Magnetic Resonance Images Implicate That Glymphatic Alterations Mediate Cognitive Dysfunction in Alzheimer Disease.

OBJECTIVE: The glymphatic system cleans amyloid and tau proteins from the brain in animal studies of Alzheimer disease (AD). However, there is no direct evidence showing this in humans. METHODS: Participants (n = 50, 62.6 ± 5.4 years old, 36 women) with AD and normal controls underwent amyloid positron emission tomography (PET), tau PET, structural T1-weighted magnetic resonance imaging, and neuropsychological evaluation. Whole-brain glymphatic activity was measured by diffusion tensor image analysis along the perivascular space (DTI-ALPS). RESULTS: ALPS-indexes showed negative correlations with deposition of amyloid and tau on PET images and positive correlations with cognitive scores even after adjusting for age, sex, years of education, and APOE4 genotype covariates in multiple AD-related brain regions (all p < 0.05). Mediation analysis showed that ALPS-index acted as a significant mediator between regional standardized uptake value ratios of amyloid and tau images and cognitive dysfunction even after correcting for multiple covariates in AD-related brain regions. These regions are responsible for attention, memory, and executive function, which are vulnerable to sleep deprivation. INTERPRETATION: Glymphatic system activity may act as a significant mediator in AD-related cognitive dysfunction even after adjusting for multiple covariates and gray matter volumes. ALPS-index may provide useful disease progression or treatment biomarkers for patients with AD as an indicator of modulation of glymphatic activity. ANN NEUROL 2023;93:164-174.

Plasma Glial Fibrillary Acidic Protein in the Alzheimer Disease Continuum: Relationship to Other Biomarkers, Differential Diagnosis, and Prediction of Clinical Progression.

BACKGROUND: Plasma glial fibrillary acidic protein (GFAP) has emerged as a promising biomarker in neurological disorders, but further evidence is required in relation to its usefulness for diagnosis and prediction of Alzheimer disease (AD). METHODS: Plasma GFAP was measured in participants with AD, non-AD neurodegenerative disorders, and controls. Its diagnostic and predictive value were analyzed alone or combined with other indicators. RESULTS: A total of 818 participants were recruited (210 followed). Plasma GFAP was significantly higher in AD than in non-AD dementia and non-demented individuals. It increased in a stepwise pattern from preclinical AD, through prodromal AD to AD dementia. It effectively distinguished AD from controls [area under the curve (AUC) > 0.97] and non-AD dementia (AUC > 0.80) and distinguished preclinical (AUC > 0.89) and prodromal AD (AUC > 0.85) from Aß-normal controls. Adjusted or combined with other indicators, higher levels of plasma GFAP displayed predictive value for risk of AD progression (adjusted hazard radio= 4.49, 95%CI, 1.18-16.97, P = 0.027 based on the comparison of those above vs below average at baseline) and cognitive decline (standard-ß=0.34, P = 0.002). Additionally, it strongly correlated with AD-related cerebrospinal fluid (CSF)/neuroimaging markers. CONCLUSIONS: Plasma GFAP effectively distinguished AD dementia from multiple neurodegenerative diseases, gradually increased across the AD continuum, predicted the individual risk of AD progression, and strongly correlated with AD CSF/neuroimaging biomarkers. Plasma GFAP could serve as both a diagnostic and predictive biomarker for AD.

18F-Florzolotau PET imaging captures the distribution patterns and regional vulnerability of tau pathology in progressive supranuclear palsy.

PURPOSE: Human post mortem studies have described the topographical patterns of tau pathology in progressive supranuclear palsy (PSP). Recent advances in tau PET tracers are expected to herald the next era of PSP investigation for early detection of tau pathology in living brains. This study aimed to investigate whether 18F-Florzolotau PET imaging may capture the distribution patterns and regional vulnerability of tau pathology in PSP, and to devise a novel image-based staging system. METHODS: The study cohort consisted of 148 consecutive patients with PSP who had undergone 18F-Florzolotau PET imaging. The PSP rating scale (PSPrs) was used to measure disease severity. Similarities and differences of tau deposition among different clinical phenotypes were examined at the regional and voxel levels. An 18F-Florzolotau pathological staging system was devised according to the scheme originally developed for post mortem data. In light of conditional probabilities for the sequence of events, an 18F-Florzolotau modified staging system by integrating clusters at the regional level was further developed. The ability of 18F-Florzolotau staging systems to reflect disease severity in terms of PSPrs score was assessed by analysis of variance. RESULTS: The distribution patterns of 18F-Florzolotau accumulation in living brains of PSP showed a remarkable similarity to those reported in post mortem studies, with the binding intensity being markedly higher in Richardson's syndrome. Moreover, 18F-Florzolotau PET imaging allowed detecting regional vulnerability and tracking tau accumulation in an earlier fashion compared with post mortem immunostaining. The 18F-Florzolotau staging systems were positively correlated with clinical severity as reflected by PSPrs scores. CONCLUSIONS: 18F-Florzolotau PET imaging can effectively capture the distribution patterns and regional vulnerability of tau pathology in PSP. The 18F-Florzolotau modified staging system holds promise for early tracking of tau deposition in living brains.

Early relapse is an adverse prognostic factor for survival outcomes in patients with oral cavity squamous cell carcinoma: results from a nationwide registry study.

BACKGROUND: The prognostic significance of the relapse interval in patients with resected oral cavity squamous cell carcinoma (OCSCC) is a matter of ongoing debate. In this large-scale, registry-based, nationwide study, we examined whether the time interval between surgery and the first disease relapse may affect survival outcomes in Taiwanese patients with OCSCC. METHODS: Data made available by the Taiwan Health Promotion Administration as of 2004 were obtained. The study cohort consisted of patients who were included in the registry between 2011 and 2017. Disease staging was performed according to the American Joint Committee on Cancer (AJCC) Staging Manual, Eight Edition. We retrospectively reviewed the clinical records of 13,789 patients with OCSCC who received surgical treatment. A total of 2327 (16.9%) patients experienced a first disease relapse. The optimal cutoff value for the relapse interval was 330 days when both 5-year disease-specific survival (DSS) and overall survival (OS) (≤ 330/>330 days, n = 1630/697) were taken into account. In addition, we undertook a propensity score (PS)-matched analysis of patients (n = 654 each) with early (≤ 330 days) versus late (> 330 days) relapse. RESULTS: The median follow-up time in the entire study cohort was 702 days (433 and 2001 days in the early and late relapse groups, respectively). Compared with patients who experienced late relapse, those with early relapse showed a higher prevalence of the following adverse prognostic factors: pT4, pN3, pStage IV, poor differentiation, depth of invasion ≥ 10 mm, and extra-nodal extension. Multivariable analysis revealed that early relapse was an independent adverse prognostic factor for both 5-year DSS and OS (average hazard ratios [AHRs]: 3.24 and 3.91, respectively). In the PS-matched cohort, patients who experienced early relapse showed less favorable 5-year DSS: 58% versus 30%, p < 0.0001 (AHR: 3.10 [2.69 - 3.57]) and OS: 49% versus 22%, p < 0.0001 (AHR: 3.32 [2.89 - 3.81]). CONCLUSION: After adjustment for potential confounders and PS matching, early relapse was an adverse prognostic factor for survival outcomes in patients with OCSCC. Our findings may have significant implications for risk stratification.

In Vivo 18 F-Florzolotau Tau Positron Emission Tomography Imaging in Parkinson's Disease Dementia.

BACKGROUND: Tau pathology is observed during autopsy in many patients with Parkinson's disease dementia (PDD). Positron emission tomography (PET) imaging using the tracer 18 F-florzolotau has the potential to capture tau accumulation in the living brain. OBJECTIVE: The aim was to describe the results of 18 F-florzolotau PET/CT (computed tomography) imaging in patients with PDD. METHODS: Ten patients with PDD, 9 with Parkinson's disease with normal cognition (PD-NC), and 9 age-matched healthy controls (HCs) were enrolled. Clinical assessments and 18 F-florzolotau PET/CT imaging were performed. RESULTS: 18 F-Florzolotau uptake was significantly higher in the cortical regions of patients with PDD compared with both PD-NC and HCs, especially in the temporal lobe. Notably, 18 F-florzolotau uptake in the occipital lobe of patients with PDD showed a significant correlation with cognitive impairment as reflected by Mini-Mental State Examination (MMSE) scores. CONCLUSIONS: 18 F-Florzolotau PET imaging can effectively capture the occurrence of tau pathology in patients with PDD, which was also linked to MMSE scores. © 2022 International Parkinson and Movement Disorder Society.

18 F-Florzolotau Positron Emission Tomography Imaging of Tau Pathology in the Living Brains of Patients with Corticobasal Syndrome.

BACKGROUND: Recent development in tau-sensitive tracers has sparkled significant interest in tracking tauopathies using positron emission tomography (PET) biomarkers. However, the ability of 18 F-florzolotau PET imaging to topographically characterize tau pathology in corticobasal syndrome (CBS) remains unclear. Further, the question as to whether disease-level differences exist with other neurodegenerative tauopathies is still unanswered. OBJECTIVE: To analyze the topographical patterns of tau pathology in the living brains of patients with CBS using 18 F-florzolotau PET imaging and to examine whether differences with other tauopathies exist. METHODS: 18 F-florzolotau PET imaging was performed in 20 consecutive patients with CBS, 20 cognitively healthy controls (HCs), 20 patients with Alzheimer's disease (AD), and 16 patients with progressive supranuclear palsy-Richardson's syndrome (PSP-RS). Cerebrospinal fluid (CSF) levels of ß-amyloid biomarkers were quantified in all patients with CBS. 18 F-florzolotau uptake was quantitatively assessed using standardized uptake value ratios. RESULTS: Of the 20 patients with CBS, 19 (95%) were negative for CSF biomarkers of amyloid pathology; of them, three had negative 18 F-florzolotau PET findings. Compared with HCs, patients with CBS showed increased 18 F-florzolotau signals in both cortical and subcortical regions. In addition, patients with CBS were characterized by higher tracer retentions in subcortical regions compared with those with AD and showed a trend toward higher signals in cortical areas compared with PSP-RS. An asymmetric pattern of 18 F-florzolotau uptake was associated with an asymmetry of motor severity in patients with CBS. CONCLUSIONS: In vivo 18 F-florzolotau PET imaging holds promise for distinguishing CBS in the spectrum of neurodegenerative tauopathies. © 2023 International Parkinson and Movement Disorder Society.

Feasibility of 18F-florzolotau quantification in patients with Alzheimer's disease based on an MRI-free tau PET template.

OBJECTIVES: Quantification of tau accumulation using positron emission tomography (PET) is critical for the diagnosis of Alzheimer's disease (AD). This study aimed to evaluate the feasibility of 18F-florzolotau quantification in patients with AD using a magnetic resonance imaging (MRI)-free tau PET template, since individual high-resolution MRI is costly and not always available in practice. METHODS: 18F-florzolotau PET and MRI scans were obtained in a discovery cohort including (1) patients within the AD continuum (n = 87), (2) cognitively impaired patients with non-AD (n = 32), and (3) cognitively unimpaired subjects (n = 26). The validation cohort comprised 24 patients with AD. Following MRI-dependent spatial normalization (standard approach) in randomly selected subjects (n = 40) to cover the entire spectrum of cognitive function, selected PET images were averaged to create the 18F-florzolotau-specific template. Standardized uptake value ratios (SUVRs) were calculated in five predefined regions of interest (ROIs). MRI-free and MRI-dependent methods were compared in terms of continuous and dichotomous agreement, diagnostic performances, and associations with specific cognitive domains. RESULTS: MRI-free SUVRs had a high continuous and dichotomous agreement with MRI-dependent measures for all ROIs (intraclass correlation coefficient ≥ 0.980; agreement ≥ 94.5%). Similar findings were observed for AD-related effect sizes, diagnostic performances with respect to categorization across the cognitive spectrum, and associations with cognitive domains. The robustness of the MRI-free approach was confirmed in the validation cohort. CONCLUSIONS: The use of an 18F-florzolotau-specific template is a valid alternative to MRI-dependent spatial normalization, improving the clinical generalizability of this second-generation tau tracer. KEY POINTS: • Regional 18F-florzolotau SUVRs reflecting tau accumulation in the living brains are reliable biomarkers for the diagnosis, differential diagnosis, and assessment of disease severity in patients with AD. • The 18F-florzolotau-specific template is a valid alternative to MRI-dependent spatial normalization, improving the clinical generalizability of this second-generation tau tracer.

Clinical Outcomes of Taiwanese Patients with Resected Oral Cavity Squamous Cell Carcinoma Who Underwent Reconstruction with Free Versus Local Flaps.

BACKGROUND: We sought to compare the clinical outcomes of Taiwanese patients with resected oral cavity squamous cell carcinoma (OCSCC) who underwent reconstruction with free versus local flaps. METHODS: From 2011 to 2017, we examined 8646 patients with first primary OCSCC who received surgery either with or without adjuvant therapy. Of these patients, 7297 and 1349 received free and local flap reconstruction, respectively. Two propensity score-matched groups of patients who underwent free versus local flap (n = 1268 each) reconstructions were examined. Margin status was not included as a propensity score-matched variable. RESULTS: Compared with local flaps, patients who received free flaps had a higher prevalence of the following variables: male sex, age < 65 years, pT3-4, pN1-3, p-Stage III-IV, depth ≥ 10 mm, margin > 4 mm, extranodal extension (ENE), and adjuvant therapy (all p < 0.0001). Multivariable analysis identified the reconstruction method (local vs. free flaps, only overall survival [OS]), age ≥ 65 years, pT3-4, pN1-3, p-Stage III-IV, depth ≥ 10 mm (only OS), margins ≤ 4 mm, and ENE as independent adverse prognosticators for disease-specific survival (DSS) and OS. The results of propensity score-matched analyses revealed that, compared with free flaps, patients who underwent local flap reconstruction showed less favorable 5-year DSS (hazard ratio [HR] 1.26, 82%/77%; p = 0.0100) and OS (HR 1.21, 73%/68%; p = 0.0079). CONCLUSIONS: After adjusting for covariates using multivariate models, and also by propensity score modeling, OCSCC patients who underwent free flap reconstruction showed a higher frequency of clear margins and a significant survival advantage compared with those who received local flaps.

18 F-Florzolotau Tau Positron Emission Tomography Imaging in Patients with Multiple System Atrophy-Parkinsonian Subtype.

BACKGROUND: Anecdotal evidence suggests that patients diagnosed with the parkinsonian subtype of multiple system atrophy (MSA-P) may show uptake of the second-generation tau positron emission tomography (PET) tracer 18 F-Florzolotau (previously known as 18 F-APN-1607) in the putamen. OBJECTIVES: This study systematically investigated the localization and magnitude of 18 F-Florzolotau uptake in a relatively large cohort of patients with MSA-P. METHODS: 18 F-Florzolotau PET imaging was performed in 31 patients with MSA-P, 24 patients with Parkinson's disease (PD), and 20 age-matched healthy controls. 18 F-Florzolotau signal in the striatum was analyzed by visual inspection and classified as either positive or negative. Regional 18 F-Florzolotau binding was also expressed as standardized uptake value ratio (SUVR) to assess whether it was associated with core symptoms of MSA-P after adjustment for potential confounders. RESULTS: By visual inspection and semiquantitative SUVR comparisons, patients with MSA-P showed elevated 18 F-Florzolotau uptake in the putamen, globus pallidus, and dentate-a finding that was not observed in PD. This increased signal was significantly associated with the core symptoms of MSA-P. In addition, patients with MSA-P with cerebellar ataxia showed an elevated 18 F-Florzolotau uptake in the cerebellar dentate. CONCLUSIONS: 18 F-Florzolotau tau PET imaging findings may reflect the clinical severity of MSA-P and can potentially discriminate between this condition and PD. © 2022 International Parkinson and Movement Disorder Society.

In Vivo 18 F-APN-1607 Tau Positron Emission Tomography Imaging in MAPT Mutations: Cross-Sectional and Longitudinal Findings.

BACKGROUND: Frontotemporal lobar degeneration with tauopathy caused by MAPT (microtubule-associated protein tau) mutations is a highly heterogenous disorder. The ability to visualize and longitudinally monitor tau deposits may be beneficial to understand disease pathophysiology and predict clinical trajectories. OBJECTIVE: The aim of this study was to investigate the cross-sectional and longitudinal 18 F-APN-1607 positron emission tomography/computed tomography (PET/CT) imaging findings in MAPT mutation carriers. METHODS: Seven carriers of MAPT mutations (six within exon 10 and one outside of exon 10) and 15 healthy control subjects were included. All participants underwent 18 F-APN-1607 PET/CT at baseline. Three carriers of exon 10 mutations received follow-up 18 F-APN-1607 PET/CT scans. Standardized uptake value ratio (SUVR) maps were obtained using the cerebellar gray matter as the reference region. SUVR values observed in MAPT mutation carriers were normalized to data from healthy control subjects. A regional SUVR z score ≥ 2 was used as the criterion to define positive 18 F-APN-1607 PET/CT findings. RESULTS: Although the seven study patients had heterogenous clinical phenotypes, all showed a significant 18 F-APN-1607 uptake characterized by high-contrast signals. However, the anatomical localization of tau deposits differed in patients with distinct clinical symptoms. Follow-up imaging data, which were available for three patients, demonstrated worsening trends in patterns of tau accumulation over time, which were paralleled by a significant clinical deterioration. CONCLUSIONS: Our data represent a promising step in understanding the usefulness of 18 F-APN-1607 PET/CT imaging for detecting tau accumulation in MAPT mutation carriers. Our preliminary follow-up data also suggest the potential value of 18 F-APN-1607 PET/CT for monitoring the longitudinal trajectories of frontotemporal lobar degeneration caused by MAPT mutations. © 2021 International Parkinson and Movement Disorder Society.

MicroRNA-485-5p targets keratin 17 to regulate oral cancer stemness and chemoresistance via the integrin/FAK/Src/ERK/ß-catenin pathway.

BACKGROUND: The development of drug resistance in oral squamous cell carcinoma (OSCC) that frequently leads to recurrence and metastasis after initial treatment remains an unresolved challenge. Presence of cancer stem cells (CSCs) has been increasingly reported to be a critical contributing factor in drug resistance, tumor recurrence and metastasis. Thus, unveiling of mechanisms regulating CSCs and potential targets for developing their inhibitors will be instrumental for improving OSCC therapy. METHODS: siRNA, shRNA and miRNA that specifically target keratin 17 (KRT17) were used for modulation of gene expression and functional analyses. Sphere-formation and invasion/migration assays were utilized to assess cancer cell stemness and epithelial mesenchymal transition (EMT) properties, respectively. Duolink proximity ligation assay (PLA) was used to examine molecular proximity between KRT17 and plectin, which is a large protein that binds cytoskeleton components. Cell proliferation assay was employed to evaluate growth rates and viability of oral cancer cells treated with cisplatin, carboplatin or dasatinib. Xenograft mouse tumor model was used to evaluate the effect of KRT17- knockdown in OSCC cells on tumor growth and drug sensitization. RESULTS: Significantly elevated expression of KRT17 in highly invasive OSCC cell lines and advanced tumor specimens were observed and high KRT17 expression was correlated with poor overall survival. KRT17 gene silencing in OSCC cells attenuated their stemness properties including markedly reduced sphere forming ability and expression of stemness and EMT markers. We identified a novel signaling cascade orchestrated by KRT17 where its association with plectin resulted in activation of integrin ß4/α6, increased phosphorylation of FAK, Src and ERK, as well as stabilization and nuclear translocation of ß-catenin. The activation of this signaling cascade was correlated with enhanced OSCC cancer stemness and elevated expression of CD44 and epidermal growth factor receptor (EGFR). We identified and demonstrated KRT17 to be a direct target of miRNA-485-5p. Ectopic expression of miRNA-485-5p inhibited OSCC sphere formation and caused sensitization of cancer cells towards cisplatin and carboplatin, which could be significantly rescued by KRT17 overexpression. Dasatinib treatment that inhibited KRT17-mediated Src activation also resulted in OSCC drug sensitization. In OSCC xenograft mouse model, KRT17 knockdown significantly inhibited tumor growth, and combinatorial treatment with cisplatin elicited a greater tumor inhibitory effect. Consistently, markedly reduced levels of integrin ß4, active ß-catenin, CD44 and EGFR were observed in the tumors induced by KRT17 knockdown OSCC cells. CONCLUSIONS: A novel miRNA-485-5p/KRT17/integrin/FAK/Src/ERK/ß-catenin signaling pathway is unveiled to modulate OSCC cancer stemness and drug resistance to the common first-line chemotherapeutics. This provides a potential new therapeutic strategy to inhibit OSCC stem cells and counter chemoresistance.

Clinical Utility of 18 F-APN-1607 Tau PET Imaging in Patients with Progressive Supranuclear Palsy.

BACKGROUND: 18 F-APN-1607 is a novel tau PET tracer characterized by high binding affinity for 3- and 4-repeat tau deposits. Whether 18 F-APN-1607 PET imaging is clinically useful in PSP remains unclear. OBJECTIVES: The objective of this study was to investigate the clinical utility of 18 F-APN-1607 PET in the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. METHODS: We enrolled 3 groups consisting of patients with PSP (n = 20), patients with α-synucleinopathies (MSA with predominant parkinsonism, n = 7; PD, n = 10), and age- and sex-matched healthy controls (n = 13). The binding patterns of 18 F-APN-1607 in PET/CT imaging were investigated. Regional standardized uptake ratios were compared across groups and examined in relation to their utility in the differential diagnosis of PSP versus α-synucleinopathies. Finally, the relationships between clinical severity scores and 18 F-APN-1607 uptake were investigated after adjustment for age, sex, and disease duration. RESULTS: Compared with healthy controls, patients with PSP showed increased 18 F-APN-1607 binding in several subcortical regions, including the striatum, putamen, globus pallidus, thalamus, subthalamic nucleus, midbrain, tegmentum, substantia nigra, pontine base, red nucleus, raphe nuclei, and locus coeruleus. We identified specific regions that were capable of distinguishing PSP from α-synucleinopathies. The severity of PSP was positively correlated with the amount of 18 F-APN-1607 uptake in the subthalamic nucleus, midbrain, substantia nigra, red nucleus, pontine base, and raphe nuclei. CONCLUSIONS: 18 F-APN-1607 PET imaging holds promise for the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. © 2021 International Parkinson and Movement Disorder Society.

Association between multidisciplinary team care and the completion of treatment for oral squamous cell carcinoma: A cohort population-based study.

OBJECTIVES: This study investigates the relationship between multidisciplinary team care (MDTC) and patient completion of their treatment regimen for oral squamous cell carcinoma (OSCC). METHODS: We conducted a retrospective cohort study in patients diagnosed with OSCC in Taiwan from 1 January 2016 to 30 June 2018 using a linked cancer registry database. RESULTS: Of the 969 OSCC MDTC patients in the study cohort, 6.3% reported incomplete treatment, with 1.3% interrupting ongoing treatment and 5.0% terminating definitive treatment. Patients who had advanced-stage disease, experienced primary cancer recurrence or a secondary cancer, or were treated with surgery combined with chemotherapy, radiotherapy or chemoradiotherapy were more likely to terminate treatment before completion. The major reasons for interruption of ongoing treatment included 'patient or their family considered the patient to be in poor physical condition' and 'difficulty enduring physical discomfort caused by treatment'. The major reason for termination of definitive treatment was 'patient or their families or friends experienced negative treatment effects and worried about the side-effects of treatment'. CONCLUSION: Advanced-stage cancer, recurrence or secondary cancer, and surgery combined with chemotherapy, radiotherapy or chemoradiotherapy negatively affected treatment completion. MDTC allows for shared decision-making to determine the optimal treatment.

Comparison between 68Ga-PSMA-11 PET/CT and multiparametric magnetic resonance imaging in patients with biochemically recurrent prostate cancer following robot-assisted radical prostatectomy.

BACKGROUND/PURPOSE: We sought to compare the diagnostic performances of 68Ga-PSMA-11 PET/CT and prostate/whole-abdomen multiparametric magnetic resonance imaging (PWAmpMRI) in Taiwanese patients with biochemically recurrent prostate cancer following robot-assisted radical prostatectomy. METHODS: Between June 2017 and December 2018, we prospectively enrolled 34 patients. Upon review of all available clinical and imaging data, a best valuable comparator (BVC) was defined on an individual basis in the light of a consensus reached by a multidisciplinary tumor board. Diagnostic positivity was investigated in relation to the different lesion types. RESULTS: On a patient-based analysis, 68Ga-PSMA-11 PET/CT and PWAmpMRI showed a moderate agreement (kappa coefficient = 0.62). 68Ga-PSMA-11 PET/CT identified local recurrences, regional, and non-regional lymph node metastases, and bone metastases in 15, 10, 1, and 5 patients, respectively. Conversely, PWAmpMRI detected these lesions in 26, 8, 1, and 4 patients, respectively. When the BVC was used as reference standard, the positive diagnostic rates for local recurrences, regional lymph node metastases, non-regional lymph node metastases, and bone metastases were 57.7%, 90.9%, 100%, and 100%, respectively for 68Ga-PSMA-11 PET/CT, and 100%, 72.7%, 100%, and 80% for PWAmpMRI, respectively. The use of both PWAmpMRI and 68Ga-PSMA-11 PET/CT showed a complete diagnostic yield for detecting both local recurrence and systemic failure when PSA levels reached 0.5 ng/mL. CONCLUSION: Due to urine radioactivity, 68Ga-PSMA-11 PET/CT performs less than PWAmpMRI on local recurrences. However, it can have a complementary diagnostic role in the detection of lymph node metastases and in identifying non-axial bone metastases beyond the PWAmpMRI scanning field.

Radiation-Induced Metabolic Shifts in the Hepatic Parenchyma: Findings from 18F-FDG PET Imaging and Tissue NMR Metabolomics in a Mouse Model for Hepatocellular Carcinoma.

PURPOSE: By taking advantage of 18F-FDG PET imaging and tissue nuclear magnetic resonance (NMR) metabolomics, we examined the dynamic metabolic alterations induced by liver irradiation in a mouse model for hepatocellular carcinoma (HCC). METHODS: After orthotopic implantation with the mouse liver cancer BNL cells in the right hepatic lobe, animals were divided into two experimental groups. The first received irradiation (RT) at 15 Gy, while the second (no-RT) did not. Intergroup comparisons over time were performed, in terms of 18F-FDG PET findings, NMR metabolomics results, and the expression of genes involved in inflammation and glucose metabolism. RESULTS: As of day one post-irradiation, mice in the RT group showed an increased 18F-FDG uptake in the right liver parenchyma compared with the no-RT group. However, the difference reached statistical significance only on the third post-irradiation day. NMR metabolomics revealed that glucose concentrations peaked on day one post-irradiation both, in the right and left lobes-the latter reflecting a bystander effect. Increased pyruvate and glutamate levels were also evident in the right liver on the third post-irradiation day. The expression levels of the glucose-6-phosphatase (G6PC) and fructose-1, 6-bisphosphatase 1 (FBP1) genes were down-regulated on the first and third post-irradiation days, respectively. Therefore, liver irradiation was associated with a metabolic shift from an impaired gluconeogenesis to an enhanced glycolysis from the first to the third post-irradiation day. CONCLUSION: Radiation-induced metabolic alterations in the liver parenchyma occur as early as the first post-irradiation day and show dynamic changes over time.

Investigation of reactive astrogliosis effect on post-stroke cognitive impairment.

BACKGROUND: The aim of this study is to investigate the associations between post-stroke cognitive impairment (PSCI) severity and reactive astrogliosis (RA) extent on normalized 18F-THK-5351 positron-emission tomography (PET) imaging in amyloid-negative patients with first-ever stroke. METHODS: We prospectively enrolled 63 amyloid-negative patients with first-ever stroke. Neurocognitive evaluation, MRI, 18F-THK-5351, and 18F-florbetapir PET were performed around 3 months after stroke. The 18F-THK-5351 uptake intensity was normalized using a signal distribution template to obtain the Z-SUM scores as the RA extent in the whole brain and cerebral hemisphere ipsilateral to stroke lesion. We evaluated stroke volume, leukoaraiosis, and brain atrophy on MRI. We used a comprehensive neurocognitive battery to obtain composite cognitive scores, and defined PSCI as a general cognitive function score < - 1. We analyzed the influence of Z-SUM scores on PSCI severity after adjusting for demographic, vascular, and neurodegenerative variables. RESULTS: Twenty-five of 63 stroke patients had PSCI. Patients with PSCI had older age, lower education, and more severe cortical atrophy and total Z-SUM scores. Total Z-SUM scores were significantly associated with general cognitive and executive functions at multiple regression models. Path analyses showed that stroke can exert cognitive influence directly by stroke itself as well as indirectly through RA, including total and ipsilateral Z-SUM scores, in patients with either right or left hemisphere stroke. CONCLUSION: The patterns and intensity of 18F-THK-5351 uptake in amyloid-negative patients with first-ever stroke were associated with PSCI manifestations, which suggests that RA presents a modulating effect in PSCI development.

18F-FDG PET/CT findings of COVID-19: a series of four highly suspected cases.

PURPOSE: The aim of this case series is to illustrate the 18F-FDG PET/CT findings of patients with acute respiratory disease caused by COVID-19 in Wuhan, Hubei province of China. METHODS: We describe the 18F-FDG PET/CT results from four patients who were admitted to the hospital with respiratory symptoms and fever between January 13 and January 20, 2020, when the COVID-19 outbreak was still unrecognized and the virus infectivity was unknown. A retrospective review of the patients' medical history, clinical and laboratory data, as well as imaging findings strongly suggested a diagnosis of COVID-19. RESULTS: All patients had peripheral ground-glass opacities and/or lung consolidations in more than two pulmonary lobes. Lung lesions were characterized by a high 18F-FDG uptake and there was evidence of lymph node involvement. Conversely, disseminated disease was absent, a finding suggesting that COVID-19 has pulmonary tropism. CONCLUSIONS: Although 18F-FDG PET/CT cannot be routinely used in an emergency setting and is generally not recommended for infectious diseases, our pilot data shed light on the potential clinical utility of this imaging technique in the differential diagnosis of complex cases.

Comparison of 18F-FDG PET/MRI, MRI, and 18F-FDG PET/CT for the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma.

PURPOSE: In this prospective study, we sought to compare the clinical utility of fluorodeoxyglucose PET/MRI, MRI, and PET/CT in the detection of synchronous cancers and distant metastases in patients with oropharyngeal and hypopharyngeal squamous cell carcinoma (OHSCC). METHODS: We examined 198 consecutive patients with biopsy-proven OHSCC who agreed to receive chemoradiation. All patients underwent pretreatment PET/MRI and PET/CT on the same day. Patients were followed-up for a minimum of 12 months or until death. The McNemar's test and receiver-operating characteristic (ROC) curves were used to compare sensitivity/specificity and the diagnostic capabilities of PET/MRI, MRI, and PET/CT, respectively. RESULTS: We identified 55 patients (27.7%) who had synchronous cancers and/or distant metastases (number of involved sites: 83). The results of site-based analysis revealed that the sensitivity of PET/MRI was 15.7% higher than that of MRI (73.5% versus 57.8%, p < 0.001) and 3.6% higher compared with PET/CT (73.5% versus 69.9%, p = 0.083), whereas the sensitivity of PET/CT was 12.1% higher than that of MRI (69.9% versus 57.8%, p = 0.012). On a patient-basis, ROC curve analysis demonstrated that PET/MRI yielded a greater area under curve than MRI (0.930 versus 0.905, p = 0.023). There were no significant differences in terms of diagnostic capability between MRI and PET/CT (0.905 versus 0.917, p = 0.469) and between PET/MRI and PET/CT (0.930 versus 0.917, p = 0.062). CONCLUSIONS: In our cohort, PET/MRI showed a significantly higher diagnostic capability than MRI and no significant difference compared with PET/CT for the detection of synchronous cancers or distant metastases in patients with OHSCC.

A combined analysis of maximum standardized uptake value on FDG-PET, genetic markers, and clinicopathological risk factors in the prognostic stratification of patients with resected oral cavity squamous cell carcinoma.

OBJECTIVE: Clinical outcomes of patients with resected oral cavity squamous cell carcinoma (OCSCC) chiefly depend on the presence of specific clinicopathological risk factors (RFs). Here, we performed a combined analysis of FDG-PET, genetic markers, and clinicopathological RFs in an effort to improve prognostic stratification. METHODS: We retrospectively reviewed the clinical records of 2036 consecutive patients with first primary OCSCC who underwent surgery between 1996 and 2016. Of them, 345 underwent ultra-deep targeted sequencing (UDTS, between 1996 and 2011) and 168 whole exome sequencing (WES, between 2007 and 2016). Preoperative FDG-PET imaging was performed in 1135 patients from 2001 to 2016. Complete data on FDG-PET, genetic markers, and clinicopathological RFs were available for 327 patients. RESULTS: Using log-ranked tests based on 5-year disease-free survival (DFS), the optimal cutoff points for maximum standardized uptake values (SUV-max) of the primary tumor and neck metastatic nodes were 22.8 and 9.7, respectively. The 5-year DFS rates were as follows: SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7 (n = 77) versus SUVtumor-max < 22.8 and SUVnodal-max < 9.7 (n = 250), 32%/62%, P < 0.001; positive UDTS or WES gene panel (n = 64) versus negative (n = 263), 25%/62%, P < 0.001; pN3b (n = 165) versus pN1-2 (n = 162), 42%/68%, P < 0.001. On multivariate analyses, SUVtumor-max ≥ 22.8 or SUVnodal-max ≥ 9.7, a positive UDTS/WES gene panel, and pN3b disease were identified as independent prognosticators for 5-year outcomes. Based on these variables, we devised a scoring system that identified four distinct prognostic groups. The 5-year rates for patients with a score from 0 to 3 were as follows: loco-regional control, 80%/67%/47%/24% (P < 0.001); distant metastases, 13%/23%/55%/92% (P < 0.001); DFS, 74%/58%/28%/7% (P < 0.001); and disease-specific survival, 80%/64%/35%/7% (P < 0.001) respectively. CONCLUSIONS: The combined assessment of tumor and nodal SUV-max, genetic markers, and pathological node status may refine the prognostic stratification of OCSCC patients.

Deep learning for fully automated tumor segmentation and extraction of magnetic resonance radiomics features in cervical cancer.

OBJECTIVE: To develop and evaluate the performance of U-Net for fully automated localization and segmentation of cervical tumors in magnetic resonance (MR) images and the robustness of extracting apparent diffusion coefficient (ADC) radiomics features. METHODS: This retrospective study involved analysis of MR images from 169 patients with cervical cancer stage IB-IVA captured; among them, diffusion-weighted (DW) images from 144 patients were used for training, and another 25 patients were recruited for testing. A U-Net convolutional network was developed to perform automated tumor segmentation. The manually delineated tumor region was used as the ground truth for comparison. Segmentation performance was assessed for various combinations of input sources for training. ADC radiomics were extracted and assessed using Pearson correlation. The reproducibility of the training was also assessed. RESULTS: Combining b0, b1000, and ADC images as a triple-channel input exhibited the highest learning efficacy in the training phase and had the highest accuracy in the testing dataset, with a dice coefficient of 0.82, sensitivity 0.89, and a positive predicted value 0.92. The first-order ADC radiomics parameters were significantly correlated between the manually contoured and fully automated segmentation methods (p < 0.05). Reproducibility between the first and second training iterations was high for the first-order radiomics parameters (intraclass correlation coefficient = 0.70-0.99). CONCLUSION: U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images. First-order radiomics features extracted from whole tumor volume demonstrate the potential robustness for longitudinal monitoring of tumor responses in broad clinical settings. U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images. KEY POINTS: • U-Net-based deep learning can perform accurate fully automated localization and segmentation of cervical cancer in diffusion-weighted MR images. • Combining b0, b1000, and apparent diffusion coefficient (ADC) images exhibited the highest accuracy in fully automated localization. • First-order radiomics feature extraction from whole tumor volume was robust and could thus potentially be used for longitudinal monitoring of treatment responses.