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Tuberculous peritonitis (TB peritonitis) is one of the most challenging forms of extrapulmonary TB to diagnose. While tumor markers can be elevated in patients with TB peritonitis, FDG-PET/CT can aid in distinguishing TB peritonitis from malignancies, if an apron-like omentum pattern is seen. Laparoscopy is crucial for accurate and early diagnosis.

The SUVmax is a measure of FDG uptake and is related with tumor aggressiveness in thyroid cancer, however, its association with molecular pathways is unclear. Here, we investigated the relationship between SUVmax and gene expression profiles in 80 papillary thyroid cancer (PTC) patients. We conducted an analysis of DEGs and enriched pathways in relation to SUVmax and tumor size. SUVmax showed a positive correlation with tumor size and correlated with glucose metabolic process. The genes that indicate thyroid differentiation, such as SLC5A5 and TPO, were negatively correlated with SUVmax. Unsupervised analysis revealed that SUVmax positively correlated with DNA replication(r = 0.29, p = 0.009), pyrimidine metabolism(r = 0.50, p

This study aimed to compare the detection rates of 68Ga-FAPI-04 PET/CT and 18F-FDG PET/CT in colorectal cancer. A systematic search of major medical databases was conducted to identify studies up to September 2023. The primary outcome assessed was the detection rate of 68Ga-FAPI-04 PET/CT and 18F-FDG PET/CT in the primary tumor. Pooled risk ratios with a 95% CI were calculated using random-effect models to adjust for heterogeneity. Eight studies were included in the meta-analysis. 68Ga-FAPI-04 PET/CT has higher uptakes in lymph nodes, bone, and peritoneal metastasis compared with 18F-FDG PET/CT. The detection rate of 68Ga-FAPI-04 PET/CT based on lesion was better for lymph node metastasis (RR = 0.63, 95% CI 0.47–0.84, P = 0.002) and peritoneal metastasis (RR = 0.52, 95% CI 0.32–0.85, P = 0.009), both imaging modalities had essentially the same diagnostic efficacy in primary tumor (RR = 0.99, 95% CI 0.96–1.02, P = 0.49). 68Ga-FAPI-04 as a highly promising PET/CT tracer was superior to 18F-FDG PET/CT in colorectal cancer, especially in detecting lymph node metastases and peritoneal metastases. [ABSTRACT FROM AUTHOR]

Objective: The effects of hormonal therapy, estrogen-based hormone replacement therapy (HRT), and anti-tumor hormone therapy, such as tamoxifen, on the physiological uptake of the endometrium on 2-deoxy-2[18F]fluoro-d-glucose ([18F]F-FDG) positron emission tomography (PET) in postmenopausal women have not been determined. We explored the effect of hormone therapy, particularly HRT, on physiological uptake in the endometrium of postmenopausal women. Materials and methods: Postmenopausal women receiving hormone therapy who underwent cancer screening using PET/computed tomography (CT) between June 2016 and April 2023 were included in the hormone therapy group (n = 21). Postmenopausal women with no history of hormone therapy were included in the control group (n = 49). First, the physiological endometrial uptake at menopausal age and at least 1 year thereafter was compared quantitatively (SUVmax) and qualitatively (4-point scale) in the control group, to assess when the endometrium ceased to show significant physiological [18F]F-FDG uptake after menopause. Endometrial uptake was compared between the hormone therapy and control groups. The association between HRT duration (months) and endometrial uptake (SUVmax) was evaluated. Endometrial thickness, measured using transvaginal ultrasonography, was also compared between the two groups. Results: Endometrial uptake was significantly reduced both qualitatively and quantitatively (P < 0.05) at least 1 year after menopause in control patients, by which time most women (89.8%) no longer had significant endometrial uptake. The hormone therapy group (n = 21) showed higher FDG uptake in the endometrium compared to the control group (median SUVmax: 2.3 vs 1.9, P = 0.0011), as well as a higher visual score (P < 0.0001). HRT duration did not correlate with endometrial uptake (P = 0.097). Endometrial thickness in the hormone therapy group was significantly thicker than in the control group (median: 3.9 mm vs 1.8 mm, P = 0.002). Conclusion: Hormone therapy may affect physiological uptake in the endometrium in postmenopausal women. [ABSTRACT FROM AUTHOR]

Background: The characterization of pathologically enlarged mediastinal lymph nodes is clinically essential for effective disease management and accurate prognosis. Malignancy (metastases and lymphoma) and granulomatous conditions (sarcoidosis and tuberculosis) are the most common causes. Magnetic resonance imaging (MRI) is a good modality to characterize the mediastinal pathologically enlarged lymph nodes based on the excellent soft tissue contrast. It can save high-risk patients from radiation exposure and hazards of intervention such as general anesthesia and biopsy. Aim of the work: To estimate the accuracy of different advanced MRI quantitative parameters in the differentiation between benign and malignant mediastinal lymphadenopathy. This would involve the lesion-to-cord signal intensity ratio (SIR) in the T2-WI and diffusion weighted image (DWI), the lesion-to-chest wall muscle SIR in T2-WI and DWI, and the mean apparent diffusion coefficient (ADC) values. These values would be correlated with the prospective pathological data and the results of the positron emission tomography (PET-CT). Results: Prospectively, the study was conducted during the period between June 2022 and September 2023 on 45 patients with indeterminate or suspicious mediastinal lymphadenopathy identified by CT. MRI examination, PET-CT, and biopsy were applied for all patients. The intra-class correlation coefficient ranged between 0.89 and 0.95. (A) The lesion-to-cord SIR in T2-WI in the malignant group (1.49 ± 0.30) was higher than that in the benign group (0.83 ± 0.24) with P < 0.001. The statistically calculated cutoff value (> 1.2) estimated 90% sensitivity, 100% specificity, with AUC = 0.989. (B) The lesion-to-chest wall muscle SIR in T2-WI in malignant nodes (3.13 ± 0.84) was significantly higher than that in the benign nodes (1.90 ± 0.80) with P < 0.001. The statistically calculated cutoff value (> 2.4) estimated 86.67% sensitivity, 86.67% specificity, with AUC = 0.88. (C) The lesion-to-cord signal SIR in b500-DWI in the malignant node (1.80 ± 0.54) was higher than that in the benign group (0.75 ± 0.29) with P < 0.001. The statistically calculated cutoff value (> 1.2) estimated 100% sensitivity and specificity with AUC = 1.00. (D) The lesion-to-chest wall SIR in b500-DWI in the malignant node (6.43 ± 1.28) was higher than that in the benign node (2.63 ± 0.94) with P < 0.001. The statistically calculated cutoff value (> 4.1) estimated 96.67% sensitivity, 100% specificity, with AUC = 0.997. € The mean ADC values in the malignant nodes (0.83 ± 0.20 × 10–3 mm2/s) were significantly lower than that in the benign nodes (1.85 ± 0.19 × 10−3 mm2/s) with P < 0.001. The statistically calculated cutoff value (≤ 1.2) estimated 100% sensitivity and specificity with AUC = 1.00. Conclusions: Biopsy remains the main diagnostic modality for the characterization of mediastinal lymphadenopathy despite its hazards and limitations. This study proved that MRI could be accepted as an alternative non-invasive imaging tool that can overcome the PET-CT limitations. The lesion signal-to-cord and to-muscle ratios in both T2-WI and DWI-MRI side by side with the mean ADC value showed high statistical accuracy. [ABSTRACT FROM AUTHOR]

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is an imaging technique that has demonstrated high sensitivity and specificity in detecting prostate cancer and its metastasis, especially in the bones. This case describes a 60-year-old man who presented for increased prostate-specific antigen (PSA) level and underwent [68Ga]gallium-PSMA-11 PET/CT imaging for better disease assessment. 68Ga-PSMA-11 PET/CT revealed numerous radiotracer-positive lesions in both prostate lobes with associated sclerotic lesions on L4 and L5, but only L5 showed increased radiotracer avidity raising the possibility of metastasis. Magnetic Resonance Imaging (MRI) raises the possibility of aggressive MODIC type 1 lesion vs. infectious/inflammatory process. A biopsy of the radiotracer avid area was performed and showed no evidence of metastasis. The final diagnosis was aggressive MODIC type 1, in keeping with the false positive result of 68Ga-PSMA-11 PET/CT. This example demonstrates the possible limitations of 68Ga-PSMA-11 PET/CT, particularly in detecting bone metastases, and emphasizes the need for cautious interpretation and additional study to improve its diagnostic accuracy. Understanding and resolving these limitations is critical for increasing the accuracy of PSMA PET/CT in prostate cancer management. [ABSTRACT FROM AUTHOR]

Objective. Head and neck (H&N) cancers are among the most prevalent types of cancer worldwide, and [18F]F-FDG PET/CT is widely used for H&N cancer management. Recently, the diffusion model has demonstrated remarkable performance in various image-generation tasks. In this work, we proposed a 3D diffusion model to accurately perform H&N tumor segmentation from 3D PET and CT volumes. Approach. The 3D diffusion model was developed considering the 3D nature of PET and CT images acquired. During the reverse process, the model utilized a 3D UNet structure and took the concatenation of 3D PET, CT, and Gaussian noise volumes as the network input to generate the tumor mask. Experiments based on the HECKTOR challenge dataset were conducted to evaluate the effectiveness of the proposed diffusion model. Several state-of-the-art techniques based on U-Net and Transformer structures were adopted as the reference methods. Benefits of employing both PET and CT as the network input, as well as further extending the diffusion model from 2D to 3D, were investigated based on various quantitative metrics and qualitative results. Main results. Results showed that the proposed 3D diffusion model could generate more accurate segmentation results compared with other methods (mean Dice of 0.739 compared to less than 0.726 for other methods). Compared to the diffusion model in 2D form, the proposed 3D model yielded superior results (mean Dice of 0.739 compared to 0.669). Our experiments also highlighted the advantage of utilizing dual-modality PET and CT data over only single-modality data for H&N tumor segmentation (with mean Dice less than 0.570). Significance. This work demonstrated the effectiveness of the proposed 3D diffusion model in generating more accurate H&N tumor segmentation masks compared to the other reference methods. [ABSTRACT FROM AUTHOR]

Introduction: Nuclear medicine infection imaging is routinely performed with the use of leukocytes radiolabelled with technetium-99m hexamethylpropyleneamine oxime ([99mTc]Tc-HMPAO) and single-photon emission computed tomography (SPECT). Positron emission tomography (PET) is more sensitive than SPECT and results in higher-quality images. Zirconium-89 (89Zr) is a positron emitter with a half-life of 78.4 h, which translates to the biological half-life and slow biodistribution of intact cells and allows delayed PET imaging for more accurate biodistribution of the labelled leukocytes to infection foci. A first-in-human study with [89Zr]Zr-oxine-leukocytes in four healthy volunteers was reported in 2022. Our first-in-human study utilising the cell surface labelling approach aimed to image infection in patients with the use of 89Zr-labelled leukocytes, using p-isothiocyanatobenzyl-desferrioxamine B (Df-Bz-NCS) as a bifunctional chelating agent, and to compare the scan quality and biodistribution of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes on PET images to SPECT images obtained with [99mTc]Tc-HMPAO-labelled leukocytes. Methods: Leukocytes were isolated from whole-blood samples of eight patients with clinically and/or radiologically confirmed infection. Isolated leukocytes were labelled with [99mTc]Tc-HMPAO according to standardised methods, and [89Zr]Zr-Df-Bz-NCS according to our previously published radiolabelling method. Whole-body SPECT imaging was performed 2 and 18 h post injection of [99mTc]Tc-HMPAO-labelled leukocytes, and whole-body PET/CT was performed 3 and 24 h post injection of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes in seven patients. Results: Successful [89Zr]Zr-Df-Bz-NCS-leukocyte labelling was achieved. High labelling efficiencies were obtained (81.7% ± 3.6%; n = 8). A mean high viability of [89Zr]Zr-Df-Bz-NCS-labelled leukocytes was observed (88.98% ± 12.51%). The [89Zr]Zr-Df-Bz-NCS-leukocyte labelling efficiency was not significantly affected by the white blood cell count of the patient. The performance of [99mTc]Tc-HMPAOand [89Zr]Zr-Df-Bz-NCS-labelled leukocytes, in terms of the ability to accurately detect infection, were similar in two out of seven patients, and [99mTc]Tc-HMPAOlabelled leukocytes outperformed [89Zr]Zr-Df-Bz-NCS-labelled leukocytes in one patient with femoral osteomyelitis. However, in two cases of pulmonary pathology, [89Zr]Zr-Df-Bz-NCS-labelled leukocytes demonstrated improved pathological uptake. No skeletal activity was observed in any of the patients imaged with [89Zr] Zr-Df-Bz-NCS-labelled leukocytes, illustrating the in vivo stability of the radiolabel. Discussion: Although the [89Zr]Zr-Df-Bz-NCS-leukocyte labelling aspect of this study was noteworthy, infection imaging did not yield convincingly positive results due to the pulmonary trapping of intravenously administered [89Zr]Zr-Df-Bz-NCS-labelled leukocytes. [ABSTRACT FROM AUTHOR]

The radiosynthesis of pharmaceutical grade [68Ga]Ga-NODAGA-Lys40-Exendin-4 was accomplished in a fixed tubing-based module, EZ Modular-Lab Standard. Purification of the product via hydrophilic-lipophilic balance cartridge, yielded satisfactory results with radiochemical purity > 98%. The decay-corrected radiochemical yield (RCY) with 50 µg of Exendin-4[Lys40(NODAGA)] was (78.7 ± 0.8)%, which, by far, to the best of our knowledge, is the highest RCY reported till date, using an automated synthesizer. The quality control parameters were in accordance with that of gallium (68Ga) Edotreotide® Injections, featuring in the European Pharmacopoeia. Pre-clinical dosimetry studies in animal models, with co-administration of kidney protectant, demonstrates promising potential of the product towards clinical translation to insulinoma patients. [ABSTRACT FROM AUTHOR]

Background: Primary hyperparathyroidism is a common endocrine disorder characterised by excessive parathormone secretion that results in hypercalcemia, primarily caused by parathyroid adenoma. Accurate localisation of hyperfunctioning tissue is essential for curative surgical treatment. Although conventional imaging modalities like ultrasonography and 99mTc-MIBI scintigraphy (SPECT) along with 18F-fluorocholine PET/CT are commonly employed, there are cases with false-negative imaging results. Case presentation: This case report presents a patient with primary hyperparathyroidism and a parathyroid adenoma detected solely through 68Ga-PSMA-11 PET/CT, typically used for prostate cancer diagnosis. The lesion observed in the PET/CT was confirmed as a parathyroid adenoma through laboratory evaluation, while other imaging techniques failed to detect it. Conclusions: This finding suggests that the PSMA ligands' particular affinity for neovascularisation in focal changes may facilitate the visualisation of parathyroid adenomas. The utilisation of 68Ga-PSMA-11 PET/CT in primary hyperparathyroidism could potentially improve the preoperative localization of parathyroid adenomas when conventional imaging methods are inconclusive. [ABSTRACT FROM AUTHOR]

Background: Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) has been suggested as a useful imaging method for diagnosing cyst infections in patients with autosomal dominant polycystic kidney disease (ADPKD). The aim of this article is to provide evidence-based data in this setting. Methods: A systematic literature review (exploring several bibliographic databases) and a bivariate meta-analysis were carried out to calculate the pooled diagnostic performance of [18F]FDG PET/CT in diagnosing probable cyst infection in ADPKD. Results: Ten studies (282 PET/CT scans and 249 patients) were included in the analysis. The pooled sensitivity and specificity of [18F]FDG PET/CT in this setting were 84.6% (95% confidence interval: 75.4–90.7) and 94.9% (95% confidence interval: 72.6–99.2), respectively, without statistical heterogeneity or significant publication bias. [18F]FDG PET/CT significantly changed patient management in more than half of ADPKD patients with suspected cyst infection. Conclusions: [18F]FDG PET/CT has high performance in diagnosing probable cyst infections in ADPKD patients with an impact on management in the majority of patients. Although more studies are warranted, the provided evidence-based data are an important step towards the integration of [18F]FDG PET/CT in clinical and diagnostic guidelines on probable cyst infection in ADPKD patients. [ABSTRACT FROM AUTHOR]

Non-somatostatin receptor expressing hypovascular insulinomas can be challenging to prove through imaging. This case highlights the utility of a structured approach to molecular imaging in patients with confirmed endogenous hyperinsulinemia. A 54-year-old woman was admitted because of a sudden loss of consciousness. Her relative reported that she complained of dizziness, intense sweating, blurry vision, and upper extremity tingling before becoming unresponsive for 20 min, after which the patient had little recollection of the event. She experienced similar episodes of shorter duration, trouble recalling everyday events, and unintentional weight gain of over 10 kg during the previous two years. Abdominal magnetic resonance imaging (MRI) and multidetector computerized tomography (MDCT) were unremarkable. Selective arterial calcium stimulation significantly increased hepatic venous insulin concentrations when the superior mesenteric and gastroduodenal arteries were stimulated. Technetium-99m (99mTc) octreotide single-photon emission computed tomography (SPECT) did not localize the lesion. Gallium-68 DOTA-Exendin-4 PET/CT acquisition was performed. A single intense 2 cm hyperperfused pancreatic lesion was located anteriorly in the head of the pancreas. Earlier targeted PET/CT imaging and recognition of significant neuropsychiatric symptoms attributable to the patient's hypoglycemic state might have accelerated the resolution of her condition and obviated the need for unnecessary testing. [ABSTRACT FROM AUTHOR]

The accurate estimation of the tracer arterial blood concentration is crucial for reliable quantitative kinetic analysis in PET. In the current work, we demonstrate the automatic extraction of an image-derived input function (IDIF) from a CT AI-based aorta segmentation subsequently resliced to a dynamic PET series acquired on a Siemens Vision Quadra long-axial field of view scanner in 10 human subjects scanned with [15O]H2O. We demonstrate that the extracted IDIF is quantitative and in excellent agreement with a delay- and dispersion-corrected sampled arterial input function (AIF). Perfusion maps in the brain are calculated and compared from the IDIF and AIF, respectively, showed a high degree of correlation. The results demonstrate the possibility of defining a quantitatively correct IDIF compared with AIFs from the new-generation high-sensitivity and high-time-resolution long-axial field-of-view PET/CT scanners. [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is a promising and recently approved treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). The aim of this study was to analyze which laboratory and PET imaging parameters are able to predict biochemical response and overall survival with this treatment. Two quantitative imaging biomarkers were identified that allow prediction of RLT outcome, further improving the pre-therapeutic characterization of mCRPC patients undergoing PSMA-RLT. The aim of this retrospective study was to identify pre-therapeutic predictive laboratory and molecular imaging biomarkers for response and overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT). Pre-therapeutic laboratory and [68Ga]Ga-PSMA-11 PET/CT data of n = 102 mCRPC patients receiving [177Lu]Lu-PSMA-617 RLT within a prospective registry (REALITY Study, NCT04833517) were analyzed including laboratory parameters such as alkaline phosphatase (ALP), prostate-specific antigen (PSA), gamma glutamyl transferase (GGT), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), neuron specific enolase (NSE), hemoglobin (Hb), and imaging parameters such as maximum standardized uptake value of the tumor lesions (SUVmax), the mean standardized uptake value of all tumor lesions (SUVmean), the whole-body molecular tumor volume (MTV), and the whole-body total lesion PSMA (TLP). Mann–Whitney U test, univariate and multivariable Cox-regression were performed to test for association of the parameters with response and OS. The SUVmean of all lesions was significantly different between responders and non-responders (SUVmean responders 8.95 ± 2.83 vs. non-responders 7.88 ± 4.46, p = 0.003), whereas all other tested biochemical and imaging parameters did not reveal significant differences. Hb and the molecular imaging parameters MTV and TLP showed a significant association with OS (p = 0.013, p = 0.005; p = 0.009) in univariant Cox regression; however, only TLP remained significant in multivariable analysis (Hazard ratio 1.033, p = 0.009). This study demonstrates a statistically significant association between the quantitative PET/CT imaging parameter SUVmean and PSA response, as well as between the baseline TLP and OS of mCRPC patients undergoing RLT. [ABSTRACT FROM AUTHOR]

Simple Summary: This review investigates how preprocessing parameters are related to the reproducibility and reliability of radiomic features derived from multimodality imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), cone-beam CT (CBCT), and positron emission tomography (PET)/CT. Radiomics, which involves extracting quantitative features from medical images, shows great potential as a source of non-invasive clinical biomarkers but is hindered by variability in imaging parameters, especially during acquisition, reconstruction, and preprocessing. Standardizing and reporting preprocessing procedures is essential for consistent extraction of radiomic features, given their significant role in determining the robustness and reproducibility of these features. Background: Lately, radiomic studies featuring the development of a signature to use in prediction models in diagnosis or prognosis outcomes have been increasingly published. While the results are shown to be promising, these studies still have many pitfalls and limitations. One of the main issues of these studies is that radiomic features depend on how the images are preprocessed before their computation. Since, in widely known and used software for radiomic features calculation, it is possible to set these preprocessing parameters before the calculation of the radiomic feature, there are ongoing studies assessing the stability and repeatability of radiomic features to find the most suitable preprocessing parameters for every used imaging modality. Materials and Methods: We performed a comprehensive literature search using four electronic databases: PubMed, Cochrane Library, Embase, and Scopus. Mesh terms and free text were modeled in search strategies for databases. The inclusion criteria were studies where preprocessing parameters' influence on feature values and model predictions was addressed. Records lacking information on image acquisition parameters were excluded, and any eligible studies with full-text versions were included in the review process, while conference proceedings and monographs were disregarded. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool to investigate the risk of bias. We synthesized our data in a table divided by the imaging modalities subgroups. Results: After applying the inclusion and exclusion criteria, we selected 43 works. This review examines the impact of preprocessing parameters on the reproducibility and reliability of radiomic features extracted from multimodality imaging (CT, MRI, CBCT, and PET/CT). Standardized preprocessing is crucial for consistent radiomic feature extraction. Key preprocessing steps include voxel resampling, normalization, and discretization, which influence feature robustness and reproducibility. In total, 44% of the included works studied the effects of an isotropic voxel resampling, and most studies opted to employ a discretization strategy. From 2021, several studies started selecting the best set of preprocessing parameters based on models' best performance. As for comparison metrics, ICC was the most used in MRI studies in 58% of the screened works. Conclusions: From our work, we highlighted the need to harmonize the use of preprocessing parameters and their values, especially in light of future studies of prospective studies, which are still lacking in the current literature. [ABSTRACT FROM AUTHOR]

Simple Summary: We present in this study novel data which demonstrates that the most common type of tumor of the salivary glands may be accurately diagnosed using a specific type of radiological imaging. This may be used to help discriminate this tumor or recurrent versions of it amid various types of benign and malignant tumors. Furthermore, this data suggest that new avenues of minimally invasive therapy may be viable for these tumors and potentially even malignant versions of these tumors and should be examined in further studies. Introduction: Currently, the diagnosis of salivary gland tumors using imaging techniques is unreliable. Methods: In this monocentric retrospective study, we examined patients who received a 68Ga-DOTATOC PET/CT and subsequently underwent a salivary gland tumor resection between 1 January 2010 and 31 December 2021. PET/CT image assessment was compared with somatostatin receptor (SSTR) expression and histology. Results: Thirteen patients (five pleomorphic adenoma (PA) and eight other parotid lesions (OPL)) received a 68Ga-DOTATOC PET/CT. Imaging displayed strong focal tracer uptake in all PA except for one with strong tumor to background discrimination. PA revealed higher SUVmax, SUVmean, liver and blood pool quotients than those of Warthin tumors (WT) and of OPL. In comparison to the contralateral parotid, SUVmax (p = 0.02), SUVmean (p = 0.02), liver quotient (p = 0.03) and blood pool quotient (p = 0.03) were all significantly higher. In contrast, WT and OPL showed in relation to the contralateral parotid no significant differences of SUVmax (WT p = 0.79; OPL p = 0.11), SUVmean (WT p = 1.0; OPL p = 0.08), liver quotient (WT p = 0.5; OPL p = 0.08) and blood pool quotient (WT p = 0.8; OPL p = 0.19). Two PA and one granuloma were not available for examination. In the immunohistochemal analysis, all PA demonstrated the highest intensity of SSTR2 expression (grade 3). Furthermore, PA had a high percentage of cells expressing SSTR2 (20%, 80% and 55%). Conclusions: A strong tracer uptake in PA was shown in 68Ga-DOTATOC PET/CT. This may allow physicians to utilize radioligated somatostatin analogue PET CT/MR imaging to accurately diagnose PA. Additionally, it may be possible in the future to treat the PA with a noninvasive peptide receptor radionuclide therapy or with somatostatin analogues. [ABSTRACT FROM AUTHOR]

Background: Enzalutamide is an antiandrogen drug used prior to lutetium-177 prostate specific membrane antigen (Lu-PSMA) radioligand therapy and has shown promising results for upregulating the PSMA expression on prostate cancer cells. In this study, we aim to compare prostate specific antigen (PSA) level changes in prostate cancer patients who received enzalutamide to those who did not. Methods: Prostate cancer patients who underwent Lu-PSMA between 2021 and 2023 were retrospectively included. Patients were grouped based on prior enzalutamide therapy: those who received enzalutamide (EZ+) for at least 14 days and those who did not (EZ−). PSA changes and F-18 DCFPyL SUV (Standardized Uptake Values) were compared. Results: Thirty-seven patients were included, 18 EZ+ and 19 EZ−. The median age, Gleason score, and prior chemo/hormonal therapies were similar for EZ+ and EZ−, except for radium-223. Eleven patients (61%) in EZ+ and 13 patients (68%) in EZ− showed a decrease in PSA after the first cycle (p = 0.64). Four patients (22%) in EZ+ and seven patients (37%) in EZ− had more than 50% decrease in PSA after the first cycle (p = 0.33). The average percent decline at the end of the treatment was 23.3% in EZ+ and 50.4% in EZ− (p = 0.4). There was no difference in terms of lesion with highest SUVmax, mean SUV, total tumor volume or activity on pre-therapy PSMA imaging. Conclusion: Enzalutamide treatment prior to Lu-PSMA does not improve patient outcomes when applied remotely. Larger studies evaluating the combination therapies and the timing of enzalutamide are needed to assess its correlation with Lu-PSMA outcomes. [ABSTRACT FROM AUTHOR]

A 58-year-old female was diagnosed with epithelioid hemangioendothelioma (EHE). The intrahepatic lesion exhibited a "Lollipop sign," associated with capsular retraction. On the PET/CT, there are multiple lesions in the lungs with variable high and low FDG uptake, and focal calcifications are present on CT. Additionally, destruction of the thoracic vertebrae has been observed. [ABSTRACT FROM AUTHOR]

Purpose: Preclinical imaging, with translational potential, lacks a standardized method for defining volumes of interest (VOIs), impacting data reproducibility. The aim of this study was to determine the interobserver variability of VOI sizes and standard uptake values (SUVmean and SUVmax) of different organs using the same [18F]FDG-PET and PET/CT datasets analyzed by multiple observers. In addition, the effect of a standardized analysis approach was evaluated. Procedures: In total, 12 observers (4 beginners and 8 experts) analyzed identical preclinical [18F]FDG-PET-only and PET/CT datasets according to their local default image analysis protocols for multiple organs. Furthermore, a standardized protocol was defined, including detailed information on the respective VOI size and position for multiple organs, and all observers reanalyzed the PET/CT datasets following this protocol. Results: Without standardization, significant differences in the SUVmean and SUVmax were found among the observers. Coregistering CT images with PET images improved the comparability to a limited extent. The introduction of a standardized protocol that details the VOI size and position for multiple organs reduced interobserver variability and enhanced comparability. Conclusions: The protocol offered clear guidelines and was particularly beneficial for beginners, resulting in improved comparability of SUVmean and SUVmax values for various organs. The study suggested that incorporating an additional VOI template could further enhance the comparability of the findings in preclinical imaging analyses. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to explore the feasibility of [68 Ga]pentixafor positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC). Procedures: This prospective study included patients with NPC who underwent [68 Ga]pentixafor PET/CT and 2-[18F]fuoro-2-deoxy-D-glucose ([18F]FDG) PET/CT within one week between November 2022 and March 2023. The [68 Ga]pentixafor and [18F]FDG uptakes in primary and metastatic lesions were measured and compared. Results: Twenty-five participants (21 patients for initial stage and four patients for recurrence detection) were enrolled in our study. The participants underwent [18F]FDG PET/CT and [68 Ga]pentixafor PET/CT. [68 Ga]pentixafor PET/CT had the same detection rate as [18F]FDG for primary tumor (96% vs. 96%). The [68 Ga]pentixafor maximum standard uptake value (SUVmax) and target-to-background ratio (TBR) of primary tumors were lower than those of [18F]FDG (SUVmax: 8.13 ± 2.78 vs. 14.25 ± 6.45; P < 0.01; TBR: 5.17 ± 2.14 vs. 9.81 ± 5.30, P < 0.01). The difference between tumor volume of [68 Ga]pentixafor (TVpentixafor) and tumor volume of [18F]FDG (TVFDG) showed no significance (median: 16.01 vs. 9.56, P = 0.332). In the detection of suspected metastatic cervical lymph nodes (CLNs), [68 Ga]pentixafor PET possessed a lower SUVmax than [18F]FDG PET/CT (SUVmax: 6.86 ± 2.63 vs. 10.39 ± 5.28, P < 0.01), but there was no significant difference in the detection rate between [68 Ga]pentixafor and [18F]FDG PET/CT (96 vs. 98, P = 0.613). Conclusions: [68 Ga]pentixafor is a promising imaging tracer for detecting primary and metastatic NPC. [68 Ga]pentixafor PET/CT is comparable to [18F]FDG PET/CT in the detection rate of primary tumors and metastatic cervical lymph nodes in nasopharyngeal carcinoma, but [68 Ga]pentixafor uptake was heterogeneous. [68 Ga]pentixafor PET/CT may help select patients most likely to benefit from CXCR4-directed endoradiotherapy. Clinical trial registration No.: ChiCTR2200065902 [ABSTRACT FROM AUTHOR]

To evaluate the ability of 18FDG PET/CT, at diagnosis of giant cell arteritis (GCA) and during follow-up, to predict occurrence of relapse in large-vessel GCA (LV-GCA). We conducted a retrospective study using the French Study Group for Large-Vessel Vasculitis (GEFA) network. Data from patients with LV-GCA diagnosed by PET/CT and who had PET/CT in the following year were collected. For each PET/CT, PET vascular activity score (PETVAS) and total vascular score (TVS) were assessed, and their ability to predict the occurrence of subsequent relapse was assessed. A total of 65 LV-GCA patients were included, of whom 55 had undergone a follow-up PET/CT 3 to 12 months after the diagnosis of GCA. Patients for whom the second PET/CT (PET2) was performed during active GCA were excluded. PETVAS and TVS decreased between PET1 and PET2 in all patients (p < 0.001). There was no correlation between vascular activity scores in PET2 and time to prednisone taper. For relapse prediction, at PET1, the AUC of the TVS and PETVAS were respectively 51.9 and 41.9 at 6 months, 55.3 and 49.7 at 1 year, 55 and 55.7 at 2 years. For PET2, the AUC were respectively 46.1 and 46.7 at 6 months, 52.1 and 48.9 at 1 year, 58.4 and 52.3 at 2 years. PET vascular activity scores at diagnosis and at follow-up PET/CT performed outside a period of GCA activity do not display high performance to predict the occurrence of subsequent relapse in LV-GCA patients. [ABSTRACT FROM AUTHOR]

Purpose: An accurate diagnosis of thymic malignancies is important, but challenging due to the broad range of differential diagnoses. This study aims to evaluate the efficacy of PET/CT and tumor markers for diagnosing thymic malignancies. Methods: Patients admitted to our department between January 2012 and December 2021 with primary anterior mediastinal tumors were retrospectively evaluated. We evaluated the relationship between the maximum standardized uptake value (SUVmax), tumor markers, and pathological diagnosis in four groups: thymic carcinoma, thymoma, lymphoma, and others. Results: In total, 139 patients were included in this study. The SUVmax was significantly higher in lymphoma, thymic carcinoma, and thymoma, in that order. The cytokeratin 19 fragment (CYFRA 21-1) was significantly higher in thymic carcinoma than in the other groups. An ROC curve analysis indicated that the optimal cut-off values of SUVmax for thymic carcinoma plus lymphoma and CYFRA 21-1 for thymic carcinoma were 7.97 (AUC = 0.934) and 2.95 (AUC = 0.768), respectively. Using a combination of cut-off values (SUVmax = 8, CYFRA 21-1 = 3), the accuracy rate for diagnosing thymic carcinoma was 91.4%. Conclusions: The SUVmax and CYFRA 21-1 levels are significant indicators for the diagnosis of thymic carcinoma. Combining these indicators resulted in a more accurate diagnosis of thymic malignancies, which could facilitate the decision-making process for determining the optimal treatment strategies. [ABSTRACT FROM AUTHOR]

Background and Objectives: The overall- and progression-free survival rates of Hodgkin's lymphoma patients have improved. Our goal was to examine the changes in our treatment results and their causes depending on the daily diagnostic and therapeutic practice. Materials and Methods: We analysed data of 776 classical Hodgkin lymphoma patients treated between 1980 and 2019. Patient data were investigated in ten-year periods (first period: 1980–1989, second period: 1990–1999, third period: 2000–2009, and fourth period: 2010–2019). Results: Radiotherapy alone as a first-line treatment was used progressively less often, and in the 4th period it was no longer used before or without chemotherapy. The use of combined chemo- and radiotherapy decreased in the last period, and the number of those patients who received only chemotherapy increased significantly. The 10-year overall survival improved significantly from 1990 to 1999 compared to 2010 to 2019 (74.9% vs. 86.9%). About 30% of patients relapsed after or were refractory to first-line therapy in each period. The incidence of relapse in the last period did not increase after two years, but there was no significant difference between the periods. Conclusions: Overall survival rates of HL patients have improved significantly in recent decades, which is due to improved diagnostic methods and modern therapies. Progression-free survival is unchanged; one-third of patients relapse or are refractory to first-line treatment within the first two years. Early recognition of R/R patients, the early application of newer and already available innovative therapies, and the finding of additional new and effective therapies are of particular importance. [ABSTRACT FROM AUTHOR]

Background: To investigate the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) semi-quantitative parameters, including the lesion diameter, maximum standardized uptake value (SUVmax), maximum standardized uptake value corrected for lean body mass (SULmax), metabolic lesion volume (MLV), and total lesion glycolysis (TLG), for classifying hepatic echinococcosis. Methods: In total, 20 patients with 36 hepatic echinococcosis lesions were included in the study. Overall, these lesions were categorized as hepatic cystic echinococcosis (HCE) or hepatic alveolar echinococcosis (HAE) according to the pathological results. Multiple semi-parameters including the maximum diameter, SUVmax, SULmax, MLV, and TLG were measured to classify HCE and HAE compared with the pathological results. The receiver operator characteristic curve and area under the curve (AUC) of each quantitative parameter were calculated. The Mann–Whitney U test was used to compare data between the two groups. Results: In total, 12 cystic lesions and 24 alveolar lesions were identified after surgery. There were significant differences in SUV max, SUL max, MLV, and TLG between the HAE and HCE groups (Z = − 4.70, − 4.77, − 3.36, and − 4.23, respectively, all P < 0.05). There was no significant difference in the maximum lesion diameter between the two groups (Z = − 0.77, P > 0.05). The best cutoffs of SUV max, SUL max, MLV, and TLG for the differential diagnosis of HAE and HCE were 2.09, 2.67, 27.12, and 18.79, respectively. The AUCs of the four parameters were 0.99, 0.99, 0.85, and 0.94, respectively. The sensitivities were 91.7%, 87.5%, 66.7%, and 85.6%, respectively, and the specificities were 90.1%, 91.7%, 83.3%, and 90.9%, respectively. Conclusion: 18F-FDG PET/CT semi-quantitative parameters had significant clinical value in the diagnosis and pathological classification of hepatic echinococcosis and evaluation of clinical treatment. [ABSTRACT FROM AUTHOR]

Purpose: Effective radiation therapy requires accurate segmentation of head and neck cancer, one of the most common types of cancer. With the advancement of deep learning, people have come up with various methods that use positron emission tomography-computed tomography to get complementary information. However, these approaches are computationally expensive because of the separation of feature extraction and fusion functions and do not make use of the high sensitivity of PET. We propose a new deep learning-based approach to alleviate these challenges. Methods: We proposed a tumor region attention module that fully exploits the high sensitivity of PET and designed a network that learns the correlation between the PET and CT features using squeeze-and-excitation normalization (SE Norm) without separating the feature extraction and fusion functions. In addition, we introduce multi-scale context fusion, which exploits contextual information from different scales. Results: The HECKTOR challenge 2021 dataset was used for training and testing. The proposed model outperformed the state-of-the-art models for medical image segmentation; in particular, the dice similarity coefficient increased by 8.78% compared to U-net. Conclusion: The proposed network segmented the complex shape of the tumor better than the state-of-the-art medical image segmentation methods, accurately distinguishing between tumor and non-tumor regions. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the difference in the diagnostic efficacy of 18F-PSMA-1007 PET/CT and pelvic MRI in primary prostate cancer, as well as the correlation between the two methods and histopathological parameters and serum PSA levels. Methods: A total of 41 patients with suspected prostate cancer who underwent 18F-PSMA-1007 PET/CT imaging in our department from 2018 to 2023 were retrospectively collected. All patients underwent 18F-PSMA-1007 PET/CT and MRI scans. The sensitivity, PPV and diagnostic accuracy of MRI and 18F-PSMA-1007 PET/CT in the diagnosis of prostate cancer were calculated after comparing the results of MRI and 18F-PSMA-1007 PET/CT with biopsy. The Spearman test was used to calculate the correlation between 18F-PSMA-1007 PET/CT, MRI parameters, histopathological indicators, and serum PSA levels. Results: Compared with histopathological results, the sensitivity, PPV and diagnostic accuracy of 18F-PSMA-1007 PET/CT in the diagnosis of prostate cancer were 95.1%, 100.0% and 95.1%, respectively. The sensitivity, PPV and diagnostic accuracy of MRI in the diagnosis of prostate cancer were 82.9%, 100.0% and 82.9%, respectively. There was a mild to moderately positive correlation between Gleason (Gs) score, Ki-67 index, serum PSA level and 18F-PSMA-1007 PET/CT parameters (p < 0.05). There was a moderately negative correlation between the expression of AMACR (P504S) and 18F-PSMA-1007 PET/CT parameters (p < 0.05). The serum PSA level and the Gs score were moderately positively correlated with the MRI parameters (p < 0.05). There was no correlation between histopathological parameters and MRI parameters (p > 0.05). Conclusion: Compared with MRI, 18F-PSMA-1007 PET/CT has higher sensitivity and diagnostic accuracy in the detection of malignant prostate tumors. In addition, the Ki-67 index and AMACR (P504S) expression were only correlated with 18F-PSMA-1007 PET/CT parameters. Gs score and serum PSA level were correlated with 18F-PSMA-1007 PET/CT and MRI parameters. 18F-PSMA-1007 PET/CT examination can provide certain reference values for the clinical diagnosis, evaluation, and treatment of malignant prostate tumors. [ABSTRACT FROM AUTHOR]

Primary thyroid squamous cell carcinoma is extremely rare. We report a case of primary thyroid squamous cell carcinoma diagnosed using 18F-FDG PET/CT. The patient presented with left axillary lymphadenopathy as the initial symptom. Fine-needle aspiration of the axillary lymph nodes indicated metastatic squamous cell carcinoma. To identify the primary tumor, the patient underwent an 18F-FDG PET/CT scan, which revealed a mass in the thyroid and multiple enlarged lymph nodes with abnormal FDG uptake. Pathological examination of the axillary lymph nodes and thyroid biopsy confirmed the diagnosis of primary thyroid squamous cell carcinoma with lymph node metastasis. [ABSTRACT FROM AUTHOR]

Background: Low-dose ungated CT is commonly used for total-body PET attenuation and scatter correction (ASC). However, CT-based ASC (CT-ASC) is limited by radiation dose risks of CT examinations, propagation of CT-based artifacts and potential mismatches between PET and CT. We demonstrate the feasibility of direct ASC for multi-tracer total-body PET in the image domain. Methods: Clinical uEXPLORER total-body PET/CT datasets of [18F]FDG (N = 52), [18F]FAPI (N = 46) and [68Ga]FAPI (N = 60) were retrospectively enrolled in this study. We developed an improved 3D conditional generative adversarial network (cGAN) to directly estimate attenuation and scatter-corrected PET images from non-attenuation and scatter-corrected (NASC) PET images. The feasibility of the proposed 3D cGAN-based ASC was validated using four training strategies: (1) Paired 3D NASC and CT-ASC PET images from three tracers were pooled into one centralized server (CZ-ASC). (2) Paired 3D NASC and CT-ASC PET images from each tracer were individually used (DL-ASC). (3) Paired NASC and CT-ASC PET images from one tracer ([18F]FDG) were used to train the networks, while the other two tracers were used for testing without fine-tuning (NFT-ASC). (4) The pre-trained networks of (3) were fine-tuned with two other tracers individually (FT-ASC). We trained all networks in fivefold cross-validation. The performance of all ASC methods was evaluated by qualitative and quantitative metrics using CT-ASC as the reference. Results: CZ-ASC, DL-ASC and FT-ASC showed comparable visual quality with CT-ASC for all tracers. CZ-ASC and DL-ASC resulted in a normalized mean absolute error (NMAE) of 8.51 ± 7.32% versus 7.36 ± 6.77% (p < 0.05), outperforming NASC (p < 0.0001) in [18F]FDG dataset. CZ-ASC, FT-ASC and DL-ASC led to NMAE of 6.44 ± 7.02%, 6.55 ± 5.89%, and 7.25 ± 6.33% in [18F]FAPI dataset, and NMAE of 5.53 ± 3.99%, 5.60 ± 4.02%, and 5.68 ± 4.12% in [68Ga]FAPI dataset, respectively. CZ-ASC, FT-ASC and DL-ASC were superior to NASC (p < 0.0001) and NFT-ASC (p < 0.0001) in terms of NMAE results. Conclusions: CZ-ASC, DL-ASC and FT-ASC demonstrated the feasibility of providing accurate and robust ASC for multi-tracer total-body PET, thereby reducing the radiation hazards to patients from redundant CT examinations. CZ-ASC and FT-ASC could outperform DL-ASC for cross-tracer total-body PET AC. [ABSTRACT FROM AUTHOR]

Purpose: Altered 18F-fluorodeoxyglucose (FDG) biodistribution due to patient factors such as exercise and inadequate fasting are well established causes of limited diagnostic efficacy. In addition, medications such as G-CSF are known to affect uptake of FDG by bone marrow and spleen. In this study, we present a case of increased white adipose uptake in a pediatric lymphoma patient who recently received high dose dexamethasone and review the relevant literature regarding this rare and poorly understood pattern of altered FDG biodistribution. Methods: A 14-year-old male patient diagnosed with B-cell lymphoblastic lymphoma underwent FDG-PET/CT for restaging shortly after completing an induction chemotherapy regimen. Images revealed diffuse FDG uptake localizing to white adipose tissue, attributed to the 29-day course of dexamethasone which was completed two days prior. A diagnostically adequate study with relative normalization of FDG biodistribution was obtained seven days later. Results: In our review of the literature, diffuse FDG uptake by white fat is a rare occurrence and has only been reported by a few case reports and early observational studies. In addition to patients receiving corticosteroids, other cases of medication-induced adipose remodeling such as patients receiving highly active antiretroviral therapy have been documented with similar patterns of increased white adipose tissue activity. Conclusion: Corticosteroid-induced white fat uptake of FDG is a rare phenomenon that can limit diagnostic accuracy of FDG-PET/CT and necessitate repeat imaging. Current evidence suggests that a wait period of at least one week after discontinuation of corticosteroids is sufficient to allow for decreased white fat uptake and increased diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Simple Summary: Rectal cancer (RC) is a prevalent malignancy associated with significant morbidity and mortality. Accurate staging is crucial for optimal treatment and patient outcomes. This review examines current literature on imaging and metabolic diagnostic methods for RC staging. Key imaging techniques include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI is the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and extramural vascular invasion. CT is essential for detecting distant metastases and evaluating surgical resectability. ERUS provides detailed assessment of tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each modality is vital for precise staging and treatment planning. Integrating multiple imaging and metabolic techniques, such as PET/CT or PET/MRI, enhances diagnostic accuracy and prognostic evaluation. This review assesses the effectiveness and accuracy of these diagnostic methods in RC staging. Rectal cancer (RC) is a prevalent malignancy with significant morbidity and mortality rates. The accurate staging of RC is crucial for optimal treatment planning and patient outcomes. This review aims to summarize the current literature on imaging and metabolic diagnostic methods used in the stage assessment of RC. Various imaging modalities play a pivotal role in the initial evaluation and staging of RC. These include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI has emerged as the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and the presence of extramural vascular invasion. CT imaging provides valuable information about distant metastases and helps determine the feasibility of surgical resection. ERUS aids in assessing tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each diagnostic modality is essential for accurate staging and treatment decisions in RC. Furthermore, the integration of multiple imaging and metabolic methods, such as PET/CT or PET/MRI, can enhance diagnostic accuracy and provide valuable prognostic information. Thus, a literature review was conducted to investigate and assess the effectiveness and accuracy of diagnostic methods, both imaging and metabolic, in the stage assessment of RC. [ABSTRACT FROM AUTHOR]

Simple Summary: The 18F-FDG PET parameters reflecting the intensity and distribution of glucose uptake by the tumor are associated with prognosis in non-small-cell lung cancer (NSCLC) patients. We developed and evaluated an imaging-based model utilizing these 18F-FDG PET-derived features for predicting the five-year survival in NSCLC patients after curative surgery. The PET-based risk score constructed using the LASSO logistic method outperformed the predictive performances of individual 18F-FDG PET parameters. The PET-based risk score was an independent prognostic factor for clinical variables. Additionally, it demonstrated better predictive performance when combined with clinical variables. The FDG PET-based imaging model could aid in risk stratification for personalized adjuvant treatment and follow-up management of NSCLC patients after surgery. The aim of our retrospective study is to develop and assess an imaging-based model utilizing 18F-FDG PET parameters for predicting the five-year survival in non-small-cell lung cancer (NSCLC) patients after curative surgery. A total of 361 NSCLC patients who underwent curative surgery were assigned to the training set (n = 253) and the test set (n = 108). The LASSO regression model was used to construct a PET-based risk score for predicting five-year survival. A hybrid model that combined the PET-based risk score and clinical variables was developed using multivariate logistic regression analysis. The predictive performance was determined by the area under the curve (AUC). The individual features with the best predictive performances were co-occurrence_contrast (AUC = 0.675) and SUL peak (AUC = 0.671). The PET-based risk score was identified as an independent predictor after adjusting for clinical variables (OR 5.231, 95% CI 1.987–6.932; p = 0.009). The hybrid model, which integrated clinical variables, significantly outperformed the PET-based risk score alone in predictive accuracy (AUC = 0.771 vs. 0.696, p = 0.022), a finding that was consistent in the test set. The PET-based risk score, especially when integrated with clinical variables, demonstrates good predictive ability for five-year survival in NSCLC patients following curative surgery. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate semi-quantitatively the diagnostic performance of PET/CT metabolic parameters in differentiating benign or malignant cardiac or pericardial masses. A total of forty-one patients with newly diagnosed cardiac/pericardial masses who underwent 18F-FDG PET/CT were recruited. PET/CT metabolic parameters including the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), total lesion glycolysis (TLG), tumor metabolic volume (MTV), the maximum tumor-to-mediastinal background ratio (TMR) and the maximum tumor-to-liver background ratio (TLR) is measured or calculated to evaluate the benign or malignant nature of cardiac/pericardial masses. Compared with benign cardiac/pericardial lesions, cardiac/pericardial malignancies had higher SUVmax, SUVmean, TLG, MTV, TMR, and TLR. All these PET/CT metabolic parameters showed high diagnostic performance in semi-quantitative evaluation of benign or malignant cardiac or pericardial masses, and SUVmean and MTV had the highest diagnostic accuracy. Therefore, PET/CT metabolic parameters can semi-quantitatively evaluate the benign or malignant cardiac/pericardial masses. [ABSTRACT FROM AUTHOR]

Purpose: Patients with fever and inflammation of unknown origin (FUO/IUO) are clinically challenging due to variable clinical presentations with nonspecific symptoms and many differential diagnoses. Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is increasingly used in FUO and IUO, but the optimal diagnostic strategy remains controversial. This consensus document aims to assist clinicians and nuclear medicine specialists in the appropriate use of [18F]FDG-PET/CT in FUO and IUO based on current evidence. Methods: A working group created by the EANM infection and inflammation committee performed a systematic literature search based on PICOs with "patients with FUO/IUO" as population, "[18F]FDG-PET/CT" as intervention, and several outcomes including pre-scan characteristics, scan protocol, diagnostic yield, impact on management, prognosis, and cost-effectiveness. Results: We included 68 articles published from 2001 to 2023: 9 systematic reviews, 49 original papers on general adult populations, and 10 original papers on specific populations. All papers were analysed and included in the evidence-based recommendations. Conclusion: FUO and IUO remains a clinical challenge and [18F]FDG PET/CT has a definite role in the diagnostic pathway with an overall diagnostic yield or helpfulness in 50–60% of patients. A positive scan is often contributory by directly guiding treatment or subsequent diagnostic procedure. However, a negative scan may be equally important by excluding focal disease and predicting a favorable prognosis. Similar results are obtained in specific populations such as ICU-patients, children and HIV-patients. [ABSTRACT FROM AUTHOR]

Purpose: Toludesvenlafaxine is a recently developed antidepressant that belongs to the triple reuptake inhibitor class. Despite the in vitro evidence that toludesvenlafaxine inhibits the reuptake of serotonin (5-HT), norepinephrine (NE) and dopamine (DA), there is no in vivo evidence that toludesvenlafaxine binds to DAT and increases DA level, a mechanism thought to contribute to its favorable clinical performance. Methods: Positron emission tomography/computed tomography (PET/CT) was used to examine the DAT binding capacity in healthy rats and human subjects and microdialysis was used to examine the striatal DA level in rats. [18F]FECNT and [11C]CFT were used as PET/CT radioactive tracer for rat and human studies, respectively. Results: In rats, 9 mg/kg of toludesvenlafaxine hydrochloride (i.v.) followed by an infusion of 3 mg/kg via minipump led to the binding rate to striatum DAT at 3.7 – 32.41% and to hypothalamus DAT at 5.91 – 17.52% during the 45 min scanning period. 32 mg/kg oral administration with toludesvenlafaxine hydrochloride significantly increased the striatal DA level with the AUC0 − 180 min increased by 63.9%. In healthy volunteers, 160 mg daily toludesvenlafaxine hydrochloride sustained-release tablets for 4 days led to an average occupancy rates of DAT at 8.04% ± 7.75% and 8.09% ± 7.00%, respectively, in basal ganglion 6 h and 10 h postdose. Conclusion: These results represent the first to confirm the binding of toludesvenlafaxine to DAT in both rats and humans using PET/CT, and its elevation of brain DA level, which may help understand the unique pharmacological and functional effects of triple reuptake inhibitors such as toludesvenlafaxine. ClinicalTrials.gov identifiers: : NCT05905120. Registered 14 June 2023. (retrospectively registered). [ABSTRACT FROM AUTHOR]

Background: Circulating-tumor DNA (ctDNA) and prostate-specific membrane antigen (PSMA) ligand positron-emission tomography (PET) enable minimal-invasive prostate cancer (PCa) detection and survival prognostication. The present study aims to compare their tumor discovery abilities and prognostic values. Methods: One hundred thirty men with confirmed PCa (70.5 ± 8.0 years) who underwent [68Ga]Ga-PSMA-11 PET/CT (184.8 ± 19.7 MBq) imaging and plasma sample collection (March 2019–August 2021) were included. Plasma-extracted cell-free DNA was subjected to whole-genome-based ctDNA analysis. PSMA-positive tumor lesions were delineated and their quantitative parameters extracted. ctDNA and PSMA PET/CT discovery rates were compared, and the prognostic value for overall survival (OS) was evaluated. Results: PSMA PET discovery rates according to castration status and PSA ranges did differ significantly (P = 0.013, P < 0.001), while ctDNA discovery rates did not (P = 0.311, P = 0.123). ctDNA discovery rates differed between localized and metastatic disease (P = 0.013). Correlations between ctDNA concentrations and PSMA-positive tumor volume (PSMA-TV) were significant in all (r = 0.42, P < 0.001) and castration-resistant (r = 0.65, P < 0.001), however not in hormone-sensitive patients (r = 0.15, P = 0.249). PSMA-TV and ctDNA levels were associated with survival outcomes in the Logrank (P < 0.0001, P < 0.0001) and multivariate Cox regression analysis (P = 0.0023, P < 0.0001). Conclusion: These findings suggest that PSMA PET imaging outperforms ctDNA analysis in detecting prostate cancer across the whole spectrum of disease, while both modalities are independently highly prognostic for survival outcomes. [ABSTRACT FROM AUTHOR]

Introduction: There is much literature about the role of 2-[18F]FDG PET/CT in patients with breast cancer (BC). However, there exists no international guideline with involvement of the nuclear medicine societies about this subject. Purpose: To provide an organized, international, state-of-the-art, and multidisciplinary guideline, led by experts of two nuclear medicine societies (EANM and SNMMI) and representation of important societies in the field of BC (ACR, ESSO, ESTRO, EUSOBI/ESR, and EUSOMA). Methods: Literature review and expert discussion were performed with the aim of collecting updated information regarding the role of 2-[18F]FDG PET/CT in patients with no special type (NST) BC and summarizing its indications according to scientific evidence. Recommendations were scored according to the National Institute for Health and Care Excellence (NICE) criteria. Results: Quantitative PET features (SUV, MTV, TLG) are valuable prognostic parameters. In baseline staging, 2-[18F]FDG PET/CT plays a role from stage IIB through stage IV. When assessing response to therapy, 2-[18F]FDG PET/CT should be performed on certified scanners, and reported either according to PERCIST, EORTC PET, or EANM immunotherapy response criteria, as appropriate. 2-[18F]FDG PET/CT may be useful to assess early metabolic response, particularly in non-metastatic triple-negative and HER2+ tumours. 2-[18F]FDG PET/CT is useful to detect the site and extent of recurrence when conventional imaging methods are equivocal and when there is clinical and/or laboratorial suspicion of relapse. Recent developments are promising. Conclusion: 2-[18F]FDG PET/CT is extremely useful in BC management, as supported by extensive evidence of its utility compared to other imaging modalities in several clinical scenarios. [ABSTRACT FROM AUTHOR]

Purpose: The 68Ga/177Lu-FAP-2286 is a newly developed tumor imaging agent that shows potential for visualizing and treating tumor stroma. The objective of this research was to evaluate the effectiveness of 68Ga-FAP-2286 PET/CT and 18F-FDG PET/CT in diagnosing advanced lung cancer. Methods: In this prospective study, patients with lung cancer who underwent 68Ga-FAP-2286 and 18F-FDG PET/CT examinations between September 2022 and June 2023 were analyzed. Lesion uptake was converted to SUVmax. A paired T-test was used to compare the SUVmax, and the number of positive lesions detected by the two methods was recorded. Results: In total, 31 participants (median age: 56 years) were assessed. The uptake of 68Ga-FAP-2286 was significantly higher than that of 18F-FDG in primary lesions (9.90 ± 5.61 vs. 6.09 ± 2.84, respectively, P < 0.001), lymph nodes (7.95 ± 2.75 vs. 5.55 ± 1.59, respectively, P=0.01), and bone metastases (7.74 ± 3.72 vs. 5.66 ± 3.55, respectively, P=0.04). Furthermore, the detection sensitivity of lymph nodes using 68Ga-FAP-2286 PET/CT was superior to that with 18F-FDG PET/CT [100% (137/137) vs. 78.8% (108/137), respectively], as well as for bonemetastases [100% (384/384) vs. 68.5% (263/384), respectively]. However, the detection sensitivity for primary tumors using both modalities was comparable [100% (13/13) for both]. Conclusion: Compared to 18F-FDG PET/CT, 68Ga-FAP-2286 PET/CT demonstrated better lesion detection capabilities for lung cancer, particularly in lymph nodes and bone metastases, providing compelling imaging evidence for the efficacy of 177Lu-FAP-2286 treatment. [ABSTRACT FROM AUTHOR]

Background: Subtype diagnosis of primary aldosteronism (PA) is used to determine treatment, and the potential utility of 68Ga-pentixafor PET/CT for investigation of PA has long been recognized. The study aimed to evaluate the clinical value of 68Ga-pentixafor PET/CT in the diagnosis and prognosis of patients with bilateral lesions identified by CT. Methods: In total, 25 patients with PA and bilateral lesions on CT were retrospectively evaluated. All patients underwent 68Ga-Pentixafor PET/CT and adrenal vein sampling. The analysis focused on establishing the relationship between bilateral adrenal lesions SUVmax and the ratio of bilateral adrenal lesions SUVmax (CON) and clinical diagnosis, treatment outcomes, and KCNJ5 gene status. Results: The concordance rate between 68Ga-Pentixafor PET/CT and adrenal venous sampling was 65.2% (15/23). The lateralization results of 68Ga-pentixafor PET/CT supported the clinical decisions of 20 patients with PA, 90% of whom showed effectiveness in treatment. The SUVmax on the dominant side of the surgically treated patients was higher than that of patients treated with drugs. The SUVmax of the KCNJ5 mutant group was higher than that of the KCNJ5 wild group, and 68Ga-Pentixafor uptake was correlated with KCNJ5 gene status. Conclusions: 68Ga-Pentixafor PET/CT proves beneficial for patients with PA with bilateral lesions on CT. The treatment is generally effective based on the results of PET lateralization. Simultaneously, a certain relationship exists between 68Ga-Pentixafor PET/CT and KCNJ5 gene status, warranting further analysis. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to analyze articles on the diagnosis and treatment of bone and soft tissue sarcoma using positron emission tomography (PET)/ computed tomography (CT) published in the last 13 years. The objective was to conduct a bibliometric analysis and identify the research hotspots and emerging trends. Methods: Web of Science was used to search for articles on PET/CT diagnosis and treatment of bone and soft tissue sarcoma published from January 2010 to June 2023. CiteSpace was utilized to import data for bibliometric analysis. Results: In total, 425 relevant publications were identified. Publications have maintained a relatively stable growth rate for the past 13 years. The USA has the highest number of published articles (139) and the highest centrality (0.35). The UDICE-French Research Universities group is the most influential institution. BYUN BH is a prominent contributor to this field. The Journal of Clinical Oncology has the highest impact factor in the field. Conclusion: The clinical application of PET/CT is currently a research hotspot. Upcoming areas of study concentrate on the merging of PET/CT with advanced machine learning and/or alternative imaging methods, novel imaging substances, and the fusion of diagnosis and therapy. The use of PET/CT has progressively become a crucial element in the identification and management of sarcomas. To confirm its efficacy, there is a need for extensive, multicenter, prospective studies. [ABSTRACT FROM AUTHOR]

An 82-year-old woman with a known chronic small "clot" in the heart presented with rapidly progressive dyspnea. A [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) and cardiac-MRI demonstrated rapid enlargement of the right ventricular presumed clot now expanding and obliterating the right ventricular cavity. Patient continued to deteriorate despite urgent cardiac surgery to remove the mass and died 8 days later. Cardiac explant pathology demonstrated phyllodes tumor. [ABSTRACT FROM AUTHOR]

Introduction: Data acquisition and image reconstruction protocols affect image quality and quantification accuracy in PET imaging. We aimed to standardize and optimize image acquisition, and reconstruction parameter sets using a simultaneous quantitative and qualitative assessment framework for a lutetium oxyorthosilicate (LSO)-based PET/CT scanner. Methods: The NEMA IEC Body Phantom acquisition was performed in list mode for 10 minutes with four spheres to background ratios (SBRs). Raw PET data were reconstructed using 60 different protocols. Image quality was evaluated for standardization using contrast, CNR, and noise. Recovery coefficient (RC) measurements were performed for different common VOI definitions. Results: No significant differences were observed between RCs for various acquisition durations. The contrast to noise ratio (CNR) increased at all SBRs by expanding the acquisition duration from 60 to 600 seconds. PET scan time was reduced to 90 seconds per bed position while preserving image quality. Up to 50% improvement in CNR for the highest sub-iteration with a high level of smoothing was observed. PSF-based reconstruction produced a positive bias of RCmax in high SBRs (8 and 10) using higher sub-iterations (30 to 60) with Gaussian filters less than 6 mm FWHM. Moreover, a Sub-iteration of more than 32 with a 4-6 mm FWHM Gaussian filter provides optimized reconstruction sets. Conclusion: Our study demonstrates it would be feasible for PET image acquisition and reconstruction settings to simultaneously allow optimal lesion detection with high image quality while providing accurate quantification. [ABSTRACT FROM AUTHOR]

Introduction: Suspected infection or inflammation of unknown origin in in-patients remains challenging. Literature on [18F]FDG-PET/CT is abundant in classic fever of unknown origin (FUO), but evidence is complex and may not always reflect clinical reality. This study explores the application of [18F]FDG-PET/CT in a diverse clinical population of in-patients with suspected infection not defined by stringent FUO-criteria. Methods: Retrospective chart review of consecutive in-patients who underwent [18F]FDG-PET/CT in the workup of suspected infection or inflammation from 1 July 2022 to 31 December 2022 was conducted. We evaluated indications, diagnostic yield, and clinical impact of [18F]FDG-PET/CT, and compared the findings of [18F]FDG-PET/CT and stand-alone CT. Univariate logistic regression assessed associations between [18F]FDG-PET/CT outcome and clinical parameters. Receiver operating characteristic curve (ROC) analysis evaluated diagnostic performance. Results: 77 patients met the inclusion criteria. [18F]FDG-PET/CT established a diagnosis in 35% of cases, ruled out focal infection in 26%, and thus was helpful in 61% of patients. It prompted 72 additional examinations resulting in seven incidental diagnoses, including two cancers. Antibiotic treatment was changed in 26% of cases. Regression analysis found white blood cell counts (WBC) associated with true positive outcomes. [18F]FDG-PET/CT was compared to stand-alone CT findings, and was concordant in 69% of cases. Conclusions: Results were comparable to findings in more classic FUO. [18F]FDG-PET/CT was clinically helpful in 61% of cases but also prompted many additional examinations with relatively few clinically important findings. WBC count was a predictor of true positive outcome. CT and [18F]FDG-PET/CT were discordant in 31%, of cases, especially in cases of endocarditis and spondylodiscitis. [ABSTRACT FROM AUTHOR]

Molecular imaging modalities show valuable non-invasive techniques capable of precisely and selectively addressing molecular markers associated with prostate cancer (PCa). This systematic review provides an overview of imaging markers utilized in positron emission tomography (PET) methods, specifically focusing on the pathways and mediators involved in PCa. This systematic review aims to evaluate and analyse existing literature on the diagnostic accuracy of molecular imaging techniques for detecting PCa. The PubMed, EBSCO, ScienceDirect, and Web of Science databases were searched, identifying 32 studies that reported molecular imaging modalities for detecting PCa. Numerous imaging modalities and radiotracers were used to detect PCa, including 68Ga-prostate-specific membrane antigen (PSMA) PET/computed tomography (CT), 68Ga-PSMA-11 PET/magnetic resonance imaging (MRI), 18F-PSMA-1007 PET/CT, 18F-DCFPyL PET/MRI, 18F-choline PET/MRI, and 18F-fluoroethylcholine PET/MRI. Across 11 studies, radiolabelled 68Ga-PSMA PET/CT imaging had a pooled sensitivity of 80 (95% confidence interval [CI]: 35–93), specificity of 90 (95% CI: 71–98), and accuracy of 86 (95% CI: 64–96). The PSMA-ligand 68Ga-PET/CT showed good diagnostic performance and appears promising for detecting and staging PCa. [ABSTRACT FROM AUTHOR]

Purpose: This systematic review aims to investigate the role of nuclear imaging techniques in detecting incidentalomas and their impact on patient management. Methods: Following PRISMA guidelines, a comprehensive literature search was conducted from February to May 2022. Studies in English involving patients undergoing nuclear medicine studies with incidental tumor findings were included. Data on imaging modalities, incidentaloma characteristics, management changes, and follow-up were extracted and analyzed. Results: Ninety-two studies involving 64.884 patients were included. Incidentalomas were detected in 611 cases (0.9%), with thyroid being the most common site. PET/CT with FDG and choline tracers showed the highest incidentaloma detection rates. Detection of incidentalomas led to a change in therapeutic strategy in 59% of cases. Various radiotracers demonstrated high sensitivity for incidentaloma detection, particularly in neuroendocrine tumors and prostate cancer. Conclusion: Nuclear imaging techniques play a crucial role in detecting incidentalomas, leading to significant changes in patient management. The high sensitivity of these modalities highlights their potential in routine oncology follow-up protocols. Future directions may include enhancing spatial resolution and promoting theranostic approaches for improved patient care. [ABSTRACT FROM AUTHOR]

Background: Oral cancer is one of the most common malignancies in the head and neck region. Approximately 90% of oral cancers are oral squamous cell carcinomas (OSCC). 18F‐FDG PET/CT has been used in OSCC patients for its high value in detecting metastatic lymph nodes and distant metastases. PET radiomics and sarcopenia can be measured on the PET and CT components of 18F‐FDG PET/CT. Purpose: This study aimed to investigate the prognostic value of radiomics and sarcopenia measured on the PET and CT components of pre‐operation 18F‐FDG PET/CT in OSCC. Methods: A total of 116 patients eventually enrolled in our study were randomly divided into two cohorts: training cohort (n = 58) and validation cohort (n = 58). The Cox model combined with the least absolute shrinkage and selection operator (LASSO) algorithm was applied to construct the radiomics score (Rad_score). The third lumber skeletal muscle index (L3 SMI) was calculated to identify sarcopenia. Univariate and multivariate Cox regression analyses were performed to identify the independent prognostic factors. Based on the clinical factors, the clinical model was constructed, and the combined model was developed through the combination of the clinical model and Rad_score. C index, time‐dependent C‐index curves, receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis were used to evaluate the performance of prediction models. Results: Three radiomics features constitute the Rad_score for overall survival (OS) and progression‐free survival (PFS), respectively. Multivariate Cox regression analysis revealed that Rad_score was an independent prognostic factor, whereas sarcopenia was not. The combined models showed satisfactory performance in both the training cohort (C‐index: OS:0.836, PFS:0.776) and the validation cohort (C‐index: OS:0.744, PFS:0.712). The combined models were visualized as nomograms. Nomogram scores can realize the risk stratification of OSCC patients. Lower nomogram score is significantly related to the poorer OS (training cohort: p < 0.0001, validation cohort: p < 0.0001, overall cohort: p < 0.0001) and PFS (training cohort: p < 0.0001, validation cohort: p = 0.00017, overall cohort: p < 0.0001). Conclusions: Rad_score, but not sarcopenia, was an independent prognostic factor for patients with OSCC. The nomograms had a satisfactory performance, which might be helpful for OSCC patients and clinicians in personalized prognostic prediction and treatment decision‐making. [ABSTRACT FROM AUTHOR]