EJNMMI Research最新文献

{"title":"Elimination of artifacts caused by residual radiopharmaceutical activity in injection site in myocardial perfusion imaging on Discovery NM 530c semiconductor gamma camera.","authors":"Aleksandra Owczarek, Zbigniew Adamczewski, Anna Plachcinska, Pawel Cichocki","doi":"10.1186/s13550-025-01222-w","DOIUrl":"10.1186/s13550-025-01222-w","url":null,"abstract":"<p><strong>Background: </strong>Cardiac gamma cameras dedicated for myocardial perfusion imaging (MPI) perform studies faster and acquire higher quality images than traditional cameras. However, they are susceptible to some artifacts. We observed a previously unreported artifact, caused by residual radiopharmaceutical activity in injection site in cubital fossa caught in camera field of view. This study aims to assess the impact of these artifacts on image quality and the possibility of their elimination. Study included 50 male patients referred for MPI using Discovery NM 530c gamma camera, in whom radiopharmaceutical activity in injection site was observed in stress or rest study. In such cases, image acquisition was immediately repeated, with the patient and the camera kept in the same position, after covering the injection site with a special lead shield. Obtained images were assessed by two experienced nuclear medicine physicians using a 0-4 point scale in each segment (where 0-normal perfusion, and 4-complete lack of perfusion). Summed stress, rest and difference scores (SSS, SRS and SDS, respectively) were calculated for the entire myocardium and 3 main vascular territories.</p><p><strong>Results: </strong>SSS, SRS and SDS were most frequently assessed as abnormal in RCA territory. Radiopharmaceutical activity in injection site was observed more frequently in stress studies (84% of cases). Covering injection site with a shield changed the assessment of SSS, SRS or SDS from normal to abnormal and vice versa in almost 20% of studies. The most frequently affected vascular territories were LAD and RCA. Elimination of the artifact changed final diagnosis in almost 1/5 of patients, most often by eliminating previously visible significant stress-induced perfusion defects (patients in whom such change occurred did not report any cardiovascular events in one-year follow-up).</p><p><strong>Conclusions: </strong>Artifacts caused by radiopharmaceutical activity in injection site reduce image quality and can potentially generate or hide perfusion defects. They can be observed mainly in patients examined in prone position, after radiopharmaceutical injection in cubital fossa. These artifacts can be eliminated by a lead shield, which can change the final assessment of MPI study in 20% of the patients.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"27"},"PeriodicalIF":3.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11953486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A biorthogonal chemistry approach for high-contrast antibody imaging of lymphoma at early time points.","authors":"Swarbhanu Sarkar, Jonathan M Pham, Kimberly J Edwards, Nitika Sharma, Kexiang Xu, A Paden King, Andres Fernandez Del Castillo, Michael D Farwell, Daniel A Pryma, Stephen J Schuster, Mark A Sellmyer","doi":"10.1186/s13550-025-01213-x","DOIUrl":"10.1186/s13550-025-01213-x","url":null,"abstract":"<p><strong>Background: </strong>Monoclonal antibodies are highly specific for their targets making them effective for cancer therapy. However, their large molecular weight causes slow blood clearance, often requiring weeks to be removed from circulation. This limitation affects companion nuclear imaging and antibody-based diagnostics, necessitating delayed imaging. We report the expansion of a methodology improving positron emission tomography (PET) contrast of the lymphoma biomarker CD20 at early time points after radiolabeled antibody administration. Intact radioimmunoconjugates are allowed to stay in circulation long enough to accumulate in tumors, and then, using a chemical trigger, we induced rapid clearance of the radioactivity from non-target tissues by cleaving the linker between the antibody and the radioactivity. For brevity, we refer to the this as the Tetrazine KnockOut (TKO) method which uses the transcyclooctene-tetrazine (TCO-Tz) reaction, wherein an antibody is conjugated with linker containing TCO and a radioisotope.</p><p><strong>Results: </strong>We optimized the TCO linker with several different radioisotopes and evaluated the ability of tetrazines to knockout radioactivity from circulating antibodies. We explored several cell types and antibodies with varying internalization rates, to characterize the parameters of TKO and tested [⁸⁹Zr]Zr-DFO-TCO-rituximab in a lymphoma model with PET imaging after Tz or vehicle administration. Treatment with Tz induced > 70% cleavage of the TCO linker in vitro within 30 min. Internalizing radioimmunoconjugates exhibited similar cellular uptake with Tz compared to vehicle, whereas decreased uptake was seen with slowly internalizing antibodies. In rodents, Tz rapidly liberated the radioactivity from the antibody, cleared from the blood, and accumulated in the bladder. TKO resulted in > 50% decreased radioactivity in non-target organs following Tz injection. No decrease in tumor uptake was observed when rate of antibody internalization is higher in a lymphoma model, and the target-to-background ratio increased by > twofold in comparison with Tz nontreated groups at 24 h.</p><p><strong>Conclusion: </strong>The TKO approach potentiates early imaging of rituximab radioimmunoconjugates and has translational potential for lymphoma imaging.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"26"},"PeriodicalIF":3.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11930911/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143691587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liver-FDG-uptake augments early PET/CT prognostic value for CD19-targeted CAR-T cell therapy in diffuse large B cell lymphoma.","authors":"Michael Beck, Viktoria Blumenberg, Veit L Bücklein, Ralph A Bundschuh, Dennis C Harrer, Klaus Hirschbühl, Johannes Jung, Wolfgang G Kunz, Karin Menhart, Michael Winkelmann, Igor Yakushev, Anna Lena Illert, Markus Eckstein, Simon Völkl, Rainer Claus, Leo Hansmann, Judith S Hecker, Torsten Kuwert, Andreas Mackensen, Marion Subklewe, Dirk Hellwig, Fabian Müller","doi":"10.1186/s13550-025-01201-1","DOIUrl":"10.1186/s13550-025-01201-1","url":null,"abstract":"<p><strong>Background: </strong>Despite revolutionary efficacy of CD19-CAR-T cell therapy (CAR-T) in aggressive B cell lymphoma, many patients still relapse mostly early. In early failure, distinct drugs support CAR-T which makes reliable and early prediction of imminent relapse/refractoriness critical. A complete metabolic remission (CR) on Fluor-18-Deoxyglucose (FDG) Positron-Emission-Computed Tomography (PET) 30 days after CAR-T (PET30) strongly predicts progression-free survival (PFS), but still fails in a relevant proportion of patients. We aimed to identify additional routine parameters in PET evaluation to enhance CAR-T response prediction.</p><p><strong>Results: </strong>Thirty patients with aggressive B cell lymphoma treated with CAR-T were retrospectively analyzed. Pre-CAR-T, LDH was the strongest PFS-predictor also by multivariate analysis. Post-CAR-T, 10 out of 14 patients (71.4%) with PET30-CR remained in disease remission, while 12 out of 16 patients (75%) with incomplete metabolic remission (PET30-nCR) relapsed after CAR-T. 28.6% of patients with PET30-CR ultimately progressed. Change of liver FDG-uptake from baseline to day30 (Delta-Liver-SUV_mean) was identified as an independent biomarker for response. PET30-nCR and a decrease of Delta-Liver-SUV_mean were associated with a high risk of tumor progression (HR 4.79 and 3.99, respectively). The combination of PET30 and Delta-Liver-SUV_mean identified patients at very low, at intermediate and at very high risk of relapse (PFS not reached, 7.5 months, 1.5 months, respectively).</p><p><strong>Conclusion: </strong>Additionally to PET30 metabolic remission, longitudinal metabolic changes in Delta-Liver-SUV_mean predicted CAR-T efficiency. Our results may guide early intervention studies aiming to enhance CAR-T particularly in the very high-risk patients.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"25"},"PeriodicalIF":3.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11914545/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multinomial logistic regression algorithm for the classification of patients with parkinsonisms.","authors":"Eva Štokelj, Tomaž Rus, Jan Jamšek, Maja Trošt, Urban Simončič","doi":"10.1186/s13550-025-01210-0","DOIUrl":"10.1186/s13550-025-01210-0","url":null,"abstract":"<p><strong>Background: </strong>Accurate differential diagnosis of neurodegenerative parkinsonisms is challenging due to overlapping early symptoms and high rates of misdiagnosis. To improve the diagnostic accuracy, we developed an integrated classification algorithm using multinomial logistic regression and Scaled Subprofile Model/Principal Component Analysis (SSM/PCA) applied to ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) brain images. In this novel classification approach, SSM/PCA is applied to FDG-PET brain images of patients with various parkinsonisms, which are compared against the constructed undetermined images. This process involves spatial normalization of the images and dimensionality reduction via PCA. The resulting principal components are then used in a multinomial logistic regression model, which generates disease-specific topographies that can be used to classify new patients. The algorithm was trained and optimized on a cohort of patients with neurodegenerative parkinsonisms and subsequently validated on a separate cohort of patients with parkinsonisms.</p><p><strong>Results: </strong>The Area Under the Curve (AUC) values were the highest for progressive supranuclear palsy (PSP) (AUC = 0.95), followed by Parkinson's disease (PD) (AUC = 0.93) and multiple system atrophy (MSA) (AUC = 0.90). When classifying the patients based on their calculated probability for each group, the desired tradeoff between sensitivity and specificity had to be selected. With a 99% probability threshold for classification into a disease group, 82% of PD patients, 29% of MSA patients, and 77% of PSP patients were correctly identified. Only 5% of PD, 6% of MSA and 6% of PSP patients were misclassified, whereas the remaining patients (13% of PD, 65% of MSA and 18% of PSP) are undetermined by our classification algorithm.</p><p><strong>Conclusions: </strong>Compared to existing algorithms, this approach offers comparable accuracy and reliability in diagnosing PD, MSA, and PSP with no need of healthy control images. It can also distinguish between multiple types of parkinsonisms simultaneously and offers the flexibility to easily accommodate new groups.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"24"},"PeriodicalIF":3.1,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11911283/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143647701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heart ketone metabolism under acute ketone supplementation in ZDF rats, a type 2 diabetes heart failure model.","authors":"Etienne Croteau, Gabriel Richard, Patrick Prud'Homme, Etienne Rousseau, Stephen C Cunnane, Véronique Dumulon-Perreault, Otman Sarrhini, Serge Phoenix, Sébastien Tremblay, Brigitte Guérin, Roger Lecomte","doi":"10.1186/s13550-025-01215-9","DOIUrl":"10.1186/s13550-025-01215-9","url":null,"abstract":"<p><strong>Background: </strong>In non-insulin-dependent, type 2, diabetes mellitus (T2D), glucose metabolism is compromised, and the heart loses its metabolic flexibility. The Zucker Diabetic Fatty rat (ZDF) model, which replicates the pathophysiology of T2D in patients, shows that as T2D progresses so does heart failure. Heart ketone metabolism seems to play a role in mitigating the heart failure process. This study assesses ketone metabolism in a ZDF heart failure model using cardiac PET imaging.</p><p><strong>Methods: </strong>Six lean ZDF rats (CTRL) and six diabetic obese ZDF rats (T2D) were evaluated for coronary flow reserve (CFR) using [¹³N]ammonia ([¹³N]NH₃) cardiac PET. In addition, rats were evaluated with [¹¹C]acetoacetate ([¹¹C]AcAc) PET during rest and stress conditions to assess ketone metabolism, both at baseline and under an acute exogenous ketone ester oral supplementation. Blood chemistry, cardiac function and hemodynamic parameters were also evaluated under these conditions.</p><p><strong>Results: </strong>CFR was impaired in the T2D model (CTRL: 1.8 ± 0.5; T2D: 1.4 ± 0.2, p < 0.05) suggesting the development of heart failure in the T2D model. Blood ketones increased more than 2-fold after supplementation. The [¹¹C]AcAc heart ketone uptake values with and without ketone supplementation were similar for the CTRL group, and these values were higher than for T2D rats. For the T2D group, the uptake decreased by 20% at rest under ketone supplementation vs. no supplementation (p < 0.05) and remained unchanged under stress with and without supplementation. Because of this decrease at rest, the stress/rest ratio after supplementation increases to the level observed in CTRL. [¹¹C]AcAc heart ketone metabolism showed a slight decrease under stress for the CTRL group, but not for the T2D. Under ketone supplementation, the metabolism stress/rest ratio increased only in T2D (1.25 ± 0.29, p = 0.03 compared to baseline).</p><p><strong>Conclusion: </strong>In a rat model of T2D and CFR impairment, we were able to measure changes in ketone metabolism using [¹¹C]AcAc PET at rest and under stress with and without acute ketone supplementation. Our findings suggest that the heart ketone metabolism of T2D rats is impaired during the heart failure process. Ketone supplementation may have the potential to restore this cardiac reserve.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"23"},"PeriodicalIF":3.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11909378/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143633589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel GAL7-targeted fluorescent molecular imaging probe for high-grade squamous intraepithelial lesion and cervical cancer screening.","authors":"Xiaohui Teng, Chu Tang, Kunshan He, Chunlin Chen, Jie Tian, Yang Du","doi":"10.1186/s13550-025-01218-6","DOIUrl":"10.1186/s13550-025-01218-6","url":null,"abstract":"<p><strong>Background: </strong>Early detection and treatment are critical for improving the survival and prognosis of patients with cervical cancer. However, there is a notable scarcity of targeted imaging probes specifically designed to detect high-grade squamous intraepithelial lesions (HSIL) and cervical cancer. Our study aimed to address this gap by identifying and validating a targeted imaging probe for these conditions.</p><p><strong>Results: </strong>Using bioinformatics data, we identified galectin-7 (GAL7) as highly expressed in patients with cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC). Immunohistochemical staining of biopsy samples from 30 HSIL and cervical cancer patients verified the high and specific expression of GAL7. Further validation was performed using mouse and human CESC cell lines and tumor xenografts, confirming the consistent expression of GAL7. Based on this finding, we synthesized a GAL7-specific antibody conjugated with FITC, creating the GAL7-FITC fluorescence imaging probe. Fluorescence molecular imaging revealed that GAL7-FITC exhibited specific binding to various CESC cell lines and xenograft mouse models. Additionally, the diagnostic capability of GAL7-FITC was demonstrated in fresh HSIL specimens from cervical cone excisions, validated through histopathology and immunohistochemical analysis.</p><p><strong>Conclusions: </strong>Our study identified GAL7 as a specific target for CESC and successfully developed the GAL7-FITC fluorescence imaging probe. GAL7-FITC has shown promising potential for clinical application in the early detection of HSIL and CESC, providing rapid fluorescence imaging diagnosis without observable toxicity. This advancement may significantly enhance the accuracy and speed of cervical cancer diagnostics, ultimately improving patient outcomes.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"22"},"PeriodicalIF":3.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11906962/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico analysis of radiation-induced double-strand breaks by internal ex vivo irradiation of lymphocytes for 45 alpha- and beta/gamma-emitting radionuclides.","authors":"Maikol Salas-Ramirez, Michael Lassmann, Uta Eberlein","doi":"10.1186/s13550-025-01214-w","DOIUrl":"10.1186/s13550-025-01214-w","url":null,"abstract":"<p><strong>Background: </strong>The aim of this study is to evaluate the induction of DNA damage by 45 radionuclides, including those used in medical applications and others relevant to radiation protection. The research focuses on understanding the differential effects of irradiating lymphocytes with beta/gamma- and alpha-emitting radionuclides using Monte Carlo simulations. A validated Monte Carlo simulation model was used to assess radiation-induced DNA damage in lymphocytes. The model integrates GATE for macroscopic radiation transport and Geant4-DNA for microscopic simulations at the cellular level. For the study, 45 radionuclides were selected and their S-values and DNA double-strand break (DSB) induction were investigated. For beta- and gamma-emitting radionuclides, DSBs per cell per mGy were quantified, while for alpha-emitters, alpha tracks per cell per mGy, DSBs per cell per mGy, and DSBs per micrometer of alpha track were calculated.</p><p><strong>Result: </strong>For beta/gamma emitters, the lowest number of DSBs was observed with ¹²⁵I at 0.006 ± 0.003 DSBs·cell⁻¹·mGy⁻¹, while ^99mTc had the highest at approximately 0.015 ± 0.005 DSBs·cell⁻¹·mGy⁻¹. The S-value for lymphocyte nuclei ranked from 0.91 ± 0.14 mGy∙h⁻¹∙MBq⁻¹ (⁶³Ni) and 1.06 ± 0.15 mGy∙h⁻¹∙MBq⁻¹ (¹²⁵I) to 61.83 ± 1.17 mGy∙h⁻¹∙MBq⁻¹ (⁹⁰Sr). For alpha-emitting radionuclides, ²¹³Bi produced 0.0677 ± 0.0005 DSB·cell⁻¹·mGy⁻¹ while ²³²Th yielded 0.0914 ± 0.0004 DSB·cell⁻¹·mGy⁻¹. The DSB linear density for alpha tracks ranged from 7.4 ± 0.1 DSBs/µm for ²⁵²Cf to 16.8 ± 0.1 DSBs/µm for ²³²Th. The S-values for lymphocyte nuclei for alpha emitters varied, from ²³²Th (0.29 ± 0.21 Gy∙h⁻¹∙MBq⁻¹) to ²²⁷Th having the highest at 2.22 ± 0.16 Gy∙h⁻¹∙MBq⁻¹, due to cumulative energy deposition.</p><p><strong>Conclusions: </strong>Differences were observed in DNA damage induced by beta/gamma- and alpha-emitting radionuclides. High-energy beta emitters induced DSBs similarly to gamma emitters, but with greater fluctuations in low-energy beta and gamma emitters due to heterogeneous energy deposition and varying interaction probabilities at the cellular level. This study highlights that long half-life alpha-emitting radionuclides may cause more extensive DNA damage due to their higher LET. This work provides a comprehensive S-values database for future experimental studies on radiation-induced DNA damage in lymphocytes.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"21"},"PeriodicalIF":3.1,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11893945/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143596611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arrival time mapping with ¹⁵O-gas PET for cerebrovascular steno-occlusive diseases: a comparative study with CT perfusion.","authors":"Masanobu Ibaraki, Yuki Shinohara, Aya Watanabe, Kaoru Sato, Tomomi Ohmura, Hiroyuki Yamamoto, Toshibumi Kinoshita","doi":"10.1186/s13550-025-01209-7","DOIUrl":"10.1186/s13550-025-01209-7","url":null,"abstract":"<p><strong>Background: </strong>Positron emission tomography (PET) with ¹⁵O-gas for quantifying cerebral blood flow (CBF) and oxygen metabolism is the gold standard for assessing hemodynamics in ischemic cerebrovascular disease. However, conventional ¹⁵O-gas PET methods do not provide information on regional arrival timing, a hemodynamic parameter typically measured using computed tomography (CT) perfusion with contrast media. This study demonstrated that ¹⁵O-gas PET with a state-of-the-art clinical PET scanner and optimized analysis can generate arrival time maps. In this retrospective study of ten patients with unilateral stenosis or occlusion of the major arteries, we compared PET-derived arrival time maps with CT perfusion Tmax maps.</p><p><strong>Results: </strong>In PET with short inhalation of [¹⁵O]-CO₂ gases, dynamic images were reconstructed with 2-sec temporal resolution, followed by weighted least-squares fitting of one-tissue compartment models, with or without the contributions from vascular components. PET arrival time maps were visually comparable to CT perfusion Tmax maps regarding the spatial extent of delayed brain regions, with less noise and higher image quality when using the model without the vascular components. Region-of-interest analyses showed good correlations between the two modalities: correlation coefficients of 0.834 for absolute values and 0.718 for ipsilateral-to-contralateral differences, respectively, indicating that ¹⁵O-gas PET can quantitatively measure the arrival time with reasonable accuracy.</p><p><strong>Conclusions: </strong>The present method generates arrival-time maps with ¹⁵O-gas PET by applying optimized kinetic analysis to dynamic [¹⁵O]-CO₂ images acquired using a state-of-the-art, high-sensitivity clinical PET scanner. Additional arrival time information for conventional PET parameters of CBF and oxygen metabolism may facilitate a more comprehensive understanding of the hemodynamic status in cerebrovascular steno-occlusive diseases.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"20"},"PeriodicalIF":3.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11889313/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RECIP 1.0 + PSA for response assessment in mCRPC patients treated with ²²⁵Ac / ¹⁷⁷Lu PSMA combination therapy.","authors":"Gabriel T Sheikh, Astrid Delker, Mathias J Zacherl, Adrien Holzgreve, Sarah L Takayama Fouladgar, Marcus Unterrainer, Johannes Rübenthaler, Jozefina Casuscelli, Andrei Gafita, Lena M Unterrainer","doi":"10.1186/s13550-025-01211-z","DOIUrl":"10.1186/s13550-025-01211-z","url":null,"abstract":"<p><strong>Background: </strong>Targeted alpha therapy (TAT) with ²²⁵Ac has shown promising results in metastatic castration-resistant prostate cancer (mCRPC) patients pre-treated with [¹⁷⁷Lu]Lu-PSMA radioligand therapy (RLT). A combination treatment regimen adding ¹⁷⁷Lu to decreased ²²⁵Ac activities may improve toxicity profile while maintaining sufficient anti-tumor effect. We therefore evaluated clinical and image-based response parameters in patients treated with ²²⁵Ac-/¹⁷⁷Lu-PSMA combination therapies (ALCT).</p><p><strong>Results: </strong>Complete response (RECIP-CR), partial response (RECIP-PR), stable disease (RECIP-SD), progressive disease (RECIP-PD) according to RECIP 1.0 was observed in 0/25 (0%), 12/25 (48%), 9/25 (36%) and 4/25 (16%) patients, respectively. Response by RECIP + PSA was observed in 14/25 (56%) patients and progression by RECIP + PSA in 8/25 (32%) patients. Interrater reliability for visual RECIP was substantial (κ = 0.757, p < 0.001), while agreement between visual and quantitative RECIP was almost fully congruent (κ = 0.879, p < 0.001). OS did not significantly vary among the four different therapy regimens (p > 0.05). When grouping patients with declining / stable PSA as responders, these patients showed no significant difference in overall survival compared to patients with progressive PSA after ALCT (p = 0.312). Similarly, there was no significant difference in median overall survival between patients without RECIP-progression (RECIP-PR + RECIP-SD) and patients with RECIP-progression (RECIP-PD) (p > 0.05), but when applying the composite classification, RECIP + PSA responders survived significantly longer compared to patients with RECIP + PSA progression (p = 0.049).</p><p><strong>Conclusions: </strong>ALCT is a promising therapeutic regimen that may prolong survival in patients who progress during [¹⁷⁷Lu]Lu-PSMA RLT. Our results motivate to further investigate the use of RECIP + PSA as tool for response assessment and for overall survival prediction in mCRPC under ALCT.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"19"},"PeriodicalIF":3.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11880445/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143556096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular imaging in hypertrophic cardiomyopathy: an exploratory study with 2-[¹⁸F]FDG and [¹³N]NH₃.","authors":"Maria João Ferreira, Patrícia Marques-Alves, Rodolfo Silva, Andreia Gomes, Antero Abrunhosa, Miguel Castelo-Branco, Wael Jaber, Lino Gonçalves","doi":"10.1186/s13550-025-01212-y","DOIUrl":"10.1186/s13550-025-01212-y","url":null,"abstract":"<p><strong>Background: </strong>Hypertrophic Cardiomyopathy (HCM), a genetic disorder with diverse phenotypes, is associated with risks of heart failure and sudden cardiac death. While the condition involves multiple pathological pathways, including myocardial inflammation, increased workload, myocyte disarray, apoptosis, and fibrosis, the role of molecular imaging via PET-CT remains unexplored in this context. This study aimed to investigate the relationship between myocardial metabolism and perfusion using PET-CT in patients with non-obstructive HCM (NOHCM).</p><p><strong>Results: </strong>Myocardial perfusion and metabolism were assessed using PET-CT with [¹³N]NH3 and 2-[¹⁸F]FDG uptake, respectively, in 30 NOHCM patients. Baseline measurements included maximal myocardial wall thickness (MMWT), left atrial volume (LAV), NT-proBNP levels, and the sudden cardiac death (SCD) risk score. Increased 2-[¹⁸F]FDG uptake (Target to Background Ratio - TBR ≥ 1.1) was detected in 53% of patients, with an average TBR of 1.4 ± 0.5. The inflammatory pattern involved 11.8 ± 17.2% of the left ventricle (LV) and correlated with MMWT (rho = 0.49, p = 0.009), LAV (rho = 0.39, p = 0.04), and NT-proBNP levels (rho = 0.63, p = 0.003). The maximum TBR within the LV correlated with MMWT (rho = 0.53, p = 0.004), NT-proBNP (rho = 0.70,p = 0.0008), and the SCD risk score (rho = 0.38,p = 0.04). Additionally, the fibrotic (scar) pattern, involving 10.3 ± 10.2% of the LV, correlated with the SCD score (rho = 0.38,p = 0.04).</p><p><strong>Conclusion: </strong>In patients with NOHCM, PET-CT imaging provides valuable insights into myocardial metabolism and fibrosis, which are closely associated with myocardial hypertrophy, left ventricular dysfunction, and the risk of sudden cardiac death.</p>","PeriodicalId":11611,"journal":{"name":"EJNMMI Research","volume":"15 1","pages":"18"},"PeriodicalIF":3.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11871154/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}