Positive Positron Emission Tomography Scan Research Articles

Postoperative 68Ga-DOTATATE positron emission tomography has a low yield in incidental appendiceal neuroendocrine tumours.

Rarely, appendiceal neuroendocrine tumours (NET) are an incidental finding when an appendicectomy is undertaken for suspected appendicitis. The role of further imaging in this setting is poorly defined. Positron emission tomography (PET) using 68Ga-DOTATATE is requested to evaluate post-surgical status, however, there is little evidence to guide how it should be employed. The aims of this project are to: (i) characterize 68Ga-DOTATATE PET findings in patients with incidental appendiceal NETs and (ii) discuss how these data might inform post-surgical imaging with PET. We reviewed 47 PET scans in 30 patients, undertaken from 2009 to 2018. Scintigraphic findings, histopathological characteristics of the initial appendiceal lesion and medical records were reviewed. Most patients (n = 15) had small (<10 mm) appendiceal NETs with low grade (Ki67 < 2%) features. Eight patients had tumours between 10 and 20 mm, and seven had tumours >20 mm. Goblet cell features were identified in two patients. Three positive PET scans were reported in one patient with an index tumour measuring 40 mm and Ki67 < 2%. The remaining 29 patients had 44 negative scans. Clinical outcome data were available in 27 patients (mean follow-up time 57 months; range 6-123 months). There was no evidence of recurrent neuroendocrine disease at the time of the last follow-up. These data indicate that in most cases, post-surgical 68Ga-DOTATATE PET is negative in patients with incidentally detected appendiceal NETs. Clinical outcome data suggest that 68Ga-DOTATATE PET should be reserved for patients with large tumours (>20 mm) or those displaying goblet cell features.

Factors Contributing to the Accuracy of PET Scans in Detecting Cancer Metastases in Cairo Hospitals, Egypt

Introduction: Positron emission tomography (PET) has become an important diagnostic tool in oncology, providing metabolic information that can aid in the detection and evaluation of cancer. However, the accuracy of PET scans in detecting cancer metastases can be influenced by various factors, including the type of cancer, location of metastases, and image acquisition protocol. This study aims to evaluate the factors that influence the accuracy of PET scans in detecting cancer metastases in patients at Cairo Hospital, Egypt.&#x0D; Methods: Patient data were collected retrospectively. A total of 5000 research subjects participated in this study. Data were analyzed to identify factors associated with false-positive or false-negative PET scan results.&#x0D; Results: Patients with lung or colorectal cancer were 2.45 times more likely to experience accurate positive PET scan results than patients with other types of cancer. Patients with metastases in lymph nodes were 1.93 times more likely to experience accurate positive PET scan results than patients with metastases in solid organs. Patients with a long PET scan image acquisition protocol were 1.78 times more likely to experience accurate positive PET scan results than patients with a short image acquisition protocol.&#x0D; Conclusion: PET scan is a valuable diagnostic tool in oncology, but its accuracy in detecting cancer metastases can be influenced by various factors. These factors should be considered when interpreting PET scan results and to improve cancer diagnosis and management.

The Use of Event Related Potentials to Predict Amyloid PET Status Among Patients from a Memory Disorders Clinic.

Amyloid positron emission tomography (PET) scans provide in vivo evidence of Alzheimer's disease (AD); however, their high cost limits their use in standard clinical care. Event related potentials (ERPs) may represent an inexpensive and non-invasive additional method for detecting AD pathology. We investigated whether ERPs, along with neuropsychological data, serve as predictors of amyloid PET status in patients with memory complaints. Veterans aged 50-100 were recruited from a memory disorders clinic. Participants underwent a neuropsychological battery and an ERP auditory oddball protocol. Twenty-eight patients had a positive amyloid PET scan, and thirty-nine patients had a negative scan. ERP-P200 target amplitude and P200 standard latency were predictors of amyloid PET status. When submitting to ROC analysis, P200 standard latency exhibited the highest specificity and sensitivity in predicting amyloid PET positivity, correctly classifying the amyloid PET status for 86% of patients. ERP-P200 measures are strong indicators of amyloid-β presence in patients from a memory disorder clinic. Increased P200 amplitude and decreased P200 latency in patients with a positive amyloid PET scan may be attributed to hyperactivation of perceptual bottom-up processes compensating for AD-related synaptic loss in the fronto-parietal networks.

5 Intraindividual Variability in Processing Speed on Digital Cognitive Assessments Differs by Amyloidosis Status in Cognitively Normal Older Adults

Objective:Intraindividual variability (IIV) is defined as fluctuations in an individual’s cognitive performance over time1. IIV has been identified as a marker of neurobiological disturbance making it a useful method for detecting changes in cognition among cognitively healthy individuals as well as those with prodromal syndromes2. IIV on laboratory-based computerized tasks has been linked with cognitive decline and conversion to mild cognitive impairment (MCI) and/or dementia (Haynes et al., 2017). Associations between IIV and AD risk factors including apolipoprotein (APOE) ε4 carrier status, neurodegeneration seen on brain imaging, and amyloid (Aß) Positron emission tomography (PET) scan status have also been observed1. Recent studies have demonstrated that evaluating IIV on smartphone-based digital cognitive assessments is feasible, has the capacity to differentiate between cognitively normal (CN) and MCI individuals, and may reduce barriers to cognitive assessment3. This study sought to evaluate whether such differences could be detected in CN participants with and without elevated AD risk.Participants and Methods:Participants (n=57) were cognitively normal older adults who previously received an Aß PET scan through the Butler Hospital Memory and Aging Program. The sample consisted of primarily non-Hispanic (n=49, 86.0%), White (n=52, 91.2%), college-educated (M=16.65 years), females (n=39, 68.4%). The average age of the sample was 68 years old. Approximately 42% of the sample (n=24) received a positive PET scan result. Participants completed brief cognitive assessments (i.e., 3-4 minutes) three times per day for eight days (i.e., 24 sessions) using the Mobile Monitoring of Cognitive Change (M2C2) application, a mobile app-based cognitive testing platform developed as part of the National Institute of Aging’s Mobile Toolbox initiative (Sliwinski et al., 2018). Participants completed visual working memory, processing speed, and episodic memory tasks on the M2C2 platform. Intraindividual standard deviations (ISDs) across trials were computed for each person at each time point (Hultsch et al., 2000). Higher ISD values indicate more variability in performance. Linear mixed effects models were utilized to examine whether differences in IIV existed based on PET scan status while controlling for age, sex at birth, and years of education.Results:n interaction between PET status and time was observed on the processing speed task such that Aß- individuals were less variable over the eight assessment days compared to Aß + individuals (B= -5.79, SE=2.67, p=.04). No main or interaction effects were observed on the visual working memory task or episodic memory task.Conclusions:Our finding that Aß- individuals demonstrate less variability over time on a measure of processing speed is consistent with prior work. No associations were found between IIV in other cognitive domains and PET status. As noted by Allaire and Marsiske (2005), IIV is not a consistent phenomenon across different cognitive domains. Therefore, identifying which tests are the most sensitive to early change is crucial. Additional studies in larger, more diverse samples are needed prior to widespread clinical use for early detection of AD.

Amyloid Positron Emission Tomography and Subsequent Health Care Use Among Medicare Beneficiaries With Mild Cognitive Impairment or Dementia

Results of amyloid positron emission tomography (PET) have been shown to change the management of patients with mild cognitive impairment (MCI) or dementia who meet Appropriate Use Criteria (AUC). To determine if amyloid PET is associated with reduced hospitalizations and emergency department (ED) visits over 12 months in patients with MCI or dementia. This nonrandomized controlled trial analyzed participants in the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) study, an open-label, multisite, longitudinal study that enrolled participants between February 2016 and December 2017 and followed up through December 2018. These participants were recruited at 595 clinical sites that provide specialty memory care across the US. Eligible participants were Medicare beneficiaries 65 years or older with a diagnosis of MCI or dementia within the past 24 months who met published AUC for amyloid PET. Each IDEAS study participant was matched to a control Medicare beneficiary who had not undergone amyloid PET. Data analysis was conducted on December 13, 2022. Participants underwent amyloid PET at imaging centers. The primary end points were the proportions of patients with 12-month inpatient hospital admissions and ED visits. One of 4 secondary end points was the rate of hospitalizations and rate of ED visits in participants with positive vs negative amyloid PET results. Health care use was ascertained from Medicare claims data. The 2 cohorts (IDEAS study participants and controls) each comprised 12 684 adults, including 6467 females (51.0%) with a median (IQR) age of 77 (73-81) years. Over 12 months, 24.0% of the IDEAS study participants were hospitalized, compared with 25.1% of the matched control cohort, for a relative reduction of -4.49% (97.5% CI, -9.09% to 0.34%). The 12-month ED visit rates were nearly identical between the 2 cohorts (44.8% in both IDEAS study and control cohorts) for a relative reduction of -0.12% (97.5% CI, -3.19% to 3.05%). Both outcomes fell short of the prespecified effect size of 10% or greater relative reduction. Overall, 1467 of 6848 participants (21.4%) with positive amyloid PET scans were hospitalized within 12 months compared with 1081 of 4209 participants (25.7%) with negative amyloid PET scans (adjusted odds ratio, 0.83; 95% CI, 0.78-0.89). Results of this nonrandomized controlled trial showed that use of amyloid PET was not associated with a significant reduction in 12-month hospitalizations or ED visits. Rates of hospitalization were lower in patients with positive vs negative amyloid PET results.

Association Between Vascular 18F-Fluorodeoxyglucose Uptake at Diagnosis and Change in Aortic Dimensions in Giant Cell Arteritis : A Cohort Study.

Previous studies have shown that patients with giant cell arteritis (GCA) who have vascular 18F-fluorodeoxyglucose (FDG) uptake at diagnosis are at increased risk for thoracic aortic complications. To measure the association between vascular FDG uptake at diagnosis and the change in aortic dimensions. Prospective cohort study. University Hospitals Leuven. 106 patients with GCA and FDG positron emission tomography (PET) imaging 3 days or less after initiation of glucocorticoids. Patients had PET and computed tomography (CT) imaging at diagnosis and CT imaging yearly for a maximum of 10 years. The PET scans were scored 0 to 3 in 7 vascular areas and summed to a total vascular score (TVS). The PET scan results were positive when FDG uptake was grade 2 or greater in any large vessel. The association between vascular FDG uptake and aortic dimensions was estimated by linear mixed-effects models with random intercept and slope. When compared with patients with a negative PET scan result, those with a positive scan result had a greater increase in the diameter of the ascending aorta (difference in 5-year progression, 1.58 mm [95% CI, 0.41 to 2.74 mm]), the diameter of the descending aorta (1.32 mm [CI, 0.38 to 2.26 mm]), and the volume of the thoracic aorta (20.5 cm³ [CI, 4.5 to 36.5 cm³]). These thoracic aortic dimensions were also positively associated with TVS. Patients with a positive PET scan result had a higher risk for thoracic aortic aneurysms (adjusted hazard ratio, 10.21 [CI, 1.25 to 83.3]). The lengthy inclusion and follow-up period resulted in missing data and the use of different PET machines. Higher TVS was associated with greater yearly increase in thoracic aortic dimensions. Performing PET imaging at diagnosis may help to estimate the risk for aortic aneurysm formation. None.

Overall survival of patients with cHL who progress after autologous stem cell transplant: results in the novel agent era

AbstractIn the pre–novel agent era, the median postprogression overall survival (PPS) of patients with classic Hodgkin lymphoma (cHL) who progress after autologous stem cell transplant (ASCT) was 2 to 3 years. Recently, checkpoint inhibitors (CPI) and brentuximab vedotin (BV) have improved the depth and durability of response in this population. Here, we report the estimate of PPS in patients with relapsed cHL after ASCT in the era of CPI and BV. In this multicenter retrospective study of 15 participating institutions, adult patients with relapsed cHL after ASCT were included. Study objective was postprogression overall survival (PPS), defined as the time from posttransplant progression to death or last follow-up. Of 1158 patients who underwent ASCT, 367 had progressive disease. Median age was 34 years (range, 27-46) and 192 were male. Median PPS was 114.57 months (95% confidence interval [CI], 91-not achieved) or 9.5 years. In multivariate analysis, increasing age, progression within 6 months, and pre-ASCT positive positron emission tomography scan were associated with inferior PPS. When adjusted for these features, patients who received CPI, but not BV, as first treatment for post-ASCT progression had significantly higher PPS than the no CPI/no BV group (hazard ratio, 3.5; 95% CI, 1.6-7.8; P = .001). Receipt of allogeneic SCT (Allo-SCT) did not improve PPS. In the era of novel agents, progressive cHL after ASCT had long survival that compares favorably with previous reports. Patients who receive CPI as first treatment for progression had higher PPS. Receipt to Allo-SCT was not associated with PPS in this population.

Sex differences in the structural rich-club connectivity in patients with Alzheimer's disease.

Alzheimer's disease (AD) is more prevalent in women than in men; however, there is a discrepancy in research on sex differences in AD. The human brain is a large-scale network with hub regions forming a central core, the rich-club, which is vital to cognitive functions. However, it is unknown whether alterations in the rich-clubs in AD differ between men and women. We aimed to investigate sex differences in the rich-club organization in the brains of patients with AD. In total, 260 cognitively unimpaired individuals with negative amyloid positron emission tomography (PET) scans, 281 with prodromal AD (mild cognitive impairment due to AD) and 285 with AD dementia who confirmed with positive amyloid PET scans participated in the study. We obtained high-resolution T1-weighted and diffusion tensor images and performed network analysis. We observed sex differences in the rich-club and feeder connections in patients with AD, suggesting lower structural connectivity strength in women than in men. We observed a significant group-by-sex interaction in the feeder connections, particularly in the thalamus. In addition, the connectivity strength of the thalamus in the feeder connections was significantly correlated with general cognitive function in only men with prodromal AD and women with AD dementia. Our findings provide important evidence for sex-specific alterations in the structural brain network related to AD.

Consolidative Autotransplantation Achieves High Cure Rates in Adverse-Risk Large B Cell Lymphoma

There remains an unmet need to optimize the first-line treatment of patients with high-risk large B cell lymphoma (LBCL), particularly those with a high International Prognostic Index (IPI) score or a positive interim positron emission tomography (PET) scan who experience poor outcomes with R-CHOP. This study was conducted to evaluate the real-world effectiveness of consolidative autologous stem cell transplantation (ASCT) among patients with high-risk LBCL. This retrospective study included consecutive patients with LBCL and IPI score 4 or 5 who underwent consolidative ASCT as part of first-line therapy in Alberta, Canada. Progression-free survival (PFS), overall survival (OS), and disease-specific survival (DSS) were determined using the Kaplan-Meier method. The study cohort comprised 114 patients with median age of 60 years (range, 18 to 73 years), of whom 81 (71%) had an IPI score of 4 and 33 (29%) had an IPI score of 5. With a median follow-up of 5.6 years, the 5-year PFS was 72% (95% confidence interval [CI], 62% to 79%), 5-year OS was 74% (95% CI, 64% to 81%), and 5-year DSS was 80% (95% CI, 71% to 87%). There was no significant difference in PFS among patients with and patients without positive interim PET scans (n = 24), MYC and BCL2 and/or BCL6 rearrangements (n = 26), or central nervous system involvement (n = 15). Consolidative ASCT is associated with high cure rates and favorable survival outcomes in patients with high-risk LBCL and may overcome the adverse prognostic impact of a positive interim PET scan.

Utility of amyloid PET Imaging in a Memory Clinic.

There is greater interest in amyloid biomarker for the diagnosis of Alzheimer disease (AD) with the recent Food and Drug Administration approval of amyloid-targeted therapy. The goal of this study was to assess the clinical utility of amyloid positron emission tomography (PET) in clinically ambiguous cases of cognitive impairment by examining outcomes of patients enrolled in the Imaging Dementia-Evidence of Amyloid Scanning study at 2 academic institutions. Of the 112 patients in the study, 66.1% (n=74) of patients had a positive amyloid PET scan, and 33.96% (n=38) had a negative amyloid PET scan. Lower cognitive test scores were predictive of positive amyloid PET scan ( P =0.001). Eighty-two percent (92/112) of the patients were seen for follow-up. Of the 30 patients with negative amyloid PET scan results, 90% had a diagnosis of non-AD etiology after receiving the negative results, suggesting a negative amyloid scan can be used to rule out AD diagnosis.

Tau as a diagnostic instrument in clinical trials to predict amyloid in Alzheimer's disease.

Alzheimer's disease (AD) is characterized by the presence of both amyloid and tau pathology. In vivo diagnosis can be made with amyloid and tau positron emission tomography (PET) imaging. Emergent evidence supports that amyloid and tau accumulation are associated and that amyloid accumulation may precede that of tau. This report further investigates the relationship between amyloid and tau to assess whether elevated cortical tau can predict elevated amyloid in participants with early symptomatic AD. Florbetapir F18 and flortaucipir F18 uptake were evaluated from baseline PET scans collected in three multi-center studies with cognitively impaired participants, including A05 (N = 306; NCT02016560), TB (N = 310; TRAILBLAZER-ALZ; NCT03367403), and TB2 (N = 1165; TRAILBLAZER-ALZ 2; NCT04437511). Images were assessed using visual and quantitative approaches to establish amyloid (A+) and tau (T+) positivity, as well as a combination method (tauVQ) to establish T+. Associations between global amyloid and tau were evaluated with positive and negative predictive values (PPV, NPV) and likelihood ratios (LR+, LR-). Predictive values within subgroups according to ethnicity, race, cognitive score, age, and sex were also evaluated. The relationship between regional tau (four target and two reference regions were tested) and global amyloid was investigated in A05 participant scans using receiver-operating characteristic (ROC) curves. PPV for amyloid positivity was ≥93% for all three trials using various A+ and T+ definitions, including visual, quantitative, and combination methods. Population characteristics did not have an impact on A+ predictability. Regional analyses (early tau (Eτ) volume of interest (VOI), temporal, parietal, frontal) revealed significant area under the ROC curve in Eτ VOI compared to frontal region, regardless of reference region and consistent among visual and quantitative A+ definitions (p < 0.001). These findings suggest that a positive tau PET scan is associated (≥93%) with amyloid positivity in individuals with early symptomatic AD, with the potential benefits of reducing clinical trial and health care expenses, radiation exposure, and participant time. Positron emission tomography (PET) evaluates candidates for Alzheimer's disease (AD) research. A positive tau PET scan is associated (≥93%) with amyloid positivity.A positive amyloid PET is not necessarily associated with tau positivity.Tau PET could be the sole diagnostic tool to confirm candidates for AD trials.

Diagnostic Performance of a Tablet Computer-Based Cognitive Screening Test for Identification of Amnestic Mild Cognitive Impairment.

Early and appropriate diagnosis of amnestic mild cognitive impairment (aMCI) is clinically important because aMCI is considered the prodromal stage of dementia caused by Alzheimer's disease (AD). aMCI is assessed using the comprehensive neuropsychological (NP) battery, but it is rater-dependent and does not provide quick results. Thus, we investigated the performance of the computerized cognitive screening test (Inbrain Cognitive Screening Test; Inbrain CST) in the diagnosis of aMCI and compared its performance to that of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test (CERAD-K), a comprehensive and pencil-and-paper NP test. A total of 166 participants were included in this cross-sectional study. The participants were recruited as part of a prospective, community-based cohort study for MCI (PREcision medicine platform for mild cognitive impairment on multi-omics, imaging, evidence-based R&amp;BD; PREMIER). All participants were assessed using the CERAD-K and the Inbrain CST. The Inbrain CST comprised seven subtests that assessed the following five cognitive domains: attention, language, visuospatial, memory, and executive functions. Seventy-six participants underwent brain magnetic resonance imaging and [18F]-flutemetamol positron emission tomography (PET). We evaluated the diagnostic performance of the Inbrain CST for the identification of aMCI by comparing the findings with those of CERAD-K. We also determined the characteristics of aMCI patients as defined by the CERAD-K and Inbrain CST. Of the 166 participants, 93 were diagnosed with aMCI, while 73 were cognitively unimpaired. The sensitivity of the Inbrain CST for aMCI diagnosis was 81.7%, and its specificity was 84.9%. Positive and negative predictive values were 87.4% and 78.5%, respectively. The diagnostic accuracy was 83.1%, and the error rate was 16.9%. Demographic and clinical characteristics between individuals with aMCI defined by the Inbrain CST and CERAD-K were not significantly different. The frequency of positive amyloid PET scan, the hippocampal/parahippocampal volumes, and AD signature cortical thickness did not differ between the patients with aMCI defined by CERAD-K and those with aMCI defined by the Inbrain CST. The Inbrain CST showed sufficient sensitivity, specificity, and positive and negative predictive values for diagnosing objective memory impairment in aMCI. In addition, aMCI patients identified by CERAD-K and the Inbrain CST showed comparable clinical and neuroimaging characteristics. Therefore, the Inbrain CST can be considered an alternative test to supplement the limitations of existing pencil-and-paper NP tests.

Racial and Ethnic Differences in Amyloid PET Positivity in Individuals With Mild Cognitive Impairment or Dementia

Racial and ethnic groups with higher rates of clinical Alzheimer disease (AD) are underrepresented in studies of AD biomarkers, including amyloid positron emission tomography (PET). To compare amyloid PET positivity among a diverse cohort of individuals with mild cognitive impairment (MCI) or dementia. Secondary analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS), a single-arm multisite cohort study of Medicare beneficiaries who met appropriate-use criteria for amyloid PET imaging between February 2016 and September 2017 with follow-up through January 2018. Data were analyzed between April 2020 and January 2022. This study used 2 approaches: the McNemar test to compare amyloid PET positivity proportions between matched racial and ethnic groups and multivariable logistic regression to assess the odds of having a positive amyloid PET scan. IDEAS enrolled participants at 595 US dementia specialist practices. A total of 21 949 were enrolled and 4842 (22%) were excluded from the present analysis due to protocol violations, not receiving an amyloid PET scan, not having a positive or negative scan, or because of small numbers in some subgroups. In the IDEAS study, participants underwent a single amyloid PET scan. The main outcomes were amyloid PET positivity proportions and odds. Data from 17 107 individuals (321 Asian, 635 Black, 829 Hispanic, and 15 322 White) with MCI or dementia and amyloid PET were analyzed between April 2020 and January 2022. The median (range) age of participants was 75 (65-105) years; 8769 participants (51.3%) were female and 8338 (48.7%) were male. In the optimal 1:1 matching analysis (n = 3154), White participants had a greater proportion of positive amyloid PET scans compared with Asian participants (181 of 313; 57.8%; 95% CI, 52.3-63.2 vs 142 of 313; 45.4%; 95% CI, 39.9-50.9, respectively; P = .001) and Hispanic participants (482 of 780; 61.8%; 95% CI, 58.3-65.1 vs 425 of 780; 54.5%; 95% CI, 51.0-58.0, respectively; P = .003) but not Black participants (359 of 615; 58.4%; 95% CI, 54.4-62.2 vs 333 of 615; 54.1%; 95% CI, 50.2-58.0, respectively; P = .13). In the adjusted model, the odds of having a positive amyloid PET scan were lower for Asian participants (odds ratio [OR], 0.47; 95% CI, 0.37-0.59; P < .001), Black participants (OR, 0.71; 95% CI, 0.60-0.84; P < .001), and Hispanic participants (OR, 0.68; 95% CI, 0.59-0.79; P < .001) compared with White participants. Racial and ethnic differences found in amyloid PET positivity among individuals with MCI and dementia in this study may indicate differences in underlying etiology of cognitive impairment and guide future treatment and prevention approaches.

18F-PSMA-11 Versus 68Ga-PSMA-11 Positron Emission Tomography/Computed Tomography for Staging and Biochemical Recurrence of Prostate Cancer: A Prospective Double-blind Randomised Cross-over Trial

BackgroundFluorine-18 (18F)-labelled prostate-specific membrane antigen (PSMA) offers several advantages over gallium-68 (68Ga) in terms of costs, yield, transport/distribution, and image resolution. ObjectiveThis trial investigates the new radiotracer 18F-PSMA-11 via a prospective, intraindividual crossover design. The trial was powered for noninferiority of 18F-PSMA-11 over 68Ga-PSMA-11 positron emission tomography (PET)/computed tomography (CT) in terms of the number of positive PET scans. Secondary endpoints were as follows: (1) superiority of 18F-PSMA-11 over 68Ga-PSMA-11 with respect to the number of positive PET scans, the total number of suspicious prostate cancer lesions, and the miPSMA expression score of corresponding lesions; (2) correlation of the PET/CT images with available follow-up data for 18F-PSMA-11 and 68Ga-PSMA-11; and (3) assessment of the interobserver variability. Design, setting, and participantsProstate cancer patients (primary or biochemical recurrence) were randomised in a double-blind crossover design whereby each patient received both 18F-PSMA-11 and 68Ga-PSMA-11 PET/CT. Outcome measurements and statistical analysisAll scans were reviewed and scored by three independent experienced nuclear physicians following the proposed guideline for the interpretation of PSMA-ligand PET/CT, as described by Eiber et al. Results and limitationsIn total, 82 patients were included for scan analyses. The primary endpoint was met: per patient, the proportions of positive scans rated by the three readers were 67%/67%, 65%/65%, and 73%/70% for 18F-PSMA-11/68Ga-PSMA-11 PET/CT. The miPSMA expression score was higher for 18F-PSMA-11 than for 68Ga-PSMA-11 for the reference reader. Follow-up data showed identical estimated sensitivity for both the 18F-PSMA-11 and the 68Ga-PSMA-11 scan (0.92, 0.83, and 0.92 for the three readers). A fair to good agreement among readers (at patient level) was obtained, which was demonstrated by a Light’s kappa value of 0.59 for both tracers. ConclusionsThe tracer 18F-PSMA-11 is noninferior to68Ga-PSMA-11. Superiority of 18F-PSMA-11 was limited to the miPSMA expression score, given by the reference reader. Inter-rater agreement was fair to good, and equal for both radiotracers. Patient summaryIn this study, we compared two radiotracers: 18F-PSMA-11 and 68Ga-PSMA-11. We proved that 18F-PSMA-11 is not inferior to 68Ga-PSMA-11 for detecting prostate cancer and thus can be used as an alternative. Possible superiority of this tracer should be further investigated in specific subpopulations.

PET positive tattoo lymphadenopathy: a case report and review of the literature

We present a case of positron emission tomography (PET)–avid internal mammary lymphadenopathy, prompting open excisional biopsy of the lymph node in the setting of concern about breast-implant associated anaplastic large cell lymphoma (BIA-ALCL) or breast cancer recurrence. Histopathological examination revealed reactive lymphadenopathy with tattoo ink and no malignancy. We undertook a review of the literature to investigate the frequency of tattoo ink related PET-avid lymphadenopathy, and false positive PET scan results from tattooing. Lymphadenopathy related to tattoo ink has been reported previously, however this is the only case of benign PET positive tattoo lymphadenopathy resulting in unnecessary invasive surgery reported to date.

Aducanumab and the “post-amyloid” era of Alzheimer research?

Aducanumab and the “post-amyloid” era of Alzheimer research?

LBA02-07 PROSPECTIVE STUDY OF 68 GA-RM2 PET/MRI IN PATIENTS WITH BIOCHEMICALLY RECURRENT PROSTATE CANCER AND NEGATIVE CONVENTIONAL IMAGING

You have accessJournal of UrologyLate-breaking Abstract II - Malignant1 Sep 2021LBA02-07 PROSPECTIVE STUDY OF 68GA-RM2 PET/MRI IN PATIENTS WITH BIOCHEMICALLY RECURRENT PROSTATE CANCER AND NEGATIVE CONVENTIONAL IMAGING Lucia Baratto, Hong Song, Heying Duan, Farshad Moradi, Guido Davidzon, and Andrei Iagaru Lucia BarattoLucia Baratto More articles by this author , Hong SongHong Song More articles by this author , Heying DuanHeying Duan More articles by this author , Farshad MoradiFarshad Moradi More articles by this author , Guido DavidzonGuido Davidzon More articles by this author , and Andrei IagaruAndrei Iagaru More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002149.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: 68Ga-RM2 is a synthetic bombesin receptor antagonist targeting gastrin-releasing peptide receptors (GRPr) that are overexpressed in several human tumors, including prostate cancer (PC). Men with biochemical recurrence (BCR) and negative CT/MRI and bone scintigraphy were evaluated for the presence of prostate cancer. METHODS: We enrolled 127 men with BCR PC, 45-83-year-old (mean±SD: 68.3±6.9). Imaging started at 40-89 minutes (mean±SD: 51.0±8.9) after injection of 113.8-152.6 MBq (mean±SD: 140.5±6.4) of 68Ga-RM2 using a time-of-flight (TOF)-enabled simultaneous positron emission tomography (PET) / magnetic resonance imaging (MRI) scanner. RESULTS: All patients had rising PSA and negative conventional imaging prior to enrollment. 68Ga-RM2 PET identified recurrent PC in 85 of the 127 participants. Positivity rate of 68Ga-RM2 PET was: 37.9% for PSA <0.5 ng/dl (n=29), 61.1% for PSA 0.5 – 1.0 ng/dl (n=18), 64.7% for PSA 1.0 – 2.0 ng/dl (n=17), 82.6% for PSA 2.0 – 5.0 ng/dl (n=23) and 87.5% for PSA >5.0 ng/dl (n=40). PSA velocity values were 1.9±2.7 ng/ml/year (range: 0-9.1) in patients with negative PET scans and 5.8±9 ng/ml/year (range: 0.2-45.4) in patients with positive PET scans (P: 0.01). CONCLUSIONS: 68Ga-RM2 PET identifies GRPr expression in BCR PC lesions despite negative conventional imaging, indicating it is a promising PET radiopharmaceutical in this clinical scenario. 68Ga-RM2 may identify higher risk patients given the highly statistically significant difference PSA velocity values between patients with negative and positive scans and may be a complementary radiopharmaceutical to the PSMA-targeting tracers to ultimately allow for personalized medicine. Source of Funding: DoD © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e1178-e1178 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Lucia Baratto More articles by this author Hong Song More articles by this author Heying Duan More articles by this author Farshad Moradi More articles by this author Guido Davidzon More articles by this author Andrei Iagaru More articles by this author Expand All Advertisement Loading ...

Abstract PS3-05: Value of [18F]-FES-PET to solve clinical dilemmas in breast cancer patients: A retrospective study

Abstract Introduction: Breast cancer (BC) is a heterogeneous disease, in which estrogen receptor (ER) expression plays an important role in the majority of breast tumors. A clinical dilemma may arise when a metastasis biopsy to determine the ER status cannot be performed safely or when ER heterogeneity is suspected between tumor lesions. Whole-body ER imaging, such as 16α-[18F]-fluoro-17β-estradiol ([18F]-FES) positron emission tomography (PET), may have additional value in these situations. However, the role of this imaging technique in routine clinical practice remains to be further determined. Therefore, we assessed the value of [18F]-FES-PET in a large retrospective set of patients, by evaluating if the physicians’ clinical dilemma that remained after standard workup was solved by the [18F]-FES-PET scan. Methods: In this single center study, [18F]-FES-PET scans, performed in patients with (suspected) ER+ metastatic BC with remaining clinical dilemma after standard workup (such as computed tomography, [18F]-fluorodeoxyglucose ([18F]-FDG)-PET, bone scintigraphy, magnetic resonance imaging, or biopsy), performed at the UMCG between November 2009 and January 2019, were included. A whole-body [18F]-FES-PET scan was performed 60 min after ~200 MBq of [18F]-FES was injected intravenously. ER antagonists had to be discontinued at least 5 weeks before [18F]-FES-PET. Primary endpoint was the percentage of cases in which the referring physician’s clinical dilemma was solved based on the [18F]-FES-PET results. The dilemma was considered solved if 1) the [18F]-FES-PET provided a solution for the clinical dilemma (for example an extra metastatic site to biopsy), or 2) a treatment decision (to change or continue) was made based on the [18F]-FES-PET result. If the physician had doubts about the diagnosis after the [18F]-FES-PET examination, and additional workup was necessary for treatment decision-making, the dilemma was considered not solved. Secondary endpoints were type of clinical dilemma, and rate of [18F]-FES positive or negative PET scans (visual interpretation), related to frequency of solved dilemmas. Results: One hundred [18F]-FES-PET scans were performed in 83 patients. Clinical dilemma types were: 1) inability to determine extent of (suspected) metastatic disease with standard workup (n=52), 2) unclear disease ER status (n=31), and 3) inability to determine which primary tumor caused metastases (n=17). Dilemmas were solved by [18F]-FES-PET in 87/100 cases (87%). In these 87 cases, treatment was changed in 52 cases, and continued in 35 cases. The frequency of solved dilemmas was not related to the type of clinical dilemma. In contrast, the frequency of solved dilemmas was related to whether scans were [18F]-FES positive or negative. Out of the 63 [18F]-FES positive scans, the clinical dilemma was solved in 61 cases (97%); in 26 out of the 37 [18F]-FES negative scans (70%) the dilemma was solved (p&amp;lt;0.001). Conclusion: In this real life study of BC patients with a clinical dilemma after standard workup, we showed that [18F]-FES-PET solved the dilemma in the large majority of cases. Relevant treatment decisions were made based on the scan, particularly in ER+ disease. This indicates that the [18F]-FES-PET can be of value to solve clinical dilemmas in BC patients. Ultimately, this can support optimal treatment in these patients and potentially improve outcome. Prospective trials are currently ongoing to further assess this. Citation Format: Jorianne Boers, Naila Loudini, Celina L. Brunsch, Sylvia A. Koza, Erik F.J. de Vries, Andor W.J.M. Glaudemans, Geke A.P. Hospers, Carolina P. Schröder. Value of [18F]-FES-PET to solve clinical dilemmas in breast cancer patients: A retrospective study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-05.

Change in cognitive function according to cholinesterase inhibitor use and amyloid PET positivity in patients with mild cognitive impairment

BackgroundCholinesterase inhibitors (ChEIs) are an FDA-approved symptomatic treatment for patients with Alzheimer’s disease (AD). Its efficacy in patients with mild cognitive impairment (MCI), however, is controversial. Nonetheless, ChEIs have often been used in patients with MCI. From the perspective that ChEIs were developed based on the pathomechanism of AD, the effect of ChEIs in MCI patients could be different depending on the amyloid burden. In this retrospective observational study, we aimed to investigate the influence of ChEIs and amyloid burden on cognitive change for 1 year in patients with MCI.MethodsWe included 111 patients with MCI with a Clinical Dementia Rating (CDR) score of 0.5, a 1-year follow-up cognitive assessment, and amyloid positron emission tomography (PET) performed within 6 months before or after the baseline cognitive assessment (73 ChEI users and 38 ChEI non-users) from the Neurocognitive Behavior Center of Seoul National University Bundang Hospital. Additionally, those who had a positive amyloid PET scan more than 6 months before the baseline cognitive assessment and those who had a negative amyloid PET scan more than 6 months after the 1-year follow-up cognitive assessment were also included. Among the total 111 patients, 25 ChEI users and 25 ChEI non-users were matched by baseline Mini-Mental State Examination (MMSE) score, age, educational level, CDR Sum of Boxes, and amyloid PET positivity using propensity score matching. Multiple linear regression analysis was performed to assess the influence of ChEI use and amyloid PET positivity on cognitive change for 1 year. Univariate and multivariate logistic regression analyses were performed to evaluate the association between ChEI use and disease progression to CDR 1 at the 1-year follow-up visit.ResultsChEI use or non-use was not associated with cognitive change for 1 year. Amyloid PET positivity or negativity did not change this non-association. Furthermore, progression to CDR 1 was related to low baseline MMSE score (OR 0.606, CI 0.381–0.873), but not with ChEI use or non-use, and not with amyloid PET result.ConclusionChEI use or non-use was not related to cognitive change at a 1-year follow-up visit in patients with or without amyloid burden. In addition, ChEI use or non-use could not predict disease progression to CDR 1 at 1-year follow-up visit.

Classification of negative and positive 18F-florbetapir brain PET studies in subjective cognitive decline patients using a convolutional neural network

PurposeVisual reading of 18F-florbetapir positron emission tomography (PET) scans is used in the diagnostic process of patients with cognitive disorders for assessment of amyloid-ß (Aß) depositions. However, this can be time-consuming, and difficult in case of borderline amyloid pathology. Computer-aided pattern recognition can be helpful in this process but needs to be validated. The aim of this work was to develop, train, validate and test a convolutional neural network (CNN) for discriminating between Aß negative and positive 18F-florbetapir PET scans in patients with subjective cognitive decline (SCD).Methods18F-florbetapir PET images were acquired and visually assessed. The SCD cohort consisted of 133 patients from the SCIENCe cohort and 22 patients from the ADNI database. From the SCIENCe cohort, standardized uptake value ratio (SUVR) images were computed. From the ADNI database, SUVR images were extracted. 2D CNNs (axial, coronal and sagittal) were built to capture features of the scans. The SCIENCe scans were randomly divided into training and validation set (5-fold cross-validation), and the ADNI scans were used as test set. Performance was evaluated based on average accuracy, sensitivity and specificity from the cross-validation. Next, the best performing CNN was evaluated on the test set.ResultsThe sagittal 2D-CNN classified the SCIENCe scans with the highest average accuracy of 99% ± 2 (SD), sensitivity of 97% ± 7 and specificity of 100%. The ADNI scans were classified with a 95% accuracy, 100% sensitivity and 92.3% specificity.ConclusionThe 2D-CNN algorithm can classify Aß negative and positive 18F-florbetapir PET scans with high performance in SCD patients.