitate research efforts to understand the stem cells therapeutic mechanisms, we need to further develop means of monitoring these cells noninvasively, longitudinally and repeatedly. Because of tissue depth and the blood-brain barrier (BBB), in vivo imaging of stem cells therapy for stroke has unique challenges. In this review, we describe existing methods of tracking transplanted stem cells in vivo, including magnetic resonance imaging (MRI), nuclear medicine imaging, and optical imaging (OI). Each of the imaging techniques has advantages and drawbacks. Finally, we describe multimodality imaging strategies as a more comprehensive and potential method to monitor transplanted stem cells for stroke.

Preliminary studies of a novel cyclopentadienyl tricarbonyl technetium-99m fatty acid derivative for myocardical imaging.

This study reports the synthesis and evaluation studies of 6'-cyclopentadienyl tricarbonyl technetium-99m 6'-oxo-11-(hexanamide)undecanoic acid (1). 1 was prepared with 26.5 ± 4.3% of radiochemical yield and more than 98% of radiochemical purity. Tissue distribution in mice showed that high radioactivity accumulated in the heart with moderate clearance. However, unfortunately, similar to those of other technetium-labeled fatty acid analogs, the biodistribution studies of 1 in mice showed poor heart-to-blood ratios, which suggested that 1 cannot be used as myocardial imaging agent, and it may provide a theoretical basis or a lab experience for corresponding fatty acid tracers studies.

PET demonstrates functional recovery after transplantation of induced pluripotent stem cells in a rat model of cerebral ischemic injury.

UNLABELLED: The purpose of this study was to determine the functionality of the transplanted induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) in a rat model of cerebral ischemia with use of (18)F-FDG small-animal PET imaging. METHODS: Middle cerebral artery occlusion was used to establish cerebral ischemia. Twenty-four male rats were randomly assigned to 1 of 3 groups: iPSC treatment, ESC treatment, and the control phosphate-buffered saline (PBS) injection. After neurologic function tests and baseline (18)F-FDG small-animal PET had been performed, 1.0 × 10(6) suspended iPSCs or ESCs were injected stereotactically into the left lateral ventricle. The treatment response was evaluated weekly by (18)F-FDG PET scans and neurologic function tests. Histologic analyses and autoradiographic imaging were performed 4 wk after stem cell transplantation. RESULTS: Compared with the PBS injection group, higher (18)F-FDG accumulation in the ipsilateral cerebral infarction was observed in both the iPSC and the ESC treatment groups during the 4-wk period (P < 0.05). (18)F-FDG accumulation in the ipsilateral cerebral infarction increased steadily over time in the iPSC treatment group. At 1 and 2 wk after stem cell transplantation, significant recovery of glucose metabolism was found in the ESC treatment group (P < 0.05) and then decreased gradually. The neurologic score in both stem cell-treated groups was significantly lower than that in the PBS group, indicating functional improvement. Immunohistochemical analysis demonstrated that transplanted stem cells survived and migrated close to the ischemic region, and most of the stem cells expressed protein markers for cells of interest. CONCLUSION: (18)F-FDG small-animal PET demonstrated metabolic recovery after iPSC and ESC transplantation in the rat model of cerebral ischemia. iPSCs could be considered a potentially better therapeutic approach than ESCs and are worthy of further translational investigation.

Frightening music triggers rapid changes in brain monoamine receptors: a pilot PET study.

UNLABELLED: Frightening music can rapidly arouse emotions in listeners that mimic those from actual life-threatening experiences. However, studies of the underlying mechanism for perceiving danger created by music are limited. METHODS: We investigated monoamine receptor changes induced by frightening music using (11)C-N-methyl-spiperone ((11)C-NMSP) PET. Ten healthy male volunteers were included, and their psychophysiologic changes were evaluated. RESULTS: Compared with the baseline condition, listening to frightening music caused a significant decrease in (11)C-NMSP in the right and left caudate nuclei, right limbic region, and right paralimbic region; a particularly significant decrease in the right anterior cingulate cortex; but an increase in the right frontal occipital and left temporal lobes of the cerebral cortex. CONCLUSION: Transient fright triggers rapid changes in monoamine receptors, which decrease in the limbic and paralimbic regions but increase in the cerebral cortex.

PET/CT in the staging of the non-small-cell lung cancer.

Lung cancer is a common disease and the leading cause of cancer-related death in many countries. Precise staging of patients with non-small-cell lung cancer plays an important role in determining treatment strategy and prognosis. Positron emission tomography/computed tomography (PET/CT), combining anatomic information of CT and metabolic information of PET, is emerging as a potential diagnosis and staging test in patients with non-small-cell lung cancer (NSCLC). The purpose of this paper is to discuss the value of integrated PET/CT in the staging of the non-small-cell lung cancer and its health economics.