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OBJECTIVES: Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. METHODS: Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). RESULTS: The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%). CONCLUSION: SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1. CLINICAL RELEVANCE STATEMENT: SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET. KEY POINTS: SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT.

Objectives: This study aimed to evaluate the diagnostic utility of [68Ga]Ga-DOTA-Siglec-9 positron emission tomography-computed tomography (PET/CT) in assessing disease activity in a patient experiencing a relapse of giant cell arteritis (GCA). Case presentation: A 90-year-old male patient with GCA, diagnosed in 2018, was enrolled. Demographic data, disease history, and laboratory parameters, including soluble VAP-1 (sVAP-1) levels, were recorded. The patient underwent a [68Ga]Ga-DOTA-Siglec-9 PET/CT scan. Additional imaging assessments included vascular ultrasound of the superficial temporal arteries, their branches, and the facial, axillary, subclavian, carotid, and vertebral arteries, along with magnetic resonance imaging (MRI) of the aorta. The patient's sVAP-1 level was 284 ng/ml compared to 123 ng/ml in the control group (SD ± 55). The [68Ga]Ga-DOTA-Siglec-9 PET/CT scan revealed increased tracer uptake (SUVmax) in the subclavian artery (2.5), aortic arch (2.9), and heart (2.9). Notably, the increased uptake in the descending aorta (3.5) abruptly diminished to 2.2 when passing the diaphragm, with no changes in vessel caliber observed in CT. The injection of [68Ga]Ga-DOTA-Siglec-9 was well tolerated. Aortic MRI revealed no signs of inflammatory involvement. Conclusions: This study introduces the first application of [68Ga]Ga-DOTA-Siglec-9 PET/CT in a patient with GCA experiencing a relapse, revealing enhanced tracer uptake in the subclavian artery and aortic arch with a localized and abrupt reduction, absent in conventional imaging. These findings suggest that [68Ga]Ga-DOTA-Siglec-9 PET/CT has significant potential for precise, inflammation-specific detection of affected vascular tissue in GCA during relapse. [ABSTRACT FROM AUTHOR]

Objectives: [18F]Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a non-invasive imaging modality used in the differential diagnosis of splenic lesions, although ideal parameters and thresholds remain unclear. The present study evaluated the ability of [18F]FDG PET/CT, including its visual and quantitative parameters, to differentiate between benign and malignant splenic lesions. Methods: Patients who underwent [18F]FDG PET/CT following the detection of splenic lesions on contrast-enhanced CT were retrospectively analysed. Visual parameters assessed on [18F]FDG PET/CT included whole spleen uptake intensity, lesion multiplicity, and lesion uptake, and quantitative parameters included maximum standardised uptake value (SUVmax), lesion-to-background ratio (LBR), metabolic tumour volume (MTV), total lesion glycolysis (TLG), and lesion size. Parameters differentiating between benign and malignant lesions were evaluated by Pearson's chi-square test, Mann–Whitney U-test, and receiver operating characteristics (ROC) curve analysis. Results: Splenic lesion uptake (p = 0.001) was the only visual parameter significantly distinguishing between benign and malignant lesions. ROC curve analysis demonstrated that SUVmax had the largest area under the ROC, 0.91 (p < 0.001), with an optimal cut-off > 5.3 having a sensitivity of 90.3% and a specificity of 80.6%. Subgroup analysis of malignant lesions showed that SUVmax (p = 0.013), LBR (p = 0.012), and TLG (p = 0.034) were significantly higher in splenic lymphomas than in splenic metastases. Conclusion: Of the [18F]FDG PET/CT parameters investigated, SUVmax had the highest accuracy in diagnosing malignant splenic lesions and was significantly higher in splenic lymphomas than in splenic metastases. Visual determination of [18F]FDG uptake by splenic lesions may be an easily evaluated parameter. Clinical relevance statement: SUVmax and visual grade of [18F]FDG PET/CT help to differentiate spleen lesions. [18F]FDG PET/CT is useful for discriminating between benign and malignant spleen lesions. Key Points: Many splenic lesions are difficult to diagnose on anatomical imaging, with histopathologic analyses are required. SUVmax of PET/CT provided the diagnostic ability to differentiate between benign and malignant splenic lesions. More than normal spleen uptake can be a convenient parameter to diagnose malignant spleen lesions. [ABSTRACT FROM AUTHOR]

Objective: This investigation aimed to elucidate alterations in metabolic brain network connectivity in drug-resistant mesial temporal lobe epilepsy (DR-MTLE) patients, relating these changes to varying surgical outcomes. Methods: A retrospective cohort of 87 DR-MTLE patients who underwent selective amygdalohippocampectomy was analyzed. Patients were categorized based on Engel surgical outcome classification into seizure-free (SF) or non-seizure-free (NSF) groups. Additionally, 38 healthy individuals constituted a control group (HC). Employing effect size (ES) methodology, we constructed individualized metabolic brain networks and compared metabolic connectivity matrices across these groups using the DPABINet toolbox. Results: Compared to HCs, both SF and NSF groups exhibited diminished metabolic connectivity, with the NSF group showing pronounced reductions across the whole brain. Notably, the NSF group demonstrated weaker metabolic links between key networks, including the default mode network (DMN), frontoparietal network (FPN), and visual network (VN), in comparison to the SF group. Conclusion: Individual metabolic brain networks, constructed via ES methodology, revealed significant disruptions in DR-MTLE patients, predominantly in the NSF group. These alterations, particularly between limbic structures and cognitive networks like the DMN, suggested impaired and inefficient information processing across the brain's networks. This study identified abnormal brain networks associated with DR-MTLE and, importantly, contributed novel insights into the mechanisms underlying poor postoperative seizure control, and offered potential implications for refining preoperative assessments. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the diagnostic utility of [68Ga]Ga-DOTA-Siglec-9 positron emission tomography-computed tomography (PET/CT) in assessing disease activity in a patient experiencing a relapse of giant cell arteritis (GCA). Case presentation: A 90-year-old male patient with GCA, diagnosed in 2018, was enrolled. Demographic data, disease history, and laboratory parameters, including soluble VAP-1 (sVAP-1) levels, were recorded. The patient underwent a [68Ga]Ga-DOTA-Siglec-9 PET/CT scan. Additional imaging assessments included vascular ultrasound of the superficial temporal arteries, their branches, and the facial, axillary, subclavian, carotid, and vertebral arteries, along with magnetic resonance imaging (MRI) of the aorta. The patient's sVAP-1 level was 284 ng/ml compared to 123 ng/ml in the control group (SD ± 55). The [68Ga]Ga-DOTA-Siglec-9 PET/CT scan revealed increased tracer uptake (SUVmax) in the subclavian artery (2.5), aortic arch (2.9), and heart (2.9). Notably, the increased uptake in the descending aorta (3.5) abruptly diminished to 2.2 when passing the diaphragm, with no changes in vessel caliber observed in CT. The injection of [68Ga]Ga-DOTA-Siglec-9 was well tolerated. Aortic MRI revealed no signs of inflammatory involvement. Conclusions: This study introduces the first application of [68Ga]Ga-DOTA-Siglec-9 PET/CT in a patient with GCA experiencing a relapse, revealing enhanced tracer uptake in the subclavian artery and aortic arch with a localized and abrupt reduction, absent in conventional imaging. These findings suggest that [68Ga]Ga-DOTA-Siglec-9 PET/CT has significant potential for precise, inflammation-specific detection of affected vascular tissue in GCA during relapse. [ABSTRACT FROM AUTHOR]

Solitary fibrous tumors (SFTs) are classified as fibroblastic/myofibroblastic tumors that originate from CD34-positive dendritic cells and usually occur in the pleura. In this paper, we describe a case of SFT within the joint cavity of the left knee. A 60-year-old man was admitted to hospital due to swelling in the left knee for the past 8 months without relevant trauma history. X-ray, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography–computed tomography (PET-CT) presented a large, ill-circumscribed, hypervascular, and highly enhanced mass with eccentric calcification and peripheral, intra-lesional vessels. Subsequently, the patient underwent surgical resection. Postoperative pathology confirmed the neoplastic cells to be positive for CD34, Bcl-2, and SATA6, therefore was finally diagnosed as malignant SFT. The patient developed bone metastases within 1 year after surgery. SFT in the joint cavity is rare, and it is difficult to make a preoperative diagnosis. [ABSTRACT FROM AUTHOR]

We present the imaging findings of a 44-year-old female patient who was diagnosed with nasopharyngeal carcinoma (NPC) extending from the nasopharynx to the external auditory canal (EAC) through the Eustachian tube (ET). The patient presented with a left neck submandibular lump on initial presentation that showed NPC upon fine needle aspiration, leading to chemoradiotherapy. Despite treatment, the patient experienced multiple relapses and later presented with aural symptoms, including left ear pain, foul-smelling drainage, and trismus on recurrence, and was subsequently diagnosed through biopsy. CT, MRI, and PET-CT scans revealed an extensive infiltrative nasopharyngeal mass extending into the left ET, involving the EAC. This rare case highlights the importance of considering the extension of NPC into the EAC as a potential etiology in patients who present with aural symptoms.

Abstract Introduction Preoperative evaluation of inferior vena cava (IVC) wall invasion is very important to improve outcomes of patients with renal cell carcinoma (RCC), and may allow surgical urologists to treat the IVC more effectively. The objective of this study was to evaluate preoperative 18F-FDG PET/CT in patients with RCC and IVC tumor thrombus (IVCTT) for the diagnosis of IVC wall invasion. Methods This retrospective case-control study evaluated 68 patients with RCC with level I-IV tumor thrombus. According to the histopathologic examination result, the patients were divided into IVC wall invasion group and non-invasion group. The 18F-FDG PET/CT features between two groups were analyzed. Furthermore, a logistic regression model was used to determine if there was an association between PET/CT features and IVC wall invasion. Results Sixty-eight patients were evaluated, and 55.9% (38/68) had IVC wall invasion. Compared with non-invasion group, invasion group had higher SUVmax of RCC, higher SURmax (tumor to tumor thrombus ratio, Tu/Th), higher IVCTT coronal diameter, and longer IVCTT craniocaudal extent (all p

Abstract Purpose Identifying primary hepatic angiosarcoma (PHA) preoperatively is challenging, often relying on postoperative pathology. Invasive biopsy increases bleeding risk, emphasizing the importance of early PHA diagnosis through imaging. However, comprehensive summaries of ultrasound, abdominal computed tomography (CT), magnetic resonance imaging (MRI), and whole- body positron emission tomography-CT (PET-CT) in this context are lacking. This study aimed to investigate the comprehensive imaging characteristics of PHA. Patients and methods Imaging data were collected from 7 patients diagnosed with PHA via pathology between January 2000 and December 2019 in two provincial grade III hospitals. All patients underwent routine color ultrasound examinations before surgery, with 3 patients receiving contrast-enhanced ultrasound (CEUS).CT scans, both plain and enhanced, were performed on 5 patients, and whole-body PET-CT examinations were conducted on 2 patients. Results Among the 7 patients with PHA, 4 presented with a single solid intrahepatic mass (2 of which were large), 1 with a single exophytic macroblock type, 1 with a mixed type featuring multiple masses and nodules, and 1 with a multiple nodule type. Conventional ultrasound of PHA showed uneven echoes within the tumor, potentially accompanied by septal zone echoes, and a blood flow grade of 0-I. CEUS displayed early-stage circular high enhancement, a central non-enhancement area, and a "vascular sign" around the tumor. CT scans revealed low-density shadows in the plain scan stage, high peripheral ring enhancement, and punctate nodular enhancement in the arterial phase, with varying intensities and the presence of a "vascular sign." During the portal vein stage, the interior of the tumor was consistently unfilled and exhibited structural disorder. PET-CT showed low-density lesions in the liver and low fluorodeoxyglucose metabolism. Conclusions Imaging diagnosis plays a crucial role in PHA diagnosis. When liver tumor imaging matches the above characteristics, consider PHA.

Objectives: To investigate the potential utility of [18F]fibroblast activation protein inhibitor (FAPI) positron emission tomography/computed tomography (PET/CT) for evaluating pulmonary artery (PA) masses, and compare it with [18F]fluorodeoxyglucose (FDG) PET/CT. Methods: Participants with clinically suspected PA malignancy were prospectively enrolled and underwent dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging. Visual analysis and semi-quantitative parameters were compared between the two types of radiotracers. The tissue specimen underwent immunohistochemical staining to verify FAP expression in the tissue. Results: Thirty-three patients (18 males/15 females; mean age 53.1 ± 15.4 years) were enrolled. All 21 patients with malignant PA masses were FDG-positive (100%), whereas 20 out of 21 patients were FAPI-positive (95.2%). All 12 patients with benign PA masses were both negative in FDG and FAPI PET. The mean maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR) of FAPI and FDG in malignant PA masses were significantly higher than those of benign masses. Although there was no significant difference in SUVmax between FDG and FAPI in malignant PA masses (11.36 vs. 9.18, p = 0.175), the TBR (liver) and TBR (left ventricle) were more favorable for FAPI than for FDG (13.04 vs. 5.17, p < 0.001); (median: 7.75 vs. 2.75, p = 0.007). Immunohistochemical analysis (n = 16) validated that the level of FAP expression corresponded strongly to the uptake of FAPI in PET/CT scans (rs = 0.712, p = 0.002). For clinical management, FAPI PET found more metastatic lesions than FDG PET in 4 patients, with 2 patients upgrading and 1 patient changing treatment decisions. Conclusions: FAPI PET/CT is feasible in the diagnosis of PA masses. Although not superior to FDG PET/CT, FAPI PET/CT showed better target-to-background contrast. Clinical relevance statement: This study found that FAPI PET/CT is not superior to FDG PET/CT in diagnosing PA masses, but FAPI PET/CT displays better target-to-background contrast and more positive lesions, which may help improve disease management. Key Points: Pulmonary malignancies lack specificity in clinical manifestations, laboratory tests, and routine imaging examinations. FAPI PET/CT is not diagnostically better than FDG PET/CT but displays better target-to-background contrast and more positive lesions. Dual-tracer PET/CT ([18F]FAPI-42 and [18F]FDG) imaging improves clinical management of pulmonary artery masses. [ABSTRACT FROM AUTHOR]

Objectives: Somatostatin receptor positron emission tomography/computed tomography (SSTR-PET/CT) using [68Ga]-labeled tracers is a widely used imaging modality for neuroendocrine tumors (NET). Recently, [18F]SiTATE, a SiFAlin tagged [Tyr3]-octreotate (TATE) PET tracer, has shown great potential due to favorable clinical characteristics. We aimed to evaluate the reproducibility of Somatostatin Receptor-Reporting and Data System 1.0 (SSTR-RADS 1.0) for structured interpretation and treatment planning of NET using [18F]SiTATE. Methods: Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points. Each reader evaluated up to five target lesions per scan. The overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered. Inter- and intra-reader agreement was determined using the intraclass correlation coefficient (ICC). Results: The ICC analysis on the inter-reader agreement using SSTR-RADS 1.0 for identical target lesions (ICC ≥ 85%), overall scan score (ICC ≥ 90%), and the decision to recommend PRRT (ICC ≥ 85%) showed excellent agreement. However, significant differences were observed in recommending PRRT among experienced readers (ER) (p = 0.020) and inexperienced readers (IR) (p = 0.004). Compartment-based analysis demonstrated good to excellent inter-reader agreement for most organs (ICC ≥ 74%), except for lymph nodes (ICC ≥ 53%). Conclusion: SSTR-RADS 1.0 represents a highly reproducible and consistent framework system for stratifying SSTR-targeted PET/CT scans, even using the novel SSTR-ligand [18F]SiTATE. Some inter-reader variability was observed regarding the evaluation of uptake intensity prior to PRRT as well as compartment scoring of lymph nodes, indicating that those categories require special attention during further clinical validation and might be refined in a future SSTR-RADS version 1.1. Clinical relevance statement: SSTR-RADS 1.0 is a consistent framework for categorizing somatostatin receptor-targeted PET/CT scans when using [18F]SiTATE. The framework serves as a valuable tool for facilitating and improving the management of patients with NET. Key Points: SSTR-RADS 1.0 is a valuable tool for managing patients with NET. SSTR-RADS 1.0 categorizes patients with showing strong agreement across diverse reader expertise. As an alternative to [68Ga]-labeled PET/CT in neuroendocrine tumor imaging, SSTR-RADS 1.0 reliably classifies [18F]SiTATE-PET/CT. [ABSTRACT FROM AUTHOR]

Introduction: Preoperative evaluation of inferior vena cava (IVC) wall invasion is very important to improve outcomes of patients with renal cell carcinoma (RCC), and may allow surgical urologists to treat the IVC more effectively. The objective of this study was to evaluate preoperative 18F-FDG PET/CT in patients with RCC and IVC tumor thrombus (IVCTT) for the diagnosis of IVC wall invasion. Methods: This retrospective case-control study evaluated 68 patients with RCC with level I-IV tumor thrombus. According to the histopathologic examination result, the patients were divided into IVC wall invasion group and non-invasion group. The 18F-FDG PET/CT features between two groups were analyzed. Furthermore, a logistic regression model was used to determine if there was an association between PET/CT features and IVC wall invasion. Results: Sixty-eight patients were evaluated, and 55.9% (38/68) had IVC wall invasion. Compared with non-invasion group, invasion group had higher SUVmax of RCC, higher SURmax (tumor to tumor thrombus ratio, Tu/Th), higher IVCTT coronal diameter, and longer IVCTT craniocaudal extent (all p < 0.05). Multivariate analysis showed that SURmax (Tu/Th) (OR 8.760 [95%CI, 1.019–75.310]; p = 0.048) and the maximum coronal diameter of IVCTT (OR 1.143 [95%CI, 1.029–1.269]; p = 0.028) were predictors of IVC wall invasion. A model combining SURmax (Tu/Th) and the maximum coronal diameter of IVCTT achieved an AUC of 0.855 (95%CI, 0.757–0.954). The specificity and sensitivity for assessing IVC wall invasion was 92.1% and 76.7%, respectively. Conclusions: Increases in SURmax (Tu/Th) and the maximum coronal diameter of IVCTT are associated with a higher probability of IVC wall invasion. Preoperative 18F-FDG PET/CT imaging may be used to assess IVC wall invasion. [ABSTRACT FROM AUTHOR]

Cystic fibrosis (CF) is a genetic disorder characterized by recurrent airway infections, inflammation, impaired mucociliary clearance, and progressive decline in lung function. The disease may start in the small airways; however, this is difficult to prove due to the limited accessibility of the small airways with the current single-photon mucociliary clearance assay. Here, we developed a dynamic positron emission tomography assay with high spatial and temporal resolution. We tested that mucociliary clearance is abnormal in the small airways of newborn cystic fibrosis pigs. Clearance of [68Ga]-tagged macroaggregated albumin from small airways started immediately after delivery and continued for the duration of the study. Initial clearance was fast but slowed down a few minutes after delivery. Cystic fibrosis pigs' small airways cleared significantly less than non-CF pigs' small airways (non-CF 25.1 ± 3.1% vs. CF 14.6 ± 0.1%). Stimulation of the cystic fibrosis airways with the purinergic secretagogue uridine-5′-triphosphate (UTP) further impaired clearance (non-CF with UTP 20.9 ± 0.3% vs. CF with UTP 13.0 ± 1.8%). None of the cystic fibrosis pigs treated with UTP (n = 6) cleared more than 20% of the delivered dose. These data indicate that mucociliary clearance in the small airways is fast and can easily be missed if the assay is not sensitive enough. The data also indicate that mucociliary clearance is impaired in the small airways of cystic fibrosis pigs. This defect is exacerbated by stimulation of mucus secretions with purinergic agonists. NEW & NOTEWORTHY: We developed a novel positron emission tomography scan assay with unprecedented temporal and spatial resolution to measure mucociliary clearance in the small airways. We proved a long-standing but unproven assertion that mucociliary clearance is inherently abnormal in the small airways of newborn cystic fibrosis piglets that are otherwise free of infection or inflammation. This technique can be easily extended to other airway diseases such as asthma, idiopathic pulmonary fibrosis, or chronic obstructive pulmonary disease. [ABSTRACT FROM AUTHOR]

Purpose: Identifying primary hepatic angiosarcoma (PHA) preoperatively is challenging, often relying on postoperative pathology. Invasive biopsy increases bleeding risk, emphasizing the importance of early PHA diagnosis through imaging. However, comprehensive summaries of ultrasound, abdominal computed tomography (CT), magnetic resonance imaging (MRI), and whole- body positron emission tomography-CT (PET-CT) in this context are lacking. This study aimed to investigate the comprehensive imaging characteristics of PHA. Patients and methods: Imaging data were collected from 7 patients diagnosed with PHA via pathology between January 2000 and December 2019 in two provincial grade III hospitals. All patients underwent routine color ultrasound examinations before surgery, with 3 patients receiving contrast-enhanced ultrasound (CEUS).CT scans, both plain and enhanced, were performed on 5 patients, and whole-body PET-CT examinations were conducted on 2 patients. Results: Among the 7 patients with PHA, 4 presented with a single solid intrahepatic mass (2 of which were large), 1 with a single exophytic macroblock type, 1 with a mixed type featuring multiple masses and nodules, and 1 with a multiple nodule type. Conventional ultrasound of PHA showed uneven echoes within the tumor, potentially accompanied by septal zone echoes, and a blood flow grade of 0-I. CEUS displayed early-stage circular high enhancement, a central non-enhancement area, and a "vascular sign" around the tumor. CT scans revealed low-density shadows in the plain scan stage, high peripheral ring enhancement, and punctate nodular enhancement in the arterial phase, with varying intensities and the presence of a "vascular sign." During the portal vein stage, the interior of the tumor was consistently unfilled and exhibited structural disorder. PET-CT showed low-density lesions in the liver and low fluorodeoxyglucose metabolism. Conclusions: Imaging diagnosis plays a crucial role in PHA diagnosis. When liver tumor imaging matches the above characteristics, consider PHA. [ABSTRACT FROM AUTHOR]

Skull base metastases, including those from small‐cell lung carcinoma (SCLC), can present with various syndromes depending on the site of involvement, such as orbital syndrome, parasellar syndrome, middle fossa syndrome, jugular foramen syndrome, and occipital condyle syndrome (OCS). One such example is OCS, which consists of unilateral occipital headache accompanied with ipsilateral hypoglossal palsy. This case report describes a 51‐year‐old man initially diagnosed with OCS, which led to the discovery of systemic bone metastases from SCLC. Magnetic resonance imaging showed lesions in the occipital condyle and hypoglossal canal, while positron emission tomography‐computed tomography identified a lung mass and widespread metastases. SCLC is highly aggressive and metastatic, with the bone being a common site of spread. In this case, the OCS preceded the diagnosis of the underlying malignancy. Prompt diagnosis and treatment are crucial, as patients with OCS often have advanced disease. This case highlights the importance of considering SCLC as a potential etiology for OCS, given the propensity for bone metastases. Early recognition and evaluation of OCS is essential to initiate appropriate management. [ABSTRACT FROM AUTHOR]

Differentiated thyroid carcinoma (DTC) metastasizing to the adrenal glands is very infrequent. We present three cases of DTC with adrenal metastasis in their follow-up, in which two were from follicular thyroid carcinoma and one from papillary thyroid carcinoma along with review of literature to emphasize the role of cross-sectional and correlative imaging in DTC with adrenal metastasis. [ABSTRACT FROM AUTHOR]

Detection of adrenal lesions either incidentally, or in symptomatic cases and/or during staging/restaging of oncological cases, it is very crucial to know the adrenal lesion is benign or malignant. Fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET/CT) helps in this comprehensive evaluating process. Here, we present the most frequently facing adrenal lesions in routine oncological PET/CT scans. The aim of this presentation is to know the FDG uptake spectrum of various adrenal lesions on PET/CT scan so that increase the diagnostic accuracy and spectrum of differential diagnosis. [ABSTRACT FROM AUTHOR]

ObjectiveThis investigation aimed to elucidate alterations in metabolic brain network connectivity in drug-resistant mesial temporal lobe epilepsy (DR-MTLE) patients, relating these changes to varying surgical outcomes.MethodsA retrospective cohort of 87 DR-MTLE patients who underwent selective amygdalohippocampectomy was analyzed. Patients were categorized based on Engel surgical outcome classification into seizure-free (SF) or non-seizure-free (NSF) groups. Additionally, 38 healthy individuals constituted a control group (HC). Employing effect size (ES) methodology, we constructed individualized metabolic brain networks and compared metabolic connectivity matrices across these groups using the DPABINet toolbox.ResultsCompared to HCs, both SF and NSF groups exhibited diminished metabolic connectivity, with the NSF group showing pronounced reductions across the whole brain. Notably, the NSF group demonstrated weaker metabolic links between key networks, including the default mode network (DMN), frontoparietal network (FPN), and visual network (VN), in comparison to the SF group.ConclusionIndividual metabolic brain networks, constructed via ES methodology, revealed significant disruptions in DR-MTLE patients, predominantly in the NSF group. These alterations, particularly between limbic structures and cognitive networks like the DMN, suggested impaired and inefficient information processing across the brain’s networks. This study identified abnormal brain networks associated with DR-MTLE and, importantly, contributed novel insights into the mechanisms underlying poor postoperative seizure control, and offered potential implications for refining preoperative assessments.

ObjectivesThis study aimed to evaluate the diagnostic utility of [68Ga]Ga-DOTA-Siglec-9 positron emission tomography-computed tomography (PET/CT) in assessing disease activity in a patient experiencing a relapse of giant cell arteritis (GCA).Case presentationA 90-year-old male patient with GCA, diagnosed in 2018, was enrolled. Demographic data, disease history, and laboratory parameters, including soluble VAP-1 (sVAP-1) levels, were recorded. The patient underwent a [68Ga]Ga-DOTA-Siglec-9 PET/CT scan. Additional imaging assessments included vascular ultrasound of the superficial temporal arteries, their branches, and the facial, axillary, subclavian, carotid, and vertebral arteries, along with magnetic resonance imaging (MRI) of the aorta.The patient’s sVAP-1 level was 284 ng/ml compared to 123 ng/ml in the control group (SD ± 55). The [68Ga]Ga-DOTA-Siglec-9 PET/CT scan revealed increased tracer uptake (SUVmax) in the subclavian artery (2.5), aortic arch (2.9), and heart (2.9). Notably, the increased uptake in the descending aorta (3.5) abruptly diminished to 2.2 when passing the diaphragm, with no changes in vessel caliber observed in CT. The injection of [68Ga]Ga-DOTA-Siglec-9 was well tolerated. Aortic MRI revealed no signs of inflammatory involvement.ConclusionsThis study introduces the first application of [68Ga]Ga-DOTA-Siglec-9 PET/CT in a patient with GCA experiencing a relapse, revealing enhanced tracer uptake in the subclavian artery and aortic arch with a localized and abrupt reduction, absent in conventional imaging. These findings suggest that [68Ga]Ga-DOTA-Siglec-9 PET/CT has significant potential for precise, inflammation-specific detection of affected vascular tissue in GCA during relapse.

This case report details a rare instance of rapid iris metastasis from esophageal cancer in a 59-year-old man. A literature review was conducted to explore recent advances in detecting, diagnosing, and treating intraocular metastatic malignancies. Positron emission tomography-computed tomography played a crucial role in identifying primary sites and systemic metastases. Local treatment combined with systemic therapy effectively reduced tumor size, preserved useful vision, and improved the patient's survival rate. A comparison was made of the characteristics of iris metastases from esophageal cancer and lung cancer, including age, gender, tumor characteristics, and treatment. The challenges associated with diagnosis and treatment are discussed, highlighting the implications for clinical practice.

Abstract Prostate-specific membrane antigen (PSMA) targeted tracers show increased uptake in several malignancies, indicating a potential for peptide radioligand therapy. Intra-arterial injection of radiotracers can increase the therapeutic window. This study aimed to evaluate the feasibility of intra-arterial injection of [68Ga]Ga-PSMA-11 for intrahepatic cholangiocarcinoma and compare tracer uptake after intrahepatic arterial injection and intravenous injection. Three patients with intrahepatic cholangiocarcinoma received [68Ga]Ga-PSMA-11 through a hepatic arterial infusion pump, followed by positron emission tomography/computed tomography (PET/CT). Two-three days later, patients underwent PET/CT after intravenous [68Ga]Ga-PSMA-11 injection. All tumours showed higher uptake on the intra-arterial scan compared with the intravenous scan: the intra-arterial / intravenous standardised uptake value normalised by lean body mass ratios were 1.40, 1.46, and 1.54. Local intra-arterial PSMA injection is possible in patients with intrahepatic cholangiocarcinoma. Local injection increases tumour-to-normal tissue ratios, increasing the therapeutic window for theranostic applications. Relevance statement Intra-arterial Prostate specific membrane antigen (PSMA) injection increases the therapeutic window for potential theranostic application in intrahepatic cholangiocarcinoma. Key Points Three patients with intrahepatic cholangiocarcinoma underwent PET/CT after intra-arterial and intravenous injection of [68Ga]Ga-PSMA-11. Intra-arterial injection showed higher uptake than intravenous injection. PSMA-targeted imaging could be valuable for a subset of intrahepatic cholangiocarcinoma patients. Graphical Abstract

Simple Summary: Despite multiple standardized interpretation criteria (SICs) for imaging response assessment in patients with head and neck squamous cell carcinoma (HNSCC), these systems remain relatively underutilized. This underutilization may in part relate to the fact that the relevant information has been published in disparate journals over multiple decades. This paper aims to review the SICs available for use in interpreting post-treatment FDG PET/CT in patients with HNSCC. We evaluate each SIC in the context of eight desired traits. Selecting a SIC that best matches the needs of one's practice is expected to facilitate multidisciplinary buy-in and maximize the likelihood of successful implementation. Introduction: There is growing interest in the development and application of standardized imaging criteria (SIC), to minimize variability and improve the reproducibility of image interpretation in head and neck squamous cell carcinoma (HNSCC). Methods: "Squamous cell carcinoma" AND "standardized interpretation criteria" OR "radiographic response assessment" were searched using PubMed and Google Scholar for articles published between 2009 and 2024, returning 56 publications. After abstract review, 18 were selected for further evaluation, and 6 different SICs (i.e., PERCIST, Porceddu, Hopkins, NI-RADS, modified Deauville, and Cuneo) were included in this review. Each SIC is evaluated in the context of 8 desired traits of a standardized reporting system. Results: Two SICs have societal endorsements (i.e., PERCIST, NI-RADS); four can be used in the evaluation of locoregional and systemic disease (i.e., PERCIST, Hopkins, NI-RADS, Cuneo), and four have specific categories for equivocal imaging results (i.e., Porceddu, NI-RADS, modified Deauville, and Cuneo). All demonstrated areas for future improvement in the context of the 8 desired traits. Conclusion: Multiple SICs have been developed for and demonstrated value in HNSCC post-treatment imaging; however, these systems remain underutilized. Selecting an SIC with features that best match the needs of one's practice is expected to maximize the likelihood of successful implementation. [ABSTRACT FROM AUTHOR]

Prostate-specific membrane antigen (PSMA) targeted tracers show increased uptake in several malignancies, indicating a potential for peptide radioligand therapy. Intra-arterial injection of radiotracers can increase the therapeutic window. This study aimed to evaluate the feasibility of intra-arterial injection of [68Ga]Ga-PSMA-11 for intrahepatic cholangiocarcinoma and compare tracer uptake after intrahepatic arterial injection and intravenous injection. Three patients with intrahepatic cholangiocarcinoma received [68Ga]Ga-PSMA-11 through a hepatic arterial infusion pump, followed by positron emission tomography/computed tomography (PET/CT). Two-three days later, patients underwent PET/CT after intravenous [68Ga]Ga-PSMA-11 injection. All tumours showed higher uptake on the intra-arterial scan compared with the intravenous scan: the intra-arterial / intravenous standardised uptake value normalised by lean body mass ratios were 1.40, 1.46, and 1.54. Local intra-arterial PSMA injection is possible in patients with intrahepatic cholangiocarcinoma. Local injection increases tumour-to-normal tissue ratios, increasing the therapeutic window for theranostic applications. Relevance statement: Intra-arterial Prostate specific membrane antigen (PSMA) injection increases the therapeutic window for potential theranostic application in intrahepatic cholangiocarcinoma. Key Points: Three patients with intrahepatic cholangiocarcinoma underwent PET/CT after intra-arterial and intravenous injection of [68Ga]Ga-PSMA-11. Intra-arterial injection showed higher uptake than intravenous injection. PSMA-targeted imaging could be valuable for a subset of intrahepatic cholangiocarcinoma patients. [ABSTRACT FROM AUTHOR]

Background: The introduction of positron emission tomography/computed tomography (PET/CT) has significantly advanced medical imaging. In oncology, 18F-fluorodeoxyglucose (18F-FDG) PET/CT is particularly crucial for staging, evaluating treatment response, monitoring follow-up, and planning radiotherapy. However, in resource limiting hospitals, the availability of fluorine-labeled 18F-FDG limits optimal scan acquisition. This study aims to determine the optimal dosage and acquisition time to maximize patient throughput during shortages. Aim and Objective: To optimize lowdose 18F-FDG scan protocols while maintaining high image quality despite radiotracer availability challenges. Materials and Methods: PET/CT scans were performed using GE's Discovery IQ 5-ring, 16-slice system within 40-60 minutes of intravenous 18F-FDG injection. The protocol was adjusted to a low-dose (0.05 mCi/kg of 18F-FDG), and the PET data acquisition time was increased to 3 min per bed position to ensure image quality. Results: Notable differences were observed in image quality scores based on varying acquisition times, with the extended acquisition time helping maintain diagnostic standards despite reduced tracer doses. Conclusion: The high sensitivity and long axial length of the PET/CT system (with five rings spanning 26 cm AFOV) can significantly alleviate the challenges faced by cyclotron-dependent centers. By leveraging the increased sensitivity, we successfully reduced the injected activity rather than the scan time to address the tracer shortage at our institute. This approach proved to be effective in maintaining image quality and patient care standards. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the feasibility and limitations of deep learning–based coronary calcium scoring using positron emission tomography-computed tomography (PET-CT) in comparison with coronary calcium scoring using ECG-gated non-contrast-enhanced cardiac computed tomography (CaCT). Materials and methods: A total of 215 individuals who underwent both CaCT and PET-CT were enrolled in this retrospective study. The Agatston method was used to calculate the coronary artery calcium scores (CACS) from CaCT, PET-CT(reader), and PET-CT(AI) to analyse the effect of using different modalities and AI-based software on CACS measurement. The total CACS and CACS classified according to the CAC-DRS guidelines were compared between the three sets of CACS. The differences, correlation coefficients, intraclass coefficients (ICC), and concordance rates were analysed. Statistical significance was set at p < 0.05. Results: The correlation coefficient of the total CACS from CaCT and PET-CT(reader) was 0.837, PET-CT(reader) and PET-CT(AI) was 0.894, and CaCT and PET-CT(AI) was 0.768. The ICC of CACS from CaCT and PET-CT(reader) was 0.911, PET-CT(reader) and PET-CT(AI) was 0.958, and CaCT and PET-CT(AI) was 0.842. The concordance rate between CaCT and PET-CT(AI) was 73.8%, with a false-negative rate of 37.3% and a false-positive rate of 4.4%. Age and male sex were associated with an increased misclassification rate. Conclusions: Artificial intelligence–assisted CACS measurements in PET-CT showed comparable results to CACS in coronary calcium CT. However, the relatively high false-negative results and tendency to underestimate should be of concern. Clinical relevance statement: Application of automated calcium scoring to PET-CT studies could potentially select patients at high risk of coronary artery disease from among cancer patients known to be susceptible to coronary artery disease and undergoing routine PET-CT scans. Key Points: • Cancer patients are susceptible to coronary disease, and PET-CT could be potentially used to calculate coronary artery calcium score (CACS). • Calcium scoring using artificial intelligence in PET-CT automatically provides CACS with high ICC to CACS in coronary calcium CT. • However, underestimation and false negatives of CACS calculation in PET-CT should be considered. [ABSTRACT FROM AUTHOR]

Solitary fibrous tumors (SFTs) are classified as fibroblastic/myofibroblastic tumors that originate from CD34-positive dendritic cells and usually occur in the pleura. In this paper, we describe a case of SFT within the joint cavity of the left knee. A 60-year-old man was admitted to hospital due to swelling in the left knee for the past 8 months without relevant trauma history. X-ray, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography–computed tomography (PET-CT) presented a large, ill-circumscribed, hypervascular, and highly enhanced mass with eccentric calcification and peripheral, intra-lesional vessels. Subsequently, the patient underwent surgical resection. Postoperative pathology confirmed the neoplastic cells to be positive for CD34, Bcl-2, and SATA6, therefore was finally diagnosed as malignant SFT. The patient developed bone metastases within 1 year after surgery. SFT in the joint cavity is rare, and it is difficult to make a preoperative diagnosis.

AIM: To explore the role of positron emission tomography-computed tomography (PET-CT) examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma (OAML). METHODS: The general clinical data, postoperative PET-CT results, treatment regimens, and the prognosis of 21 histopathologically confirmed OAML patients between October 2017 and September 2021 were collected. Among the 21 patients, five patients underwent surgical treatment alone, 13 patients underwent surgical treatment combined with radiotherapy, and three patients underwent surgical treatment combined with chemotherapy. RESULTS: The follow-up period ranged from 8 to 79mo, with four cases of recurrence and no deaths. Through PET-CT examination, two patients exhibited both local ocular metabolic elevation and systemic metastasis, and one of these patients had cervical lymph node metastasis, while the other had submandibular and parotid gland metastasis. Nine patients showed only local ocular metabolic elevation, while 10 patients had no abnormal metabolic activity locally. CONCLUSION: PET-CT examination plays a crucial role in detecting residual lesions and recurrence following tumor resection, aiding in precise disease staging, and facilitating the development of personalized treatment plans, ultimately improving patient prognosis.

Objective (1): To develop and validate a machine learning (ML) model using radiomic features (RFs) extracted from [18F]FDG PET-CT to predict abdominal aortic aneurysm (AAA) growth rate. Methods (2): This retrospective study included 98 internal and 55 external AAA patients undergoing [18F]FDG PET-CT. RFs were extracted from manual segmentations of AAAs using PyRadiomics. Recursive feature elimination (RFE) reduced features for model optimisation. A multi-layer perceptron (MLP) was developed for AAA growth prediction and compared against Random Forest (RF), XGBoost, and Support Vector Machine (SVM). Accuracy was evaluated via cross-validation, with uncertainty quantified using dropout (MLP), standard deviation (RF), and 95% prediction intervals (XGBoost). External validation used independent data from two centres. Ground truth growth rates were calculated from serial ultrasound (US) measurements or CT volumes. Results (3): From 93 initial RFs, 29 remained after RFE. The MLP model achieved an MAE ± SEM of 1.35 ± 3.2e−4 mm/year with the full feature set and 1.35 ± 2.5e−4 mm/year with RFE. External validation yielded 1.8 ± 8.9e−8 mm/year. RF, XGBoost, and SVM models produced comparable accuracies internally (1.4–1.5 mm/year) but showed higher errors during external validation (1.9–1.97 mm/year). The MLP model demonstrated reduced uncertainty with the full feature set across all datasets. Conclusions (4): An MLP model leveraging [18F]FDG PET-CT radiomics accurately predicted AAA growth rates and generalised well to external data. In the future, more sophisticated stratification could guide individualised patient care, facilitating risk-tailored management of AAAs.

Purpose: Incidental gallbladder carcinoma (IGBC) is diagnosed in post-cholecystectomy specimens for benign indications, where the role of 2-fluro-2-deoxyglucose positron emission tomography/computed tomography(FDG-PET/CT) is not clearly defined. The present study aimed to assess the benefits of staging and prognosticating with FDG-PET/CT in IGBC. Materials and Methods: A retrospective observational study from a tertiary-care center from January 2010 to July 2020 was performed. The demographic, clinical, histopathological, and treatment-related histories were collected. FDG-PET/CT-image findings were compared with survival outcomes through telephonic follow-up. The chi-square test was used for comparing frequencies. The univariate and multivariate survival estimates were analyzed using the Kaplan–Meier analysis and the Cox-proportional hazard model, respectively. Log-rank test was used to compare the Kaplan–Meier curves. Results: The study included 280 postcholecystectomy participants (mean age: 52 ± 11 years; women: 227) of whom 52.1% had open surgery(146/280). Residual disease in the gallbladder fossa (54.8% vs. 36.6%, p = 0.002) and liver infiltration (32.9% vs. 22.4%, p = 0.05) were seen more frequently in open surgery compared to laparoscopic surgery, while anterior abdominal wall deposits were more common in laparoscopy(35.1% vs. 24%,p = 0.041). FDG-PET/CT changed the management in 10% (n = 28) of patients compared to contrast-enhanced CT. The median survival was 14 months (95%CI-10.3–17.7). A higher stage of the disease on the FDG-PET/CT (loco-regional disease-HR 4.86, p = 0.006; metastatic disease-HR 7.53, p < 0.001) and the presence of liver infiltration (HR-1.92, p = 0.003) were independent predictors of poor survival outcomes. Conclusion: FDG-PET/CT detects residual and metastatic disease in patients with IGBC, enabling the institution of appropriate management and acting as a tool for prognostication of survival. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Sarcomatoid carcinoma, a rare and aggressive subtype of bladder cancer, accounting for 0.3% of cases, is more aggressive than urothelial carcinomas. Accurate diagnosis, crucial for treatment, can be challenging. We present a characterized case of sarcomatoid carcinoma of the urinary bladder using multimodal imaging and pathology. [ABSTRACT FROM AUTHOR]

Objective: Uptake of the imaging tracers [18F]AlF-NOTA-FAPI-04 and [18F]FDG varies in some inflammatory lesions, which may result in false-positive findings for malignancy on PET/CT. Our aim was to compare the [18F]AlF-NOTA-FAPI-04 and [18F]FDG PET/CT imaging features of malignant and various inflammatory lung lesions and to analyze their value for differential diagnosis. Methods: We retrospectively analyzed [18F]AlF-NOTA-FAPI-04 PET/CT scans from 67 cancer patients taken between December 2020 and January 2022, as well as the scans of 32 patients who also underwent [18F]FDG PET/CT imaging. The maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) and lesion-to-background ratio (LBR) were calculated. The predictive capabilities of semiquantitative PET/CT parameters were analyzed by receiver operating characteristic curve analysis. Results: A total of 70 inflammatory and 37 malignant lung lesions were evaluated by [18F]AlF‑NOTA‑FAPI‑04 PET/CT, and 33 inflammatory and 26 malignant lung lesions also were evaluated by [18F]FDG PET/CT. Inflammatory lesions exhibited lower [18F]AlF-NOTA-FAPI-04 and [18F]FDG uptake compared to malignant lesions, with statistically significant differences in SUVmax, SUVmean, and LBR (all p < 0.001). [18F]AlF-NOTA-FAPI-04 uptake also varied among different types of inflammatory lesions (SUVmax, p = 0.005; SUVmean, p = 0.008; LBR, p < 0.001), with the highest uptake observed in bronchiectasis with infection, followed by postobstructive pneumonia, and the lowest in pneumonia. [18F]FDG uptake was higher in postobstructive pneumonia than in pneumonia (SUVmax, p = 0.009; SUVmean, p = 0.016; LBR, p = 0.004). Conclusion: [18F]AlF-NOTA-FAPI-04/[18F]FDG PET/CT showed significantly lower uptake in inflammatory lesions than malignancies as well as variation in different types of inflammatory lesions, and thus, may be valuable for distinguishing malignant and various inflammatory findings. Clinical relevance statement: Our study confirmed that the uptake of [18F]AlF-NOTA-FAPI-04/[18F]FDG PET/CT in inflammatory and malignant lung lesions is different, which is beneficial to distinguish inflammatory and malignant lung lesions in clinic. Key Points: • Malignant and different inflammatory lung lesions showed varying degrees of uptake of [18F]AlF-NOTA-FAPI-04 and [18F]FDG. • Inflammatory lung lesions showed significantly less uptake than malignancies, and uptake varied among different types of inflammatory lesions. • Both types of PET/CT could differentiate malignant and various inflammatory lung findings. [ABSTRACT FROM AUTHOR]

Introduction: The goal of this study is to compare the prognostic performance of NETPET scores, based on gallium-68 DOTANOC (68Ga-DOTANOC) and fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography-Computed Tomography (PET-CT), and PET-CT metabolic parameters in metastatic gastrointestinal neuroendocrine tumors (GI-NET), while constructing and validating a nomogram derived from dual-scan PET-CT. Methods: In this retrospective study, G1–G3 GI-NET patients who underwent 68Ga-DOTANOC and 18F-FDG PET scans were enrolled and divided into training and internal validation cohorts. Three grading systems were constructed based on NETPET scores and standardized uptake value maximum (SUVmax). LASSO regression selected variables for a multivariable Cox model, and nomograms predicting progression-free survival (PFS) and overall survival (OS) were created. The prognostic performance of these systems was assessed using time-dependent receiver-operating characteristic (ROC) curves, concordance index (C-index), and other methods. Nomogram evaluation involved calibration curves, decision curve analysis (DCA), and the aforementioned methods in both cohorts. Results: In this study, 223 patients (130 males; mean age ±  SD: 52.6 ± 12 years) were divided into training (148) and internal validation (75) cohorts. Dual scans were classified based on NETPET scores (D1–D3). Single 68Ga-DOTANOC and 18F-FDG PET-CT scans were stratified into S1-S3 and F1-F3 based on SUVmax. The NETPET score-based grading system demonstrated the best OS and PFS prediction (C-index, 0.763 vs. 0.727 vs. 0.566). Nomograms for OS and PFS exhibited superior prognostic performance in both cohorts (all AUCs > 0.8). Conclusions: New classification based on NETPET score predicts patient OS/PFS best. PET-CT-based nomograms show accurate OS/PFS forecasts. [ABSTRACT FROM AUTHOR]

Pyomyositis is an acute pyogenic infection of the muscles and tissues which results in localized pus collections and abscess formation. This entity at times becomes difficult to diagnose due to lack of specific signs and atypical or nonspecific manifestations. This condition is a mimic for a wide range of differential diagnoses due to which the patient often receives many unwarranted antibiotics. Furthermore, the deep location of the muscles makes the clinical signs in apparent leading to misdiagnosis as rarer entities such as inflammatory myositis. In the last 1 year, four such interesting cases were admitted in this tertiary care center with different clinical presentations. All these cases were healthy, immunocompetent individuals who presented to smaller hospitals with clinical presentation of muscle and joint pain with fever. The muscle groups affected were different in all these cases. All four patients were transferred to this hospital due to the diagnostic dilemma between inflammatory and infective myositis. After a thorough workup including imaging and tissue diagnostics, they were labeled pyomyositis. This further stresses the need for physicians to become acquainted with this potentially life-threatening yet curable infective disease entity. The patients were managed with antibiotics for a minimum duration of 3 weeks and a maximum duration of 8 weeks for complete recovery. Pyomyositis in immunocompetent hosts was related to factors affecting the muscles without any strenuous exercise or direct trauma. Comprehensive evaluation of the muscles is facilitated by assessment of fluorodeoxyglucose uptake on positron emission tomography–computed tomography scan. The initial therapy consisting of cephalosporin and teicoplanin was found effective in our patients. The minimum length of in-hospital treatment was 4 weeks. This series further reinforces the fact that tropical pyomyositis is not exclusive to immunocompromised persons.

Abstract Identification of patients with idiopathic normal pressure hydrocephalus (iNPH) in a collective with suspected neurodegenerative disease is essential. This study aimed to determine the metabolic spatial covariance pattern of iNPH on FDG PET using an established technique based on scaled subprofile model principal components analysis (SSM-PCA). We identified 11 patients with definite iNPH. By applying SSM-PCA to the FDG PET data, they were compared to 48 age-matched healthy controls to determine the whole-brain voxel-wise metabolic spatial covariance pattern of definite iNPH (iNPH-related pattern, iNPHRP). The iNPHRP score was compared between groups of patients with definite iNPH, possible iNPH (N = 34), Alzheimer’s (AD, N = 38), and Parkinson’s disease (PD, N = 35) applying pairwise Mann–Whitney U tests and correction for multiple comparisons. SSM-PCA of FDG PET revealed an iNPHRP that is characterized by relative negative voxel weights at the vicinity of the lateral ventricles and relative positive weights in the paracentral midline region. The iNPHRP scores of patients with definite iNPH were substantially higher than in patients with AD and PD (both p

This study aimed to evaluate the predictive and monitoring role of somatostatin receptor (SSTR) positron emission tomography-computed tomography (PET/CT) and clinical parameters in patients with neuroendocrine liver metastases (NELM) from pancreatic neuroendocrine tumors (pNET) receiving capecitabine and temozolomide (CAPTEM).

Artifacts in nuclear medicine imaging are not uncommon. We are aware of some of these, for which we follow necessary protocols to avoid them. However, there are some unusual and unavoidable artifacts that we come across in daily imaging, which may be of concern and need to be detected and corrected on time. Hence, sharing a few such unusual artifacts we encountered while performing routine studies on positron emission tomography-computed tomography and gamma cameras, evaluating the cause and possible precautions. [ABSTRACT FROM AUTHOR]

Watchful waiting is an acceptable management strategy for advanced‐stage, low tumor burden (LTB) patients with follicular lymphoma (FL). However, the prediction of how long this treatment‐free observation period will last remains imperfect. We explored whether total metabolic tumor volume (TMTV) and other positron emission tomography parameters were predictive of time to first treatment (TTFT). We analyzed 97 grade 1–3A advanced‐stage LTB FL patients and found that a high TMTV was associated with other tumor burden features at diagnosis. Patients with a TMTV above our established cutoff of 50 mL had a significantly shorter median duration of observation (2.6 vs. 8.8 years; p = 0.001). At 5 years, 77% of patients with a high TMTV and 46% of patients with a low TMTV required treatment. In the multivariable analysis, a high TMTV was the only independent factor predicting TTFT (hazard ratio = 2.09; p = 0.017). Overall, TMTV is a strong predictor of the duration of observation in LTB FL patients. Upon validation of our cutoff in external series and standardization of the methodology, the TMTV could become an additional factor to consider deferring or initiating treatment in otherwise LTB patients. [ABSTRACT FROM AUTHOR]

BackgroundAlthough many patients with follicular lymphoma (FL) undergo routine radiographic surveillance during their first remission, no consensus exists on the modality, duration, frequency, or need for routine imaging studies. The authors retrospectively examined the effect of surveillance imaging on relapse detection and overall survival (OS) in patients with FL.MethodsPatients with newly diagnosed FL who had a response to induction therapy were identified from the Lymphoid Malignancies Enterprise Architecture Database (LEAD) at Emory University and from the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic. Patients were evaluated for both relapse and method of relapse detection (ie, clinical concerns vs radiologic detection through surveillance imaging in an asymptomatic patient).ResultsOf 148 patients in the LEAD cohort, 55 (37%) relapsed, and the majority (n = 35; 64%) of relapses were detected clinically. In the MER cohort, 63 of 177 relapses (54%) were detected clinically. There was no significant difference in OS from the date of diagnosis between the 2 methods of relapse detection in the LEAD (hazard ratio [HR], 0.61; 95% CI, 0.13-2.94; P = .54) and MER (HR, 1.02; 95% CI, 0.47-2.21; P = .96) cohorts. Similarly, there was no significant difference in OS from the date of relapse between the 2 methods of relapse detection in the LEAD (HR, 0.47; 95% CI, 0.10-2.27; P = .35) and MER (HR, 1.02; 95% CI, 0.47-2.21; P = .96) cohorts.ConclusionsThese findings suggest a limited role for routine surveillance imaging in patients with FL who complete front-line therapy. Future studies should evaluate which patients may benefit from a more aggressive surveillance approach and should explore novel methods of relapse detection.

The metastatic lesions to pancreas are reported in various malignancies. However, pancreatic metastasis from breast cancer is rare and difficult to diagnose due to nonspecific symptoms and imaging findings. At the time of diagnosis, there may already be an associated widespread metastasis. In this case report, a woman in her forties with a history of breast cancer was found to have widespread metastases, including in the pancreas. The patient was treated with chemotherapy and hormonal therapy. [ABSTRACT FROM AUTHOR]

Identification of patients with idiopathic normal pressure hydrocephalus (iNPH) in a collective with suspected neurodegenerative disease is essential. This study aimed to determine the metabolic spatial covariance pattern of iNPH on FDG PET using an established technique based on scaled subprofile model principal components analysis (SSM-PCA). We identified 11 patients with definite iNPH. By applying SSM-PCA to the FDG PET data, they were compared to 48 age-matched healthy controls to determine the whole-brain voxel-wise metabolic spatial covariance pattern of definite iNPH (iNPH-related pattern, iNPHRP). The iNPHRP score was compared between groups of patients with definite iNPH, possible iNPH (N = 34), Alzheimer's (AD, N = 38), and Parkinson's disease (PD, N = 35) applying pairwise Mann–Whitney U tests and correction for multiple comparisons. SSM-PCA of FDG PET revealed an iNPHRP that is characterized by relative negative voxel weights at the vicinity of the lateral ventricles and relative positive weights in the paracentral midline region. The iNPHRP scores of patients with definite iNPH were substantially higher than in patients with AD and PD (both p < 0.05) and non-significantly higher than those of patients with possible iNPH. Subject scores of the iNPHRP discriminated definite iNPH from AD and PD with 96% and 100% accuracy and possible iNPH from AD and PD with 83% and 86% accuracy. We defined a novel metabolic spatial covariance pattern of iNPH that might facilitate the differential diagnosis of iNPH versus other neurodegenerative disorders. The knowledge of iNPH-associated alterations in the cerebral glucose metabolism is of high relevance as iNPH constitutes an important differential diagnosis to dementia and movement disorders. Key points: • Subprofile model principal components analysis revealed a distinct metabolic spatial covariance pattern of definite idiopathic normal pressure hydrocephalus (iNPH). • This iNPH-related pattern delineates patients with definite iNPH from patients with Alzheimer's or Parkinson's disease. • The iNPH-related pattern expression was higher in definite than in probable iNPH. [ABSTRACT FROM AUTHOR]

Aim: To investigate the clinical and radiological outcomes and glucocorticoid‐sparing effect of rituximab therapy in 13 patients with retroperitoneal fibrosis (RPF). Methods: We analyzed the data of both glucocorticoid‐naive and glucocorticoid‐resistant RPF patients who were treated with rituximab. Demographic features, positron emission tomography computed tomography (PET‐CT) findings, and clinical and histopathologic outcomes were collected retrospectively. Results: We evaluated the data of 13 RPF patients (8M/5F). The median follow‐up duration was 28 months (interquartile range [IQR] 24.5–55.5 months) and median age at the time of diagnosis was 50.8 years (IQR 46.5–54.5 years). PET‐CT scans showed that following the rituximab therapy, the craniocaudal diameter of the RPF mass reduced from 74 mm (IQR 50.5–130 mm) to 52 mm (IQR 35–77 mm; p =.06), and periaortic thickness of the RPF mass reduced from 14 mm (5.5–21.9 mm) to 7 mm (4.5–11 mm; p =.12). The maximum standardized uptake value (based on body weight) of the RPF mass decreased from 5.8 (4.3–9.7) to 3.1 (2.8–5.3) after the therapy (p =.03). The number of patients with hydronephrosis reduced from 11 to 6 following rituximab therapy (p =.04). Before rituximab, nine patients received a median dose of 10 mg (IQR 0–27.5 mg) prednisolone per day. After the rituximab treatment, we discontinued prednisolone treatment for four out of nine patients and reduced the daily dose for the remaining patients. At the time of the final evaluation of the patients, the median prescribed prednisolone dose was 5 mg/day (IQR 2.5–7.5 mg/day; p =.01). Conclusion: Our study shows that rituximab may be a favorable treatment option for glucocorticoid‐refractory RPF patients with high disease activity on PET‐CT scans. [ABSTRACT FROM AUTHOR]

Novel coronavirus-19 (COVID-19) variants continue to spread worldwide with the development of highly transmissible strains. Several guidelines addressing management of cancer patients during the COVID-19 pandemic have been published, primarily based upon expert opinion. The COVID-19 pandemic has affected all aspects of breast cancer care including screening, diagnosis, treatment, and long-term follow-up. Recent reports indicate that mRNA COVID-19 vaccines can provoke lymphadenopathy in both cancer patients and healthy individuals. Unilateral axillary lymphadenopathy (UAL) post-COVID-19 vaccination is a challenging presentation for cancer patients because of the potential for misinterpretation as malignancy. The World Health Organization’s target to vaccinate 70% of the world’s population by mid-2023 is likely to increase the incidence of post-COVID-19 vaccination UAL. In this article, we review the published evidence regarding UAL post-COVID-19 vaccination and present diverse cases of breast cancer patients where false-positive UAL post-COVID-19 vaccination proved to be a therapeutic challenge. The United Arab Emirates (UAE) vaccination program is well ahead of other countries in the world, having accomplished the target of 100% vaccination of the population with at least one dose. Therefore, an increasing number of recently vaccinated patients are likely to present with UAL, detected by surveillance imaging, post-vaccination. We have therefore made recommendations regarding the management of cancer patients with UAL post-COVID-19 vaccination in order to avoid misdiagnosis and unnecessary imaging or invasive biopsy procedures.

Abstract A 45‐year‐old male with cardiac sarcoidosis verified by cardiac biopsy presented with multiple coexisting arrhythmias, including ventricular tachycardia of more than 1000 episodes per 24 h, paroxysmal atrial fibrillation, and third‐degree atrioventricular block. He did not respond to corticosteroids dose of 20–60 mg once daily and mycophenolate mofetil dose of 1 g twice daily for 6 months. Cardiac magnetic resonance (CMR) demonstrated inflammation and late gadolinium enhancement on right ventricular wall and interventricular septum. Positron emission tomography‐computed tomography (PET‐CT) showed multifocal 18F‐fluorodeoxyglucose uptake in the heart. We replaced mycophenolate mofetil with adalimumab, a tumour necrosis factor‐α inhibitor. After 3 months, his arrhythmias improved significantly, manifesting as premature ventricular contractions of only 500 beats per 24 h and first‐degree atrioventricular block. CMR showed a significant reduction in inflammation and late gadolinium enhancement, and PET‐CT showed a complete resolution of fluorodeoxyglucose uptake.