[18F]FDG PET/CT versus [18F]FDG PET/MRI in the evaluation of liver metastasis in patients with primary cancer: A head-to-head comparative meta-analysis.

PURPOSE: This meta-analysis aimed to compare the diagnostic effectiveness of [18F]FDG PET/CT with that of [18F]FDG PET/MRI in terms of identifying liver metastasis in patients with primary cancer. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched, and studies evaluating the diagnostic efficacy of [18F]FDG PET/CT and [18F]FDG PET/MRI in patients with liver metastasis of primary cancer were included. We used a random effects model to analyze their sensitivity and specificity. Subgroup analyses and corresponding meta-regressions focusing on race, image analysis, study design, and analysis methodologies were conducted. Cochrane Q and I2 statistics were used to assess intra-group and inter-group heterogeneity. RESULTS: Seven articles with 343 patients were included in this meta-analysis. The sensitivity of [18F]FDG PET/CT was 0.82 (95 % CI: 0.63-0.96), and that of [18F]FDG PET/MRI was 0.91 (95 % CI: 0.82-0.98); there was no significant difference between the two methods (P = 0.32). Similarly, both methods showed equal specificity: 1.00 (95 % CI: 0.95-1.00) for [18F]FDG PET/CT and 1.00 (95 % CI: 0.96-1.00) for [18F]FDG PET/MRI, and thus, there was no significant difference between the methods (P = 0.41). Furthermore, the subgroup analyses revealed no differences. Meta-regression analysis revealed that race was a potential source of heterogeneity for [18F]FDG PET/CT (P = 0.01), while image analysis and contrast agent were found to be potential sources of heterogeneity for [18F]FDG PET/MRI (P = 0.02). CONCLUSIONS: [18F]FDG PET/MRI has similar sensitivity and specificity to [18F]FDG PET/CT for detecting liver metastasis of primary cancer in both the general population and in subgroups. [18F]FDG PET/CT may be a more cost-effective option. However, the conclusions of this meta-analysis are tentative due to the limited number of studies included, and further research is necessary for validation.

Endocrinology application of molecular imaging: current role of PET/CT.

BACKGROUND: In recent years, nuclear medicine imaging methods have proven to be of paramount importance in a wide variety of diseases, particularly in oncology, where they are crucial for assessing the extent of disease when conventional methods fall short. Moreover, nuclear imaging modalities are able to better characterize lesions using target agents related to specific pathways (e.g. glucose metabolism, cellular proliferation, amino acid transport, lipid metabolism, specific receptor ligands). The clinical presentation of endocrine diseases encompasses a broad spectrum of sign and symptoms. Moreover, endocrine tumors show varying degrees of aggressiveness from well differentiated and indolent to highly aggressive cancers, respectively. RATIONALE: With the application of new medicinal radio-compounds and increasingly advanced tomographic imaging technology, the utility of Positron Emission Tomography/Computed Tomography (PET/CT) in the field of endocrine diseases is expanding. AIM: This review aims to analyze and summarize the primary indications of PET/CT, providing a practical approach for clinicians. A comprehensive literature search on PubMed was conducted to provide an updated overview of the available evidence regarding the use of PET/CT in endocrinology. Within this review, we will discuss the applications of PET/CT, compare different radiopharmaceuticals and highlight the uptake mechanism, excluding neuroendocrine carcinomas from discussion. CONCLUSIONS: PET/CT is a valuable tool in diagnosing and managing endocrine disorders due to its capacity to furnish both functional and anatomical information, facilitate early lesion detection, guide treatment decisions, and monitor treatment response. Its non-invasive nature and precision make it an integral component of modern endocrine healthcare. This review aims to provide physicians with a clear perspective on the role of PET/CT imaging, discussing its emerging opportunities and appropriateness of use in endocrinological diseases.

Effect of a multimodal intervention in breast Cancer patients undergoing neoadjuvant therapy: A study protocol of the multimodal project.

BACKGROUND AND AIMS: To determine the effect of a multimodal intervention (nutritional behavior change and physical exercise) on quality of life, chemotherapy response rate and tolerance, histopathological level of the tumor, body composition, and biochemical parameters, in patients diagnosed with breast cancer during neoadjuvant chemotherapy treatment, and to compare them with the control group. METHODS: Anticipated 80 patients diagnosed with breast cancer aged 18-70 years will be recruited for this randomized, unblinded clinical trial based on a nutritional behavior change and physical exercise in patients during the approximately 6 months in which the patient receives neoadjuvant treatment. Participants will be randomly allocated (1:1) to one of two groups (intervention or control). Primary and secondary outcomes will be assessed before the beginning and after the neoadjuvant treatment (before surgery). The primary outcome is quality of life, whereas secondary outcomes include chemotherapy response rate and tolerance, histopathological level of the tumor and body composition (i.e., visceral adipose tissue activity, bone, lean and fat masses). We will analyze blood parameters (i.e., biochemical, inflammatory, and tumor markers) as exploratory outcomes. CONCLUSION: This study will address the influence of a practical and viable multimodal intervention (i.e., nutritional behavior change and physical exercise) on breast cancer patients undergoing neoadjuvant chemotherapy. Given the practical viability of the intervention in real-world settings, our study holds promise for significant scientific and clinical implications.

Vesicourachal Diverticulum: An Uncommon Incidental Finding on Staging 18F-FDG PET/CT in a Patient with Suspected Malignant Transformation of Neurofibromatosis.

In a 32-y-old man with neurofibromatosis type 1, 18F-FDG PET/CT incidentally revealed a vesicourachal diverticulum, a rare anatomic variant. The PET/CT, performed for staging a malignant peripheral nerve sheath tumor, highlighted a distinctive 18F-FDG-avid pattern crucial for accurate diagnosis. Recognizing such features enhances disease assessment and clarifies distinctions between benign urogenital anomalies and malignancies in 18F-FDG PET/CT staging.

Detection of Esophageal Tuberculosis, a Rare Cause of Abdominal Pain, on 18F-FDG PET/CT.

The esophagus is rarely affected by Mycobacterium A 75-y-old man presented with upper abdominal pain and significant weight loss for 2 mo. Contrast-enhanced CT, upper gastrointestinal endoscopy, and abdominal vessel angiography gave normal results. To clarify the facts, 18F-FDG PET/CT was performed, revealing an 18F-FDG-avid lesion in the posterior wall of the lower thoracic esophagus. On endoscopic ultrasound-guided fine-needle aspiration of this lesion, puslike material was released. On microscopic examination, acid-fast bacilli were noted. The patient then began receiving standard antitubercular therapy.

Deep generative denoising networks enhance quality and accuracy of gated cardiac PET data.

BACKGROUND: Cardiac positron emission tomography (PET) can visualize and quantify the molecular and physiological pathways of cardiac function. However, cardiac and respiratory motion can introduce blurring that reduces PET image quality and quantitative accuracy. Dual cardiac- and respiratory-gated PET reconstruction can mitigate motion artifacts but increases noise as only a subset of data are used for each time frame of the cardiac cycle. AIM: The objective of this study is to create a zero-shot image denoising framework using a conditional generative adversarial networks (cGANs) for improving image quality and quantitative accuracy in non-gated and dual-gated cardiac PET images. METHODS: Our study included retrospective list-mode data from 40 patients who underwent an 18F-fluorodeoxyglucose (18F-FDG) cardiac PET study. We initially trained and evaluated a 3D cGAN-known as Pix2Pix-on simulated non-gated low-count PET data paired with corresponding full-count target data, and then deployed the model on an unseen test set acquired on the same PET/CT system including both non-gated and dual-gated PET data. RESULTS: Quantitative analysis demonstrated that the 3D Pix2Pix network architecture achieved significantly (p value<0.05) enhanced image quality and accuracy in both non-gated and gated cardiac PET images. At 5%, 10%, and 15% preserved count statistics, the model increased peak signal-to-noise ratio (PSNR) by 33.7%, 21.2%, and 15.5%, structural similarity index (SSIM) by 7.1%, 3.3%, and 2.2%, and reduced mean absolute error (MAE) by 61.4%, 54.3%, and 49.7%, respectively. When tested on dual-gated PET data, the model consistently reduced noise, irrespective of cardiac/respiratory motion phases, while maintaining image resolution and accuracy. Significant improvements were observed across all gates, including a 34.7% increase in PSNR, a 7.8% improvement in SSIM, and a 60.3% reduction in MAE. CONCLUSION: The findings of this study indicate that dual-gated cardiac PET images, which often have post-reconstruction artifacts potentially affecting diagnostic performance, can be effectively improved using a generative pre-trained denoising network.

Two cases of misleading Epstein-Barr virus infection and the role of EBV-DNA.

Two atypical cases of infectious mononucleosis in two teenagers with initially negative serology and non-evocative blood examinations are reported. The first patient had recently traveled to Africa, and Epstein-Barr virus negative serology led us to make many extensive investigations. The second patient complained of asthenia for a month, and PET/CT was performed to suspicion of lymphoma. PET scan revealed hypermetabolic lymph nodes in the supradiaphragmatic and subdiaphragmatic stations, along with18F-FDG uptake in the spleen and pharynx, raising more suspicion of lymphoma. Fortunately, Epstein-Barr virus DNA testing was performed and turned positive in both cases, and Epstein-Barr virus serology subsequently became positive. Diagnosing EBV infection can be challenging in rare cases, as EBV-specific serology may be negative in the early stages and confounding factors may be present. Therefore, Epstein-Barr virus DNA testing should be considered early in the diagnostic algorithm to prevent unnecessary investigations in similar cases.

Application value of 18F-FDG PET/CT in primary spleen angiosarcoma with liver metastasis: a case report and literature review.

Background: Primary splenic angiosarcoma (PSA) is a rare neoplasm. It is a malignant tumor derived from endothelial cells of the splenic sinuses. PSA has an unknown etiology, a high degree of malignancy, easy early metastasis, atypical clinical symptoms and imaging findings, and difficult early diagnosis. This paper reports the 18F-FDG PET/CT findings of a case of PSA with intrahepatic metastasis; summarizes its clinical, imaging, and pathological data; and reviews the literature. Case description: A 64-year-old male patient presented with left lower abdominal distending pain without obvious causes on 13 March 2022. The pain was persistent and dull and worsened after sitting and eating. Blood routine examination results were RBC ↓ 3.33 × 1012/L, WBC ↑ 12.32 × 109/L, and PLT ↓ 40 × 109/L. The tumor markers indicated CA125 ↑ 47.0 U/ml, AFP (-), CEA (-), CA199 (-), and CA724 (-). Non-contrast-enhanced CT scan of the abdomen showed that the spleen was significantly enlarged in volume and irregular in shape and had multiple nodules and clumpy low-density shadows, unclear boundaries, uneven density, and multiple necrotic areas. Enhanced CT showed diffuse uneven mild enhancement of the spleen, and the degree of enhancement increased with time. Multiple nodular low-density shadows were seen in the liver, which were slightly enhanced by the enhanced scan.18F-FDG PET/CT showed multiple nodular and massive lesions in the spleen with multiple necrotic areas. There were multiple nodular lesions in the liver, the level of FDG metabolism increased, the SUVmax of the spleen lesions was 9.0, and the SUVmax of the liver lesions was 5.6. The 18F-FDG PET/CT diagnosis was splenic malignancy with liver metastasis. Finally, after a multidisciplinary discussion, it was decided to perform laparoscopic total splenectomy and portal vein infusion chemotherapy. Pathological examination showed that the tumor cells were round, oval, or fusiform, with obvious atypia, arranged into a cable or anastomosed vascular lumen. The final diagnosis was primary splenic angiosarcoma with massive necrosis. After surgery, the patient received antitumor combined therapy and died 5 months later. Conclusion: The incidence of PSA is very low, and its clinical and radiological manifestations lack specificity. 18F-FDG PET/CT imaging has a certain diagnostic value for PSA and significant utility in preoperative staging, guiding biopsy procedures, evaluating postoperative treatment response, and monitoring disease recurrence. PSA should be considered in the presence of a space-occupying lesion within the spleen that exhibits necrotic areas, shows progressive enhancement on contrast-enhanced scans, and demonstrates heterogeneous increases in FDG uptake.

Gene expression and ultra-structural evidence for metabolic derangement in the primary mitral regurgitation heart.

Aims: Chronic neurohormonal activation and haemodynamic load cause derangement in the utilization of the myocardial substrate. In this study, we test the hypothesis that the primary mitral regurgitation (PMR) heart shows an altered metabolic gene profile and cardiac ultra-structure consistent with decreased fatty acid and glucose metabolism despite a left ventricular ejection fraction (LVEF) > 60%. Methods and results: Metabolic gene expression in right atrial (RA), left atrial (LA), and left ventricular (LV) biopsies from donor hearts (n = 10) and from patients with moderate-to-severe PMR (n = 11) at surgery showed decreased mRNA glucose transporter type 4 (GLUT4), GLUT1, and insulin receptor substrate 2 and increased mRNA hexokinase 2, O-linked N-acetylglucosamine transferase, and O-linked N-acetylglucosaminyl transferase, rate-limiting steps in the hexosamine biosynthetic pathway. Pericardial fluid levels of neuropeptide Y were four-fold higher than simultaneous plasma, indicative of increased sympathetic drive. Quantitative transmission electron microscopy showed glycogen accumulation, glycophagy, increased lipid droplets (LDs), and mitochondrial cristae lysis. These findings are associated with increased mRNA for glycogen synthase kinase 3ß, decreased carnitine palmitoyl transferase 2, and fatty acid synthase in PMR vs. normals. Cardiac magnetic resonance and positron emission tomography for 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake showed decreased LV [18F]FDG uptake and increased plasma haemoglobin A1C, free fatty acids, and mitochondrial damage-associated molecular patterns in a separate cohort of patients with stable moderate PMR with an LVEF > 60% (n = 8) vs. normal controls (n = 8). Conclusion: The PMR heart has a global ultra-structural and metabolic gene expression pattern of decreased glucose uptake along with increased glycogen and LDs. Further studies must determine whether this presentation is an adaptation or maladaptation in the PMR heart in the clinical evaluation of PMR.

SUVmean ratios of liver/muscle and lung/muscle from 13N-NH3 PET perfusion outperformed traditional myocardial viability parameters in predicting survival after CABG.

PURPOSE: Myocardial viability evaluation in predicting survival after coronary artery bypass graft (CABG) remains debatable. Thus, this study aimed to investigate the role of 13N-NH3/18F-FDG PET myocardial viability scan in predicting treatment outcomes and survival. METHODS: 90 patients with CABG and pre-surgical PET-based myocardial viability scan were retrospectively reviewed. Perfusion-metabolism features, myocardium motion parameters, and patient characteristics were recorded. Additionally, the SUVmean of blood pool, lung, liver, spleen, and muscle were measured and the SUVmean ratios were calculated. Factors associated with treatment outcomes and survival were analyzed by Logistic and Cox regressions. Nomogram models were subsequently established to predict ejection fraction (EF) improvement and survival outcomes. RESULTS: The mean EF of these 90 patients was 38.1 ± 9.5% and 46.0 ± 9.2% before and after CABG surgery, and 35 patients (38.9%) achieved EF improvement ≥ 10%. EF measurements by PET and echocardiogram showed a reasonable linear correlation (R = 0.752). Sex, pre-surgical EF, mismatch of the left ventricle, total perfusion deficit (TPD), and peak ejection rate (PER) were independent predictive factors of EF improvements. Surgery waiting time, valve damage, and SUVmean ratio of Liver/Muscle were independently predictive of event-free survival (EFS), while valve damage, together with SUVmean ratio of either Liver/Muscle or Lung/Muscle, were independently predictive of overall survival (OS). CONCLUSION: Although traditional cardiac parameters from PET-based myocardial viability can effectively predict EF improvements after CABG, SUVmean ratios of liver/muscle and lung/muscle from 13N-NH3 PET perfusion outperformed these parameters in predicting survival.

Pulmonary mediastinal actinomycosis with "pound cake sign" on magnetic resonance imaging mimicking an infiltrative malignant tumor: A case report.

Actinomycosis is a rare chronic suppurative granulomatous disease. Surgical biopsy is often performed in patients with chest actinomycosis because malignancy is suspected in most cases. A 62-year-old man presented to our hospital with fever and exertional dyspnea that had persisted for several months. Contrast-enhanced computed tomography showed an irregularly shaped mass with contrast enhancement in the anterior mediastinum and consolidation in the left upper lung lobe contiguous with this mass, as well as multiple nodules in both lungs. The pulmonary artery trunk was stenotic and surrounded by the mass, and the right heart system was enlarged. Thoracoscopic biopsy was performed but failed to yield a diagnosis. Contrast-enhanced computed tomography after one month revealed an increased mass and worsening right heart strain. 18F-FDG (fluorodeoxyglucose) positron emission tomography/computed tomography and contrast-enhanced magnetic resonance imaging also suggested a malignant tumor, and an open chest biopsy was performed. No malignant cells were identified and actinomycetes were detected by histopathology and bacterial culture. The patient was treated with antibiotics, following which his contrast-enhanced computed tomography findings and general condition improved.

A PET/MRI study on the effect of obesity and NAFLD on hepatic [18F]FDG uptake.

PURPOSE: The potential limitations of hepatic [18F]FDG-PET imaging for individuals with obesity and excessive liver fat (NAFLD) are being investigated. In this study, we aim to determine the reliability of standardized uptake values (SUVs) focusing on adjustment for liver fat content (LFC) derived from DIXON images and the effects of whole-body normalizations. METHODS: Lean and with obesity volunteers who underwent [18F]FDG-PET/MRI were reviewed retrospectively. DIXON fat images were used to determine LFC and for adjustment of SUVmean. The hepatic SUVs (mean, fat adjusted mean and max) were normalized to body weight, lean body mass and body surface area. Blood samples were analysed for glucose, serological liver enzymes and lipoproteins for further correlation of [18F]FDG uptake. RESULTS: Out of 11 volunteers with obesity (M:8, F:3, BMI:30-39 kg/m2), 9 confirmed the presence of NAFLD (>5.6 % fat). 22 age-matched lean volunteers (M:10, F:11, BMI:19-26 kg/m2) were used as control group. Both SUVmean, before and after adjustment to LFC, did not provide any difference between lean and with obesity groups under BW, LBM and BSA. SUVmax BW showed a difference between groups (p = 0.05). SUVs were independent of levels of GPT, GOT, gGT, insulin, HOMA-IR, triglycerides, cholesterol and LDL. Volunteers with low HDL were clustered with an increased hepatic [18F]FDG uptake. CONCLUSION: Our method for adjustment of hepatic [18F]FDG-PET with DIXON fat images allows to achieve accurate results for individuals with NAFLD and obesity. For homogenic results, raw SUVmean should be combined with adjustment for liver fat, appropriate normalization and consideration of HDL levels.

BATF promotes tumor progression and association with FDG PET-derived parameters in colorectal cancer.

PURPOSE: The purpose of the study was to evaluate the expression and function of basic leucine zipper ATF-like transcription factor (BATF) in colorectal cancer (CRC), and its correlation with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters. METHODS: The TIMER database, GEPIA database, TCGA, and GEO database were used to analyze the expression profile of BATF in human cancers. The reverse transcription­quantitative PCR and western blot analyses were used to evaluate the mRNA level and protein expression in different CRC cell lines. The expression of BATF in SW620 and HCT116 cells was silenced and cell counting kit-8 assays and clonogenic assay were utilized to evaluate the role of BATF in CRC proliferation. The expression of tumor BATF and glucose transporter 1 (GLUT-1) were examined using immunohistochemical tools in 37 CRC patients undergoing preoperative 18F-FDG PET/CT imaging. The correlation between the PET/CT parameters and immunohistochemical result was evaluated. RESULTS: In database, BATF was highly expressed in pan-cancer analyses, including CRC, and was associated with poor prognosis in CRC. In vitro, the results showed that knocking down of BATF expression could inhibit the proliferation of SW620 and HCT116 cells. In CRC patients, BATF expression was upregulated in tumor tissues compared with matched para-tumoral tissues, and was related with gender and Ki-67 levels. BATF expression was positively related to GLUT-1 expression and PET/CT parameters, including tumor size, maximum standard uptake value, metabolic tumor volume, and total lesion glycolysis. The multiple logistic analyses showed that SUVmax was an independent predictor of BATF expression. With 15.96 g/cm3 as the cutoff, sensitivity was 85.71%, specificity 82.61%, and area-under-the-curve 0.854. CONCLUSION: BATF may be an oncogene associated with 18F-FDG PET/CT parameters in CRC. SUVmax may be an independent predictor of BATF expression.

A Case of Large Vessel Giant Cell Arteritis Presenting With Cough and Diagnosed Using an FDG-PET Scan.

Giant-cell arteritis (GCA) is a type of vasculitis characterised by the presence of granulomas. It is the predominant form of systemic vasculitis in adults and primarily affects the larger arteries in individuals aged ≥ 50 years. GCA affects the major arteries, such as the aorta and its branches, particularly the outer branches of the external carotid artery. Signs and symptoms can be categorised into cranial, extracranial, and systemic manifestations. Patients with headaches, jaw claudication, and vision disturbances usually have extracranial branches of the external carotid artery. Aside from being the prevailing manifestation of GCA, our primary concern regarding this variant is the potential for irreversible vision loss if not properly identified and addressed. Conversely, the GCA can also affect other major blood vessels such as the aorta. Here, we present the case of a 70-year-old Caucasian female patient with cranial GCA who had experienced a temporal headache three years prior. The patient was successfully treated with prednisolone, which was gradually reduced to a very low level with the assistance of methotrexate. Recently, the patient presented with a dry cough that lasted for two months and elevated inflammatory markers. After thorough research, it was determined that there was no evidence of infection, including atypical infections, and that no abnormalities were found in the lungs. Ultimately, via an 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan, the patient was diagnosed with large vessel giant cell arteritis (LV-GCA). This impacted the aorta, carotid arteries, and subclavian arteries. The patient experienced notable improvement in her cough and a reduction in inflammatory markers after receiving a high dosage of oral prednisolone. This case exemplifies the unusual manifestation of LV-GCA and verifies that recurring symptoms may differ from the original presentation. While dry cough is not commonly listed as a symptom of LV-GCA, it can be present as a manifestation or the sole presentation in certain patients, particularly when inflammatory markers are consistently high and there is no pulmonary disease.

Development and validation of an 18F-FDG PET/CT-based radiomics nomogram for predicting the prognosis of patients with esophageal squamous cell carcinoma.

RATIONALE AND OBJECTIVES: The aim of this study was to develop and validate a nomogram, integrating clinical factors and radiomics features, capable of predicting overall survival (OS) in patients diagnosed with esophageal squamous cell carcinoma (ESCC). METHODS: In this study, we retrospectively analyzed the case data of 130 patients with ESCC who underwent 18F-FDG PET/CT before treatment. Radiomics features associated with OS were screened by univariate Cox regression (p < 0.05). Further selection was performed by applying the least absolute shrinkage and selection operator Cox regression to generate the weighted Radiomics-score (Rad-score). Independent clinical risk factors were obtained by multivariate Cox regression, and a nomogram was constructed by combining Rad-score and independent risk factors. The predictive performance of the model for OS was assessed using the time-dependent receiver operating characteristic curve, concordance index (C-index), calibration curve, and decision curve analysis. RESULTS: Five radiomics features associated with prognosis were finally screened, and a Rad-score was established. Multivariate Cox regression analysis revealed that surgery and clinical M stage were identified as independent risk factors for OS in ESCC. The combined clinical-radiomics nomogram exhibited C-index values of 0.768 (95% CI: 0.699-0.837) and 0.809 (95% CI: 0.695-0.923) in the training and validation cohorts, respectively. Ultimately, calibration curves and decision curves for the 1-, 2-, and 3-year OS demonstrated the satisfactory prognostic prediction and clinical utility of the nomogram. CONCLUSION: The developed nomogram, leveraging 18F-FDG PET/CT radiomics and clinically independent risk factors, demonstrates a reliable prognostic prediction for patients with ESCC, potentially serving as a valuable tool for guiding and optimizing clinical treatment decisions in the future.

Lactate Dehydrogenase A is Associated with Elevated FDG Metabolism, Radioiodine Non-avidity, and Poor Prognosis in Differentiated Thyroid Cancer.

RATIONALE AND OBJECTIVES: The role of lactate dehydrogenase A (LDHA) expression in differentiated thyroid cancer (DTC), especially in radioiodine-refractory DTC, remains unclear. The aim of this study was to analyse the relationships and the prognostic value of LDHA, glycolysis, and radioactive iodine (RAI) avidity in DTC. METHODS: DTC patients who underwent 18F-FDG PET/CT and subsequent total thyroidectomy or metastasectomy were enroled. The expression levels of LDHA, glucose transporters (Glut) and Ki67 proteins in tumour tissue were measured using immunohistochemistry. The maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of 18F-FDG PET/CT were measured. A radioiodine whole body scan was used to determine lesion radioiodine avidity. RESULTS: 69 patients with DTC were enroled in this study, including 37 women (53.6%) and 32 men (46.4%), with a median age of 52 years (11 to 77 years). Regarding the pathological category, papillary thyroid cancer was documented in 50 patients (72.5%), while follicular and poorly differentiated thyroid cancer were found in 12 patients (17.4%) and seven patients (10.1%), respectively. Distant metastases were observed in 27 (39.1%) patients; 34 (49.3%) were classified as stage I, 16 (23.2%) as stage II, and 3 (4.3%) and 16 (23.2%) patients in stages III and IV, respectively. LDHA expression levels were correlated with Glut3 expression levels (r = 0.395, P = 0.003) and SUVmax (r = 0.408, P = 0.002). The median LDHA expression and lesion SUVmax of the RAI avidity group were lower than those of the non-RAI avidity group (200 vs. 285, P = 0.036; 3.06 vs. 8.38, P = 0.038, respectively). Elevated SUVmax (P = 0.004), MTV (P = 0.014), TLG (P = 0.001) and LDHA expression (P = 0.048) led to shorter time to progression (TTP); Cox regression analysis revealed that TLG (HR: 4.773, P = 0.047) was an independent prognostic factor of TTP. CONCLUSION: Elevated LDHA is correlated with increased glucose metabolism, decreased radioiodine avidity, and accelerated disease progression. Moreover, 18F-FDG PET/CT acting as "in vivo pathology" is an excellent predictor of DTC prognosis.

Whole-tumoral metabolic heterogeneity in 18F-FDG PET/CT is a novel prognostic marker for neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is a highly heterogeneous tumor, and more than half of newly diagnosed NB are associated with extensive metastases. Accurately characterizing the heterogeneity of whole-body tumor lesions remains clinical challenge. This study aims to quantify whole-tumoral metabolic heterogeneity (WMH) derived from whole-body tumor lesions, and investigate the prognostic value of WMH in NB. METHODS: We retrospectively enrolled 95 newly diagnosed pediatric NB patients in our department. Traditional semi-quantitative PET/CT parameters including the maximum standardized uptake value (SUVmax), the mean standardized uptake value (SUVmean), the peak standardized uptake value (SUVpeak), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured. These PET/CT parameters were expressed as PSUVmax, PSUVmean, PSUVpeak, PMTV, PTLG for primary tumor, WSUVmax, WSUVmean, WSUVpeak, WMTV, WTLG for whole-body tumor lesions. The metabolic heterogeneity was quantified using the areas under the curve of the cumulative SUV-volume histogram index (AUC-CSH index). Intra-tumoral metabolic heterogeneity (IMH) and WMH were extracted from primary tumor and whole-body tumor lesions, respectively. The outcome endpoints were overall survival (OS) and progression-free survival (PFS). Survival analysis was performed utilizing the univariate and multivariate Cox proportional hazards regression. The optimal cut-off values for metabolic parameters were obtained by receiver operating characteristic curve (ROC). RESULTS: During follow up, 27 (28.4%) patients died, 21 (22.1%) patients relapsed and 47 (49.5%) patients remained progression-free survival, with a median follow-up of 35.0 months. In survival analysis, WMTV and WTLG were independent indicators of PFS, and WMH was an independent risk factor of PFS and OS. However, IMH only showed association with PFS and OS. In addition to metabolic parameters, the International Neuroblastoma Staging System (INSS) was identified as an independent risk factor for PFS, and neuron-specific enolase (NSE) served as an independent predictor of OS. CONCLUSION: WMH was an independent risk factor for PFS and OS, suggesting its potential as a novel prognostic marker for newly diagnosed NB patients.

Value of Semi-Quantitative Parameters of 68Ga-FAPI-04 PET/CT in Primary Malignant and Benign Diseases: A Comparison with 18F-FDG.

Objectives: We aimed to compare the value of the semiquantitative parameters of 68Ga-labeled FAP inhibitor (68Ga-FAPI)-04 positron emission tomography/computed tomography (PET/CT) and 18F-fluorodeoxyglucose (18F-FDG) in diagnosing primary malignant and benign diseases. Materials and Methods: 18F-FDG and 68Ga-FAPI-04 PET/CT images of 80 patients were compared. Semiquantitative parameters, including maximum standardized uptake value (SUVmax), mean SUV (SUVmean), peak SUV (SUVpeak), peak SUV by lean body mass (SULpeak), metabolic tumor volume (or tumor volume of FAPI; FAPI-TV), and TLG (or total lesion activity of FAPI; FAPI-TLA), were automatically obtained using the IntelliSpace Portal image processing workstation with a threshold of 40% SUVmax. The liver blood pool was measured as the background, and the tumor-to-background ratio (TBRliver) was calculated. Results: In all malignant lesions, FAPI-TV and FAPI-TLA were higher in 68Ga-FAPI-04 PET/CT than in 18F-FDG. In the subgroup analysis, 68Ga-FAPI-04 had higher FAPI-TV and FAPI-TLA and lower SUVmax than 18F-FDG had in group A, including gynecological tumor, esophageal, and colorectal cancers. However, six semiquantitative parameters were higher in group B (the other malignant tumors). For the benign diseases, SUVmax, SUVmean, SUVpeak, and SULpeak were lower in 68Ga-FAPI-04 PET/CT than in 18F-FDG. 68Ga-FAPI-04 PET/CT showed a lower liver background and a higher TBRliver than 18F-FDG did. 68Ga-FAPI-04 PET/CT had higher accuracy, sensitivity, and specificity than 18F-FDG had. Conclusion: More accurate semiquantitative parameters and lower abdominal background in 68Ga-FAPI-04 PET/CT make it more competitive in the differential diagnosis of malignant and benign diseases than in 18F-FDG.

The relationship between the uptake of alveolar bone inflammation and of cervical lymph nodes on FDG-PET.

OBJECTIVES: To elucidate the relationships between the maximum standardized uptake value (SUVmax) of alveolar bone and those of lymph nodes (LNs) around the neck on 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET). METHODS: The SUVmax values of alveolar bone and of level IA, level IB, and level IIA LNs of 174 patients, including those with and without active odontogenic inflammation, on PET/computed tomography (PET/CT) performed for a health check were retrospectively evaluated. The upper and lower jaws were divided into four blocks (right maxilla, left maxilla, right mandible, and left mandible). The SUVmax values of each block and of the LNs were calculated. The differences in the SUVmax of each LN level between patients with and without odontogenic inflammation, and the relationship between the SUVmax values of alveolar bone and of the LNs were analyzed statistically. RESULTS: Significant differences in SUVmax values of bilateral level IB and IIA LNs were found between patients with and without odontogenic inflammation (Mann-Whitney U test: right level IB, p = 0.008; left level IB, p = 0.006; right level IIA, p < 0.001; left level IIA, p = 0.002), but not in bilateral level IA LNs (Mann-Whitney U test: right level IA, p = 0.432; left level IA, p = 0.549). The inflammatory site with the highest SUVmax in level IB LNs was the ipsilateral mandible (multivariate analysis: right, beta = 0.398, p < 0.001; left, beta = 0.472, p < 0.001), and the highest SUVmax in level IIA LNs was the ipsilateral maxilla (multivariate analysis: right, beta = 0.223, p = 0.002; left, beta = 0.391, p < 0.001). CONCLUSIONS: The SUVmax values of level IB and IIA LNs were associated with a tendency toward a higher SUVmax value of alveolar bone on 18F-FDG-PET.

Prognostic Implications of 68Ga-FAPI-46 PET/CT-Derived Parameters on Overall Survival in Various Types of Solid Tumors.

Tumoral fibroblast activation protein expression is associated with proliferation and angiogenesis and can be visualized by PET/CT. We examined the prognostic value of [68Ga]Ga-fibroblast activation protein inhibitor (FAPI) (68Ga-FAPI)-46 PET/CT for different tumor entities in patients enrolled in 2 prospective imaging studies (NCT05160051, n = 30; NCT04571086, n = 115). Methods: Within 4 wk, 145 patients underwent 68Ga-FAPI-46 and [18F]FDG (18F-FDG) PET/CT. The association between overall survival (OS) and sex, age, tumor entity, total lesion number, highest SUVmax, and the presence of each nodal, visceral, and bone metastasis was tested using univariate Cox regression analysis. Multivariate analyses were performed for prognostic factors with P values of less than 0.05. Results: In the univariate analysis, shorter OS was associated with total lesion number and the presence of nodal, visceral, and bone metastases on 68Ga-FAPI-46 PET/CT (hazard ratio [HR], 1.06, 2.18, 1.69, and 2.05; P < 0.01, < 0.01, = 0.04, and = 0.02, respectively) and 18F-FDG PET/CT (HR, 1.05, 2.31, 1.76, and 2.30; P < 0.01, < 0.01, = 0.03, and < 0.01, respectively) and with SUVmax on 68Ga-FAPI-46 PET/CT (HR, 1.03; P = 0.03). In the multivariate analysis, total lesion number on 68Ga-FAPI-46 PET/CT was an independent risk factor for shorter OS (HR, 1.05; P = 0.02). In patients with pancreatic cancer, shorter OS was associated with total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.09; P < 0.01) and bone metastases on 18F-FDG PET/CT (HR, 31.39; P < 0.01) in the univariate analysis and with total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.07; P = 0.04) in the multivariate analyses. In breast cancer, total lesion number on 68Ga-FAPI-46 PET/CT (HR, 1.07; P = 0.02), as well as bone metastases on 18F-FDG PET/CT (HR, 9.64; P = 0.04), was associated with shorter OS in the univariate analysis. The multivariate analysis did not reveal significant prognostic factors. In thoracic cancer (lung cancer and pleural mesothelioma), the univariate and multivariate analyses did not reveal significant prognostic factors. Conclusion: Disease extent on 68Ga-FAPI-46 PET/CT is a predictor of short OS and may aid in future risk stratification by playing a supplemental role alongside 18F-FDG PET/CT.