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The role of torso computed tomography (CT) in evaluating body composition has been unexplored. This study assessed the potential of low-dose torso CT from positron emission tomography (PET)/CT for analyzing body composition and its relation to muscle strength. We retrospectively recruited 384 healthy Korean adults (231 men, 153 women) who underwent torso 18F-FDG PET/CT, bioelectrical impedance analysis (BIA), and muscle strength tests (handgrip strength [HGS] and knee extension strength [KES]). CT images were segmented into three compartments: torso volumetric, abdominal volumetric, and abdominal areal. Muscle amounts from each compartment were indexed to height (m2). BIA and HGS served as reference standards, with correlation coefficients (r) calculated. Torso muscle volumetric index (TorsoMVI) had the strongest correlations with BIA-derived values (r = 0.80 for men; r = 0.73 for women), surpassing those from the abdominal compartments. TorsoMVI was also correlated significantly with HGS (r = 0.39, p < 0.01) and differentiated between normal and possible sarcopenia in men (n = 225, 5960 ± 785 cm3/m2 vs. n = 6, 5210 ± 487 cm3/m2, p = 0.02). In women, KES correlated more strongly with muscle parameters than HGS. Despite gender-specific variations, torso CT-derived parameters show promise for evaluating body composition and sarcopenia. [ABSTRACT FROM AUTHOR]

We present the case of a 70-year-old male patient who underwent a gallium-68 (68Ga)-DOTATOC brain positron emission tomography (PET)/computed tomography (CT) for the assessment of a tumorous lesion on the dura. The patient had previously undergone below-knee amputation due to a mass of synovial sarcoma on the left foot and completed adjuvant chemotherapy approximately 3 months ago. Subsequently, a well-demarcated papillary solid mass located on the dura was surgically excised. Pathological examination confirmed that the dural metastasis originated from synovial sarcoma and post-operative magnetic resonance imaging (MRI) revealed no residual tumor. We conducted a 68Ga-DOTATOC brain PET/CT suspecting a meningioma given the presence of a dural mass. The result showed lower uptake (maximum standardized uptake [SUVmax 4.9]) than the pituitary gland (SUVmax 9.3). Thus, we successfully conducted a differential diagnosis of metastasis from the preexisting malignancy rather than the meningioma. 68Ga-DOTATOC PET/CT is a valuable tool for the differential diagnosis of meningioma. However, metastasis should also be considered, especially in patients with a history of malignancy and lesions showing mild 68Ga-DOTATOC uptake. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare the clinical significance of two parameters, division of standardized uptake value (SUV) of target arterial activity by background venous blood pool activity (SUVA/V) and subtraction of background venous blood pool activity from SUV of target arterial activity (SUVA-V) of carotid arteries with atherosclerotic plaques using 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT). Methods: Patients aged 50 years or more who were diagnosed with carotid artery stenosis of 50% or more with carotid Doppler ultrasonography and had torso 18F-FDG PET/CT were enrolled retrospectively and classified patients who developed cerebrovascular events (CVEs) within 5 years after 18F-FDG PET/CT scan as the active group and patients who did not experience the CVE within 5 years as an inactive group. We calculated SUVA/V and SUVA-V using measurements of SUVmax of carotid arteries and mean SUV of superior vena cava (SVC). Results: SUVA-V, SUVA-V_high, and SUVA-V_low were significantly higher in the active group than in the inactive group, but neither SUVA/V, SUVA/V_high, nor SUVA/V_low showed significant differences between the active and inactive groups. The difference in rank between groups of SUVA/V_high and SUVA/V_low was greater than the difference in rank between groups of SUVA-V_high and SUVA-V_low. The CVE incidence differed between SUVA/V_high and SUVA/V_low of high carotid FDG uptake, but the CVE incidence did not differ between SUVA-V_high and SUVA-V_low of high carotid FDG uptake. Conclusion: SUVA-V may be a more rational solution than SUVA/V for evaluating atherosclerotic plaque inflammation on 18F-FDG PET/CT. [ABSTRACT FROM AUTHOR]

18F-FP-CIT is a high-resolution imaging marker of nigrostriatal neuronal integrity, differentiating Parkinsonism with loss of dopaminergic terminals (presynaptic Parkinsonian syndrome [PS]) from Parkinsonism without nigrostriatal degeneration (non-PS). We assessed the diagnostic accuracy of 18F-FP-CIT PET in patients with clinically uncertain PS (CUPS) at the first visit. Among the 272 patients who underwent 18F-FP-CIT PET imaging at the first visit between September 2008 and July 2012, 111 had CUPS (age, 62.6 ± 10.5 y; male:female, 45:66; symptom duration, 13.1 ± 8.8 months). Uncertainty criteria included only one of the three cardinal signs of Parkinsonism, two signs without bradykinesia, or atypical signs. The baseline clinical and 18F-FP-CIT PET imaging diagnostic accuracy was compared with the accuracy of clinical diagnosis after > 2-year follow-up. Nuclear medicine physicians assessed the 18F-FP-CIT PET images visually. Focal dopamine transporter binding deficit in the posterior putamen was considered PS. Bilateral symmetric striatum without focal deficit, suggesting normal 18F-FP-CIT PET, and focal deficits elsewhere in the striatum suggesting vascular Parkinsonism were considered non-PS. Seventy-nine patients had PS, and 32 did not. Baseline clinical diagnosis included PS in 45 patients, non-PS in 24, and inconclusive in 42. Among patients in whom initial clinical diagnosis (PS or non-PS) was possible, the sensitivity, specificity, and accuracy of the baseline clinical and 18F-FP-CIT PET imaging diagnoses were 54.4, 50.0, and 53.2%, and 98.7, 100, and 99.1%, respectively. The respective positive and negative predictive values were 95.6 and 66.7%, and 100 and 97.0%. Among those with initially inconclusive diagnosis, 64.2% were eventually diagnosed with PS while 35.7% were diagnosed with non-PS. The final clinical diagnosis of these patients all matched those made by 18F-FP-CIT PET imaging, except in one patient with scan without evidence of dopaminergic deficit (SWEDD). 18F-FP-CIT PET diagnosis was more accurate than clinical diagnosis, reducing the false-negative and inconclusive clinical diagnosis rates at baseline in patients with CUPS. [ABSTRACT FROM AUTHOR]

We developed a novel quantification method named "shape feature" by combining the features of amyloid positron emission tomography (PET) and brain magnetic resonance imaging (MRI) and evaluated its significance in predicting the conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. From the ADNI database, 334 patients with MCI were included. The brain amyloid smoothing score (AV45_BASS) and brain atrophy index (MR_BAI) were calculated using the surface area and volume of the region of interest in AV45 PET and MRI. During the 48-month follow-up period, 108 (32.3%) patients converted from MCI to AD. Age, Mini-Mental State Examination (MMSE), cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog), apolipoprotein E (APOE), standardized uptake value ratio (SUVR), AV45_BASS, MR_BAI, and shape feature were significantly different between converters and non-converters. Univariate analysis showed that age, MMSE, ADAS-cog, APOE, SUVR, AV45_BASS, MR_BAI, and shape feature were correlated with the conversion to AD. In multivariate analyses, high shape feature, SUVR, and ADAS-cog values were associated with an increased risk of conversion to AD. In patients with MCI in the ADNI cohort, our quantification method was the strongest prognostic factor for predicting their conversion to AD. [ABSTRACT FROM AUTHOR]

We aimed to examine the associations of cardiovascular risk factors with myocardial perfusion reserve (MPR) in patients with type 2 diabetes and stable coronary artery disease. The study patients were retrospectively identified from a database of patients with diabetes and stable coronary artery disease at Asan Medical Center (Seoul, Republic of Korea), covering the period from 2017 to 2019. The primary outcome variable was MPR assessed by dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT. Univariable and stepwise multivariable analyses were performed to assess the associations of cardiovascular risk factors with MPR. A total of 276 patients (236 men and 40 women) were included. The median global MPR was 2.4 (interquartile range 1.9–3.0). Seventy-five (27.2%) patients had an MPR < 2.0. Multivariable linear regression showed that smoking (ß = − 0.44, 95% confidence interval − 0.68 to − 0.21, P < 0.001), hypertension (ß = − 0.24, 95% confidence interval − 0.47 to − 0.02, P = 0.033), and summed difference score (ß = − 0.05, 95% confidence interval − 0.07 to − 0.03, P < 0.001) were independently associated with MPR. Abnormal MPR (< 2.0) was associated with a higher incidence of cardiac death or myocardial infarction (P = 0.034). MPR assessed by dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT was impaired in a large cohort of patients with diabetes. After adjusting for risk variables, including standard myocardial perfusion imaging characteristics, smoking, and hypertension were associated with MPR. Our results may aid in identifying patients with impaired MPR and stratifying patients with type 2 diabetes. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is one of the most common neurodegenerative diseases caused by the loss of dopaminergic neurons in the substantia nigra pars compacta. Although the etiology of PD is still unclear, the death of dopaminergic neurons during PD progression was revealed to be associated with abnormal aggregation of α-synuclein, elevation of oxidative stress, dysfunction of mitochondrial functions, and increased neuroinflammation. In this study, the effects of Licochalcone D (LCD) on MG132-induced neurotoxicity in primitive neural stem cells (pNSCs) derived from reprogrammed iPSCs were investigated. A cell viability assay showed that LCD had anti-apoptotic properties in MG132-induced oxidative-stressed pNSCs. It was confirmed that apoptosis was reduced in pNSCs treated with LCD through 7-AAD/Annexin Ⅴ staining and cleaved caspase3. These effects of LCD were mediated through an interaction with JunD and through the EGFR/AKT and JNK signaling pathways. These findings suggest that LCD could be a potential antioxidant reagent for preventing disease-related pathological phenotypes of PD. [ABSTRACT FROM AUTHOR]

Background: Cerebral amyloid angiopathy (CAA) often presents as cognitive impairment, but the mechanism of cognitive decline is unclear. Recent studies showed that number of microbleeds were associated with cognitive decline.Objective: We aimed to investigate how microbleeds contribute to cognitive impairment in association with white matter tract abnormalities or cortical thickness in CAA.Methods: This retrospective comparative study involved patients with probable CAA according to the Boston criteria (Aβ+ CAA) and patients with Alzheimer's disease (Aβ+ AD), all of whom showed severe amyloid deposition on amyloid PET. Using mediation analysis, we investigated how FA or cortical thickness mediates the correlation between the number of lobar microbleeds and cognition.Results: We analyzed 30 patients with Aβ+ CAA (age 72.2±7.6, female 53.3%) and 30 patients with Aβ+ AD (age 71.5±7.6, female 53.3%). The two groups showed similar degrees of cortical amyloid deposition in AD-related regions. The Aβ+ CAA group had significantly lower FA values in the clusters of the posterior area than did the Aβ+ AD group(family-wise error-corrected p < 0.05). The correlation between the number of lobar microbleeds and visuospatial function was indirectly mediated by white matter tract abnormality of right posterior thalamic radiation (PTR) and tapetum, while lobar microbleeds and language function was indirectly mediated by the abnormality of left PTR and sagittal stratum. Cortical thickness did not mediate the association between lobar microbleeds and cognition.Conclusion: This result supports the hypothesis that microbleeds burden leads to white matter tract damage and subsequent cognitive decline in CAA. [ABSTRACT FROM AUTHOR]

The concept of cognitive reserve (CR) has been proposed as a protective factor that modifies the effect of brain pathology on cognitive performance. It has been characterized through CR proxies; however, they have intrinsic limitations. In this study, we utilized two different datasets containing tau, amyloid PET, and T1 magnetic resonance imaging. First, 91 Alzheimer's disease (AD) continuum subjects were included from Alzheimer's Disease Neuroimaging Initiative 3. CR was conceptualized as the residual between actual cognition and estimated cognition based on amyloid, tau, and neurodegeneration. The proposed marker was tested by the correlation with CR proxy and modulation of brain pathology effects on cognitive function. Second, longitudinal data of baseline 53 AD spectrum and 34 cognitively unimpaired (CU) participants in the MEMORI dataset were analyzed. CR marker was evaluated for the association with disease conversion rate and clinical progression. Applying our multimodal CR model, this study demonstrates the differential effect of CR on clinical progression according to the disease status and the modulating effect on the relationship between brain pathology and cognition. The proposed marker was associated with years of education and modulated the effect of pathological burden on cognitive performance in the AD spectrum. Longitudinally, higher CR marker was associated with lower disease conversion rate among prodromal AD and CU individuals. Higher CR marker was related to exacerbated cognitive decline in the AD spectrum; however, it was associated with a mitigated decline in CU individuals. These results provide evidence that CR may affect the clinical progression differentially depending on the disease status. [ABSTRACT FROM AUTHOR]

Amyloid (Aβ) and tau proteins are pathologic hallmarks of Alzheimer disease (AD). It is well known that there is spatial disparity between Aβ and tau protein deposition but, crossed hemispheric accumulation of these 2 proteins has not been reported. Here we report the case of a 76-year-old woman with typical AD who underwent amyloid positron emission tomography (PET) ([ 18 F]-florbetaben) and tau PET scans ([ 18 F]PI-2620), revealing crossed accumulation of Aβ and tau in the cerebral hemisphere. A neuropsychological assessment showed impairment in memory with spared activities of daily living. In the PET analysis, amyloid deposition was observed only in the left side of the cerebral hemisphere and tau only in the right side. Neuroimaging follow-up indicated that the spatial pattern of these protein accumulations had not changed. This case suggests the possibility of independent Aβ and tau pathogenic pathways in AD. [ABSTRACT FROM AUTHOR]

Background: We investigated longitudinal changes in cortical tau accumulation and their association with cognitive decline in patients with Alzheimer's disease (AD) spectrum using [18F]PI‐2620 PET. Method: We enrolled 54 (69.9±8.5 y, M:F = 16:38) participants (8 cognitively normal [NC], 28 mild cognitive impairment [MCI], 18 AD) who completed [18F]PI‐2620 PET scans at baseline and 1 y follow up. Subject also underwent [18F]florbetaben PET (baseline only), MRI and neuropsychological tests. Aβ PET images were visually scored as positive or negative. Aβ+ MCI & AD were classified into early onset (<65 y, EO+) and late onset (≥65, LO+) group. Standardized uptake value ratios (SUVr) of [18F]PI‐2620 PET were determined by cerebral to inferior cerebellar ratio and corrected for partial volume effect. Cortical volumes were calculated from 3D T1‐weighted MR images. We also investigated a correlation between the progression of tau accumulation and cognitive decline. Result: Thirty eight out of 57 participants showed Aβ+ (1 NC, 20 MCI, 17 AD). Global SUVr values of [18F]PI‐2620 PET were 0.96±0.07 in 7 Aβ‐ NC, 1.23±0.41 in 17 LO+ (76.7±3.8y) and 1.86±0.87 in 20 EO+ (63.4±5.4y) (p<0.001). It increased by 0.09±0.14 (7.0%) in LO+ and 0.14±0.27 (11.6%) in EO+ in contrast to no change in NC‐. EO+ showed abundant tau accumulation in Braak III‐V areas at baseline with rapid accumulation in Braak V area (0.33±0.41 [13.9%] vs. 0.08±0.14 [6.7%], p = 0.010) than LO+ group. It showed abundant and rapid accumulation on Braak 3 areas in LO+ group (1.61±0.53 at baseline, change: 0.15±0.25 [8.2%]). Deterioration of the visuospatial function and verbal memory was associated with the progression of tau accumulation in Braak III‐V areas in EO+ group. Progressive atrophy in Braak III‐V areas were associated with the progression of tau accumulation in LO+ group whereas hippocampal atrophy did in EO+ group. Conclusion: Tau accumulation measured by [18F]PI‐2620 in EO+ showed rapid accumulation in Braak III‐V areas and correlated with deterioration of the visuospatial function and verbal memory. It suggests that [18F]PI‐2620 PET is potential biomarker for selecting therapeutic target and monitoring treatment effect for tau targeting treatment. [ABSTRACT FROM AUTHOR]

Background: The role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in the prognostication and response evaluation of primary central nervous system lymphoma (PCNSL) remains inadequately defined., Methods: We conducted a retrospective analysis of 268 consecutive newly diagnosed patients with PCNSL between 2006 and 2020. Of these patients, 105 and 110 patients were included to evaluate the prognostic value of baseline and post-treatment 18F-FDG-PET/CT scans, respectively. Tumor uptake was considered positive when it exceeded that of the contralateral brain upon visual assessment. Quantitative analysis of baseline 18F-FDG-PET/CT included measurement of the maximal standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG)., Results: The median age of the 268 patients was 62 years (range: 17-85), with 55% being male. The median progression-free survival (PFS) was 24.5 months (95% confidence interval [CI], 19.9-29.1), and the median overall survival (OS) was 34.5 months (95% CI, 22.9-46.1). The average SUVmax was 15.3 ± 5.7 and the mean TMTV and TLG were 12.6 ± 13.9 cm3 and 135.0 ± 152.7 g, respectively. Patients with a baseline TMTV ≥17.0 cm3 had significantly shorter OS (12.5 vs. 74.0 months, p=0.011). Post-treatment metabolic response by 18F-FDG-PET/CT significantly predicted PFS (median: 10.5 vs. 46.0 months, p=0.001) and OS (median: 21.0 vs. 62.0 months, p=0.002), whereas anatomic response by contrast-enhanced MRI showed no statistically significant differences in PFS (p=0.130) or OS (p=0.540)., Conclusion: Baseline TMTV and post-treatment metabolic response, as assessed by 18F-FDG-PET/CT, are significant prognostic factors in patients with PCNSL., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Objective: To develop and validate a preoperative risk score incorporating carbohydrate antigen (CA) 19-9, CT, and fluorine-18-fluorodeoxyglucose ( 18 F-FDG) PET/CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma (PDAC)., Materials and Methods: Patients with resectable PDAC who underwent upfront surgery between 2014 and 2017 (development set) or between 2018 and 2019 (test set) were retrospectively evaluated. In the development set, a risk-scoring system was developed using the multivariable Cox proportional hazards model, including variables associated with RFS. In the test set, the performance of the risk score was evaluated using the Harrell C-index and compared with that of the postoperative pathological tumor stage., Results: A total of 529 patients, including 335 (198 male; mean age ± standard deviation, 64 ± 9 years) and 194 (103 male; mean age, 66 ± 9 years) patients in the development and test sets, respectively, were evaluated. The risk score included five variables predicting RFS: tumor size (hazard ratio [HR], 1.29 per 1 cm increment; P < 0.001), maximal standardized uptake values of tumor ≥ 5.2 (HR, 1.29; P = 0.06), suspicious regional lymph nodes (HR, 1.43; P = 0.02), possible distant metastasis on 18 F-FDG PET/CT (HR, 2.32; P = 0.03), and CA 19-9 (HR, 1.02 per 100 U/mL increment; P = 0.002). In the test set, the risk score showed good performance in predicting RFS (C-index, 0.61), similar to that of the pathologic tumor stage (C-index, 0.64; P = 0.17)., Conclusion: The proposed risk score based on preoperative CA 19-9, CT, and 18 F-FDG PET/CT variables may have clinical utility in selecting high-risk patients with resectable PDAC., Competing Interests: Seung Soo Lee, who holds the respective position of Editorial Board Member of the Korean Journal of Radiology, was not involved in the editorial evaluation or decision to publish this article. The remaining author has declared no conflicts of interest., (Copyright © 2024 The Korean Society of Radiology.)

Background: There is no standardized assessment for evaluating response although neoadjuvant chemotherapy (NAT) is widely accepted for borderline resectable or locally advanced pancreatic cancer (BRPC or LAPC). This study was aimed to evaluate NAT response using positron emission tomography (PET) with 2-deoxy-2-[fluorine-18]fluoro-D-glucose ( 18 F-FDG-PET/CT) parameters alongside carbohydrate antigen (CA) 19-9 levels., Methods: Patients who underwent surgery after NAT for BRPC and LAPC between 2017 and 2021 were identified. The study assessed the prognostic value of PET-derived parameters after NAT, determining cutoff values using the K-adaptive partitioning method. It created four groups based on the elevation or normalization of PET parameters and CA19-9 levels, comparing survival between these groups., Results: Of 200 eligible patients, FOLFIRINOX and gemcitabine-based NAT was administered in 166 and 34 patients, respectively (mean NAT cycles, 8.3). In a multivariate analysis, metabolic tumor volume (MTV) demonstrated the most robust performance in assessing response [hazard ratio (HR) 3.11, 95% confidence interval (CI) 1.73-5.58, P <0.001] based on cutoff value of 2.4. Patients with decreased MTV had significantly better survival than those with elevated MTV among individuals with CA19-9 levels less than 37 IU/l (median survival; 35.5 vs. 20.9 months, P <0.001) and CA19-9 levels at least 37 IU/l (median survival; 34.3 vs. 17.8 months, P =0.03). In patients suspected to be Lewis antigen negative, the predictive performance of MTV was found to be limited ( P =0.84)., Conclusion: Elevated MTV is an influential prognostic factor for worse survival, regardless of post-NAT CA19-9 levels. These results could be helpful in identifying patients with a poor prognosis despite normalization of CA19-9 levels after NAT., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

We investigated the longitudinal changes in cortical tau accumulation and their association with cognitive decline in patients in the Alzheimer disease (AD) continuum using 2-(2-([ 18 F]fluoro)pyridin-4-yl)-9 H -pyrrolo[2,3-b:4,5c']dipyridine ([ 18 F]PI-2620) PET. Methods: We prospectively enrolled 52 participants (age, 69.7 ± 8.4 y; 18 men and 34 women): 7 with normal cognition, 28 with mild cognitive impairment, and 17 with AD. They all completed the [ 18 F]PI-2620 and [ 18 F]florbetaben PET, MRI, and neuropsychologic tests at baseline and, excepting the [ 18 F]florbetaben PET, at the 1-y follow-up. Amyloid-β (Aβ) PET images were visually scored as positive (+) or negative (-). Patients on the AD continuum, including Aβ+ mild cognitive impairment and AD, were classified into early-onset (EO+) (<65 y old) or late-onset (LO+) (≥65 y old) groups. [ 18 F]PI-2620 PET SUV ratios (SUVRs) were determined by calculating the cerebral-to-inferior cerebellar ratio. Cortical volumes were calculated using 3-dimensional T1-weighted MRI. The correlation between tau accumulation progression and cognitive decline was also investigated. Results: The global [ 18 F]PI-2620 PET SUVRs were 1.04 ± 0.07 in 15 Aβ- patients, 1.18 ± 0.21 in 20 LO+ patients (age, 76.7 ± 3.8 y), and 1.54 ± 0.38 in 17 EO+ patients (age, 63.4 ± 5.4 y; P < 0.001) at baseline. The global SUVR increased over 1 y by 0.05 ± 0.07 (3.90%) and 0.13 ± 0.22 (8.41%) in the LO+ and EO+ groups, respectively, whereas in the Aβ- groups, it remained unchanged. The EO+ group showed higher global and regional tau deposition than did the Aβ- and LO+ groups ( P < 0.05 for each) and rapid accumulation in Braak stage V (0.15 ± 0.25; 9.10% ± 12.27%; P = 0.016 and 0.008), Braak stage VI (0.08 ± 0.12; 7.16% ± 10.06%; P < 0.006 and 0.005), and global SUVR ( P = 0.013) compared with the Aβ- group. In the EO+ group, the changes in SUVR in Braak stages II-VI were strongly correlated with the baseline and changes in verbal memory ( P < 0.03). The LO+ group showed higher tau accumulation in Braak stage I-IV areas than did the Aβ- group ( P < 0.001 for each). In the LO+ group, the change in SUVR in Braak stages III and IV moderately correlated with the change in attention ( P < 0.05), and the change in SUVR in Braak stages V and VI moderately correlated with the change in visuospatial function ( P < 0.005). Conclusion: These findings suggest that [ 18 F]PI-2620 PET can be a biomarker to provide regional and chronologic information about tau pathology in the AD continuum., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Background and Purpose: Alzheimer's disease (AD) does not always mean amyloid positivity. [ 18 F]THK-5351 has been shown to be able to detect reactive astrogliosis as well as tau accompanied by neurodegenerative changes. We evaluated the [ 18 F]THK-5351 retention patterns in positron-emission tomography (PET) and the clinical characteristics of patients clinically diagnosed with AD dementia who had negative amyloid PET findings., Methods: We performed 3.0-T magnetic resonance imaging, [ 18 F]THK-5351 PET, and amyloid PET in 164 patients with AD dementia. Amyloid PET was visually scored as positive or negative. [ 18 F]THK-5351 PET were visually classified as having an intratemporal or extratemporal spread pattern., Results: The 164 patients included 23 (14.0%) who were amyloid-negative (age 74.9±8.3 years, mean±standard deviation; 9 males, 14 females). Amyloid-negative patients were older, had a higher prevalence of diabetes mellitus, and had better visuospatial and memory functions. The frequency of the apolipoprotein E ε4 allele was higher and the hippocampal volume was smaller in amyloid-positive patients. [ 18 F]THK-5351 uptake patterns of the amyloid-negative patients were classified into intratemporal spread ( n =10) and extratemporal spread ( n =13). Neuropsychological test results did not differ significantly between these two groups. The standardized uptake value ratio of [ 18 F]THK-5351 was higher in the extratemporal spread group (2.01±0.26 vs. 1.61±0.15, p =0.001). After 1 year, Mini Mental State Examination (MMSE) scores decreased significantly in the extratemporal spread group (-3.5±3.2, p =0.006) but not in the intratemporal spread group (-0.5±2.8, p =0.916). The diagnosis remained as AD ( n =5, 50%) or changed to other diagnoses ( n =5, 50%) in the intratemporal group, whereas it remained as AD ( n =8, 61.5%) or changed to frontotemporal dementia ( n =4, 30.8%) and other diagnoses ( n =1, 7.7%) in the extratemporal spread group., Conclusions: Approximately 70% of the patients with amyloid-negative AD showed abnormal [ 18 F]THK-5351 retention. MMSE scores deteriorated rapidly in the patients with an extratemporal spread pattern., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2022 Korean Neurological Association.)

Purpose: This work aimed to explore in depth the genomic and molecular underpinnings of hepatocellular carcinoma (HCC) with increased 2[18F]fluoro-2-deoxy-d-glucose (FDG) uptake in PET and to identify therapeutic targets based on this imaging-genomic surrogate., Experimental Design: We used RNA sequencing and whole-exome sequencing data obtained from 117 patients with HCC who underwent hepatic resection with preoperative FDG-PET/CT imaging as a discovery cohort. The primary radiogenomic results were validated with transcriptomes from a second cohort of 81 patients with more advanced tumors. All patients were allocated to an FDG-avid or FDG-non-avid group according to the PET findings. We also screened potential drug candidates targeting FDG-avid HCCs in vitro and in vivo., Results: High FDG avidity conferred worse recurrence-free survival after HCC resection. Whole transcriptome analysis revealed upregulation of mTOR pathway signals in the FDG-avid tumors, together with higher abundance of associated mutations. These clinical and genomic findings were replicated in the validation set. A molecular signature of FDG-avid HCCs identified in the discovery set consistently predicted poor prognoses in the public-access datasets of two cohorts. Treatment with an mTOR inhibitor resulted in decreased FDG uptake followed by effective tumor control in both the hyperglycolytic HCC cell lines and xenograft mouse models., Conclusions: Our PET-based radiogenomic analysis indicates that mTOR pathway genes are markedly activated and altered in HCCs with high FDG retention. This nuclear imaging biomarker may stimulate umbrella trials and tailored treatments in precision care of patients with HCC., (©2022 American Association for Cancer Research.)

Purpose: Neuroinflammation is considered an important pathway associated with several diseases that result in cognitive decline. 18 F-THK5351 positron emission tomography (PET) signals might indicate the presence of neuroinflammation, as well as Alzheimer's disease-type tau aggregates. β-amyloid (Aβ)-negative (Aβ-) amnestic mild cognitive impairment (aMCI) may be associated with non-Alzheimer's disease pathophysiology. Accordingly, we investigated associations between 18 F-THK5351 PET positivity and cognitive decline among Aβ- aMCI patients., Materials and Methods: The present study included 25 amyloid PET negative aMCI patients who underwent a minimum of two follow-up neuropsychological evaluations, including clinical dementia rating-sum of boxes (CDR-SOB). The patients were classified into two groups: 18 F-THK5351-positive and -negative groups. The present study used a linear mixed effects model to estimate the effects of 18 F-THK5351 PET positivity on cognitive prognosis among Aβ- aMCI patients., Results: Among the 25 Aβ- aMCI patients, 10 (40.0%) were 18 F-THK5351 positive. The patients in the 18 F-THK5351-positive group were older than those in the 18 F-THK5351-negative group (77.4±2.2 years vs. 70.0±5.5 years; p <0.001). There was no difference between the two groups with regard to the proportion of apolipoprotein E ε4 carriers. Interestingly, however, the CDR-SOB scores of the 18 F-THK5351-positive group deteriorated at a faster rate than those of the 18 F-THK5351-negative group (B=0.003, p =0.033)., Conclusion: The results of the present study suggest that increased 18 F-THK5351 uptake might be a useful predictor of poor prognosis among Aβ- aMCI patients, which might be associated with increased neuroinflammation (ClinicalTrials.gov NCT02656498)., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2022.)

Objectives: In this study, we aimed to analyze patient mortality rate after non-operative treatment of hip fractures to determine the distribution of causes of death and to compare factors affecting mortality., Patients and Methods: Between January 2013 and March 2019, a total of 93 patients (17 males, 76 females; mean age: 86.0±7.4 years; range, 64 to 98 years) who had hip fractures and were treated non-operatively were analyzed retrospectively. Survival, date of death, and cause of death were collected and analyzed. Baseline demographics, pre-trauma ambulation, pre- and post-trauma residence status, American Society of Anesthesiologists Physical Status (ASA PS) classification, and Parker's mobility score were compared with one-year mortality rates., Results: The mean follow-up of survivors was 16.1±11.9 (range, 6.3 to 79.6) months. The mean survival of non-survivors was 4.9±6.1 (range, 0.007 to 27.3) months. The 3-, 6-, 12-, and 24-month mortality rates were 40.9%, 53.3%, 74.4%, and 87.5%, respectively. Respiratory diseases (33.3%) and cardiovascular diseases (13.6%) were the main causes of death among the patients. There was no statistically significant difference between the patients' age, sex, fracture site, pre-trauma ambulation, pre- and post-trauma residence status, ASA PS classification, Parker's mobility score, and one-year mortality., Conclusion: A significant number of patients are still treated non-operatively after hip fractures, and they have a high mortality rate. Efforts and research are needed to reduce mortality and improve the quality of life.

Background: The optimal prognostic markers for neoadjuvant chemotherapy in patients with borderline resectable or locally advanced pancreatic cancer are not yet established., Method: Patients who received neoadjuvant chemotherapy prior to surgery and underwent FDG-PET/CT between July 2012 and December 2017 were included. Metabolic parameters including standardized uptake value (SUV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) on PET/CT, and response evaluations using PERCIST criteria, were investigated for its impact on survival and recurrence. Cox proportional hazards model was performed. Differences in risk were expressed as hazard ratio (HR) with 95 per cent confidence interval., Results: The patients with borderline resectable (N = 106) or locally advanced pancreatic cancer (N = 82) were identified. The median survival was 33.6 months. Decreased metabolic parameters of PET/CT after neoadjuvant chemotherapy were associated with positive impacts on survival and recurrence such as SUVmax (HR 1.16, 95 per cent c.i. 1.01 to 1.32, P = 0.025), SUVpeak (HR 1.26, 95 per cent c.i. 1.05 to 1.51, P = 0.011), and MTV (HR 1.15, 95 per cent c.i. 1.04 to 1.26, P = 0.005). Large delta values were related to a positive impact on recurrence such as SUVmax (HR 1.21, 95 per cent c.i. 1.06 to 1.38, P = 0.005). Post-neoadjuvant chemotherapy SUVmax ≥3 (HR 3.46, 95 per cent c.i. 1.21 to 9.91; P = 0.036) was an independent prognostic factor for negative impact on survival. Patients with post-neoadjuvant chemotherapy SUVmax <3 showed more chemotherapy cycles (8.7 versus 6.2, P = 0.001), more frequent complete metabolic response (25 versus 2.2 per cent, P = 0.002), smaller tumour size (2.1 versus 3.1 cm, P = 0.002), and less frequent lymphovascular invasion (23.7 versus 51.1 per cent, P = 0.020) than patients with SUVmax ≥3., Conclusion: Reduction in metabolic tumour parameters of FDG- PET/CT after neoadjuvant chemotherapy indicates improved overall survival and recurrence-free survival., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd. All rights reserved. For permissions, please email: journals.permissions@oup.com.)