Cerebral tau pathology in cerebral amyloid angiopathy

Tau, a hallmark of Alzheimer's disease, is poorly characterized in cerebral amyloid angiopathy. We aimed to assess the clinico-radiological correlations between tau positron emission tomography scans and cerebral amyloid angiopathy. We assessed cerebral amyloid and hyperphosphorylated tau in patients with probable cerebral amyloid angiopathy (n = 31) and hypertensive small vessel disease (n = 27) using 11C-Pittsburgh compound B and 18F-T807 positron emission tomography. Multivariable regression models were employed to assess radio-clinical features related to cerebral tau pathology in cerebral amyloid angiopathy. Cerebral amyloid angiopathy exhibited a higher cerebral tau burden in the inferior temporal lobe [1.25 (1.17-1.42) versus 1.08 (1.05-1.22), P < 0.001] and all Braak stage regions of interest (P < 0.05) than hypertensive small vessel disease, although the differences were attenuated after age adjustment. Cerebral tau pathology was significantly associated with cerebral amyloid angiopathy-related vascular markers, including cortical superficial siderosis (β = 0.12, 95% confidence interval 0.04-0.21) and cerebral amyloid angiopathy score (β = 0.12, 95% confidence interval 0.03-0.21) after adjustment for age, ApoE4 status and whole cortex amyloid load. Tau pathology correlated significantly with cognitive score (Spearman's ρ=-0.56, P = 0.001) and hippocampal volume (-0.49, P = 0.007), even after adjustment. In conclusion, tau pathology is more frequent in sporadic cerebral amyloid angiopathy than in hypertensive small vessel disease. Cerebral amyloid angiopathy-related vascular pathologies, especially cortical superficial siderosis, are potential markers of cerebral tau pathology suggestive of concomitant Alzheimer's disease.

PET/MRI in Endometrial Cancer: Imaging Biomarkers are Associated with Disease Progression and Overall Survival

RATIONALE AND OBJECTIVES

To evaluate the association between positron emission tomography (PET)/magnetic resonance imaging (MRI) biomarkers and survival outcomes in patients with endometrial cancer.

MATERIALS AND METHODS

Between April 2014 and April 2016, 88 patients with newly diagnosed endometrial cancer participated this prospective study and underwent [18F] fluorodeoxyglucose PET/MRI. Sixty-nine patients with measurable tumors on PET/MRI were included in the image analysis. Imaging biomarkers included the minimum and mean apparent diffusion coefficients (ADCmin and ADCmean), maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors. The log-rank test and Cox proportional hazards model were used to assess the relationship between imaging biomarkers and survival.

RESULTS

After a median follow-up of 80 months, 15 (22%) patients had tumor progression and six (9%) patients died. The results of ADCmin, ADCmean, and SUVmax did not show a significant association with progression-free survival (PFS) and overall survival (OS). Significantly shorter PFS was noted in patients with primary tumors with higher MTV (P < 0.001) and TLG (P < 0.001). Significantly shorter OS was also noted in patients with primary tumors with higher MTV (P = 0.048) and TLG (P = 0.034). In the multivariate analysis, MTV was an independent predictor of PFS (hazard ratio = 10.84, P = 0.033).

CONCLUSION

PET/MRI biomarkers, particularly MTV and TLG, are associated with PFS and OS in patients with endometrial cancer. MTV was an independent predictor of PFS.

Differences in lobar microbleed topography in cerebral amyloid angiopathy and hypertensive arteriopathy

Lobar cerebral microbleeds are a characteristic neuroimaging finding in cerebral amyloid angiopathy (CAA) but can also be found in hypertensive arteriolosclerosis. We aimed to investigate whether CAA is more associated with intracortical lobar microbleeds than hypertensive arteriosclerosis. Ninety-one survivors of spontaneous intracerebral hemorrhage with at least one lobar microbleed were included and underwent brain MRI and amyloid PET. We categorized lobar microbleeds as intracortical, juxtacortical, or subcortical. We assessed the associations between the lobar microbleed categories and microangiopathy subtypes or cerebral amyloid load based on the Pittsburgh Compound-B PET standardized uptake value ratio (SUVR). Patients with CAA had a higher prevalence of intracortical lobar microbleeds (80.0% vs. 50.8%, P = 0.011) and lower prevalence of subcortical lobar microbleeds (13.3% vs. 60.1%, P < 0.001) than patients with hypertensive arteriolosclerosis. Strictly intracortical/juxtacortical lobar microbleeds were associated with CAA (OR 18.9 [1.9-191.4], P = 0.013), while the presence of subcortical lobar microbleeds was associated with hypertensive arteriolosclerosis (OR 10.9 [1.8-68.1], P = 0.010). Amyloid retention was higher in patients with strictly intracortical/juxtacortical CMBs than those without (SUVR = 1.15 [1.05-1.52] vs. 1.08 [1.02-1.19], P = 0.039). Amyloid retention positively correlated with the number of intracortical lobar microbleeds (P < 0.001) and negatively correlated with the number of subcortical lobar microbleeds (P = 0.018). CAA and cortical amyloid deposition are more strongly associated with strictly intracortical/juxtacortical microbleeds than subcortical lobar microbleeds. Categorization of lobar microbleeds based on anatomical location may help differentiate the underlying microangiopathy and potentially improve the accuracy of current neuroimaging criteria for cerebral small vessel disease.

Clinical practice consensus for the diagnosis and management of melanoma in Taiwan

Melanoma is rare in Taiwan. Asian melanoma is distinct from Western melanoma because acral and mucosal melanoma accounts for the majority of melanoma cases, leading to distinct tumor behaviors and genetic profiling. With consideration of the clinical guidelines in Western countries, Taiwanese experts developed a local clinical practice consensus guideline. This consensus includes diagnosis, staging, and surgical and systemic treatment, based only on clinical evidence, local epidemiology, and available resources evaluated by experts in Taiwan. This consensus emphasizes the importance of surgical management, particularly for sentinel lymph node biopsies. In addition, molecular testing for BRAF is mandatory for patients before systemic treatment. Furthermore, immunotherapy and targeted therapy are prioritized for systemic treatment. This consensus aimed to assist clinicians in Taiwan in diagnosing and treating patients according to available evidence.

Comparison of post-COVID-19 vaccination hypermetabolic lymphadenopathy on 18F-fluorodeoxyglucose PET/CT between virus-vector vaccine and mRNA vaccine

PURPOSE

We compared hypermetabolic lymphadenopathy (HLN) on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) after virus-vector and mRNA vaccines for coronavirus disease 2019 (COVID-19).

METHODS

This retrospective study included 573 participants who underwent FDG PET/CT after receiving a virus-vector vaccine (ChAdOx1, AstraZeneca [AZ] group) or an mRNA vaccine (mRNA-1273, Moderna [M] group) from July 2021 to October 2021. The incidence and avidity of HLN were evaluated and correlated with clinical features and vaccine type. The final analysis was conducted with 263 participants in the AZ group and 310 participants in the M group.

RESULTS

The HLN incidence was significantly lower in the AZ group than in the M group (38/263 [14%] vs. 74/310 [24%], p = 0.006). The FDG avidity of HLN was comparable between the two groups. The HLN incidence in both groups was significantly higher within 4 weeks after the vaccination compared with more than 4 weeks. The HLN incidence within 4 weeks of the vaccination was significantly higher in the M group than in the AZ group (p = 0.008), whereas a difference in HLN incidence between the two groups was not observed after the same duration (p = 0.11).

CONCLUSIONS

The mRNA mRNA-1273 COVID-19 vaccine was found to be associated with higher glucose hypermetabolism in regional lymph nodes within the first 4 weeks compared with the virus-vector vaccine, as indicated by the presence of HLN on FDG PET/CT. The degree of glucose hypermetabolism was comparable between the two vaccines.

Myocardial Flow Assessment After Heart Transplantation Using Dynamic Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography With 201Tl and 99mTc Tracers and Validated by 13N-NH3 Positron Emission Tomography

BACKGROUND

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse form of vasculopathy and is the most common cause of long-term cardiovascular mortality in heart transplant patients. This study aimed to investigate the diagnostic performance of ^99mTc and ²⁰¹Tl tracers in the assessment of CAV using cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) for myocardial blood flow (MBF) and myocardial flow reserve (MFR) quantification, which was further validated using ¹³ N-NH₃ positron emission tomography (PET).

METHODS

Thirty-eight patients with prior heart transplantation who underwent CZT SPECT and ¹³ N-NH₃ PET dynamic scans were included in this study. CZT SPECT with ^99mTc-sestamibi was used in the first 19 patients and ²⁰¹Tl-chloride for the remaining patients. To determine the diagnostic accuracy of angiographically defined moderate-to-severe CAV, the analysis included patients who underwent angiographic examinations within 1 year of their second scan.

RESULTS

There were no significant differences in the patient characteristics between the ²⁰¹Tl and ^99mTc tracer groups. Both ²⁰¹Tl and ^99mTc CZT SPECT-derived stress MBF and MFR values globally and in 3 coronary territories showed good correlations with ¹³ N-NH₃ PET. The ²⁰¹Tl and ^99mTc cohorts did not differ significantly in the correlation coefficients of CZT SPECT versus PET for MBF and MFR, except for stress MBF (²⁰¹Tl:0.95 versus ^99mTc:0.80, P=0.03). ²⁰¹Tl and ^99mTc CZT SPECT were satisfactory for detecting PET MFR <2.0 (²⁰¹Tl area under the curve, 0.92 [0.71-0.99], ^99mTc area under the curve, 0.87 [0.64-0.97]) and angiographically defined moderate-to-severe CAV, and CZT SPECT results were comparable to that of ¹³ N-NH₃ PET (CZT area under the curve, 0.90 [0.70-0.99], PET area under the curve, 0.86 [0.64-0.97]).

CONCLUSIONS

This small study suggests that CZT SPECT using ²⁰¹Tl and ^99mTc tracers showed comparable MBF and MFR, and the results correlated well with those of ¹³ N-NH₃ PET. Hence, CZT SPECT with ²⁰¹Tl or ^99mTc tracers can be used to detect moderate-to-severe CAV in patients with prior heart transplantation. However, validation using larger studies is warranted.

Pretherapy 18F-FDG PET/CT in Predicting Disease Relapse in Patients With Immunoglobulin G4-Related Disease: A Prospective Study

OBJECTIVE

To investigate whether the levels of inflammation detected by ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can predict disease relapse in immunoglobulin G4-related disease (IgG4-RD) patients receiving standard induction steroid therapy.

MATERIALS AND METHODS

This prospective study analyzed pretherapy FDG PET/CT images from 48 patients (mean age, 63 ± 12.9 years; 45 males and 3 females) diagnosed with IgG4-RD between September 2008 and February 2018, who subsequently received standard induction steroid therapy as the first-line treatment. Multivariable Cox proportional hazards models were used to identify the potential prognostic factors associated with relapse-free survival (RFS).

RESULTS

The median follow-up time for the entire cohort was 1913 days (interquartile range [IQR], 803-2929 days). Relapse occurred in 81.3% (39/48) patients during the follow-up period. The median time to relapse was 210 days (IQR, 140-308 days) after completion of standardized induction steroid therapy. Among the 17 parameters analyzed, Cox proportional hazard analysis identified whole-body total lesion glycolysis (WTLG) > 600 on FDG-PET as an independent risk factor for disease relapse (median RFS, 175 vs. 308 days; adjusted hazard ratio, 2.196 [95% confidence interval: 1.080-4.374]; P = 0.030).

CONCLUSION

WTLG on pretherapy FDG PET/CT was the only significant factor associated with RFS in IgG-RD patients receiving standard steroid induction therapy.

Cerebral Venous Reflux and Cerebral Amyloid Angiopathy: An Magnetic Resonance Imaging/Positron Emission Tomography Study

BACKGROUND

Cerebral venous outflow alterations contribute to central nervous system pathology in aging and neurodegenerative disorders and are potentially linked to underlying cerebral microangiopathy. We investigated whether cerebral venous reflux (CVR) is more closely associated with cerebral amyloid angiopathy (CAA) than hypertensive microangiopathy in intracerebral hemorrhage (ICH) survivors.

METHODS

This cross-sectional study included 122 patients of spontaneous ICH with magnetic resonance and positron emission tomography imaging studies (2014-2022) in Taiwan. The presence of CVR was defined as abnormal signal intensity in the dural venous sinus or internal jugular vein on magnetic resonance angiography. Cerebral amyloid load was measured using the Pittsburgh compound B standardized uptake value ratio. Clinical and imaging characteristics associated with CVR were evaluated in univariable and multivariable analyses. In the subset of patients with CAA, we applied univariable and multivariable linear regression analyses to evaluate the association between CVR and cerebral amyloid retention.

RESULTS

Compared with patients without CVR (n=84, 64.5±12.1 years), patients with CVR (n=38, 69.4±11.5 years) were significantly more likely to have CAA-ICH (53.7% versus 19.8%; P<0.001) and had a higher cerebral amyloid load (standardized uptake value ratio [interquartile range], 1.28 [1.12-1.60] versus 1.06 [1.00-1.14]; P<0.001). In a multivariable model, CVR was independently associated with CAA-ICH (odds ratio, 4.81 [95% CI, 1.74-13.27]; P=0.002) after adjustment for age, sex and conventional small vessel disease markers. In CAA-ICH, higher PiB retention was observed in patients with CVR than patients without CVR (standardized uptake value ratio [interquartile range], 1.34 [1.08-1.56] versus 1.09 [1.01-1.26]; P<0.001). In multivariable analysis after adjustment for potential confounders, the presence of CVR was independently associated with a higher amyloid load (standardized β=0.40; P=0.001).

CONCLUSIONS

In spontaneous ICH, CVR is associated with CAA and a higher amyloid burden. Our results suggest venous drainage dysfunction potentially plays a role in CAA and cerebral amyloid deposition.

New-onset diabetes mellitus risk associated with concurrent autonomous cortisol secretion in patients with primary aldosteronism

Concurrent autonomous cortisol secretion (ACS) in patients with primary aldosteronism (PA patients) is not uncommon. This work aimed to determine the effect of cortisol levels on incident new-onset type 2 diabetes mellitus (NODM) in PA patients. Using the prospectively designed observational TAIPAI cohort, the PA patients were grouped by cortisol level after an overnight low-dose dexamethasone suppression test (1-mg DST). Of the 476 PA patients, 387 (43.7% men; mean age 52.8 years) did not have baseline DM. After a mean follow-up of 4.3 ± 2.9 years, 32 patients (8.3%) developed NODM. The cutoff value obtained via a generalized additive model showed that a serum cortisol level ≥ 2.65 µg/dL after 1-mg DST was a risk factor for developing NODM (HR, 3.5, p = 0.031) by Cox proportional- hazards model.. In PA patients with a higher body mass index (>25 kg/m²; HR, 3.16), lower estimated glomerular filtration rate (<90 ml/min/1.73 m²; HR, 3.18), longer hypertension duration (>7 years; HR, 3.34), and higher waist-to-hip ratio (>0.9; HR, 3.07), a concomitant cortisol level ≥ 2.65 μg/dL after 1-mg DST were more likely to develop NODM. The high-cortisol group of patients with aldosterone-producing adenoma (APA) using mineralocorticoid receptor antagonist (MRA) was associated with an increased risk of NODM (HR, 5.72). Our results showed that PA patients with a concomitant cortisol level ≥ 2.65 µg/dL after 1-mg DST, independent of the aldosterone level, had a higher incidence of NODM. Such PA patients should be carefully evaluated and managed to achieve better glucose control and prevent metabolic syndrome.

Abstract 163: Cerebral Amyloid Deposition Predicts Long-term Cognitive Decline In Intracerebral Hemorrhage Survivors

Background: To investigate the role of cerebral amyloid deposition for long-term cognitive outcomes in spontaneous intracerebral hemorrhage (ICH) survivors.

Methods: Patients experiencing an ICH without over dementia were included (n = 68). Each patient received the brain MRI and Pittsburgh Compound B (PiB) PET at baseline, and the cognitive function was followed up using Mini-mental Status Examination (MMSE) and clinical dementia rating (CDR) with an overall median of 3.8 years. The association between follow-up cognitive outcomes and neuroimaging markers was explored using multivariable Cox regression models. Positive amyloid scan was defined as global PiB standardized uptake value ratio > 1.2.

Results: Patients with PiB(+) were older (72.1 ± 7.8 vs. 59.9 ± 11.7, p = 0.002) and were more frequently associated with probable CAA (54.5% vs. 8.8%, p=0.001) than patients with PiB(-). PiB(+) was associated with a higher risk of dementia conversion (32.9 vs. 4.0 per 100-person-years, HR=16.4 [3.5-75.5], p <0.001) and cognitive decline (defined as MMSE decline≥ 2, 58.8 vs.9.9 per 100-person-years, HR=6.1 [2.0-18.8], p=0.002) compared to PiB(-). Higher lobar microbleed number and the presence of lacune were also associated with cognitive worsening (both p<0.005). In the cox models, PiB(+) was an independent predictor of dementia conversion (HR=12.3 [2.9-52.6], p=0.001) or cognitive decline (HR=7.9 [2.4-26.0], p=0.001) after adjustment for age, sex, educational years, lobar microbleeds and lacune. In the subgroup of patients who were non-CAA (n=57), PiB(+) remained an independent predictor of cognitive worsening (both p<0.005).

Conclusions: We demonstrate the strong association between positive amyloid scan and long-term cognitive change in ICH survivors, suggesting cerebral amyloid deposition as an important driving factor for cognitive impairment in hemorrhagic small vessel disease.

[Normal and Near Normal Myocardial Perfusion Imaging Data Analysis: Two-Year Major Adverse Cardiac Event]

BACKGROUND

Myocardial perfusion imaging (MPI) is the method most commonly used to assess patients with suspected coronary artery disease for the presence of myocardial ischemia and risk of subsequent adverse cardiac events. Studies are limited on the incidence of major adverse cardiac event (MACE) in patients with normal MPI results.

PURPOSE

The aim of this study was to investigate the incidence and risk factors of MACE in patients with normal or near-normal MPI results.

METHODS

In this single-center retrospective chart review study, patients who had received MPI tests at a nuclear medicine department of a medical center in 2017 were consecutively enrolled. All of the participants in this study were patients with normal or near-normal MPI results, and were followed for two years to assess the incidence of MACE (death, hospitalized for percutaneous coronary intervention; CABG, heart failure and stroke). Participants with or without MACE were compared to determine whether demographic, comorbidity, and MPI data were significant risk factors.

RESULTS

Of the 1,629 participants (age = 70.4 ± 11.3 years, 49.4% male) enrolled, 387 (23.8%) were classified into the normal MPI group and 1,242 (76.2%) were classified into the near-normal MPI group. Notably, 61 participants (15.8%) in the normal MPI group and 206 (16.6%) in the near-normal MPI group experienced MACE events during the two-year follow-up. The risk factors of MACE identified in this study included being older in age, being male, and having poor myocardial perfusion parameters (i.e., ejection fraction) during MPI.

CONCLUSIONS / IMPLICATIONS FOR PRACTICE

Over the two-year study period, 15.8% of the participants with normal MPI results and 16.6% of those with near-normal MPI results experienced major adverse cardiac events. Thus, it is critical to inform patients regarding the potential risk of MACE risk and to educate them on how to mitigate this risk by actively managing their hyperlipidemia level and left ventricular ejection fraction.

Prognostic Value of Interim 18F-DOPA and 18F-FDG PET/CT Findings in Stage 3-4 Pediatric Neuroblastoma

PURPOSE

This retrospective study aimed to determine the prognostic value of imaging parameters derived from midtherapy 18F-fluorodihydroxyphenylalanine (18F-DOPA) and 18F-FDG PET in pediatric patients with stage 3-4 neuroblastoma.

METHODS

We enrolled 32 stage 3-4 pediatric neuroblastoma patients who underwent 18F-DOPA and 18F-FDG PET/CT scans before and after 3 chemotherapy cycles. We measured metabolic and volumetric parameters and applied a metabolic burden scoring system to evaluate the primary tumor extent and soft tissue metastases and that of bone/bone marrow involvement. The associations between these parameters and clinical outcomes were investigated.

RESULTS

Over a median follow-up period of 47 months (range, 3-137 months), 16 patients experienced disease progression, and 13 died. After adjustment for clinical factors, multivariate Cox proportional hazard models showed that interim tumor FDG/FDOPA SUVmax (hazard ratio [HR], 5.94; 95% confidence interval [CI], 1.10-34.98) and interim FDOPA whole-body metabolic burden scores (WBMB) (HR, 7.30; 95% CI, 1.50-35.50) were significant prognostic factors for overall survival (OS). Only interim FDOPA WBMB scores (HR, 7.05; 95% CI, 1.02-48.7) were predictive of progression-free survival. Based on median cutoff values, prognosis (OS and progression-free survival) was significantly associated with an interim FDOPA WBMB score ≥21.92 (all P < 0.05) and interim tumor FDG/FDOPA (SUVmax) score ≥0.57 with poor OS (P < 0.05).

CONCLUSIONS

Our results indicate that midtreatment FDG and FDOPA PET/CT could serve as prognostic markers in stage 3-4 neuroblastoma patients.

Diagnostic Performance of Proton Magnetic Resonance Spectroscopy and 18F-Fluorocholine PET to Differentiate Benign From Malignant Breast Lesions

PURPOSE

The aim of this study was to evaluate the diagnostic performance of the proton magnetic resonance spectroscopy (MRS) and 18F-fluorocholine (FCH) PET for suspicious breast findings on conventional imaging (mammography and breast ultrasound).

METHODS

From September 2012 to December 2015, 37 women with 39 breast lesions on conventional imaging were enrolled and underwent proton MRS and FCH PET. The MRS parameters of choline signal-to-noise ratio (SNR), choline integral (I(cho)), and the PET parameters including SUVmax in the prone (SUV1) and supine (SUV2) positions were analyzed. Receiver operating characteristic curves with the area under the curve, sensitivity, and specificity under the optimal cutoff points for the different parameters were determined.

RESULTS

Twenty-three lesions (59%) were malignant, and 16 (41.0%) were benign. The malignant lesions tended to show significantly higher MRS and PET parameters than benign lesions (choline SNR, P = 0.007; I(cho), P = 0.003; SUV1 and SUV2, P < 0.0001). Fair to moderate correlations were noted between the choline SNR and PET parameters (SUV1, Spearman rank correlation coefficient, ρ = 0.477; SUV2, ρ = 0.483), as well as I(cho) and PET parameters (SUV1, ρ = 0.493; SUV2, ρ = 0.549). The SUV2 showed the highest diagnostic performance (area under the curve, 0.918). Using 2.5 as the optimal cutoff point, the SUV2 yields 89.5% sensitivity and 87.5% specificity for differentiating malignant from benign lesions.

CONCLUSION

The MRS parameters were fairly to moderately correlated with FCH PET parameters, and both could differentiate malignant from benign breast lesions with SUV2 showing best diagnostic performance.

Diagnostic Effect of Attenuation Correction in Myocardial Perfusion Imaging in Different Coronary Arteries: A Systematic Review and Meta-Analysis

Background: The aim of this study was to determine whether, and if so how, attenuation correction (AC) improves the diagnostic performance of myocardial perfusion imaging (MPI) in different coronary artery-supplied territories, using coronary angiography as the reference standard.

Methods: PubMed and EMBASE were searched until December 2020 for studies evaluating AC MPI for the diagnosis of coronary artery disease (CAD) with vessel-based data. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. For each study, the sensitivity, specificity, diagnostic odds ratios and areas under summary receiver operating characteristic curves (AUC) with 95% confidence intervals were calculated to determine the diagnostic accuracy of AC compared to non-AC MPI. A bivariate mixed-effects model was used to pool the data. Subgroup analyses considering the type of radiotracer and type of AC were performed.

Results: A total of 264 articles were screened, of which 22 studies (2,608 patients) were enrolled. Significant improvements in specificity [0.78 vs. 0.58 in overall CAD, 0.87 vs. 0.61 in right coronary artery (RCA)] and diagnostic odds ratios (16 vs. 8 in overall CAD, 18 vs. 7 in RCA) after AC were shown in overall CAD at a patient level and RCA stenosis. Improvements in AUC were also noted. MPI had a similar diagnostic performance for detecting left anterior descending and left circumflex coronary artery stenosis with or without AC. There were trends of decreased sensitivity after AC, but none were significant. Diagnostic odds ratio showed significant improvement after AC only in the technetium-99m subgroup.

Conclusion: The results of this study suggest that AC should be applied to MPI to improve the diagnosis of CAD regardless of which type of radiotracer, and that AC MPI can improve the specificity of detecting RCA stenosis.

Long-term prognostic value of computed tomography-based attenuation correction on thallium-201 myocardial perfusion imaging: A cohort study

BACKGROUND

Myocardial perfusion imaging (MPI) is a well-established diagnostic tool to evaluate coronary artery disease (CAD) and also an effective prognostic tool for patients with CAD. However, few studies investigated the prognostic value of attenuation correction (AC) in MPI, and the results were controversial.

OBJECTIVES

To investigate the prognostic value of computed tomography (CT)-based AC thallium-201 (Tl-201) MPI.

METHODS

A total of 108 consecutive patients who underwent Tl-201 MPI and received coronary angiography within 90 days were included. Medical records were reviewed and missing information was completed after telephone contact. The prognostic value was evaluated by Kaplan-Meier analysis, univariable and multivariable Cox proportional hazards model.

RESULTS

After a mean follow-up of 7.72 ± 3.72 years, 27 patients had died, 41 had been readmitted for cardiovascular (CV)-related events and 44 had reached the composite of death plus CV-related re-admission. Kaplan-Meier curves for all-cause mortality for SSS with a cutoff value of 13 for AC and 16 for non-AC (NAC) images showed a significant difference between the two curves for both AC and NAC images (p = 0.011 for AC and p = 0.021 for NAC). In the multivariable model, SSS and SRS showed similar independent predictive values in predicting all-cause mortality and composite of all-cause mortality plus CV-related re-admission, in both AC and NAC images. Subgroup analysis implicated that AC MPI possibly provided better risk stratification in obese patients.

CONCLUSION

CT-based AC and NAC MPI showed similar value and were the only significant predictors for the composite of mortality and CV events.

Factors predicting one or two sentinel lymph nodes to be accepted for sentinel lymph node biopsy alone after neoadjuvant therapy in initially node-positive breast cancer patients

BACKGROUND

Current guidelines recommend harvesting ≥3 sentinel nodes if sentinel lymph node biopsy (SLNB) alone is considered after neoadjuvant therapy (NAT) for initially node-positive (cN+) breast cancer. We attempted to investigate factors predicting one or two sentinel lymph nodes harvested to be accepted for SLNB alone after NAT in initially cN + patients.

METHODS

Overall, 157 patients who received NAT (clinically T1-3/N1-2/M0) and underwent SLNB were identified from a prospectively maintained database. Significant factors were identified using a multiple logistic regression model.

RESULTS

The overall SLN identification rate was 83.4%. Failed SLN identification was associated with a 2-day protocol using a single tracer (odds ratio: 0.331 [95% confidence interval {CI}: 0.132-0.830], p = 0.018), age >52 years (0.345 [0.131-0.913], p = 0.032), and lobular histology (0.156 [0.026-0.944], p = 0.043). The overall false-negative SLNB rate was 14.7%. Its increased risk was associated with radioactivity count >530 for any SLN during SLNB (96.4 [4.00-2320], p = 0.005), age ≥57 years (34.2 [1.92-610], p = 0.016), and taxane use (105 [1.02-10700], p = 0.049); its decreased risk was associated with more harvested SLNs (0.191 [0.054-0.669], p = 0.01) and dual tracers (0.101 [0.012-0.843], p = 0.034). A predictive model using these factors achieved an area under the curve of 0.935 (95% CI: 0.878-0.991).

CONCLUSION

When taxane was administered during NAT, the false-negative rate was predicted at <5% for patients aged <57 years, if 1-2 SLNs were harvested using dual tracers, and when the count of every SLN was lower than 530 after NAT in cN + breast cancer.

Plasma soluble TREM2 is associated with white matter lesions independent of amyloid and tau

Cerebral small vessel disease is one of the most common causes of cognitive decline and stroke. While several lines of evidence have established a relationship between inflammation and cerebrovascular pathology, the mechanistic link has not yet been elucidated. Recent studies suggest activation of immune mediators, including the soluble form of triggering receptor expressed on myeloid cells 2 (TREM2), may be critical regulators. In this study, we compared the plasma levels of soluble TREM2 and its correlations with neuroimaging markers and cerebral amyloid load in ten patients with Alzheimer's disease and 66 survivors of spontaneous intracerebral haemorrhage with cerebral amyloid angiopathy or hypertensive small vessel disease, two of the most common types of sporadic small vessel disease. We performed brain MRI and 11C-Pittsburgh compound B PET for all participants to evaluate radiological small vessel disease markers and cerebral amyloid burden, and 18F-T807 PET in a subgroup of patients to evaluate cortical tau pathology. Plasma soluble TREM2 levels were comparable between patients with Alzheimer's disease and small vessel disease (P=0.690). In patients with small vessel disease, plasma soluble TREM2 was significantly associated with white matter hyperintensity volume (P<0.001), but not with cerebral amyloid load. Among patients with Alzheimer's disease and cerebral amyloid angiopathy, plasma soluble TREM2 was independently associated with a tau-positive scan (P=0.001) and white matter hyperintensity volume (P=0.013), but not amyloid load (P=0.221). Our results indicate plasma soluble TREM2 is associated with white matter hyperintensity independent of amyloid and tau pathology. These findings highlight the potential utility of plasma soluble TREM2 as a strong predictive marker for small vessel disease-related white matter injury and hold clinical implications for targeting the innate immune response when treating this disease.

2021 Advocacy Statements for the Role of 99mTc-Pyrophosphate Scintigraphy in the Diagnosis of Transthyretin Cardiac Amyloidosis: A Report of the Taiwan Society of Cardiology and the Society of Nuclear Medicine of the Republic of China

Transthyretin cardiac amyloidosis (ATTR-CM) is an increasingly recognized cause of heart failure with preserved ejection fraction. Favorable prognosis depends on early diagnosis and correct treatment strategy. Among patients for whom there is a high clinical suspicion of cardiac amyloidosis, 99mTc-labeled bone avid scintigraphy including 99mTc-pyrophosphate (PYP) scintigraphy may be of diagnostic and prognostic importance. Various international guidelines support the non-biopsy diagnosis of ATTR-CM using 99mTc-PYP scintigraphy, yet emphasize the gap in standardization of acquisition and imaging analysis protocols, as well as the appropriateness of its clinical use. Therefore, a joint expert consensus has been reached by the Taiwan Society of Cardiology and the Society of Nuclear Medicine of the Republic of China, to advocate for the application of 99mTc-PYP scintigraphy in the diagnosis of ATTR-CM. This article aims to highlight the recommendations on image acquisition, qualitative and quantitative assessments of cardiac 99mTc-PYP uptake, and diagnostic algorithms. We hope the implementation of these recommendations in Taiwan will facilitate the process and enhance the diagnostic rate of ATTR-CM.

Centrum Semiovale Perivascular Space and Amyloid Deposition in Spontaneous Intracerebral Hemorrhage

[Figure: see text].

Preoperative 2-[18F]FDG PET-CT aids in the prognostic stratification for patients with primary ampullary carcinoma

OBJECTIVES

We sought to investigate whether preoperative dual-phase 2-[¹⁸F]FDG PET-CT identify predictors for poor survival in patients with ampullary carcinoma receiving pancreaticoduodenectomy.

METHODS

The preoperative PET-CT images of patients with resected ampullary carcinoma from June 2007 to July 2017 were analyzed. Survival curves were analyzed using the Kaplan-Meier method and compared with the log-rank test. Cox proportional hazard model was used to identify potential prognostic factors associated with disease-free survival (DFS) and overall survival (OS).

RESULTS

Fifty-four subjects (26 men, 28 women) were enrolled with a median tumor size of 20 mm. All patients were followed for a median period of 36.9 months with 3- and 5-year DFS of 50.3% and 44.2%, and OS of 77.0% and 68.2%, respectively. Parameters associated with DFS in multivariate analysis were lymphovascular invasion (hazard ratio [HR]: 9.45, p < 0.001), involved margin in pathology (HR: 7.67, p < 0.001), and tumor retention index (RI) from the dual-phase PET (HR: 2.41, p = 0.03), whereas involved margin (HR: 13.14, p < 0.001), post-recurrence chemotherapy (HR: 0.10, p < 0.001), and metabolic tumor volume (MTV) (HR: 4.62, p = 0.009) emerged as independent prognostic factors for OS.

CONCLUSIONS

Preoperative 2-[¹⁸F]FDG PET-CT offered independent prognostic biomarkers in patients with ampullary carcinoma receiving standard surgical resection.

KEY POINTS

• 2-[¹⁸F]FDG PET-CT offers good survival prediction before operation in primary malignant neoplasms at ampulla of Vater. • Dual-phase PET scan with bowel distention can better delineate Ampulla of Vater and characterize tumor physiology. • Preoperative risk stratification might aid in better treatment planning.

Assessing tumor angiogenesis using dynamic contrast-enhanced integrated magnetic resonance-positron emission tomography in patients with non-small-cell lung cancer

Background

Angiogenesis assessment is important for personalized therapeutic intervention in patients with non-small-cell lung cancer (NSCLC). This study investigated whether radiologic parameters obtained by dynamic contrast-enhanced (DCE)-integrated magnetic resonance-positron emission tomography (MR-PET) could be used to quantitatively assess tumor angiogenesis in NSCLC.

Methods

This prospective cohort study included 75 patients with NSCLC who underwent DCE-integrated MR-PET at diagnosis. The following parameters were analyzed: metabolic tumor volume (MTV), maximum standardized uptake value (SUV_max), reverse reflux rate constant (k_ep), volume transfer constant (K^trans), blood plasma volume fraction (v_p), extracellular extravascular volume fraction (v_e), apparent diffusion coefficient (ADC), and initial area under the time-to-signal intensity curve at 60 s post enhancement (iAUC₆₀). Serum biomarkers of tumor angiogenesis, including vascular endothelial growth factor-A (VEGF-A), angiogenin, and angiopoietin-1, were measured by enzyme-linked immunosorbent assays simultaneously.

Results

Serum VEGF-A (p = 0.002), angiogenin (p = 0.023), and Ang-1 (p <  0.001) concentrations were significantly elevated in NSCLC patients compared with healthy individuals. MR-PET parameters, including MTV, K^trans, and k_ep, showed strong linear correlations (p <  0.001) with serum angiogenesis-related biomarkers. Serum VEGF-A concentrations (p = 0.004), MTV values (p <  0.001), and k_ep values (p = 0.029) were significantly higher in patients with advanced-stage disease (stage III or IV) than in those with early-stage disease (stage I or II). Patients with initial higher values of angiogenesis-related MR-PET parameters, including MTV > 30 cm³ (p = 0.046), K^trans > 200 10^− 3/min (p = 0.069), and k_ep > 900 10^− 3/min (p = 0.048), may have benefited from angiogenesis inhibitor therapy, which thus led to significantly longer overall survival.

Conclusions

The present findings suggest that DCE-integrated MR-PET provides a reliable, non-invasive, quantitative assessment of tumor angiogenesis; can guide the use of angiogenesis inhibitors toward longer survival; and will play an important role in the personalized treatment of NSCLC.

Integrated 18F-T807 Tau PET, Structural MRI, and Plasma Tau in Tauopathy Neurodegenerative Disorders

Background and Objective: Tau-specific positron emission topography (PET) imaging enables in vivo assessment of Alzheimer's disease (AD). We aimed to investigate its performance in combination with plasma tau levels in patients with non-AD tauopathy.

Methods: A total of 47 participants were enrolled, including 10 healthy controls, 16 with tauopathy parkinsonism syndromes (9 with corticobasal syndrome [CBS], 7 with progressive supranuclear palsy [PSP]), 9 with frontotemporal dementia (FTD), 4 with AD, and 8 with Parkinson's disease (PD). All participants underwent clinical assessments, ¹⁸F-T807 tau PET, brain MRI, and plasma tau assay.

Results: The global cortical standard uptake value ratio (SUVR) of ¹⁸F-T807 PET was comparable between PD and control (p = 0.088). The cortical SUVR was significantly higher in AD group (p = 0.002) but was modestly increased in PSP group compared to the PD group (p = 0.044), especially in parietal and pallidal regions. Asymmetric ¹⁸F-T807 uptake at the pallidum was noted in patients with CBS and FTD. Cortical tau tracer uptake was associated with increased plasma total tau level (p = 0.016), especially in frontal and parietal regions. Regional tracer uptake was correlated with cortical thinning in patients with CBS and PSP (CBS: r = −0.092, p = 0.025; PSP: r = −0.114, p = 0.015).

Conclusions: The ¹⁸F-T807 tau tracer uptake was only modestly increased in patients with PSP. Although the cortical tau tracer uptake correlated with regional cortical atrophy and plasma tau levels, a four-repeated tau-specific tracer is needed for future classifying tauopathy parkinsonism syndromes.

Mitochondrial UQCRC1 mutations cause autosomal dominant parkinsonism with polyneuropathy

Parkinson's disease is a neurodegenerative disorder with a multifactorial aetiology. Nevertheless, the genetic predisposition in many families with multi-incidence disease remains unknown. This study aimed to identify novel genes that cause familial Parkinson's disease. Whole exome sequencing was performed in three affected members of the index family with a late-onset autosomal-dominant parkinsonism and polyneuropathy. We identified a novel heterozygous substitution c.941A>C (p.Tyr314Ser) in the mitochondrial ubiquinol-cytochrome c reductase core protein 1 (UQCRC1) gene, which co-segregates with disease within the family. Additional analysis of 699 unrelated Parkinson's disease probands with autosomal-dominant Parkinson's disease and 1934 patients with sporadic Parkinson's disease revealed another two variants in UQCRC1 in the probands with familial Parkinson's disease, c.931A>C (p.Ile311Leu) and an allele with concomitant splicing mutation (c.70-1G>A) and a frameshift insertion (c.73_74insG, p.Ala25Glyfs*27). All substitutions were absent in 1077 controls and the Taiwan Biobank exome database from healthy participants (n = 1517 exomes). We then assayed the pathogenicity of the identified rare variants using CRISPR/Cas9-based knock-in human dopaminergic SH-SY5Y cell lines, Drosophila and mouse models. Mutant UQCRC1 expression leads to neurite degeneration and mitochondrial respiratory chain dysfunction in SH-SY5Y cells. UQCRC1 p.Tyr314Ser knock-in Drosophila and mouse models exhibit age-dependent locomotor defects, dopaminergic neuronal loss, peripheral neuropathy, impaired respiratory chain complex III activity and aberrant mitochondrial ultrastructures in nigral neurons. Furthermore, intraperitoneal injection of levodopa could significantly improve the motor dysfunction in UQCRC1 p.Tyr314Ser mutant knock-in mice. Taken together, our in vitro and in vivo studies support the functional pathogenicity of rare UQCRC1 variants in familial parkinsonism. Our findings expand an additional link of mitochondrial complex III dysfunction in Parkinson's disease.

Endoscopic ultrasound ablation in a patient with multiple metastatic pancreatic tumors from adrenocorticotropic hormone-producing thymic neuroendocrine neoplasm

Adrenocorticotropic hormone (ACTH)-producing neuroendocrine neoplasm (NEN) of the thymus is rare. Lymph nodes and bones are the most common metastatic sites. Most cases present with florid Cushing's syndrome (CS). Here, we reported a 58-year-old woman, who presented with intermittent flush and weight loss. Imaging studies revealed tumors in the mediastinum, pancreas, and bones. Contrast-enhanced harmonic endoscopic ultrasound (EUS) of the pancreatic tumors showed heterogeneous and hyperenhancing characteristics. EUS elastography revealed a heterogeneous stiff pattern. EUS-fine needle biopsy to the pancreatic lesion confirmed the NEN nature. Serum ACTH and cortisol levels were abnormally high. Immunohistochemical staining of the thymic and pancreatic specimens was positive for ACTH. However, the patient did not have obvious CS appearance. The patient underwent surgery, radiation, EUS-guided ethanol injection, and anti-cancer medications, but the disease still progressed. The patient died from infection 16 months after NEN was diagnosed. In conclusion, the pancreas can be a metastatic site for ACTH-producing thymic NEN. EUS-associated procedures can help in the diagnosis and treatment of pancreatic metastatic NEN.

A Double-Blind, Randomized, Controlled Trial of Lovastatin in Early-Stage Parkinson's Disease

BACKGROUND

Recent evidence indicates that lipophilic statins have a neuroprotective benefit in animal models of Parkinson's disease (PD). The objective of this study was to evaluate whether lovastatin has the potential to slow motor symptom progression in patients with early-stage PD.

METHODS

This double-blind, randomized, placebo-controlled trial enrolled 77 patients with early-stage PD between May 23, 2017, and July 12, 2018, with follow-up ending September 1, 2019. Lovastatin 80 mg/day or placebo with 1:1 randomization was administered for 48 weeks. Mean change in the parts I-III scores of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), changes in the striatal dopamine uptake ratio measured by ¹⁸ F-dopa PET scan, and changes in PD medications between baseline and the week 48 visit were measured.

RESULTS

Of the 77 randomized patients, 70 (90.9%) completed the study. There was a slightly beneficial trend of the MDS-UPDRS motor score in the lovastatin group (-3.18 ± 5.50) compared with the placebo group (-0.50 ± 6.11); P = 0.14 adjusted for age, sex, disease duration, and baseline LEDD. Mean percentage change in the striatal ¹⁸ F-dopa uptake ratio deteriorated less in the lovastatin group than in the placebo group on the dominant side of caudate (1.2% ± 7.3% vs -7.1% ± 8.2%, P < 0.01) and putamen (2.3% ± 7.1% vs -6.4% ± 8.1%, P < 0.01). We found no between-group differences in the change in part I or part II MDS-UPDRS scores. Lovastatin was generally well tolerated.

CONCLUSIONS

Lovastatin treatment in patients with early-stage PD was associated with a trend of less motor symptom worsening and was well tolerated. A future larger long-term follow-up study is needed to confirm our findings. © 2021 International Parkinson and Movement Disorder Society.

NP-59 Adrenal Scintigraphy as an Imaging Biomarker to Predict KCNJ5 Mutation in Primary Aldosteronism Patients

PURPOSE

Somatic KCNJ5 mutation occurs in half of unilateral primary aldosteronism (PA) and is associated with more severe phenotype. Mutation status can only be identified by tissue sample from adrenalectomy. NP-59 adrenal scintigraphy is a noninvasive functional study for disease activity assessment. This study aimed to evaluate the predictive value of NP-59 adrenal scintigraphy in somatic KCNJ5 mutation among PA patients who received adrenalectomy.

METHODS

Sixty-two PA patients who had NP-59 adrenal scintigraphy before adrenalectomy with available KCNJ5 mutation status were included. Two semiquantitative parameters, adrenal to liver ratio (ALR) and lesion to contralateral ratio of bilateral adrenal glands (CON) derived from NP-59 adrenal scintigraphy, of mutated and wild-type patients were compared. Cutoff values calculated by receiver-operating characteristic (ROC) analysis were used as a predictor of KCNJ5 mutation.

RESULTS

Twenty patients had KCNJ5 mutation and 42 patients were wild type. Patients harboring KCNJ5 mutation had both higher ALR and CON (p = 0.0031 and 0.0833, respectively) than wild-type patients. With ALR and CON cutoff of 2.10 and 1.95, the sensitivity and specificity to predict KCNJ5 mutation were 85%, 57% and 45%, 93%, respectively. Among 20 patients with KCNJ5 mutation, 16 showed G151R point mutation (KCNJ5- G151R) and 4 showed L168R point mutation (KCNJ5-L168R), which former one had significantly lower ALR (p=0.0471).

CONCLUSION

PA patients harboring somatic KCNJ5 mutation had significantly higher NP-59 uptake regarding to ALR and CON than those without mutation. APAs with KCNJ5-L168R point mutation showed significantly higher ALR than those with KCNJ5-G151R point mutation.

Effects of Focal Radiation on [18 F]-Fluoro-D-Glucose Positron Emission Tomography in the Brains of Miniature Pigs: Preliminary Findings on Local Metabolism

OBJECTIVES

It would be a medically important advance if durable and focal neuromodulation of the brain could be delivered noninvasively and without ablation. This ongoing study seeks to elucidate the effects of precisely delivered ionizing radiation upon focal brain metabolism and the corresponding cellular integrity at that target. We hypothesize that focally delivered ionizing radiation to the brain can yield focal metabolic changes without lesioning the brain in the process.

MATERIALS AND METHODS

We used stereotactic radiosurgery to deliver doses from 10 Gy to 120 Gy to the left primary motor cortex (M1) of Lee Sung miniature pigs (n = 8). One additional animal served as a nonirradiated control. We used positron emission tomography-computed tomography (PET-CT) to quantify radiation dose-dependent effects by calculating the ratio of standard uptake values (SUV) of 2-deoxy-2-[¹⁸ F]-fluoro-D-glucose (¹⁸ F-FDG) between the radiated (left) and irradiated (right) hemispheres across nine months.

RESULTS

We found that the FDG-PET SUV ratio at the targeted M1 was significantly lowered from the pre-radiation baseline measurements for animals receiving 60 Gy or higher, with the effect persisting at nine months after radiosurgery. Only at 120 Gy was a lesion suggesting ablation visible at the M1 target. Animals treated at 60-100 Gy showed a reduced signal in the absence of an identifiable lesion, a result consistent with the occurrence of neuromodulation.

CONCLUSION

Focal, noninvasive, and durable changes in brain activity can be induced without a magnetic resonance imaging (MRI)-visible lesion, a result that may be consistent with the occurrence of neuromodulation. This approach may provide new venues for the investigation of neuromodulatory treatments for disorders involving dysfunctional brain circuits. Postmortem pathological analysis is needed to elucidate whether there have been morphological changes not detected by MRI.

Dermoid cyst with secretion of CA 19-9 detected by 18F-FDG PET/CT: A case report

INTRODUCTION

Carbohydrate antigen 19-9 (CA 19-9) is a tumor glycolipid, frequently elevated in the serum of patients due to malignancies from gastrointestinal organs; in particular, the pancreas. This carbohydrate antigen is also expressed in benign diseases.

PATIENT CONCERNS

A case of a 27-year-old female who has an unknown origin CA 19-9 elevation for 2 years.

DIAGNOSIS

After the left ovarian cystectomy and microscopic examination, the final diagnosis is a dermoid cyst. The dermoid cyst shows increased F-fluorodeoxyglucose (F-FDG) uptake in the F-FDG positron emission tomography (PET)/computed tomography (CT) study.

INTERVENTION AND OUTCOMES

The laparoscopic oophorocystectomy was performed. It was observed that the patient's CA 19-9 level returned to normal after the surgery 6 months later. This showed that the dermoid cyst was responsible for the abnormal CA 19-9 level.

CONCLUSION

In this case, we can learn that the F-FDG PET/CT scan has potential use in patients with unknown origin of elevation CA 19-9.

Frontal variant of Alzheimer's disease with asymmetric presentation mimicking frontotemporal dementia: Case report and literature review

INTRODUCTION

Frontal variant of Alzheimer's disease (fvAD) is a rare nonamnestic syndrome of Alzheimer's disease (AD). Differentiating it from behavior variant of frontotemporal dementia (bvFTD), which has implications for treatment responses and prognosis, remains a clinical challenge.

METHODS

Molecular neuroimaging and biofluid markers were performed for the index patient for accurate premortem diagnosis of fvAD. The clinical, neuroimaging, and biofluid characteristics of the patient were compared to those reported in previous studies of fvAD from 1999 to 2019.

RESULTS

A 66-year-old man presented with progressive executive dysfunction, personality and behavioral changes, and memory decline since age 59. He had no family history of neurodegenerative disorders. A stimulus-sensitive myoclonus was noted over his left upper extremity. Neuropsychological assessment revealed moderate dementia with a Mini-Mental State Exam score of 10/30 and compromised executive and memory performance. Brain imaging showed asymmetrical atrophy and hypometabolism over the right frontal and temporal areas, mimicking bvFTD. However, we observed increased tau depositions based on ¹⁸ F-labeled T807 Tau PET in these areas and diffusely increased amyloid deposition based on ¹¹ C-labeled Pittsburgh compound B positron emission tomography (PET). Plasma biomarker measures indicated an AD profile with increased Aβ1-42 (18.66 pg/ml; cutoff: 16.42 pg/ml), Aβ1-42/Aβ1-40 ratio (0.45; cutoff: 0.30), total tau (29.78 pg/ml; cutoff: 23.89 pg/ml), and phosphorylated tau (4.11 pg/ml; cutoff: 3.08 pg/ml). These results supported a diagnosis of fvAD.

CONCLUSIONS

Our results with asymmetrical presentations extend current knowledge about this rare AD variant. Application of biofluid and molecular imaging markers could assist in early, accurate diagnosis.

Abstract WP417: Relevance of Lobar Cerebral Microbleeds in Patients With Deep Intracerebral Hemorrhage

Background: Markers of cerebral small vessel disease (cSVD) severity and prognosis in strictly lobar or strictly deep intracerebral hemorrhages (ICH)/cerebral microbleeds (CMB) are well defined but data are scarce for mixed-location ICH/CMB. We aimed to compare neuroimaging features and outcomes between deep ICH patients with and without lobar CMBs.

Methods: Patients with first-ever deep ICH from a prospectively maintained single-center registry were analyzed. Demographics, risk factors and neuroimaging markers of cSVD including CMBs, cortical superficial siderosis, enlarged perivascular spaces (EPVS), white matter hyperintensity volumes (WMH) and brain atrophy scores (range 0-15) were compared between deep ICH patients with lobar CMBs and those without lobar CMBs. The follow-up data were analyzed for ICH recurrence, ischemic stroke (IS) and all-cause mortality.

Results: Of 208 patients, 98 (47.1%) had lobar CMBs. Patients with L-CMBs were older (65.3±12.1 vs. 57.4±12.5, p<0.001) and more likely to be hypertensive (98% vs. 90.9%, p=0.037) than those without L-CMBs. Deep CMBs (83.7% vs 56.4%, p<0.001), lacunes (53.1% vs 31.8%, p=0.003) and severe basal ganglia EPVS (40.8% vs 17.3%, p<0.001) were more common in patients with L-CMBs. Patients with L-CMBs had higher volumes of WMH (17.4 ml [IQR 9-38] vs 4.8 ml [IQR 1-13], p<0.001) and atrophy scores (4 [IQR 2-7] vs 3 [IQR 0-6], p=0.007) as compared to patients without L-CMBs. During a median follow-up of 21 months, the ICH recurrence rate was similar between groups (p=0.2), but higher incident IS (3.0 vs 0.0 per 1000-person-months, p=0.016) and all-cause mortality (4.9 vs 1.5 per 1000-person-months, p=0.026) were observed in patients with L-CMBs. In a cox regression model, the presence of lobar CMBs was independently associated with a composite outcome measure (ICH/IS/mortality) after adjusting for age, hypertension, WMH volume, lacune, BG-EPVS and atrophy scores (odds ratio: 2.9, 95%CI:1.01-8.4 p=0.046).

Conclusions: Presence of lobar CMBs in patients with deep ICH is associated with parenchymal markers of more severe cSVD and poor prognosis, suggesting a more advanced vasculopathy compared to patients with strictly deep ICH.

Clinical significance of quantitative assessment of glucose utilization in patients with ischemic cardiomyopathy

BACKGROUND

The aim of this study was to prospectively quantify the rate of myocardial glucose uptake (MRGlu) in myocardium with different perfusion-metabolism patterns and determine its prognostic value in patients with ischemic cardiomyopathy.

METHODS AND RESULTS

79 patients with ischemic cardiomyopathy were prospectively enrolled for dynamic cardiac FDG PET, and then followed for at least 6 months. Perfusion-metabolism patterns were determined based on visual score analysis of 201Tl SPECT and FDG PET. MRGlu was analyzed using the Patlak kinetic model. The primary end-point was cardiovascular mortality. Significantly higher MRGlu was observed in viable compared with non-viable areas. Negative correlations were found between MRGlu in transmural match and a history of hyperlipidemia, statin usage, and triglyceride levels. Diabetic patients receiving dipeptidyl peptidase-4 inhibitors (DPP4i) had a significantly lower MRGlu in transmural match, mismatch, and reverse mismatch. Patients with MRGlu in transmural match ≥ 23.40 or reverse mismatch ≥ 36.90 had a worse outcome.

CONCLUSIONS

Myocardial glucose utilization was influenced by substrates and medications, including statins and DPP4i. MRGlu could discriminate between viable and non-viable myocardium, and MRGlu in transmural match and reverse mismatch may be prognostic predictors of cardiovascular death in patients with ischemic cardiomyopathy.

Abstract WMP107: Outcomes in Mixed Location Intracerebral Hemorrhage and Microbleeds

Objective: Patients with mixed location intracerebral hemorrhages/microbleeds (Mixed-ICH) have predominantly hypertensive vasculopathy rather than cerebral amyloid angiopathy (CAA), but the long-term outcomes in Mixed-ICH is unknown. In this study, we aimed to determine whether Mixed-ICH is a risk factor for vascular unfavorable outcome compared to CAA-ICH or strictly deep hypertensive intracerebral hemorrhage/microbleeds (HTN-ICH).

Methods: 305 consecutive ICH patients were included. Clinical data, neuroimaging markers and follow-up outcomes (recurrent ICH, ischemic stroke and vascular death) were compared between Mixed-ICH (n=151), CAA-ICH (n=33) and HTN-ICH (n=121). The association between follow-up events and neuroimaging markers were explored using multivariable Cox regression models.

Results: Mixed-ICH patients were older (65.9±12.4 vs 58.1±13.2, p<0.001) than HTN-ICH, but younger than CAA-ICH patients (73.8 ± 13.9, p=0.001). The survival curves of follow-up outcomes were shown in the Figure. Compared to CAA-ICH, Mixed-ICH has similar incidence of vascular event (all P>0.05). Compared to HTN-ICH, Mixed-ICH is associated with higher ICH recurrence (hazard ratio [HR]=3.0 [1.2-7.7], p=0.021), more ischemic stroke (HR=8.2 [1.0-65.8], p=0.048), and vascular composite outcome (HR=3.5 [1.5-8.2], p=0.003) after adjustment for age and sex. In patients of Mixed-ICH, the presence of cortical superficial siderosis (cSS) is associated the development of ICH recurrence (p=0.048), ischemic stroke (p=0.009), and vascular composite outcome (p=0.008). The association between cSS and vascular composite outcome remains significant after further adjustment for microbleed number, lacune and WMH volume (p=0.019).

Conclusions: Mixed-ICH harbors higher risk of unfavorable vascular outcome than HTN-ICH. Presence of cSS in Mixed-ICH independently predicts vascular event, suggesting the contribution of detrimental effect due to coexisting CAA.

Abstract TP342: Asymptomatic Striatocapsular Slit-Like Hemorrhage as a Severity Marker in Patients With Hypertensive Intracerebral Hemorrhage/Microbleeds

Background: Concomitant asymptomatic striatocapsular slit-like hemorrhage (SSH) is occasionally found in patients of hypertensive intracerebral hemorrhage (ICH), but was seldom reported. The correlation between hypertension severity and cerebral hemorrhagic pattern has not been well investigated, either. In this study, we described the clinico-radiological features of previous asymptomatic SSH in ICH patients with hypertensive angiopathy.

Methods: 246 patients with strictly deep or mixed deep and lobar ICH/CMBs were included. SSH was defined as hypointense lesions involving the lateral aspect of lentiform nucleus or external capsule in slit shape (>1.5cm) on susceptibility-weighted imaging without history of associated symptoms (Figure 1). Demographics and neuroimaging markers were compared between patients with SSH and those without. The association between SSH and left ventricular hypertrophy (LVH) or proteinuria was investigated in univariable and multivariable logistic regression models.

Results: Patients with SSH (n=24, 10%) and without SSH (n=222, 90%) had comparable age (62.0 ± 12.6 vs. 62.3 ± 13.5, p=0.912) and vascular risk factor profiles (all p>0.05). SSH was associated with more common lobar CMBs (79.2% vs 48.2%, p=0.005), lacunes (75% vs. 41.4%, p=0.002) and higher white matter hyperintensity (WMH) volumes (12.0 [7.7-26.8] vs. 8.7 [4.3-16.1] mL, p=0.016) on MRI, as well as more frequent LVH (50.0% vs. 20.3%, p=0.004) and proteinuria (41.7% vs. 19.4%, p=0.018). In multivariable analyses, SSH remains independently associated with LVH (Odds ratio 2.8 [1.1-7.3], p=0.033) and proteinuria (Odds ratio 2.6 [1.0-6.6], p=0.041) after adjustment for age, sex, CMBs, lacune and WMH volume.

Conclusions: Asymptomatic SSH is associated with more severe cerebral small vessel disease-related change on brain MRI, and hypertensive cardiac and renal injury, suggesting a more advanced stage of chronic hypertension.

Superficial Cerebellar Microbleeds and Cerebral Amyloid Angiopathy

Background and Purpose—

The differentiation between cerebral amyloid angiopathy (CAA) and hypertensive small vessel disease in primary intracerebral hemorrhage is mainly based on hemorrhagic neuroimaging markers in the supratentorial regions, and the cause for cerebellar microbleeds remains unknown. Our aim was to investigate whether superficial cerebellar microbleeds are more likely to be related to CAA rather than hypertensive small vessel disease.

Methods—

Two hundred seventy-five consecutive patients with intracerebral hemorrhage were retrospectively reviewed from a prospectively maintained hospital-based stroke registry. Eighty-five (33.1%) patients had cerebellar microbleeds and were categorized into superficial (gray matter, vermis), deep (white matter, deep nucleus, cerebellar peduncle), or mixed type based on the location of cerebellar hemorrhagic lesions. Amyloid imaging was obtained using 11C-Pittsburgh Compound B–positron emission tomography in a subgroup of patients. The associations between cerebellar microbleed locations and the type of small vessel disease (CAA versus hypertensive small vessel disease) based on distribution of supratentorial hemorrhagic lesions as well as other magnetic resonance imaging and positron emission tomography markers were analyzed.

Results—

The presence of cerebellar microbleed was independently associated with supratentorial microbleed and lacunar infarcts (both P <0.01). Strictly superficial cerebellar microbleeds were significantly related to CAA–intracerebral hemorrhage, cortical superficial siderosis and high-grade enlarged perivascular space in centrum semiovale (all P <0.05); deep or mixed cerebellar microbleeds were related to hypertension and deep microbleed (all P <0.05). In multivariable models, superficial cerebellar microbleeds were independently associated with CAA–intracerebral hemorrhage ( P =0.03). Of 33 patients assessed by amyloid positron emission tomography, cerebral and cerebellar amyloid load (standardized uptake value ratio) was higher in patients with superficial cerebellar microbleeds compared with deep/mixed cerebellar microbleeds (cerebrum standardized uptake value ratio [reference: cerebellum] 1.33±0.24 versus 1.05±0.09, P <0.001; cerebellum standardized uptake value ratio [reference: pons] 0.58±0.08 versus 0.51±0.09, P =0.03).

Conclusions—

Patients with strictly superficial cerebellar microbleeds are associated with a clinicoradiological diagnosis of CAA as well as increased cerebral and cerebellar amyloid deposition on Pittsburgh Compound B–positron emission tomography, suggesting underlying CAA pathology.

Plasma Aldosterone After Seated Saline Infusion Test Outperforms Captopril Test at Predicting Clinical Outcomes After Adrenalectomy for Primary Aldosteronism

OBJECTIVE

The saline infusion test (SIT) and the captopril test (CT) are widely used as confirmatory tests for primary aldosteronism (PA). We hypothesized that post-SIT and post-CT plasma aldosterone concentrations (PAC) indicate the severity of aldosterone-producing adenoma (APA) and might predict clinical outcome.

METHODS

We recruited 216 patients with APA in the Taiwan Primary Aldosteronism Investigation (TAIPAI) registry who received both seated SIT and CT as confirmatory tests. The data of 143 patients who underwent adrenalectomy with complete follow-up after diagnosis were included in the final analysis. We determined the proportion of patients achieving clinical success in accordance with the Primary Aldosteronism Surgical Outcome consensus. Logistic regression analysis was conducted to identify preoperative factors associated with cure of hypertension.

RESULTS

Complete clinical success was achieved in 48 (33.6%) patients and partial clinical success in 59 (41.2%) patients; absent clinical success was seen in 36 (25.2%) of 143 patients. Post-SIT PAC but not post-CT PAC was independently associated with clinical outcome. Higher levels of post-SIT PAC had a higher likelihood of clinical benefit (complete plus partial clinical success; odds ratio = 1.04 per ng/dl increase, 95% confidence interval = 1.01, 1.06; P = 0.004). Patients with post-SIT PAC > 25 ng/dl were more likely to have a favorable clinical outcome after adrenalectomy. This cutoff value translated into a positive predictive value of 86.0%.

CONCLUSIONS

We suggest that post-SIT PAC is a better predictor than post-CT PAC for clinical success in PA post adrenalectomy.

Improved diagnostic accuracy of thallium-201 myocardial perfusion single-photon emission computed tomography with CT attenuation correction

BACKGROUND

The benefits of attenuation correction (AC) in technetium-99m myocardial perfusion imaging (MPI) have been well established. However, the value of thallium (Tl-201) AC and routine computed tomography AC (CTAC) were less well established. The aims of this study were to evaluate the diagnostic performance of thallium (Tl-201) MPI with additional CTAC and to determine which participants would benefit most.

METHODS AND RESULTS

A total of 108 consecutive patients who underwent Tl-201 MPI and received coronary angiography within 3 months were enrolled. Diagnostic performance was determined by sensitivity, specificity, and receiver operating characteristic curve analysis. Subgroup analyses were performed using gender and obesity. CTAC improved the area under the curve (0.84 vs. 0.77, P = 0.037 at patient level), primarily due to a significant improvement in specificity (0.78 vs. 0.57, P = 0.013) and no significant difference in sensitivity (0.79 vs. 0.82, P = 0.75). In subgroup analysis, CTAC was most helpful in obese subjects, men, and especially right coronary artery lesions.

CONCLUSIONS

CTAC significantly improved diagnostic performance primarily by increasing the specificity, and the improvements were significantly greater in obese patients and male patients. These findings suggest that CTAC should be applied to Tl-201 MPI as routine clinical practice.

Three-step two-pot automated production of NCA [18F]FDOPA with FlexLab module

Automated three-step two-pot production of no-carrier-added (NCA) [¹⁸F]FDOPA was first implemented in the iPHASE FlexLab module. Decay-corrected radiochemical yield (RCY) of [¹⁸F]FDOPA synthesized by this method was 10~14% (n = 7) with a synthesis time of ~110 min [¹⁸F]FDOPA was obtained in > 95% of radiochemical purity with a molar activity of ~431 GBq/μmol. With the method successfully implementing on the commercial FlexLab module and its built-in step-by-step activity monitoring, further processes optimization would be achieved.

An one-pot two-step automated synthesis of [18F]T807 injection, its biodistribution in mice and monkeys, and a preliminary study in humans

[18F]T807 is a potent tau protein imaging agent. In order to fulfill the demand from preclinical and clinical studies, we developed an automated one-pot two-step synthesis of this potent tau imaging agent and studied its stability, and dosimetry in mice and monkeys. We also conducted a preliminary study of this imaging agent in humans. Using this one-pot two-step method, the radiochemical yield (RCY) of [18F]T807 was 20.5 ± 6.1% (n = 15) at the end of bombardment (EOB) in a synthesis time of 70±5 min. The chemical and radiochemical purities were >90% and the specific activities were 151 ± 52 GBq/μmol. The quality of [18F]T807 synthesized by this method met the U.S. Pharmacopoeia (USP) criteria. The stability test showed that the [18F]T807 injection was stable at room temperature for up to 4 h after the end of synthesis (EOS). The estimated effective dose of the [18F]T807 injection extrapolated from monkeys was 19 μSv/MBq (n = 2), while the estimated effective doses of the [18F]T807 injection extrapolated from fasted and non-fasted mice were 123 ± 27 (n = 3) and 94 ± 19 (n = 4) μSv/MBq, respectively. This one-pot two-step automated method produced the [18F]T807 injection with high reproducibility and high quality. PET imaging and radiation dosimetry evaluation in mice and Formosan rock monkeys suggested that the [18F]T807 injection synthesized by this method is suitable for use in human PET imaging studies. Thus, this method could fulfill the demand for the [18F]T807 injection in both preclinical and clinical studies of tauopathies, especially for nearby study sites without cyclotrons.

Advances in cerebral amyloid angiopathy imaging

Cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease caused by β -amyloid (Aβ) deposition at the leptomeningeal vessel walls. It is a common cause of spontaneous intracerebral hemorrhage and a frequent comorbidity in Alzheimer’s disease. The high recurrent hemorrhage rate in CAA makes it very important to recognize this disease to avoid potential harmful medication. Imaging studies play an important role in diagnosis and research of CAA. Conventional computed tomography and magnetic resonance imaging (MRI) methods reveal anatomical alterations, and remains as the most reliable tool in identifying CAA according to modified Boston criteria. The vascular injuries of CAA result in both hemorrhagic and ischemic manifestations and related structural changes on MRI, including cerebral microbleeds, cortical superficial siderosis, white matter hyperintensity, MRI-visible perivascular spaces, and cortical microinfarcts. As imaging techniques advance, not only does the resolution of conventional imaging improve, but novel skills in functional and molecular imaging studies also enable in vivo analysis of vessel physiological changes and underlying pathology. These modern tools help in early detection of CAA and may potentially serve as sensitive outcome markers in future clinical trials. In this article, we reviewed past studies of CAA focusing on utilization of various conventional and novel imaging techniques in both research and clinical aspects.

Microangiopathy underlying mixed-location intracerebral hemorrhages/microbleeds: A PiB-PET study

OBJECTIVE

To test the hypothesis that patients with concomitant lobar and deep intracerebral hemorrhages/microbleeds (mixed ICH) have predominantly hypertensive small vessel disease (HTN-SVD) rather than cerebral amyloid angiopathy (CAA), using in vivo amyloid imaging.

METHODS

Eighty Asian patients with primary ICH without dementia were included in this cross-sectional study. All patients underwent brain MRI and 11C-Pittsburgh compound B (PiB)-PET imaging. The mean cortical standardized uptake value ratio (SUVR) was calculated using cerebellum as reference. Forty-six patients (57.5%) had mixed ICH. Their demographic and clinical profile as well as amyloid deposition patterns were compared to those of 13 patients with CAA-ICH and 21 patients with strictly deep microbleeds and ICH (HTN-ICH).

RESULTS

Patients with mixed ICH were younger (62.8 ± 11.7 vs 73.3 ± 11.9 years in CAA, p = 0.006) and showed a higher rate of hypertension than patients with CAA-ICH (p < 0.001). Patients with mixed ICH had lower PiB SUVR than patients with CAA (1.06 [1.01-1.13] vs 1.43 [1.06-1.58], p = 0.003). In a multivariable logistic regression model, mixed ICH was associated with hypertension (odds ratio 8.9, 95% confidence interval 1.4-58.4, p = 0.02) and lower PiB SUVR (odds ratio 0.03, 95% confidence interval 0.001-0.87, p = 0.04) compared to CAA after adjustment for age. Compared to HTN-ICH, mixed ICH showed a similar mean age (62.8 ± 11.7 vs 60.1 ± 14.5 years in HTN-ICH) and risk factor profile (all p > 0.1). Furthermore, PiB SUVR did not differ between mixed ICH (values presented above) and HTN-ICH (1.10 [1.00-1.16], p = 0.45).

CONCLUSIONS

Patients with mixed ICH have much lower amyloid load than patients with CAA-ICH, while being similar to HTN-ICH. Overall, mixed ICH is probably caused by HTN-SVD, an important finding with clinical relevance.

Abstract WP350: Detecting Endogenous Neurogenesis After Ischemic Stroke: A F-18-fluorothymidine PET Study

Background and Purpose: Adult neural stem cells (NSCs) can be activated after stroke, but currently noninvasive imaging technique to visualize cerebral neurogenesis is lacking. F-18-fluorothymidine (FLT) has been used as a PET tracer to image cell proliferation and could detect endogenous NSCs in vivo . In this study, we assessed the change in cerebral FLT uptake in a rat model of ischemic stroke.

Methods: Cerebral FLT PET was performed in rats subjected to transient middle cerebral artery occlusion (MCAO). PET data were semiquantitatively analyzed and expressed as average mean standardized uptake value ratios (SUVRs) of regions of interest using cerebellar cortex as the reference region. Neurological function was assessed via modified Neurological Severity Score (mNSS) 1 day after MCAO, and infarct volume was analyzed by 2,3,5-Triphenyltetrazolium chloride staining method 7 days after MCAO.

Results: Seven days after MCAO, rats exhibited a higher number of Ki67 immunoreactive cells at the subventricular zone, striatum, frontal and temporal cortices in the infarcted brain, indicating promotion of neurogenesis (Figure 1A). The FLT PET showed higher SUVR in the infarcted brain compared to the unaffected side (Figure 1B; Striatum: 1.03±0.36 vs 0.74±0.16, p=0.001; Frontal: 1.14±0.27 vs 0.96±0.13, p=0.004; Temporal: 1.16±0.26 vs 1.00±0.15, p=0.01). The cerebral FLT binding activity gradually declined from post MCAO day 7 to day 28 in the infarcted brain (Figure 1C and D). The FLT binding ratio (global SUVR in the infarcted brain divided by that in the contralateral side) was positively correlated to the severity of stroke, including mNSS (r=0.70, p<0.001) and infarct volume (r=0.90, p<0.001).

Conclusion: In vivo FLT PET can detect NSCs in a rat model of ischemic stroke. The promising results of FLT PET suggest that it can be potentially applied in clinical studies as noninvasive longitudinal monitoring and quantification of endogenous NSC activation in the human brain.

Surgical outcomes of patients with primary aldosteronism lateralized with I-131-6 β-iodomethyl-norcholesterol single photon emission/computed tomography without discontinuation or modification of antihypertensive medications

Objectives

Adrenocortical scintigraphy for patients with primary aldosteronism (PA) without discontinuation or modification of antihypertensive medications is of concern because of drug interference with the renin-angiotensin-aldosterone system. We report the surgical outcomes of patients with PA lateralized with adrenocortical scintigraphy without drug discontinuation or modification.

Materials and Methods

We retrospectively reviewed 34 patients with PA with computed tomography (CT)-documented adrenal tumors who had undergoing subsequent I-131-6 β-iodomethyl-norcholesterol (NP-59) single photon emission CT (SPECT)/CT followed by unilateral adrenalectomy according to the results of NP-59 uptake between May 2005 and December 2014. All enrolled patients underwent standard confirmatory tests and lateralization with NP-59 SPECT/CT without discontinuation of existing antihypertensive medications, including spironolactone. The pathological findings, hypertension outcomes, and biochemical changes were reported. The accuracy of NP-59 SPECT/CT without drug discontinuation or modification was also evaluated.

Results

None of the 34 enrolled patients (M:F = 16:18) had complications such as a hypertensive crisis, life-threatening hypokalemic event, or cardiac arrhythmia. Pathology disclosed 31 (91%) adenomas and three cases of hyperplasia. Hypertension cure and improvement were observed in 12 (35%) and 18 (53%) patients, respectively. All of the 30 patients (100%) without postoperative use of beta-blockers and with an available postoperative aldosterone/renin ratio achieved a biochemical cure. The positive predictive values of NP-59 SPECT/CT were 91%, 88%, and 100% for the pathological findings, hypertension outcomes, and biochemical changes, respectively.

Conclusion

Noninvasive NP-59 SPECT/CT without discontinuation or modification of antihypertensive medications not only provided accurate lateralization and safety but also resulted in a high improvement rate for PA-associated hypertension.

The Relation Between Brain Amyloid Deposition, Cortical Atrophy, and Plasma Biomarkers in Amnesic Mild Cognitive Impairment and Alzheimer's Disease

Background: Neuritic plaques and neurofibrillary tangles are the pathological hallmarks of Alzheimer’s disease (AD), while the role of brain amyloid deposition in the clinical manifestation or brain atrophy remains unresolved. We aimed to explore the relation between brain amyloid deposition, cortical thickness, and plasma biomarkers.

Methods: We used ¹¹C-Pittsburgh compound B-positron emission tomography to assay brain amyloid deposition, magnetic resonance imaging to estimate cortical thickness, and an immunomagnetic reduction assay to measure plasma biomarkers. We recruited 39 controls, 25 subjects with amnesic mild cognitive impairment (aMCI), and 16 subjects with AD. PiB positivity (PiB+) was defined by the upper limit of the 95% confidence interval of the mean cortical SUVR from six predefined regions (1.0511 in this study).

Results: All plasma biomarkers showed significant between-group differences. The plasma Aβ₄₀ level was positively correlated with the mean cortical thickness of both the PiB+ and PiB- subjects. The plasma Aβ₄₀ level of the subjects who were PiB+ was negatively correlated with brain amyloid deposition. In addition, the plasma tau level was negatively correlated with cortical thickness in both the PiB+ and PiB- subjects. Moreover, cortical thickness was negatively correlated with brain amyloid deposition in the PiB+ subjects. In addition, the cut-off point of plasma tau for differentiating between controls and AD was higher in the PiB- group than in the PiB+ group (37.5 versus 25.6 pg/ml, respectively). Lastly, ApoE4 increased the PiB+ rate in the aMCI and control groups.

Conclusion: The contributions of brain amyloid deposition to cortical atrophy are spatially distinct. Plasma Aβ₄₀ might be a protective indicator of less brain amyloid deposition and cortical atrophy. It takes more tau pathology to reach the same level of cognitive decline in subjects without brain amyloid deposition, and ApoE4 plays an early role in amyloid pathogenesis.

Distribution of Lacunar Infarcts in Asians With Intracerebral Hemorrhage: A Magnetic Resonance Imaging and Amyloid Positron Emission Tomography Study

BACKGROUND AND PURPOSE

We evaluated whether lacunes in centrum semiovale (lobar lacunes) were associated with cerebral amyloid angiopathy (CAA) markers in an Asian intracerebral hemorrhage (ICH) population.

METHODS

One hundred ten patients with primary ICH were classified as CAA-ICH (n=24; mean age, 70.9±13.9) or hypertensive ICH (n=86; mean age, 59.3±13.0) according to the presence of strictly lobar (per modified Boston criteria) or strictly deep bleeds (both ICH and cerebral microbleeds), respectively. Lacunes were evaluated in the supratentorial area and classified as lobar or classical deep based on the location. A subgroup of 36 patients also underwent Pittsburgh Compound B positron emission tomography to measure cerebral amyloid deposition and global standardized uptake value ratio were calculated.

RESULTS

Lobar lacunes were more frequent in CAA-ICH than hypertensive ICH (29.2 versus 11.6%; P=0.036). In multivariable models, lobar lacunes were associated with lobar cerebral microbleed (odds ratio, 6.8; 95% confidence interval, 1.6-29.9; P=0.011) after adjustment for age, sex, hypertension, and white matter hyperintensity. In 15 CAA-ICH and 21 hypertensive ICH patients with Pittsburgh Compound B positron emission tomography, correlation analyses between lobar lacune counts and global standardized uptake value ratio showed positive association (ρ=0.40; P=0.02) and remained significant after adjustment for age (r=0.34; P=0.04).

CONCLUSIONS

Our findings expand on recent work showing that lobar lacunes are more frequent in CAA-ICH than hypertensive ICH. Their independent association with lobar cerebral microbleeds and brain amyloid deposition suggests a relationship with CAA even in an Asian cohort with overall higher hypertensive load.

Multiparametric PET/MR imaging biomarkers are associated with overall survival in patients with pancreatic cancer

PURPOSE

To correlate the overall survival (OS) with the imaging biomarkers of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted imaging (DWI), magnetic resonance spectroscopy, and glucose metabolic activity derived from integrated fluorine 18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/MRI in patients with pancreatic cancer.

METHODS

This prospective study was approved by the institutional review board and informed consent was obtained from all participants. Sixty-three consecutive patients (mean age, 62.7 ± 12 y; men/women, 40/23) with pancreatic cancer underwent PET/MRI before treatment. The imaging biomarkers were comprised of DCE-MRI parameters (peak, IAUC ₆₀ , K ^trans , k _ep , v _e ), the minimum apparent diffusion coefficient (ADC_min), choline level, standardized uptake values, metabolic tumor volume, and total lesion glycolysis (TLG) of the tumors. The relationships between these imaging biomarkers with OS were evaluated with the Kaplan-Meier and Cox proportional hazard models.

RESULTS

Seventeen (27%) patients received curative surgery, with the median follow-up duration being 638 days. Univariate analysis showed that patients at a low TNM stage (≦3, P = 0.041), high peak (P = 0.006), high ADC_min (P = 0.002) and low TLG (P = 0.01) had better OS. Moreover, high TLG/peak ratio was associated with poor OS (P = 0.016). Multivariate analysis indicated that ADC_min (P = 0.011) and TLG/peak ratio (P = 0.006) were independent predictors of OS after adjustment for age, gender, tumor size, and TNM stage. The TLG/peak ratio was an independent predictor of OS in a subgroup of patients who did not receive curative surgery (P = 0.013).

CONCLUSION

The flow-metabolism mismatch reflected by the TLG/peak ratio may better predict OS than other imaging biomarkers from PET/MRI in pancreatic cancer patients.

A multidisciplinary team care approach improves outcomes in high-risk pediatric neuroblastoma patients

We assessed the impact of a multidisciplinary team care program on treatment outcomes in neuroblastoma patients. Newly diagnosed neuroblastoma patients received treatment under the Taiwan Pediatric Oncology Group (TPOG) N2002 protocol at the National Taiwan University Hospital beginning in 2002. A multidisciplinary team care approach that included nurse-led case management for patients treated under this protocol began in January 2010. Fifty-eight neuroblastoma patients, including 29 treated between 2002 and 2009 (Group 1) and 29 treated between 2010 and 2014 (Group 2), were enrolled in the study. The 5-year overall survival (OS) and event-free survival (EFS) rates for all 58 patients were 59% and 54.7%, respectively. Group 2 patients, who were treated after implementation of the multidisciplinary team care program, had better 3-year EFS (P = 0.046), but not OS (P = 0.16), rates than Group 1 patients. In a multivariate analysis, implementation of the multidisciplinary team approach was the only significant independent prognostic factor for neuroblastoma patients. In further subgroup analyses, the multidisciplinary team approach improved EFS, but not OS, in patients with stage 4 disease, those in the high-risk group, and those with non-MYCN amplified tumors. These data indicate a multidisciplinary team care approach improved survival outcomes in high-risk neuroblastoma patients. However, further investigation will be required to evaluate the long-term effects of this approach over longer follow-up periods.

Targeting histone deacetylase 4/ubiquitin-conjugating enzyme 9 impairs DNA repair for radiosensitization of hepatocellular carcinoma cells in mice

Several strategies to improve the efficacy of radiation therapy against hepatocellular carcinoma (HCC) have been investigated. One approach is to develop radiosensitizing compounds. Because histone deacetylase 4 (HDAC4) is highly expressed in liver cancer and known to regulate oncogenesis through chromatin structure remodeling and controlling protein access to DNA, we postulated that HDAC4 inhibition might enhance radiation's effect on HCC cells. HCC cell lines (Huh7 and PLC5) and an ectopic xenograft were pretreated with HDAC inhibitor or short hairpin RNA to knock down expression of HDAC4 and then irradiated (2.5-10.0 Gy). We evaluated cell survival by a clonogenic assay; apoptosis by Annexin V immunofluorescence; γH2AX, Rad51, and HDAC4 by immunofluorescence staining; HDAC4, Rad51, and ubiquitin-conjugating enzyme 9 (Ubc9) in HCC cell nuclei by cell fractionation and confocal microscopy; physical interaction between HDAC4/Rad51/Ubc9 by immunoprecipitation; and the downstream targets of HDAC4 knockdown by immunoblotting. Both HDAC4 knockdown and HDAC inhibitor enhanced radiation-induced cell death and reduced homologous recombination repair of DNA double-strand breaks and protein kinase B activation, leading to increased apoptosis. HDAC4 knockdown with or without an HDAC inhibitor significantly delayed tumor growth in a radiation-treated xenograft model. Radiation stimulated nuclear translocation of Rad51 in an HDAC4-dependent manner and the binding of Ubc9 directly to HDAC4, which led to Ubc9 acetylation. Moreover, these effects were accompanied by HDAC4/Ubc9/Rad51 complex dissociation through inhibiting nuclear translocation. Conclusion: HDAC4 signaling blockade enhances radiation-induced lethality in HCC cells and xenografts. These findings raise the possibility that HDAC4/Ubc9/Rad51 complex in DNA repair may be a target for radiosensitization of HCC. (Hepatology 2018;67:586-599).

Abstract TP340: Centrum-semiovale Enlarged Perivascular Space and Amyloid Deposition in Primary Intracerebral Hemorrhage

Background: Higher load of MRI visible enlarged perivascular spaces in centrum-semiovale (CSO-EPVS) are found in cerebral amyloid angiopathy (CAA), but their association to brain amyloid has been rarely investigated, especially in Asians. We explored whether high degree of CSO-EPVS is associated to other MRI signatures of CAA and its relationship to brain amyloid retention in patients with primary intracerebral hemorrhage (ICH).

Methods: 110 patients with either CAA-ICH, strictly lobar ICH and microbleeds (MB) or hypertensive ICH (HTN-ICH), strictly deep-seated ICH/MBs, were included in this study. CSO-EPVS and basal ganglia EPVS (BG-EPVS) were assesd using an established 4-point semiquantitative score. EPVS degree was classified as high (score>2) or low (≤2). We also evaluated MBs, cortical superficial siderosis (cSS), white matter hyperintensities (WMH) and brain atrophy severity on MRIs. Cerebral amyloid deposition was quantified on 11 C-Pittsburgh Compound B (PiB) PETs in 36 patients (15 CAA; 21 HA) as standardized uptake value ratio (SUVR).

Results: Patients with CAA-related ICH (n=24) and HTN-ICH (n=86) had similar prevalence of high-degree CSO-EPVS (37.5% and 26.7%, p=0.305) and high-degree BG-EPVS (25% and 18.6%, p=0.489). Patients with high-degree CSO-EPVS were associated with presence of lobar MB (p=0.01) and higher WMH (p=0.008), while patients with high-degree EPVS-BG were associated with older age (p=0.002), higher WMH (p=0.021) and more cortical atrophy (p=0.023). The amyloid burden (global SUVR) was higher in high-degree vs low-degree EPVS-CSO in CAA-ICH (p=0.045), but not in HTN-ICH (p=0.586). On multivariate logistic regression analysis, the degree of EPVS-CSO remains an independent indicator for positive amyloid scan (defined as global SUVR>1.2) even after adjustment for age, WMH, the degree of EPVS-BG and ICH/MBs distribution (Odds ratio 6.2 [1.2-31.6], p=0.029).

Conclusion: Although the presence of EPVS-CSO could not directly distinguish CAA-ICH and HTN-ICH in our Asian cohort, high-degree EPVS-CSO was associated with CAA-related MRI markers such as lobar MBs, and higher amyloid load on PiB-PET. The burden of CSO-EPVS can be seen as an indicator of higher brain amyloid deposition in patients with CAA-related ICH.

Abstract TP330: Lacune Distribution in Asians With Primary Intracerebral Hemorrhage: An MRI and Amyloid PET Study

Background: Lacunar infarcts located in centrum-semiovale and lobar regions were more frequent in Caucasians with intracerebral hemorrhage related to cerebral amyloid angiopathy (CAA-ICH) while deep-seated lacunes in ICH related to hypertension (HTN-ICH), but these associations have never been validated in Asian patients. In the present study, we evaluated whether lobar lacunes were associated with core CAA markers such as lobar microbleeds (CMB) and higher amyloid load on 11 C-Pittsburgh Compund B (PiB) PET in an Asian ICH population.

Methods: One hundred and ten patients of primary ICH who received MRI scans were classified as CAA-ICH or HTN-ICH according with the presence of strictly lobar or strictly deep bleeds (both ICH and CMBs), respectively. Lacunes were evaluated in the supratentorial area and classified as lobar (when located in CSO, frontal, parietal, insular/subinsular, temporal, and occipital lobes) or deep (when located in thalamus, basal ganglion, internal and external capsule) based on the location. A subgroup of 36 patients also underwent PiB-PET and global standardized uptake value ratio (SUVR) were calculated.

Results: There were 24 CAA-ICH (mean age 70.9 ± 13.9) and 86 HTN-ICH (mean age 59.3 ± 13.0). Lobar lacunes were more frequent in CAA-ICH than HTN-ICH (29.2 vs 11.6%, p=0.036). In univariate analysis, lobar lacunes were significantly related to lobar CMB (p<0.001) and white matter hyperintensity (WMH) severity (p=0.001). In multivariable models, lobar lacunes were again associated with lobar CMB (Odds ratio 6.9, 95 % confidence interval 1.5-31.3, p=0.011) after adjustment for age, sex, hypertension and WMH. In 15 CAA-ICH and 21 HTN-ICH patients with PiB PET, correlation analyses between lobar lacune counts and global SUVR was high (r=0.40, p=0.02) and remained significant after adjustment for age ( r =0.34, p=0.04).

Conclusion: Lobar lacunes were more frequent in Asian patients with CAA-related strictly lobar hemorrhages. Their independent association with lobar CMB and brain amyloid deposition suggests a strong relationship with CAA even in an Asian cohort with overall higher hypertensive load.

Abstract WMP100: Underlying Microangiopathy of Mixed Location Intracerebral Hemorrhage and Microbleeds: a PiB-PET Study

Background: Recent MRI-based work suggested that the predominant type of cerebral small vessel disease (SVD) in patients with a combination of lobar and deep intracerebral hemorrhage (ICH)/microbleed (MB) locations (Mixed-ICH) was hypertensive (HTN) SVD. We sought to use in vivo amyloid imaging to test the hypothesis that mixed-ICH is related to HTN-SVD rather than cerebral amyloid angiopathy (CAA).

Methods: Eighty Asian primary ICH patients without dementia were included in this study. All patients underwent brain MRI and 11 C-Pittsburgh Compound B (PiB) PET. The global, occipital and frontal standardized uptake value ratio (SUVR) were calculated using cerebellum as reference. Fourty-six (51%) patients had Mixed-ICH. Their demographic and clinical profile as well as amyloid deposition patterns were compared to 13 probable CAA (Boston criteria; CAA-ICH) and 21 strictly deep-MB and ICH (HTN-ICH) patients.

Results: Mixed-ICH patients were younger (62.8±11.7 vs 71.0±14.5 in CAA) and showed a higher burden of vascular risk factors such as hypertension and diabetes than CAA-ICH (all p<0.05). Patients with Mixed-ICH had lower mean global (1.11±0.2 vs 1.31±0.3), frontal (1.09±0.2 vs 1.31±0.3) and occipital SUVR (1.16±0.1 vs 1.32±0.2) than CAA-ICH (all p<0.05). In multivariable analyses, Mixed-ICH diagnosis was associated with hypertension (β=-1.09, 95% Confidence interval [CI]: - 2.5- -0.1, p=0.02) while diagnosis of probable CAA with global-SUVR (β=3.5, CI: 0.3-7.3 p=0.04) after adjustment for age. Mean frontal and occipital-SUVR measures were both associated with probable CAA diagnosis in similar multivariable models. Compared to HTN-ICH, Mixed-ICH showed a similar mean age (62.8±11.7 vs 60±14.5 in HTN-ICH) and risk factor profile (all p>0.1). Furthermore, mean global, frontal and occipital SUVR did not differ between Mixed ICH (values presented above) and HTN-ICH (1.08±0.1, 1.04±0.2 and 1.14±0.1 respectively, all p>0.1).

Conclusions: In addition to validating previous results in an Asian cohort, our study also brings the unique insight that Mixed-ICH patients have much lower amyloid load than CAA-ICH, while being very similar to HTN-ICH. Overall, Mixed-ICH is probably caused by HTN-SVD, an important conclusion with clinical relevance.