Frontiers in nuclear medicine (Lausanne, Switzerland)最新文献

{"title":"αvβ6-integrin targeted PET/CT imaging in pancreatic cancer patients using ⁶⁸Ga-Trivehexin.","authors":"Jana Rehm, Robert Winzer, Marc Pretze, Juliane Müller, Johannes Notni, Sebastian Hempel, Marius Distler, Gunnar Folprecht, Jörg Kotzerke","doi":"10.3389/fnume.2024.1487602","DOIUrl":"https://doi.org/10.3389/fnume.2024.1487602","url":null,"abstract":"<p><strong>Purpose: </strong>⁶⁸Ga-Trivehexin is a PET tracer targeting αvβ6-integrin, a transmembrane receptor that is frequently expressed by pancreatic cancer cells. This study aimed to determine the biokinetics, image contrast, and acquisition parameters for ⁶⁸Ga-Trivehexin PET imaging in pancreatic cancers.</p><p><strong>Methods: </strong>44 patients with pancreatic cancer underwent Trivehexin PET/CT between June 2021 and November 2022 (EK-242052023). Biokinetics and -distribution were extracted. Previous imaging follow-up imaging, and histological findings were used as reference standards. A one-way ANOVA test, followed by Tukey HSD post-hoc test was conducted. <i>T</i>-tests for subgroups ± chemotherapy prior to PET were performed. Based on dynamic PET data (<i>n</i> = 11) recorded over 45 min, time-activity curves were generated.</p><p><strong>Results: </strong>⁶⁸Ga-Trivehexin PET/CT detected 40 pancreatic cancers, SUVmax 12.6; range [5.1-30.8]; 39 liver metastases, SUVmax 7.9 [2.7-16.3]; 21 lymph node metastases, SUVmax 8.6 [2.5-15.0]; 17 peritoneal metastases, SUVmax 9.5 [4.0-16.9] and 14 other metastases, SUVmax 7.2 [2.9-13.1]. Tukey post-hoc analysis revealed significant differences for SUVmax in pancreatic cancer compared to SUVmax in liver metastases [4.74, 95%-CI (1.74, 7.75)], for SUVmax in pancreatic cancer to SUVmax in lymph node metastasis [4.07, 95%-CI (0.47, 7. 67)], for tumor-to-liver ratio (TLR) of liver metastasis to TLR of pancreatic cancer [1.82, 95%-CI (0.83, 2.80)], for TLR of pancreatic cancer to TLR of peritoneal carcinomatoses [-1.88, 95%-CI (-3.15, -0.61)], and TLR of pancreatic cancer to TLR of pleural carcinomatosis [-2.79, 95%-CI (-5.42, -0.18)]. When comparing subgroups ± chemotherapy prior to PET, TLR of pancreatic cancers and TLR of peritoneal carcinomatoses were significantly different. At 45 min p.i., the highest tumor-to-backround (TBR) was observed.</p><p><strong>Conclusion: </strong>⁶⁸Ga-Trivehexin is suitable for imaging of αvβ6-integrin expression in pancreatic cancer due to its ability to distinguish primary carcinoma and metastases from background tissue.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1487602"},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11604418/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142775206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrastive learning for neural fingerprinting from limited neuroimaging data.","authors":"Nikolas Kampel, Farah Abdellatif, N Jon Shah, Irene Neuner, Jürgen Dammers","doi":"10.3389/fnume.2024.1332747","DOIUrl":"10.3389/fnume.2024.1332747","url":null,"abstract":"<p><strong>Introduction: </strong>Neural fingerprinting is a technique used to identify individuals based on their unique brain activity patterns. While deep learning techniques have been demonstrated to outperform traditional correlation-based methods, they often require retraining to accommodate new subjects. Furthermore, the limited availability of samples in neuroscience research can impede the quick adoption of deep learning methods, presenting a challenge for their broader application in neural fingerprinting.</p><p><strong>Methods: </strong>This study addresses these challenges by using contrastive learning to eliminate the need for retraining with new subjects and developing a data augmentation methodology to enhance model robustness in limited sample size conditions. We utilized the LEMON dataset, comprising 3 Tesla MRI and resting-state fMRI scans from 138 subjects, to compute functional connectivity as a baseline for fingerprinting performance based on correlation metrics. We adapted a recent deep learning model by incorporating data augmentation with short random temporal segments for training and reformulated the fingerprinting task as a contrastive problem, comparing the efficacy of contrastive triplet loss against conventional cross-entropy loss.</p><p><strong>Results: </strong>The results of this study confirm that deep learning methods can significantly improve fingerprinting performance over correlation-based methods, achieving an accuracy of about 98% in identifying a single subject out of 138 subjects utilizing 39 different functional connectivity profiles.</p><p><strong>Discussion: </strong>The contrastive method showed added value in the \"leave subject out\" scenario, demonstrating flexibility comparable to correlation-based methods and robustness across different data sizes. These findings suggest that contrastive learning and data augmentation offer a scalable solution for neural fingerprinting, even with limited sample sizes.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1332747"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11598699/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142741567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can ChatGPT help patients understand radiopharmaceutical extravasations?","authors":"Madeleine Alvarez","doi":"10.3389/fnume.2024.1469487","DOIUrl":"10.3389/fnume.2024.1469487","url":null,"abstract":"<p><p>A previously published paper in the official journal of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) concluded that the artificial intelligence chatbot ChatGPT may offer an adequate substitute for nuclear medicine staff informational counseling to patients in an investigated setting of ¹⁸F-FDG PET/CT. To ensure consistency with the previous paper, the author and a team of experts followed a similar methodology and evaluated whether ChatGPT could adequately offer a substitute for nuclear medicine staff informational counseling to patients regarding radiopharmaceutical extravasations. We asked ChatGPT fifteen questions regarding radiopharmaceutical extravasations. Each question or prompt was queried three times. Using the same evaluation criteria as the previously published paper, the ChatGPT responses were evaluated by two nuclear medicine trained physicians and one nuclear medicine physicist for appropriateness and helpfulness. These evaluators found ChatGPT responses to be either highly appropriate or quite appropriate in 100% of questions and very helpful or quite helpful in 93% of questions. The interobserver agreement among the evaluators, assessed using the Intraclass Correlation Coefficient (ICC), was found to be 0.72, indicating good overall agreement. The evaluators also rated the inconsistency across the three ChatGPT responses for each question and found irrelevant or minor inconsistencies in 87% of questions and some differences relevant to main content in the other 13% of the questions. One physician evaluated the quality of the references listed by ChatGPT as the source material it used in generating its responses. The reference check revealed no AI hallucinations. The evaluator concluded that ChatGPT used fully validated references (appropriate, identifiable, and accessible) to generate responses for eleven of the fifteen questions and used generally available medical and ethical guidelines to generate responses for four questions. Based on these results we concluded that ChatGPT may be a reliable resource for patients interested in radiopharmaceutical extravasations. However, these validated and verified ChatGPT responses differed significantly from official positions and public comments regarding radiopharmaceutical extravasations made by the SNMMI and nuclear medicine staff. Since patients are increasingly relying on the internet for information about their medical procedures, the differences need to be addressed.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1469487"},"PeriodicalIF":0.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11576157/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142683657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel method in myocardial injury risk stratification using intravenous fat emulsion as sole rapid preparation for unfasted patients to suppress myocardial 18F-fluorodeoxyglucose uptake for optimal cardiac PET imaging: a proof-of-concept randomized-crossover trial.","authors":"Michael H-G Li, Raef R Boktor, Christopher Rowe, Laurence Weinberg, Bernhard Riedel","doi":"10.3389/fnume.2024.1412917","DOIUrl":"https://doi.org/10.3389/fnume.2024.1412917","url":null,"abstract":"<p><strong>Objectives: </strong>Optimal imaging of ischemic or inflammed myocardium via ¹⁸F-FDG PET imaging requires suppression of background carbohydrate metabolism in normal myocardium. Sole administration of intravenous lipid emulsion has not previously been used to rapidly prepare unfasted patients, such as in emergent clinical situations. In this proof-of-concept pilot, we posited that intravenous fat emulsion suppresses physiological metabolic uptake of in non-ischemic, non-inflammatory myocardium in unprepared and unfasted setting for enhanced cardiac positron emission tomography (PET) imaging.</p><p><strong>Methods: </strong>We conducted an ethics-approved, single-blind, prospective randomized crossover trial of 10 healthy volunteers from January 2020 to June 2021. Participants were unfasted and rendered hyperglycemic before being administered either high dose intravenous lipid emulsion-1.5 ml kg of 20% lipid emulsion, followed by 15 ml/kg/hr for 30mins-or saline prior to ¹⁸F-FDG injection and subsequent cardiac PET imaging. Assessors undertook image analysis for maximum standard uptake value (SUVmax), minimum standard uptake value (SUVmin) and qualitative assessment, and groups were compared using univariate analysis.</p><p><strong>Results: </strong>The study population age was 44.5 years [IQR 32.5-56.5], with 50% male and a median BMI of 22.75 [IQR 25.0-28.5] kg/m². The study was feasible and there were no adverse side effects from the interventions. In these participants with normal myocardium, ¹⁸F-FDG uptake was reduced by intravenous lipid emulsion as assessed by SUVmax and qualitative assessment (<i>p</i> = 0.042, <i>r</i> = 0.454 and <i>p</i> = 0.009, <i>r</i> = -0.581, respectively).</p><p><strong>Conclusions: </strong>Intravenous lipid emulsion suppresses background metabolic uptake of ¹⁸F-FDG even in unprepared and unfasted patients. Our findings prove and expand the possible applications for cardiac ¹⁸F-FDG PET in various settings, including in emergent settings as a means of rapid preparation in place of current more time-consuming standard protocols, allowing time-critical management to be effected.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1412917"},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11541950/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142607728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case Report: All that glitters is not cancer; perihepatic hibernoma with fluctuating FDG uptake on PET/CT.","authors":"Amaila Ramzan, Amarjot Chander, Thomas Westwood, Mark Elias, Prakash Manoharan","doi":"10.3389/fnume.2024.1477467","DOIUrl":"10.3389/fnume.2024.1477467","url":null,"abstract":"<p><p>Hibernomas are rare brown fat tumors that garnered attention in the literature with the increasing use of [¹⁸F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography ([¹⁸F] FDG PET/CT) for the staging workup and follow-up of solid malignancies. Despite being benign tumors, they exhibit high metabolic activity due to their thermogenic nature, leading to significant radiotracer uptake on functional imaging. This can pose a challenge in differentiating them from the malignant lesions, especially the fat-containing malignancies such as liposarcoma. Hibernomas are typically found in the thigh, shoulder, back, and neck. Here, we present a unique case of Hibernoma in a patient undergoing PET/CT for melanoma follow-up in an unusual perihepatic location. To the best of the authors' knowledge, this represents the first reported case of a perihepatic hibernoma in the literature. The report also offers a literature review on hibernomas, including the influence of ambient temperature on their metabolism, diagnostic challenges, management strategies, and reports of hibernomas detected on functional imaging with a range of radiotracers. These observations could serve as a valuable clue in identifying hibernomas, potentially aiding in avoiding unnecessary biopsies or resections.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1477467"},"PeriodicalIF":0.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11537942/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionising radiation exposure-induced regulation of selected biomarkers and their impact in cancer and treatment.","authors":"Yonwaba Mzizi, Saidon Mbambara, Boitumelo Moetlhoa, Johncy Mahapane, Sipho Mdanda, Mike Sathekge, Mankgopo Kgatle","doi":"10.3389/fnume.2024.1469897","DOIUrl":"10.3389/fnume.2024.1469897","url":null,"abstract":"<p><p>Ionising radiation (IR) is a form of energy that travels as electromagnetic waves or particles. While it is vital in medical and occupational health settings, IR can also damage DNA, leading to mutations, chromosomal aberrations, and transcriptional changes that disrupt the functions of certain cell regulators, genes, and transcription factors. These disruptions can alter functions critical for cancer development, progression, and treatment response. Additionally, IR can affect various cellular proteins and their regulators within different cell signalling pathways, resulting in physiological changes that may promote cancer development, progression, and resistance to treatment. Understanding these impacts is crucial for developing strategies to mitigate the harmful effects of IR exposure and improve cancer treatment outcomes. This review focuses on specific genes and protein biomarkers regulated in response to chronic IR exposure, and how their regulation impacts disease onset, progression, and treatment response.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1469897"},"PeriodicalIF":0.0,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11532091/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Terbium sisters: current development status and upscaling opportunities.","authors":"Anzhelika N Moiseeva, Chiara Favaretto, Zeynep Talip, Pascal V Grundler, Nicholas P van der Meulen","doi":"10.3389/fnume.2024.1472500","DOIUrl":"10.3389/fnume.2024.1472500","url":null,"abstract":"<p><p>The interest in terbium radionuclides, which can be used in nuclear medicine, has increased tremendously over the last decade. Several research studies have shown the potential of four terbium radionuclides ^{149,152,155,161}Tb both for cancer diagnosis as well as therapy. The comparison of ¹⁶¹Tb and ¹⁷⁷Lu showed ¹⁶¹Tb as the preferred candidate not only for standard radiotherapy, but also for the treatment of minimal residual disease. Nevertheless, among the terbium sisters, currently, only ¹⁶¹Tb has an established production protocol where its no-carrier-added form is obtained via neutron irradiation of enriched ¹⁶⁰Gd targets. The other terbium radioisotopes face challenges related to production capacity and production yield, which currently restricts their use in nuclear medicine. The purpose of this review is to report on recent research on the production and separation of terbium sisters and to assess the prospects for upscaling their production for nuclear medicine applications.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1472500"},"PeriodicalIF":0.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11502363/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142514128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Copper-61 is an advantageous alternative to gallium-68 for PET imaging of somatostatin receptor-expressing tumors: a head-to-head comparative preclinical study.","authors":"Tais Basaco Bernabeu, Rosalba Mansi, Luigi Del Pozzo, Raghuvir Haridas Gaonkar, Lisa McDougall, Anass Johayem, Milen Blagoev, Francesco De Rose, Leila Jaafar-Thiel, Melpomeni Fani","doi":"10.3389/fnume.2024.1481343","DOIUrl":"10.3389/fnume.2024.1481343","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Gallium-68 positron emission tomography (&lt;sup&gt;68&lt;/sup&gt;Ga-PET) with the two registered somatostatin analogs, [&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-Tyr&lt;sup&gt;3&lt;/sup&gt;-octreotide ([&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-TOC) and [&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-Tyr&lt;sup&gt;3&lt;/sup&gt;-octreotate ([&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-TATE), where DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, is routinely used for imaging of somatostatin receptor (SST)-expressing tumors. We investigated copper-61 (&lt;sup&gt;61&lt;/sup&gt;Cu) as an alternative radiometal for PET imaging of SST-expressing tumors. Compared to gallium-68, copper-61 (t&lt;sub&gt;1/2&lt;/sub&gt; = 3.33 h, E &lt;i&gt;&lt;sub&gt;β&lt;/sub&gt;&lt;/i&gt; &lt;sup&gt;+&lt;/sup&gt; &lt;sub&gt;max&lt;/sub&gt; = 1.22 MeV) can be produced on a large scale, enables late time point imaging, and has the therapeutic twin copper-67. Herein, DOTA-TOC and 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA)-TOC were labeled with copper-61 and compared with the clinically used [&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-TOC.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;[&lt;sup&gt;61&lt;/sup&gt;Cu]CuCl&lt;sub&gt;2&lt;/sub&gt; was produced from an irradiated natural nickel target. DOTA-TOC and NODAGA-TOC were labeled with [&lt;sup&gt;61&lt;/sup&gt;Cu]CuCl&lt;sub&gt;2&lt;/sub&gt; in ammonium acetate buffer so to achieve a reaction pH of 5-6 and a temperature of 95°C for DOTA-TOC or room temperature for NODAGA-TOC. The radioligands were evaluated head-to-head &lt;i&gt;in vitro&lt;/i&gt; using human embryonic kidney (HEK)-SST&lt;sub&gt;2&lt;/sub&gt; cells (affinity, binding sites, cellular uptake, and efflux) and &lt;i&gt;in vivo&lt;/i&gt; using HEK-SST&lt;sub&gt;2&lt;/sub&gt; xenografts [PET/computed tomography (CT) imaging, biodistribution, and pharmacokinetics] and compared with [&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-TOC, which was prepared using a standard procedure. Dosimetry estimates were made for [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;[&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-DOTA-TOC and [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC were prepared at an apparent molar activity of 25 MBq/nmol with radiochemical purities of ≥96% and ≥98%, respectively. &lt;i&gt;In vitro&lt;/i&gt;, both presented a sub-nanomolar affinity for SST&lt;sub&gt;2&lt;/sub&gt; (IC&lt;sub&gt;50&lt;/sub&gt; = 0.23 and 0.34 nM, respectively). They were almost entirely internalized upon binding to SST&lt;sub&gt;2&lt;/sub&gt;-expressing cells and had similar efflux rates at 37°C. &lt;i&gt;In vivo&lt;/i&gt;, [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-DOTA-TOC and [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC showed the same accumulation in SST&lt;sub&gt;2&lt;/sub&gt;-expressing tumors. However, PET/CT images and biodistribution analyses clearly showed an unfavorable biodistribution for [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-DOTA-TOC, characterized by accumulation in the liver and the abdomen. [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC displayed favorable biodistribution, comparable with [&lt;sup&gt;68&lt;/sup&gt;Ga]Ga-DOTA-TOC at 1 h post-injection (p.i.). Notwithstanding, [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC showed advantages at 4 h p.i., due to the tumor retention and improved tumor-to-non-tumor ratios. The effective dose (2.41 × 10&lt;sup&gt;-3&lt;/sup&gt; mSv/MBq) of [&lt;sup&gt;61&lt;/sup&gt;Cu]Cu-NODAGA-TOC, but also the dose t","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1481343"},"PeriodicalIF":0.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11503464/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142514127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mixture prior distributions and Bayesian models for robust radionuclide image processing.","authors":"Muyang Zhang, Robert G Aykroyd, Charalampos Tsoumpas","doi":"10.3389/fnume.2024.1380518","DOIUrl":"10.3389/fnume.2024.1380518","url":null,"abstract":"<p><p>The diagnosis of medical conditions and subsequent treatment often involves radionuclide imaging techniques. To refine localisation accuracy and improve diagnostic confidence, compared with the use of a single scanning technique, a combination of two (or more) techniques can be used but with a higher risk of misalignment. For this to be reliable and accurate, recorded data undergo processing to suppress noise and enhance resolution. A step in image processing techniques for such inverse problems is the inclusion of smoothing. Standard approaches, however, are usually limited to applying identical models globally. In this study, we propose a novel Laplace and Gaussian mixture prior distribution that incorporates different smoothing strategies with the automatic model-based estimation of mixture component weightings creating a locally adaptive model. A fully Bayesian approach is presented using multi-level hierarchical modelling and Markov chain Monte Carlo (MCMC) estimation methods to sample from the posterior distribution and hence perform estimation. The proposed methods are assessed using simulated <math><mi>γ</mi> <msup><mtext>-eye</mtext> <mrow><mtext>TM</mtext></mrow> </msup> </math> camera images and demonstrate greater noise reduction than existing methods but without compromising resolution. As well as image estimates, the MCMC methods also provide posterior variance estimates and hence uncertainty quantification takes into consideration any potential sources of variability. The use of mixture prior models, part Laplace random field and part Gaussian random field, within a Bayesian modelling approach is not limited to medical imaging applications but provides a more general framework for analysing other spatial inverse problems. Locally adaptive prior distributions provide a more realistic model, which leads to robust results and hence more reliable decision-making, especially in nuclear medicine. They can become a standard part of the toolkit of everyone working in image processing applications.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1380518"},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11440870/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Case Report: Application of ¹⁸F-FDG PET/CT in identifying plasmacytoma in monoclonal gammopathy associated peripheral neuropathy.","authors":"Jiequn Weng, Jie Lin, Chong Sun","doi":"10.3389/fnume.2024.1446780","DOIUrl":"10.3389/fnume.2024.1446780","url":null,"abstract":"<p><p>Peripheral neuropathy is a prevalent complication in plasma cell disorders, posing significant diagnostic and therapeutic challenges. This study presents three cases initially diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP). Despite initial symptom regression post-immunomodulatory treatment, the patients exhibited progressive neurological deficits. Advanced laboratory evaluation confirmed monoclonal protein presence, yet traditional diagnostic methods, including bone marrow biopsy and flow cytometry, yielded normal results. Utilizing ¹⁸F-FDG PET/CT, we identified multiple hypermetabolic vertebral lesions, which upon biopsy, confirmed the diagnosis of plasmacytoma. Our findings underscore the utility of PET/CT as a reliable diagnostic tool for monoclonal gammopathy associated neuropathy, advocating for its consideration in cases with equivocal diagnosis. When the diagnosis is in doubt, biopsy of a lesion may facilitate early and accurate diagnosis, potentially influencing treatment strategies and patient outcomes.</p>","PeriodicalId":73095,"journal":{"name":"Frontiers in nuclear medicine (Lausanne, Switzerland)","volume":"4 ","pages":"1446780"},"PeriodicalIF":0.0,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11440967/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142360726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}