European Journal of Nuclear Medicine and Molecular Imaging最新文献

{"title":"Serial amyloid PET as a decision tool for switching anti-amyloid therapy in Alzheimer's disease.","authors":"Massimo Filippi, Alma Ghirelli, Giordano Cecchetti, Ana Maria Samanes Gajate, Giulia Rugarli, Edoardo Gioele Spinelli, Stefano Pisano, Andrea Panzacchi, Gino Pepe, Arturo Chiti, Federica Agosta","doi":"10.1007/s00259-026-07912-4","DOIUrl":"10.1007/s00259-026-07912-4","url":null,"abstract":"","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6134-6136"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147971519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling silent CAD in an oncology patient: stress delayed defect filling of [¹⁸F]Flurpiridaz as a potential viability biomarker.","authors":"Yunfeng Wang, Zhixing Qin, Zhenyu Xiang, Yulong Dou, Kewei Zhou, Lili Wang, Yanjie Hou, Sijin Li, Ping Wu","doi":"10.1007/s00259-026-07922-2","DOIUrl":"10.1007/s00259-026-07922-2","url":null,"abstract":"","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6131-6133"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147959695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antitumor efficacy and safety of locoregional [¹⁷⁷Lu]Lu-RM26 radionuclide therapy in glioblastoma.","authors":"Li'ao Wang, Jialin Xiang, Linlin Li, Yangyang Liu, Liangpeng Chen, Rongxi Wang, Xueyuan Ling, Ziyang Li, Chirag B Patel, Richard P Baum, Wang Jia, Jingjing Zhang, Zhaohui Zhu, Xiaoyuan Chen, Deling Li","doi":"10.1007/s00259-026-07993-1","DOIUrl":"10.1007/s00259-026-07993-1","url":null,"abstract":"<p><strong>Purpose: </strong>Glioblastoma multiforme (GBM) remains an aggressive brain malignancy with dismal prognosis despite current standard-of-care therapies. The gastrin-releasing peptide receptor (GRPR) is overexpressed in gliomas and represents a potential therapeutic target. However, systemic radionuclide delivery is limited by poor tumor penetration and off-target toxicity.</p><p><strong>Methods: </strong>GRPR expression and prognostic relevance were analyzed using Chinese Glioma Genome Atlas and a clinical-trial dataset, respectively at the transcriptomic and protein levels. [¹⁷⁷Lu]Lu-RM26, a lutetium-177-labeled GRPR-targeting antagonist, was evaluated in vitro, and administered intratumorally via convection-enhanced delivery in an orthotopic GL261^Fluc+ glioblastoma model. Pharmacokinetic characteristics, including tumor retention and biodistribution, were evaluated by serial single-photon emission computed tomography and gamma-counting. Efficacy was assessed by tumor volume, bioluminescence signal, and overall survival. Safety was evaluated through body weight monitoring, neurological scoring, rotarod testing, hematology, and immunohistochemical staining. Mechanistic insights were obtained via bulk RNA-sequencing and Western blotting.</p><p><strong>Results: </strong>Higher GRPR expression correlated with poorer-prognosis glioma subtypes and reduced survival. In vitro assays showed dose-dependent inhibition of GL261^Fluc+ cell viability, proliferation, and invasion. Locoregional [¹⁷⁷Lu]Lu-RM26 administration led to prolonged tumor retention (74.7 h), high absorbed dose (2.71 × 10⁶ mGy·MBq^- 1), and minimal off-target uptake. Treated mice exhibited marked tumor growth inhibition, reduced bioluminescence signal, and extended survival compared to controls. No significant short-term systemic toxicity or neurological impairment was observed. Transcriptome and Western blotting findings were consistent with DNA replication stalling and G2/M arrest.</p><p><strong>Conclusion: </strong>Locoregional [¹⁷⁷Lu]Lu-RM26 therapy enables sustained, tumor-specific β-radiation with minimal systemic exposure, representing a promising locoregional strategy for GRPR-positive GBM.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6473-6489"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148257799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic metabolic breast cancer staging using [¹⁸F]FDG PET/CT: comparison with nuclear medicine physician-based and clinical staging.","authors":"Cláudia Santos Constantino, Carla Oliveira, Francisco P M Oliveira, Inês Moreira, Andrea DeCensi, Susana Vinga, Durval C Costa","doi":"10.1007/s00259-026-08005-y","DOIUrl":"10.1007/s00259-026-08005-y","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to evaluate a deep-learning (DL)-based framework to automatically perform breast cancer (BC) metabolic staging on [¹⁸F]FDG PET/CT, and to assess agreement among DL-based, nuclear medicine (NM) physician-based, and clinical staging.</p><p><strong>Methods: </strong>A total of 403 histologically confirmed BC patients who underwent whole-body staging [¹⁸F]FDG PET/CT were retrospectively included. All [¹⁸F]FDG avid lesions suspected of malignancy were segmented by an NM physician and classified into four key tumor regions: primary tumor (pT), regional axillary lymph nodes (ALN), extra-axillary locoregional nodes (extra-ALN), and distant metastases (dM). Data were split into training (n = 303) and testing (n = 100) sets using a stratified approach. Class-specific DL segmentation networks were developed. A post-processing pipeline was implemented to derive metabolic TNM staging from the DL-based segmentation. Using NM-based and clinical staging segmentation as reference, accuracy, sensitivity, and specificity were computed for T, N, and M. Segmentation performance was evaluated using the Dice coefficient (DC) and lesion detection (LD) metrics. NM-based metabolic staging was also compared with clinical staging.</p><p><strong>Results: </strong>DL-based staging showed concordance with NM-based/clinical staging of 75/62%, 87/74%, and 83/82% for T, N, and M, respectively. For N3 (presence of extra-ALN) and M1 (presence of dM), where [¹⁸F]FDG PET/CT is particularly relevant, sensitivity/specificity of DL-based (NM-based reference) were 0.86/0.96, and 0.97/0.78, respectively. Segmentation performance was good to excellent for pT, ALN, and dM (median DC ≥ 0.83 and LD ≥ 0.78), and moderate for extra-ALN (median DC = 0.63 and LD ≥ 0.71). NM-based metabolic staging agreed with clinical staging in 63%, 80%, and 99% of cases for T, N, and M, respectively.</p><p><strong>Conclusion: </strong>Although expert supervision remains essential, the developed DL-based framework demonstrates potential as a supportive tool for metabolic staging in BC patients, facilitating a workflow-efficient [¹⁸F]FDG PET/CT-based staging assessment.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6339-6350"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13525970/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148276290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lutetium-177-PSMA I&T (Lu-PSMA) with radiosensitising capecitabine in patients with metastatic castration-resistant prostate cancer (mCRPC): results of phase Ia study.","authors":"Claudia Leslie, Zeyad Al-Ogaili, Leone Oh, Tim Slattery, Sachin Shaji, Gabriela Marsavela, Alana Mills, Caroline Stone, Tom Ferguson","doi":"10.1007/s00259-026-08006-x","DOIUrl":"10.1007/s00259-026-08006-x","url":null,"abstract":"<p><strong>Purpose: </strong>Lu-PSMA is an effective therapy for mCRPC. Capecitabine is an established radiosensitiser in several solid tumours and may enhance therapeutic response when combined with radioligand therapy. We evaluated the safety and maximum tolerated dose (MTD) of capecitabine with Lu-PSMA in a heavily pre-treated mCRPC cohort.</p><p><strong>Methods: </strong>Men with mCRPC previously treated with ≥ 1 taxane and ≥ 1 androgen receptor pathway inhibitor, and deemed suitable for Lu-PSMA on PSMA-PET, were enrolled in a 3 + 3 dose-escalation study. Capecitabine was administered at four dose levels (275 mg/m² - 1000 mg/m²) on days 1-14, with Lu-PSMA on day 10 of a 42-day cycle, for up to six cycles. The primary endpoint was the MTD; secondary endpoints included safety, PSA-50 and objective response rates (RR), PSA-progression free survival (PFS), clinical and radiological PFS, and overall survival (OS). PSA was assessed every two weeks; imaging every 12 weeks.</p><p><strong>Results: </strong>12 patients received at least one dose of Lu-PSMA. Median age was 75. No dose-limiting toxicities occurred, establishing the MTD at 1000 mg/m². Common treatment-related adverse events were nausea, fatigue, and diarrhoea. Across dose levels, the PSA-50 RR was 50%, and PSA-PFS was 4.7 months (95% CI 2.3-21.6). One patient with measurable disease achieved a partial response. Exploratory PSMA PET biomarker analyses were negative, likely limited by small sample size.</p><p><strong>Conclusion: </strong>Capecitabine 1000 mg/m² in combination with Lu-PSMA is safe and tolerable in heavily pre‑treated mCRPC. A dose‑expansion cohort is ongoing to further evaluate efficacy.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6452-6460"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13526046/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148276357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Survival benefit of ⁶⁸Ga-FAPI PET/CT staging for prognostic assessment in gastric and colorectal cancer compared with CE-CT and ¹⁸F-FDG PET/CT: a single-center retrospective study.","authors":"Xiaoxiao Wu, Lingyu Ma, Yan Zhao, Guohong Cai, Jingyi Wang, Ying Guo, Yuanyuan Lu, Yan Pan, Xinyu Du, Yongzhan Nie, Fei Kang, Jing Wang","doi":"10.1007/s00259-026-07991-3","DOIUrl":"10.1007/s00259-026-07991-3","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this retrospective study was to investigate whether gallium-68-labeled fibroblast activation protein inhibitor (⁶⁸Ga-FAPI) positron emission tomography/computed tomography (PET/CT) that provided altered staging and adjusted treatment decisions was more effective for prolonging patient survival compared to that achieved by either contrast-enhanced computed tomography (CE-CT) or fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT.</p><p><strong>Methods: </strong>We analyzed patients diagnosed with untreated gastric or colorectal cancer between March 2021 and March 2023 who were staged using these three imaging diagnostic modes described above. The accuracy of staging, reduction of unnecessary surgery, progression-free survival (PFS), and overall survival (OS) were used as the main comparative indicators. The potential independent risk factors affecting the prognosis of patients with gastric or colorectal cancer were also analyzed.</p><p><strong>Results: </strong>A total of 270 patients (137 gastric and 133 colorectal cancers) were enrolled, with a median follow-up of 3.02 years (95%CI: 2.7-3.3 years). The baseline characteristics of the patient groups were comparable. For both cancers, patients staged by ⁶⁸Ga-FAPI PET/CT had significantly longer median OS than those staged by either CE-CT or ¹⁸F-FDG PET/CT (colorectal cancer: p = 0.0123; gastric cancer: p = 0.037). ⁶⁸Ga-FAPI PET/CT also improved the accuracy of staging and altered staging in 41%-52% of patients, with a reduction in unnecessary surgeries of 42%-69%. Cox multivariate regression identified CE-CT and ¹⁸F-FDG PET/CT as prognostic risk factors relative to ⁶⁸Ga-FAPI PET/CT.</p><p><strong>Conclusion: </strong>In patients with gastric or colorectal cancer, those who underwent staging with ⁶⁸Ga‑FAPI PET/CT showed improvements in disease progression and survival outcomes compared with those staged with either CE‑CT or ¹⁸F‑FDG PET/CT. The underlying mechanisms of these improvements may be related to increased staging accuracy and the subsequent selection of less invasive therapeutic strategies. These findings highlight the clinical value of ⁶⁸Ga‑FAPI PET/CT in these patient populations. (Trial registration: ChiCTR ChiCTR2400081233. Registered 27 February 2024).</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6386-6397"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148224147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating early vs. late static SUVR windows of [¹⁸F]MK-6240 tau PET in Alzheimer disease: a head-to-head comparison study.","authors":"Tsung-Wei Hu, Jennette Prince, Liangdong Zhou, Xiuyuan Hugh Wang, Emily B Tanzi, Mohammad Khalafi, Sadek A Nehmeh, Silky Singh Pahlajani, Hani Hojjati, Lidia Glodzik, Tracy Butler, Gloria C Chiang, Yi Li","doi":"10.1007/s00259-026-07976-2","DOIUrl":"10.1007/s00259-026-07976-2","url":null,"abstract":"<p><strong>Purpose: </strong>[¹⁸F]MK-6240 is a widely used second-generation tau PET tracer in Alzheimer disease (AD) and is under FDA review, making it important to refine practical static imaging windows for clinical use. Prior dynamic studies have supported late static windows (~ 90-110 min) because they improve agreement between standard uptake value ratios (SUVR) and kinetic models in high-binding regions, but extracerebral skull and meningeal uptake becomes more prominent at later times and may confound visual interpretation and SUVR quantification. In this study, we aim to determine whether an earlier static window (40-60 min) provides comparable discrimination of tau burden while reducing extracerebral spill-in and SUVR instability.</p><p><strong>Methods: </strong>In this retrospective within-subject study, 67 participants across the AD spectrum (normal controls (cognitively unimpaired) [NL], mild cognitive impairment [MCI], and AD) underwent [¹⁸F]MK-6240 PET with early (40-60 min) and late (90-120 min) frames. SUVRs were computed in the cerebral cortex (CTX) and Braak ROIs using cerebellar cortex as reference. Early-late agreement was assessed using correlation, regression, and Kolmogorov-Smirnov (KS) tests. Diagnostic and tau-status classification performance was evaluated with ROC analyses. Skull/meningeal uptake was graded visually and quantified, and PET-MRI misregistration simulations assessed SUVR robustness. Time-resolved analyses (30-120 min) evaluated temporal changes in stability and discrimination.</p><p><strong>Results: </strong>Early and late SUVRs were highly correlated (r ≥ 0.97; p < 0.01) and showed similar cohort-level distributions (CTX KS D = 0.060; p > 0.99). Discrimination was comparable for diagnosis and tau status (e.g., CTX AUC 0.88 vs. 0.85 for NL vs. MCI/AD). Late frames showed greater skull/meningeal uptake with increased spill-in and reference-region sensitivity; in tau-negative participants, skull SUVR exceeded entorhinal SUVR after ~ 60 min. Misregistration simulations showed greater variability for late versus early entorhinal SUVR (σ = 0.071 vs. 0.017). Time-resolved analyses showed that in this cohort, later acquisition did not materially improve diagnostic discrimination and was associated with more extracerebral contamination and instability.</p><p><strong>Conclusion: </strong>The 40-60-minute window provides discrimination comparable to 90-120 min while reducing extracerebral contamination and improving robustness, supporting shorter static [¹⁸F]MK-6240 protocols for clinical and research applications.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6226-6237"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemispheric lateralization of Tau associations with visual and verbal memory in Alzheimer's disease.","authors":"Jaime Fernández Arias, Etienne Aumont, Joseph Therriault, Lydia Trudel, Nina Margherita-Poltronetti, Emilie Thomas, Gleb Bezgin, Stijn Servaes, Yi-Ting Wang, Nesrine Rahmouni, Arthur Macedo, Kely Quispialaya, Seyyed Ali Hosseini, Brandon Hall, Peter Kunach, Wan Lu Jia, Tevy Chan, Yansheng Zheng, Marcel Seungsu Woo, Sulantha S Mathotaarachchi, Paolo Vitali, Tharick Pascoal, Yasser Iturria-Medina, Maxime Montembeault, Pedro Rosa-Neto","doi":"10.1007/s00259-026-07898-z","DOIUrl":"10.1007/s00259-026-07898-z","url":null,"abstract":"<p><strong>Purpose: </strong>Alzheimer's disease affects the brain in complex ways, and the location of tau tangles may influence specific types of memory problems. In this study, we examined how tau accumulation relates to verbal and visual memory performance, and whether these associations show a preference for one hemisphere of the brain over the other.</p><p><strong>Methods: </strong>We administered the Rey Auditory Verbal Learning Test (RAVLT) and its nonverbal analog, the Aggie Figures Learning Test (AFLT), to 132 cognitively unimpaired elderly participants and 44 cognitively impaired, amyloid-positive individuals from the Translational Biomarkers in Aging and Dementia cohort. All participants underwent [18 F]MK6240 tau PET, [18 F]AZD4694 amyloid PET, and structural MRI scans. We analyzed the data using region-of-interest and voxel-wise regression models, as well as correlation analyses.</p><p><strong>Results: </strong>Voxel-wise analyses showed that higher tau load in the right hemisphere was associated with worse visual memory, confirming a lateralized relationship. Left-hemisphere tau associations with verbal memory were observed at higher t-values. In regression models including both memory scores, visual memory remained significantly associated with tau on the right hemisphere (β_AFLT~Rtau=-0.22, p=0.001; β_RAVLT~Rtau=-0.1, p=0.13), whereas both visual and verbal memory remained significant on the left hemisphere (β_AFLT~Ltau=-0.16, p=0.03; β_RAVLT~Ltau=-0.14, p=0.04). These patterns were also reflected in Braak regions, except for Braak I, where only left tau-verbal and right tau-visual associations remained significant.</p><p><strong>Conclusion: </strong>Our findings support lateralized associations between tau accumulation and memory deficits, with visual memory linked to right-hemisphere tau and verbal memory to left-hemisphere tau. This pattern is consistent with lateralization of memory functions observed in other neurological conditions and highlights the importance of considering hemisphere-specific tau pathology in Alzheimer's disease.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6195-6211"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13525940/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148162233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incident learning systems to improve patient safety in nuclear medicine across Europe: results of the MARLIN study.","authors":"Carlos Prieto, Ana Geao, Stephan G Nekolla, Erik Björn Mille, Ora Israel, Gianfranco Brusadin, Jonas Andersson, Maeve Kearney, Andy Rogers, Deniz Akata, Nicolas Pourel, Graciano Paulo, Olivier Pellerin, Barry Hallinan, Monika Hierath, Nathan Peld, Colin Kelly","doi":"10.1007/s00259-026-07973-5","DOIUrl":"10.1007/s00259-026-07973-5","url":null,"abstract":"<p><strong>Purpose: </strong>To enhance patient safety in nuclear medicine (NM) across Europe by operationalising MARLIN recommendations for implementing incident learning systems (ILSs), including barriers/enablers and practical implementation guidance.</p><p><strong>Methods: </strong>A mixed‑methods study (combining a survey, semi‑structured interviews, and a targeted literature review) was performed within the MARLIN project. This was a 24‑month initiative conducted under the European Commission's Strategic Agenda for Medical Ionising Radiation Applications (SAMIRA) Action Plan, involving European organisations such as EANM, EIBIR, ESTRO, and EFOMP. Surveys were distributed to Clinical Facilities (CFs), Competent Authorities (CAs), and professional societies (PSs). Interviews were used to explore implementation barriers and examples of good practice. Data were analysed using descriptive statistics and thematic analysis.</p><p><strong>Results: </strong>The study revealed significant variability in the criteria for defining and reporting significant radiation events in NM across Europe. While all surveyed countries had designated authorities for managing reported events, only 11/23 had specific criteria for NM. The study identified key enablers and barriers to ILS implementation, including the need for a just culture to encourage reporting without fear of punitive measures. The guidelines recommended criteria for significant radiation events in NM and the organisation of ILSs.</p><p><strong>Conclusion: </strong>The MARLIN study provides a comprehensive framework for the systematic implementation of ILSs in NM, highlighting the importance of standardised reporting criteria in several categories, multidisciplinary involvement, and a culture of safety. Addressing the identified barriers and promoting a coordinated effort among stakeholders are crucial for enhancing patient safety in NM across Europe.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6661-6669"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148101259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Head-to-head comparison of [¹⁸F]CHL2205 versus [¹⁸F]T008 as PET radioligands to study brain cholesterol homeostasis in rodent models and nonhuman primates.","authors":"Sébastien Goutal, Fabien Caille, Françoise Piguet, Maud Goislard, Sophie Amargier-Barrial, Sarah Leterrier, Solène Marie, Michel Bottlaender, Nicolas Tournier","doi":"10.1007/s00259-026-07937-9","DOIUrl":"10.1007/s00259-026-07937-9","url":null,"abstract":"<p><strong>Purpose: </strong>Cholesterol 24-hydroxylase (C24H) is central to brain cholesterol metabolism and is thought to be altered in many neurodegenerative diseases, including Alzheimer's disease (AD). Only two fluorinated C24H-targeting PET radioligands, [¹⁸F]CHL-2205 and [¹⁸F]T008, have recently entered clinical use. Direct comparison is needed to guide radiotracer selection for future translational studies.</p><p><strong>Methods: </strong>Dynamic PET imaging was performed using either [¹⁸F]CHL-2205 or [¹⁸F]T008 in parallel conditions in cynomolgus macaques, healthy rats, the TgF344-AD rat model, and C24H-overexpressing mice. Arterial blood sampling enabled full kinetic modeling in healthy rats and nonhuman primates. An image-derived input function was validated in rats, and the specific binding was evaluated under C24H saturation using soticlestat.</p><p><strong>Results: </strong>[¹⁸F]CHL-2205 and [¹⁸F]T008 showed similar metabolism profiles in either macaques or rats. In macaques, brain uptake values (V_T, Logan plot analysis) were 1.6-fold higher for [¹⁸F]CHL-2205 relative to [¹⁸F]T008. Healthy rats showed a similar pattern, with [¹⁸F]CHL-2205 exhibiting 1.5-fold higher brain V_T. In rats, soticlestat blockade revealed C24H-specific binding for both ligands, with an estimated binding potential (BPND) 1.3-fold higher for [¹⁸F]CHL-2205 compared to [¹⁸F]T008. In TgF344-AD rats, brain uptake increased by 1.9-fold with [¹⁸F]CHL-2205 versus 1.6-fold with [¹⁸F]T008 compared to wild-type controls. In C24H-overexpressing mice, [¹⁸F]CHL-2205 detected measurable increases in brain signal in several brain regions (up to 1.5-fold), while [¹⁸F]T008 did not in the same animals.</p><p><strong>Conclusion: </strong>Across species and models, both radioligands demonstrated appropriate characteristics for imaging C24H in vivo. However, [¹⁸F]CHL-2205 generally displayed higher specific binding and appeared more sensitive to detect moderate increases in C24H expression.</p>","PeriodicalId":11909,"journal":{"name":"European Journal of Nuclear Medicine and Molecular Imaging","volume":" ","pages":"6154-6166"},"PeriodicalIF":7.6,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13526071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148101300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}