Background Accurate interpretation of dopamine transporter (DAT)-SPECT depends on clinical context, including symptoms, medication, comorbidities, and structural imaging findings. In routine practice, however, this information is often documented as heterogeneous free text, which may hinder consistent consideration of clinically relevant parameters and limit guideline-compliant reporting. We therefore developed and evaluated a locally deployable small language model (SLM)-based pipeline to structure and standardize the clinical information section for DAT-SPECT reporting. Two retrospective datasets were used. The in-house dataset included clinical information sections from 2,990 DAT-SPECT examinations and was split into training (n = 2,700) and internal test data (n = 290). The external validation dataset comprised 595 clinical information sections from a second institution. A structured dictionary (466 entries across 12 categories) was created by two experienced DAT-SPECT readers and used to manually annotate the training and internal test samples. A Qwen3 1.7B model was fine-tuned by supervised learning to reproduce expert annotations. A rule-based postprocessing pipeline converted model outputs into report-ready structured text, including removal of redundant entries, automated suggestion of scan indication, consolidation of symptom lateralization and time course, reminders for missing guideline-relevant elements, and medication interaction checks. Internal test performance was assessed by expert comparison of SLM output with manual annotation. External performance was assessed by counting the manual corrections required in the postprocessed output under strict criteria. Results In the internal test dataset, the postprocessed SLM output provided the same information as the expert annotation in 196/290 cases (67.6%), including exact matches in 147/290 (50.7%). Interpretation differences due to free-text ambiguity occurred in 13/290 cases (4.5%), and SLM errors in 41/290 cases (14.1%). In 40/290 cases (13.8%), the SLM output was judged superior to the manual annotation. Among the error cases, 36/41 (87.8%) involved only a single erroneous or missing item. In the external dataset, 446/595 postprocessed outputs (75.0%) required no manual correction before inclusion in the report. Among the remaining 149/595 cases (25.0%), correction of only a single item was required in 111 cases (18.7% of all cases). The mean number of corrections was 0.34 items per case, corresponding to 6.0% of all structured items. Conclusions A locally deployable SLM combined with rule-based postprocessing can transform free-text clinical information for DAT-SPECT into standardized, report-ready documentation with high clinical usability and robust external performance. By improving consistency, highlighting missing guideline-relevant information, and enabling real-time support during clinical assessment, the pipeline may facilitate structured reporting without reliance on cloud-based infrastructure.

Background/Objectives: Quantifying cerebrovascular reactivity (CVR) is essential for stroke risk assessment in patients with Moyamoya Angiopathy (MMA). Breath-hold functional MRI (bh-fMRI) is an easily implementable method to assess CVR. Determining the optimal time period of the BOLD signal for analyzing the best bh-fMRI data quality remains an open question. Methods: A retrospective analysis of 46 bh-fMRI data sets of MMA patients was conducted. The percentage BOLD signal changes were evaluated at different time periods (time point of the maximum cerebellar signal peak (TPcereb. max) ± 0 s, TPcereb. max ± 1 s, TPcereb. max ± 2 s, TPcereb. max ± 3 s, TPcereb. max ± 4 s, TPcereb. max ± 5 s). The agreement between the bh-fMRI maps and [15O]water PET maps was independently and consensually rated on a 4-point Likert scale (1 = poor, 2 = moderate, 3 = good, 4 = excellent) and compared with the Friedman test. The inter-rater agreement was calculated separately for each time period using quadratic weighted Cohen's kappa κw. Results: The selected time period had a significant impact on the agreement between bh-fMRI and [15O]water PET (χ2(5) = 79.448, p < 0.001, W = 0.345). Short time periods of TPcereb.max ± 0 s or TPcereb.max ±1 s demonstrated the highest level of concordance between bh-fMRI and [15O]water PET (median = 3.5 for TPcereb.max ± 0 s; median = 3 for TPcereb.max ± 1 s, modus = 4 in both cases). The agreement between bh-fMRI and [15O]water PET was significantly higher when evaluating time periods of TPcereb.max ± 0 s than when evaluating all time periods ≥ TPcereb. max ± 2 s. The inter-rater agreement was almost perfect for all time periods except one (TPcereb. max ± 1 s). Conclusions: Short time periods should be selected when evaluating CVR with bh-fMRI, as this study suggests a high level of validity in comparison to [15O]water PET.

Objectives: Fluorescence-guided surgery (FGS) targeting prostate-specific membrane antigen (PSMA) holds promise for improving surgical precision in prostate cancer. Since conjugation of fluorescent dyes to targeting vectors can substantially alter pharmacokinetic properties, we systematically evaluated a library of fluorescent dyes conjugated to a PSMA-617-derived scaffold incorporating sarcosine-based spacers to identify candidates with favorable biodistribution and optical profiles for clinical translation. Methods: Nineteen fluorescent dyes spanning NIR, large Stokes shift, and STED-compatible categories were conjugated to a dual-labeled PSMA-617-derived precursor (Glu-urea-Lys-2Nal-TXA-Sar10-Lys(DOTA)-Sar5-βAla; hereafter DP). Compounds were radiolabeled with 68Ga or 177Lu and characterized for serum stability, lipophilicity, binding affinity, and internalization in LNCaPPSMA+ cells. In vivo pharmacokinetics were assessed in LNCaP xenograft-bearing BALB/c nu/nu mice by µPET/MRI (1 and 2 h p.i., 500 pmol 68Ga), organ distribution (0.5, 1, and 2 h p.i., 60 pmol 177Lu), and clinical-grade endoscopic fluorescence imaging. Results: All conjugates retained hydrophilic character (logD: −3.72 to −1.79), low nanomolar binding affinity (Ki: 18–87 nM), and high serum stability (94–100% intact at 24 h). Despite comparable in vitro properties, dye conjugation markedly influenced in vivo pharmacokinetics: tumor uptake at 2 h p.i. ranged from 1 to 23%ID/g and kidney accumulation from 3 to 82%ID/g. Visible-range dyes exhibited faster renal washout within the imaging window and higher tumor-to-background contrast than NIR fluorophores. Fluorescence signal intensity did not correlate with radiotracer-derived uptake, underscoring the importance of dye-specific photophysical properties. Conclusions: DP-12 (SulfoCy5), DP-15 (Alexa Fluor 647), and DP-18 (Tide Fluor 5WS) were identified as lead candidates combining favorable pharmacokinetics with strong fluorescence contrast, warranting further evaluation toward fluorescence-guided prostate cancer surgery.

Rationale: The introduction of Pluvicto® ([177Lu]Lu-vipivotide tetraxetan; [177Lu]Lu-PSMA-617) marks a milestone in radioligand therapy (RLT) for PSMA-positive metastatic castration-resistant prostate cancer (mCRPC). While dose escalation of [177Lu]Lu-PSMA-617 and alpha-emitting agents like [225Ac]Ac-PSMA-617 improves efficacy, it is limited by dose-dependent toxicity in critical organs, including kidneys, bone marrow and salivary glands. Modifications of the linker region in PSMA inhibitors have been proven to highly influence the pharmacokinetic profile. The utilization of charged linker moieties resulted in clinically used PSMA-targeting radiotracers such as [18F]PSMA-1007. This study explores histidine and/or glutamic acid-modified variants of PSMA-617 to investigate their effects on pharmacokinetic properties. Methods: Based on the core structure of PSMA-617, eleven novel PSMA-targeting inhibitors were synthesized by introducing histidine and/or glutamic acid moieties at three positions within the linker region. Compounds were radiolabeled with [68Ga]Ga3+ and [177Lu]Lu3+ to assess their chemical and stability properties. Biological activity was evaluated in competitive cell binding and internalization assays with PSMA-expressing LNCaP cells. Dynamic and static small-animal PET imaging studies were conducted with the 68Ga-labeled inhibitors in LNCaP bearing BALB/c nu/nu xenografts to investigate their pharmacokinetic profiles. Results: Precursors of linker-modified PSMA inhibitors presented high radiochemical purities (RCPs) for the complexation reactions with both radionuclides (>94%). 68Ga-labeled compounds demonstrated significantly lower lipophilicity (ranging from -3.4 to -3.9) compared to the reference compound [68Ga]Ga-PSMA-617 (-2.8 ± 0.3). Substantial effects on the affinity to PSMA were observed depending on the position and nature of modification (IC50 ranging from 10.40 ± 2.94 nM to 78.6 ± 44.1 nM). Modification with glutamic acid adjacent to the chelator resulted in a two-fold increase in affinity, while variants containing histidine and glutamic acid led to significant improvements in cell surface binding and internalization (p < 0.05). Dynamic small-animal PET scans with the novel 68Ga-labeled variants revealed an improved accumulation in LNCaP xenograft tumors (SUV1 h: 0.21 ± 0.05 to 1.32 ± 0.08 g/ml) accompanied by a fast clearance from the kidneys and background tissue within the initial 60 min. Static PET scans 2 h p.i. confirmed a high tumor uptake and a rapid renal excretion. Conclusion: The introduction of histidine and/or glutamic acid moieties into the linker region of PSMA-617 resulted in measurable changes in pharmacokinetic properties both in vitro and in vivo. While some modifications led to improved tumor-to-kidney ratios and favorable early-stage excretion, it remains challenging to predict clinical off-targeting effects like salivary gland uptake. This study provides important insights into the structure-activity relationships of PSMA-617-related linker modifications and warrant additional investigation, including mechanistic and translational studies, to more accurately evaluate their therapeutic potential.

Summary:This procedure guideline for SPECT examinations of striatal dopamine transporter availability is intended to support the planning, execution, quality control, interpretation and reporting of cerebral SPECT scans with [123I]ioflupane. It is an update and expansion built on the 2019 version of the procedure guideline. It was developed through an informal process as a consensus of the Neuroimaging Working Group of the German Society of Nuclear Medicine and in consultation with the German Neurological Society. It is intended for use by physicians and technical staff working in the field of nuclear medicine.

Abstract Background: Erythropoietin-producing hepatocellular receptor A2 (EphA2) is a tyrosine kinase receptor overexpressed in multiple solid tumors including pancreatic, bladder, head and neck, breast, colon, prostate, and lung cancers. EphA2 is associated with increased severity, metastatic disease and poor clinical prognosis. Following successful preclinical optimization of a phage display-derived EphA2-specific bicyclic peptide1, this study outlines the first in-human application of EphA2-targeting [68Ga]Ga-BCY18469 in PET/CT imaging. Methods: Preclinical characterization of the EphA2-targeting bicyclic peptide BCY18469 was conducted by assessing stability, binding affinity, internalization, biodistribution and μPET/MR imaging in EphA2+ HT1080 and EphA2- MCF-7 xenograft tumor-bearing nude mice. For clinical translation, seven patients with histologically confirmed pancreatic cancer (5 metastatic, 2 newly diagnosed) underwent [68Ga]Ga-BCY18469-PET/CT (compassionate use). Four patients were examined at 15, 30, 45, 60, and 180 min p.i. for biodistribution and dosimetry assessment, three additional patients at 45 min p.i. (172±42 MBq). Time-activity curves were fitted monoexponentially, and dosimetry calculations were done using IDAC-Dose-Software. Results: [68Ga]Ga-BCY18469 demonstrated EphA2-specific binding and internalization, proteolytic stability up to 72 hours, and rapid background clearance with high tumor uptake, thereby enhancing imaging contrast within 30 minutes in mice. In clinical cases, [68Ga]Ga-BCY18469 demonstrated rapid tumor uptake and was predominantly excreted via the kidneys. Notably, hepatic uptake remained favorably low (SUVmean 0.9±0.3 at 45 min p.i). Mean absorbed doses were 0.49 ± 0.24 mGy/MBq (kidneys), 0.14 ± 0.08 mGy/MBq (salivary glands), and 0.016 ± 0.003 mGy/MBq (liver). EphA2-targeted PET imaging successfully detected 13 liver metastases (SUVmax 6.9±3.4), 2 bone lesions (SUVmax 6.1±0.5), 13 lymph node metastases (SUVmax 5.0±1.1), and 2 peritoneal lesions (SUVmax 5.1±0.8). Primary tumor uptake was observed in 6 of 7 patients, albeit with lower intensity compared to liver metastases (SUVmax 4.8±1.6). Two pulmonary foci and 7 liver lesions identified on CT as morphologically consistent with metastases showed no uptake on EphA2-PET. Conclusion: This first-in-human application of EphA2-targeting [68Ga]Ga-BCY18469 demonstrates the feasibility for visualization of EphA2-expressing primary tumors and metastases, which is in line with the preclinical findings. These initial clinical results support further investigation of [68Ga]Ga-BCY18469 as a diagnostic tool with potential to improve tumor characterization and patient management strategies in EphA2-positive cancers. Reference: 1El Fakiri M, et al. Theranostics. 2024 Aug 6;14(12):4701-4712. Citation Format: Ann-Christin Eder, Mohamed A. Omrane, Christoph-Ferdinand Wielenberg, Mohamed El Fakiri, Aikaterini Klotsotyra, Katia Brüggemann, Heiko Becker, Michael Quante, Michael Mix, Anusha Regupathy, Ben Blakeman, Francesca Wood, Gemma E. Mudd, Matthias Eder, Philipp T. Meyer, Martin T. Freitag. Development and first clinical experiences of a phage display derived bicyclic peptide for EphA2-specific PET imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6520.

Preamble:This represents a substantial development of the guideline on the topic first published in 2016. The following notable points have been updated: the sections on background information; the clinical benefit of the method; the resulting differential diagnostic considerations; the outlook for possible future extensions of the indication spectrum; the quantitative analysis of the PET images; the embedding of the method in diagnostic pathways; and the relation to alternative biomarker methods such as amyloid measurement in CSF/blood.

The purpose of these recommendations is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting tau PET imaging of the brain (tau PET) in patients with cognitive impairment suspected of Alzheimer’s disease (AD). Tau pathology represents a central hallmark of AD and an important biomarker within the biological AT(N) framework, where tau PET imaging enables in vivo assessment for diagnostic evaluation, prognosis, and patient stratification.These joint recommendations from the European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) provide a framework to support the clinical and research use of tau PET imaging. The document covers the currently approved radiotracer [18F]flortaucipir as well as several widely used next-generation tau PET radiotracers. It provides guidance on appropriate clinical indications, patient preparation, image acquisition, visual interpretation, quantitative analysis, and standardized reporting procedures.Particular emphasis is placed on harmonized procedures for image interpretation and quantification, including the use of standardized uptake value ratios (SUVRs), appropriate reference regions, and emerging harmonization approaches that enable comparison of quantitative measures across radiotracers and imaging centers. Standardized imaging procedures are essential to ensure robust and reproducible measurements and to facilitate the integration of tau PET into clinical workflows and multicenter studies.

BACKGROUND:Determination of time-integrated activity (TIA) with a reduced number of imaging sessions is essential for minimizing patient burden and clinical workload in the dosimetry of [177Lu]Lu-PSMA-617. One approach to achieve this is by performing single-time-point (STP) dosimetry. However, STP dosimetry may be associated with significant accuracy errors in certain patients, potentially impacting the reliability of dose calculations. Moreover, the assessment of precision is crucial to evaluating the stability and reliability of estimated doses. PURPOSE:This study aims to investigate the accuracy and precision of few-time-points (FTP) TIA calculation in kidneys for [177Lu]Lu-PSMA-617 using nonlinear mixed-effects modeling (NLMEM). METHODS:Biokinetic data of kidneys from 63 patients with metastatic castration-resistant prostate cancer (mCRPC) treated with [177Lu]Lu-PSMA-617 in the first treatment cycle were used. The SPECT/CT measurement was done at time points (TP) 1) (1.8 ± 0.8) h, 2) (18.7 ± 0.9) h, 3) (42.6 ± 1.0) h, 4) (66.3 ± 0.9) h, and 5) (160.3 ± 24.2) h after injection. This study used the sum-of-exponentials function (SOEF) with six parameters, previously selected as the best fit function for the biokinetic data (PMID: 38423787). Reference TIAs (rTIAs) were derived from fitting the SOEF parameters to all-time-points (ATP) data within the NLMEM framework. Estimated TIAs (eTIAs) were calculated by fitting the FTP data, which consist of one-, two-, three-, and four-time points combinations of the biokinetic data. The accuracy of FTP-NLMEM TIA calculations was quantified using the root-mean-square error (RMSE) and mean absolute percentage error (MAPE) of the relative deviation between eTIAs and rTIAs. Precision was assessed from the coefficient of variation (CV) of individual TIA estimates at each optimal time-point combination. RESULTS:For each optimal TP combination, the RMSEs and MAPEs were (11.0 ± 2.5)% and (7.0 ± 2.3)% for TP3, (6.3 ± 1.6)% and (4.8 ± 1.3)% for TP25, (3.9 ± 1.1)% and (2.3 ± 1.0)% for TP135, and (1.4 ± 0.8)% and (0.9 ± 0.8)% for TP1235. The %CV values of individual TIAs for each best TP combination were (17.1 ± 4.9)% for TP3, (8.5 ± 2.4)% for TP25, (6.3 ± 0.9)% for TP135, (5.1 ± 0.6)% for TP1235, and (4.4 ± 0.3)% for ATP. CONCLUSION:The accuracy and precision of various FTP schemes have been determined and can be used to decide on the number of measurements required. Our study showed that incorporating TP3 in FTP dosimetry could lead to a high accuracy and precision of calculated individual TIAs in [177Lu]Lu-PSMA-617therapy.

Surgery remains the cornerstone of prostate cancer treatment, demanding accurate tumor delineation and margin assessment. The hybrid molecule PSMA-914, which combines positron emission tomography (PET) and near-infrared fluorescence (NIRF) detection capabilities, was developed to improve preoperative imaging and intraoperative guidance during prostate cancer surgery. Methods:In this first-in-human series, prostate cancer patients underwent preoperative PET/CT imaging with 68Ga-labeled PSMA-914 (n = 10), followed by fluorescence-guided surgery after intraoperative PSMA-914 administration (n = 7, doses ranging from 200 -1500 µg/patient). The optimal dose for effective tumor visualization was retrospectively evaluated, and both preoperative and postoperative imaging results were correlated with histopathological findings. Results:Preoperative PET/CT with [68Ga]Ga-PSMA-914 showed high tracer uptake in primary tumors and metastases, facilitating accurate tumor localization. Intraoperatively, PSMA-914 at doses exceeding 1000 µg/patient provided a clear fluorescence signal, allowing for precise tumor and lymph node delineation. This approach significantly aided surgical resection by providing real-time guidance to differentiate malignant tissue from healthy tissue without altering the standard surgical workflow. Histopathological analysis confirmed the accuracy of [68Ga]Ga-PSMA-914 PET/CT staging. The procedure was well tolerated without adverse effects. Conclusion:The dual modality of PSMA-914 has the potential to significantly advance prostate cancer surgery by combining diagnostic imaging and intraoperative guidance. These first results warrant further large-scale clinical trials to validate efficacy and safety across diverse patient populations. The integration of PSMA-914 into clinical protocols promises to benefit prostate cancer surgery by facilitating real-time, high-contrast visualization to aid in complete tumor resection.

CONTEXT:Insulinomas are the main cause of endogenous hyperinsulinemic hypoglycemia (EHH) in adults, with surgery as the only cure. Pancreas-preserving surgery is preferred, making precise preoperative localization crucial. GLP-1R-targeted imaging, such as [68Ga]Ga-DOTA-exendin-4 PET/CT, outperforms other imaging procedures for insulinoma localization. OBJECTIVE:To investigate the performance and clinical impact of [68Ga]Ga-DOTA-exendin-4 PET/CT for the detection of insulinomas in patients with EHH and prior negative or inconclusive conventional imaging. METHODS:In this retrospective, real-world, dual-center imaging study, 101 patients with biochemically proven EHH and/or a positive Whipple's triad underwent [68Ga]Ga-DOTA-exendin-4 PET/CT at two tertiary centers between April 2017 and March 2024. Among these, 58 patients with prior negative or inconclusive conventional imaging constituted the primary analysis cohort. Endpoints: Insulinoma detection rate and sensitivity by [68Ga]Ga-DOTA-exendin-4 PET/CT after negative or inconclusive conventional imaging and impact on clinical management. RESULTS:Among the 58 patients with prior negative or inconclusive conventional imaging, [68Ga]Ga-DOTA-exendin-4 PET/CT was positive in 42 patients, corresponding to a detection rate of 72% (95% CI, 59-83%). Thirty patients subsequently underwent PET/CT-guided surgery. Overall, 32 patients had histological verification (including two PET/CT-negative cases), corresponding to a sensitivity of 93.8% (95% CI, 79-99%). CONCLUSION:In real-world clinical practice, [68Ga]Ga-DOTA-exendin-4 PET/CT provides a high detection rate of 72% for localizing insulinomas, including one case of diffuse nesidioblastosis in patients with EHH and prior negative or inconclusive conventional imaging, thereby enabling PET/CT-guided surgical approaches. These findings underscore the substantial clinical impact of GLP-1R-targeted PET/CT on patient management and prognosis.GLP-1 receptor.

Importance:Amyloid positron emission tomography (PET) is increasingly used in research and clinical settings to determine the etiology of cognitive decline and eligibility for amyloid-targeting therapies. To assist with amyloid PET evaluation and to guide clinical decision-making, images can be quantified in a standardized unit called Centiloid, the interpretation of which can vary according to the method and threshold used. Objective:To collect Centiloid values from available studies and determine robust positivity cutoffs using data-driven methods and correspondence with visual reads. Data Sources:PubMed search (October 2024) identified studies with Centiloid values. Corresponding authors were invited to share individual participant data. Additional data were obtained through access-controlled repositories and conference outreach (July 2024-July 2025). Study Selection:Studies were included if they provided Centiloids, radiotracer, age, and sex. Data Extraction and Synthesis:Each study was analyzed using a unified statistical pipeline; study estimates were pooled using random-effects meta-analysis. Main Outcomes and Measures:Gaussian mixture models (GMMs) were fitted to Centiloid values for each study. In studies with a bimodal distribution (per integrated completed likelihood), single cutoffs for positivity were set as mean plus 2 SDs of the lower gaussian component. Using GMMs, a double-cutoff approach defined a lower certainty range using a 90% posterior probability cutoff for assignment to the low (amyloid-negative) vs high (amyloid-positive) component. An alternative Centiloid cutoff was derived from maximizing the correspondence (Cohen κ) with the binary visual reads when available. Results:This meta-analysis included cross-sectional amyloid PET scans acquired with 5 radiotracers from 49 227 participants across 53 studies from 15 countries (mean age, 71 years; 54% female, 62% cognitively impaired). The data-driven GMM approach identified a bimodal distribution in 51 studies (n = 48 786), resulting in a single cutoff for positivity of 18 Centiloids (95% CI,16-19; I2 = 97%). The double-cutoff approach revealed high confidence for interpreting scans as negative when Centiloid values were lower than 11 (95% CI, 9-13; I2 = 95%) and interpreting scans as positive if Centiloid values were higher than 26 (95% CI, 24-28; I2 = 95%). In analyses of correspondence with binary (positive or negative) visual reads of amyloid PET scans (n = 35 045; 36 studies), Centiloids were highly predictive of visual positivity (Cohen κ, 0.86; 95% CI, 0.83-0.89; I2 = 96%) with a cutoff of 27 Centiloids (95% CI, 24-30; I2 = 80%). Conclusions and Relevance:In this individual participant data meta-analysis, positivity cutoffs converged around 18 Centiloids (data-driven) and 27 Centiloids (visual reads). Findings from a double-cutoff analysis suggest that scans in the 11 to 26 Centiloid range should be interpreted with caution depending on the context of use.

Current radiotherapy for malignant tumors often adopts a "one-size-fits-all" approach, prescribing the same irradiation dose for patients with similar clinical indications. However, advancements in functional imaging allow for biologically individualized strategies, with dose distribution tailored to the specific tumor biology. This study proposes a novel approach to biologically individualized radiotherapy, exploiting the synergistic combination of the tumor clonogenic cell information from [18F]FDG PET images and radiosensitivity from [18F]fluoromisonidazole (FMISO) PET images. Methods: Twenty-eight patients with head and neck squamous cell carcinoma (HNSCC) were analyzed. Using imaging biomarkers, individualized tumor profiles were obtained from oxygen partial pressure and clonogenic cell density maps derived from [18F]FMISO and [18F]FDG PET, respectively. Dose-escalated radiotherapy plans aiming at 95% tumor control probability (TCP) were generated using automated planning. Plans were assessed for clinical feasibility and expected TCP. Results: Planned dose distributions achieved greater than 90% TCP in all cases. All treatment plans met standard clinical feasibility criteria for the main organs-at-risk constraints, except for the few cases with significant target overlap, demonstrating the overall feasibility of the personalized strategy. Conclusion: The proposed biologically individualized treatment strategy demonstrated feasibility and clinical applicability. Combining [18F]FDG and [18F]FMISO PET imaging potentially shifts the success rate of HNSCC treatment from approximately 60% at 5 y, as reported in the literature, to a projected TCP of 90%. This treatment strategy holds promise for improving patient outcomes through more precise and effective treatment.

Erythropoietin-producing hepatocellular receptor A2 (EphA2) is overexpressed in various malignancies, including pancreatic ductal adenocarcinoma (PDAC), in which it correlates with poor prognosis. Although EphA2 is considered a promising target receptor for theranostic applications, suitable radiotracers for clinical imaging have been lacking. This study reports first clinical experiences with [68Ga]Ga-BCY18469, a bicyclic peptide radiotracer for EphA2-targeted PET imaging. Seven patients with histologically confirmed PDAC (5 after chemotherapy, 2 at initial staging) underwent PET/CT imaging. Four were scanned at 15, 30, 45, 60 and 180 min. and three at 45 min. after injection of [68Ga]Ga-BCY18469. Dosimetry calculations were performed based on organ-specific time-activity curves from whole-body PET acquisitions. Imaging findings were compared with contrast-enhanced CT or MRI (interval: 9–50 days). No adverse events were observed. The kidneys received the highest absorbed dose (0.31 ± 0.02 mGy/MBq), while the effective dose was 0.017 ± 0.002 mSv/MBq. [68Ga]Ga-BCY18469 demonstrated rapid tumor uptake at 15 min. post-injection with predominantly renal excretion. Of 45 total lesions EphA2-PET detected 36 lesions with tracer uptake suspicious for metastasis. 11 of 45 lesions were detected only on EphA2-PET, whereas 9 of 45 lesions were detected only on CT and/or MRI. The tracer identified 13 liver metastases (SUVmax 6.9 ± 3.4) and 13 lymph node metastases (SUVmax 5.0 ± 1.1), among other findings. Our initial clinical experiences demonstrate that [68Ga]Ga-BCY18469 enables safe, rapid, and high-contrast visualization of EphA2-expressing PDAC lesions. These results strongly support further investigation of [68Ga]Ga-BCY18469 as a diagnostic tool for EphA2-positive malignancies.

BACKGROUND:Assessment of cerebrovascular reserve capacity (CVRC) is central to treatment planning in adult Moyamoya disease. [15O]-water-PET with acetazolamide challenge (PET-ACZ) serves as the reference standard but is resource-intensive and not universally available, whereas breathhold BOLD MRI (bh-fMRI) may offer a practical noninvasive alternative for screening and triage. METHODS:This retrospective diagnostic accuracy study compared bh-fMRI and PET-ACZ in 67 adult MMD patients (1072 ROIs across 402 supratentorial vascular territories) to determine correlation and clinically useful MRI thresholds for impaired cerebrovascular reserve. Data were analyzed using Pearson's correlation and ROC curves (STARD-compliant). Cerebellum-normalized percent signal change (CN-PSC) was referenced against PET-ACZ < 66% for pathological CVRC. RESULTS:Supratentorial territories showed strong correlation (r = 0.71, 95%CI 0.62-0.80). Optimal diagnostic threshold was <28.2% CN-PSC on bh-fMRI (Youden index; sensitivity 83.8%, specificity 80.9%, AUROC = 0.87); screening threshold < 60% CN-PSC yielded sensitivity 94.6% and NPV 91.1%. No patient factors (age, Suzuki stage, etc.) influenced agreement (univariate/multivariate analyses). CONCLUSIONS:Bh-fMRI supplements PET-ACZ as a screening and diagnostic tool for cerebrovascular reserve impairment in adult MMD. PET remains the reference standard for confirmation, especially in intermediate or discordant cases, and the proposed thresholds (<30% CN-PSC: impaired CVRC; 30-60%: confirm with PET-ACZ; >60%: monitor) require prospective validation before routine decision-making use.

Abstract:This procedure guideline for brain perfusion SPECT is intended to support the planning, execution, quality control, evaluation and reporting of brain perfusion SPECT studies using the 99 mTc-labelled radiopharmaceuticals [99 mTc]Tc-HMPAO and [99 mTc]Tc-ECD. It is an update and expansion built on the 2019 version of the procedure guideline. It was developed through an informal process as a consensus of the Neuroimaging Working Group of the German Society of Nuclear Medicine. It is intended for use by physicians and physical-technical staff (technologists, physicists) working in nuclear medicine.

A strong increase in the prevalence and deaths of Parkinson’s disease (PD) has been reported over the last three decades. Ageing societies, genetic and environmental factors and access to health care contribute to these increases. Using data of the German National Cohort (NAKO) PD classifications based on self-report, claims data and a brief medication based algorithm to increase validity in the absence of neurologic examinations, were compared and the PD incidence, selected non-motor symptoms, functions and vital status were analysed. The algorithm based PD prevalence among 205.000 participants was 0.13% but it was 2.5-fold higher in claims data. Self-reported PD incidence was 0.13% over a median of 4.8 years follow-up, but cases had a 4-fold higher mortality, worse emotional, motoric and olfactory functions and higher prevalences of diabetes, obesity, depression and anxiety. The algorithm based PD prevalence and the mortality risk was similar to considerable older population studies from Europe.

Summary This procedure guideline for SPECT examinations of striatal dopamine transporter availability is intended to support the planning, execution, quality control, interpretation and reporting of cerebral SPECT scans with [123I]ioflupane. It is an update and expansion built on the 2019 version of the procedure guideline. It was developed through an informal process as a consensus of the Neuroimaging Working Group of the German Society of Nuclear Medicine and in consultation with the German Neurological Society. It is intended for use by physicians and technical staff working in the field of nuclear medicine.