Nuklearmedizin. Nuclear medicine最新文献

Radioactive gold isotopes, particularly the element-matched theranostic pair ¹⁹⁸Au and ¹⁹⁹Au, hold significant promise for targeted radionuclide therapy and SPECT imaging. This review critically evaluates their medical potential by contextualizing historical development, nuclear properties, production physics, radiochemical separations, and contemporary radiopharmaceutical applications to identify pathways for clinical translation.We comprehensively surveyed literature on gold isotope decay characteristics, reactor and accelerator based production from Au, Pt, and Hg targets, purification strategies including ion-exchange chromatography, solid-phase extraction, polymer/zeolite adsorption, and liquid-liquid extraction, alongside reviewing a spectrum of ¹⁹⁸Au/¹⁹⁹Au radiotracers from small-molecule complexes to nanostructures and bioconjugates. ¹⁹⁸Au and ¹⁹⁹Au offer complementary β^- emissions for therapy and their γ photons are ideal for SPECT imaging, with scalable carrier-added production routes from ¹⁹⁷Au and non-carrier-added routes via enriched Pt/Hg. Robust separation techniques deliver radioactive gold with higher purity, enabling the production of diverse agents including but not limited to Au(III) Schiff-bases, phosphine/dithiocarbamate/NHC complexes, thioglucose derivatives, intrinsically doped nanoparticles (RGD-, bombesin-, HER2-targeted), and antibody conjugates.While radioactive gold research has progressed from colloidal ¹⁹⁸Au brachytherapy to modern small molecule based complexes, barriers persist in sustainable high-specific-activity production, target recycling, in vivo stability, and clinical validation. Nevertheless, gold's chemical and physical characteristics position ¹⁹⁸Au/¹⁹⁹Au as candidates for next-generation radio-theranostics.

This paper presents the results of the 10^th survey of myocardial perfusion SPECT (MPS) from the year 2024.A total of 198 questionnaires were evaluated, comprising 115 practices (PR), 57 hospitals (HO) and 26 university hospitals (UH). The results of the previous survey 2021 are shown in squared brackets.MPS data from 128.707 [133.057] patients (-3.3%) with 125.175 [131.868] stress and 102.903 [106.546] rest MPS were analysed. A comparison with official data revealed that 53% of all MPS were recorded. From 2018 to 2024, official data showed an increase in MPS every year. In 2024, on average, 650 [610] MPS patients (+7%) were examined in each department. Of the participating departments, 69% [74%] reported an increase or no changes in their patient numbers. As always ambulatory care cardiologists represented the major referral group (68% [69%]). Pharmacological stress was performed more frequently than ergometry (43% [42%]). Regadenoson was mostly used. The use of the different protocols remained almost unchanged. Two-day protocols were predominantly applied (49% [49%]). Multi-head cameras were used in (56% [58%] of the departments and SPECT-CT systems in (31% [28%]). Attenuation correction was performed in 35% [33%] of all MPS. 95% [89%] of all stress, 93% [88%] of all rest and 92% [87%] of all stress and rest scan were acquired as gated SPECT. 84% [72%] of the departments performed scoring by default. The proportion of departments not scoring decreased to 4% [13%].The MPS 2024 survey indicates that the long-term positive development of MPS imaging is continuing. The procedural and technical details of MPS imaging demonstrate a high level of conformity with guidelines, with a slight improvement observed from 2021 to 2024.

Nuclear medicine landscape has been changing over the past decade due to the rise of radioligand therapies. However, patients receiving radioiodine therapy for benign thyroid disease still account for approx. one third of the patients on a regular nuclear medicine ward. A substantial part of these patients are hospitalized for radiation protection only and do not require nursing staff. This report aims at describing the implementation of a "no-care" nuclear medicine ward with medical students as staff. We report on the training process, patient and student satisfaction as well as the impact and strengths of this concept.A separated nuclear medicine ward (10 beds) was established at a university hospital in Germany. After specific training, two students were assigned per working shift in a regular three-shift-system. Patients were evaluated according to predefined inclusion and exclusion criteria. Patients and students answered two separate surveys, assessing the satisfaction with the concept.172/319 (53.9%) of the patients met the inclusion criteria. The "no-care" ward was opened six times between April 2024 and June 2025 and the duration was between 10 and 20 days. 101 patients were treated using I-131 sodium iodine, achieving 68.5 DRG relative units. Patient satisfaction survey revealed very high positive response rates. 27 medical students were assigned to the "no-care" ward. The majority of students stated a positive effect on overall medical knowledge and workflow understanding in a hospital.Using medical students as staff on a "no-care" nuclear medicine ward is feasible and safe. In view of nursing staff shortage, this concept might contribute to adaptive caring in nuclear medicine therapies after careful patient selection.

Alveolar echinococcosis (AE) is a rare, potentially fatal zoonosis with highly heterogeneous morphology. This study compares AE lesions in B-scan ultrasound, categorized according to the Echinococcus multilocularis Ulm Classification - Ultrasound (EMUC-US), with the maximum standardized uptake value (SUVmax) in 18F-Fluorodeoxyglucose Positron-Emission-Tomography (18F-FDG-PET/CT). 18F-FDG-PET/CT is the gold standard for evaluating disease activity, with SUVmax as the key parameter indirectly reflecting AE lesion activity.Retrospective analysis of data from the German National Echinococcosis Database. A total of 121 patients with 18F-FDG-PET/CT and B-scan ultrasound (US) between 2018-2019 were included. Based on EMUC-US, AE liver lesions were compared with the corresponding SUVmax in PET/CT. Additionally, SUV ratios (SUVTLR=tumor SUVmax/liver SUVmean) were calculated.The mean SUVmax, regardless of the EMUC-US subtype, was 6.0 ± 3.3 (range: 2.4-18.0). SUVmax comparison between subtypes shows significant differences (p<0.001). The highest SUVmax and SUVTLR were measured for the pseudocystic pattern with a mean of 9.2 ± 3.5 (range: 4.1-18.0). In contrast, the metastasis-like pattern yielded 3.7 ± 0.9 (range: 2.4-5.8) and the lowest SUVTLR. An SUVmax of 6.1 ± 3.3 (range: 2.6-16.8) was measured for the hailstorm pattern and 5.8 ± 2.2 (range: 3.6-10.4) for the hemangioma-like pattern.The results show significant differences between specific US patterns and the corresponding SUVmax. Lesions with very high or low SUV correlate with characteristic morphological patterns. Hence, in clinical practice B-scan can be a valuable bedside tool for assessing certain lesions. For evaluating inflammatory activity, 18F-FDG-PET/CT remains the method of choice.

This retrospective study aimed to investigate whether the differing biology of right-sided primary tumors (RSP) and left-sided primary tumors (LSP) in metastatic colorectal cancer (mCRC) affects survival outcomes following selective internal radiation therapy (SIRT).A cohort of 140 mCRC patients with liver metastases treated with SIRT between 2009 and 2016 was analyzed. Patients were stratified by tumor localization (RSP: proximal colon; LSP: distal colon and rectum), clinical, histopathological, and molecular data, were collected. Survival outcomes (OS and PFS) were evaluated using Kaplan-Meier analysis. Cox regression analysis identified independent predictors of survival, and subgroup analyses examined differences between RSP and LSP patients.Of the patients, 80.7% had LSP, and 19.3% had RSP. RSP patients demonstrated more aggressive tumor biology, with a higher frequency of poorly differentiated tumors (G3), extrahepatic metastases and K-RAS mutations. Median OS was significantly longer for LSP patients (7.0 months) compared to RSP patients (4.0 months, p<0.005). Similarly, PFS was longer for LSP patients (3.0 months) than for RSP patients (1.6 months, p<0.032). Multivariable Cox regression analysis revealed that K-RAS mutation (HR 3.345, p=0.017), N2 lymph node involvement (HR 2.458, p=0.015), and RSP localization (HR 0.338, p=0.001) were independently associated with poor survival.This study demonstrates that right-sided tumor localization, K-RAS mutation, and N2 lymph node involvement are key predictors of poor survival following SIRT in mCRC patients. RSP tumors, with distinct molecular and clinical profiles, exhibit shorter median OS and PFS after SIRT compared to LSP tumors.

Neuroendocrine tumors (NETs) are a heterogeneous group of malignancies characterized by variable immune microenvironment. This study aimed to analyze the infiltration of NETs by CD68⁺ tumor-associated macrophages (TAMs) and FoxP3⁺ regulatory T cells (Tregs) using Qupath software for semi-automated histopathological quantificationThirty-two patients with resected NETs were included. CD68 and FoxP3 expression were assessed by immunohistochemistry followed by automated cell detection and spatial analysis.The mean percentage of CD68⁺ cells was 0.35%, with no significant differences between pancreatic and gastrointestinal NETs. FoxP3⁺ cells were less frequent (mean: 0.06%), with higher levels in gastrointestinal NETs compared to pancreatic NETs (p < 0.05). Kaplan-Meier analysis revealed that CD68⁺ cells showed a trend to positive correlation with progression-free survival (PFS) and overall survival (OS). Thereby, patients exceeding a 0.1% CD68⁺ cell threshold exhibited longer survival (PFS: not reached vs. 106 months). In contrast, FoxP3⁺ cells showed a trend to inverse correlation with survival; patients with >0.05% FoxP3⁺ cells had shorter PFS (36 months vs. 147 months) and OS (180 months vs. not reached). Multivariate Cox regression identified N-stage as the sole predictor of OS. CD68⁺ TAM density was not associated with other clinical parameters, while FoxP3⁺ cell infiltration correlated significantly with venous invasion and advanced N- and M-stages.These findings highlight the potential prognostic relevance of immune cell infiltration in NETs and underscore the utility of Qupath for quantifying immune markers in histopathological analyses. The contrasting roles of CD68⁺ TAMs and FoxP3⁺ Tregs in the NET microenvironment warrant further exploration to inform immunotherapeutic strategies.

The study investigated routinely used radiopharmaceuticals containing lutetium-177 (¹⁷⁷Lu), providing reference values for their effective half-life (T_1/2,eff). So far, no guidelines regarding discharging this patients exist, are essential to ensure radiation protection of the public. This study contributes to the development of binding discharge criteria regarding ¹⁷⁷Lu therapies.This retrospective multicenter study comprised eight nuclear medicine departments. Two commercially available products and two in-house preparations were considered. Radiation measurement methods, in terms of measuring device, setup, and time points were reported, as well as dose rate measurements for T_1/2,eff calculation.The study includes 210 dose rate measurement sets with a mean administered activity of (7149 ± 522) MBq. When only measurements up to 48 h p.i. were taken into account the T_{1/2, eff} were shorter (Pluvicto 1.30 d, Lutathera 1.40 d, ihPSMA 1.45 d, ihRRT 1.97 d) compared to 168 h (1.60 d, 1.89 d, 2.10 d, and 2.85 d, respectively). Differences were statistically significant for all compounds except Lutathera. The 90^th percentile of the T_1/2,eff observed in late measurements (Pluvicto 2.0 d, Lutathera 3.0 d, ihPSMA 3.5 d, ihRRT 4.0 d) can be considered conservative values for discharge calculations.The T_1/2,eff of ¹⁷⁷Lu is considerably shorter than its T_1/2,phy, owing to the pharmacokinetics of the entire molecule. This highlights the need of considering biological clearance mechanisms into calculations of discharge times for patients treated with ¹⁷⁷Lu. If direct measurements are not feasible in clinical routine, reference values support inpatient planning while ensuring radiation protection.

This updated position paper from the German Society of Nuclear Medicine (DGN) and the German Cardiac Society (DGK) replaces the original statement from 2018. It gives an overview of the fields of application and the current value of nuclear cardiological imaging. The topics covered include chronic coronary syndrome, including viability diagnostics and the special value of positron emission tomography (PET), cardiomyopathies, cardiac sarcoidosis, amyloidosis, infectious endocarditis and inflammation of cardiac implants.

This study aimed to determine the optimized scan time and injected activity regimen for clinical ⁶⁸Ga DOTATATE PET/CT in neuroendocrine tumor imaging through an experimental approach without using machine learning techniques.A NEMA PET body phantom was used with Ga-⁶⁸ to simulate a 9:1 sphere-to-background ratio. PET data were acquired on a high-sensitivity scanner at various scan times (15-300 s/bed). For each scan time, coefficient of variation (COV) and contrast-to-noise ratio (CNR) were calculated. The minimum scan time (T_min) needed to meet the Rose Criterion (CNR > 5) for the smallest sphere was identified. This T_min was then applied to patient scans with neuroendocrine tumors (originally acquired at 120 s/bed) to evaluate image quality and determine an optimized activity regimen for clinical ⁶⁸Ga-DOTATATE PET imaging.Phantom experiments showed that a COV_max of 20% is the highest acceptable noise level for detecting the smallest lesions, corresponding to a minimum scan time of about 1 minute per bed position. Patient image analysis confirmed that all tumors visible at routine scan times were still detectable at this minimum duration. This supports the use of a lower activity regimen (~1 MBq/kg), which can reduce patient radiation exposure compared to the standard 1.85 MBq/kg protocol.This work demonstrated that scan time and activity for ⁶⁸Ga-DOTATATE NET imaging can be significantly minimized without compromising image interpretation and quantification.