1,721,010 research outputs found
Artificial intelligence & nuclear medicine: an emerging partnership
No full textThis letter addresses a recently published article evaluating the performance of 3D U-Net–based deep learning models for automated lesion segmentation in PET/CT imaging. The study represents a significant advancement in the integration of artificial intelligence (AI) into Nuclear Medicine. By comparing volumetric, MIP-based, and hybrid segmentation approaches using [18F]FDG and [68Ga]Ga-PSMA radiotracers, the authors demonstrate that hybrid models can enhance lesion detection and contouring accuracy. These findings underscore the potential of AI-based segmentation to improve consistency and reduce the manual workload in clinical PET/CT interpretation. We consider this work a pivotal step toward the clinical adoption of AI tools, offering tangible benefits for routine practice and radiomic analysis, while preserving the essential supervisory role of the Nuclear Medicine Physician
99mTc-labeled FAPI compounds for cancer and inflammation: from radiochemistry to the first clinical applications
No full textBackground: In recent years, fibroblast activating protein (FAP), a biomarker overexpressed by cancer-associated fibroblasts, has emerged as one of the most promising biomarkers in oncology. Similarly, FAP overexpression has been detected in various fibroblast-mediated inflammatory conditions such as liver cirrhosis and idiopathic pulmonary fibrosis. Along this trajectory, FAP-targeted positron emission tomography (PET), utilizing FAP inhibitors (FAPi) labeled with positron emitters, has gained traction as a powerful imaging approach in both cancer and inflammation. However, PET represents a high-cost technology, and its widespread adoption is still limited compared to the availability of gamma cameras. To address this issue, several efforts have been made to explore the potential of [99mTc]Tc-FAPi tracers as molecular probes for imaging with gamma cameras and single photon emission computed tomography (SPECT). Main body: Several approaches have been investigated for labeling FAPi-based compounds with 99mTc. Specifically, the mono-oxo, tricarbonyl, isonitrile, and HYNIC strategies have been applied to produce [99mTc]Tc-FAPi tracers, which have been tested in vitro and in animal models. Overall, these labeling approaches have demonstrated high efficiency and strong binding. The resulting [99mTc]Tc-FAPi tracers have shown high specificity for FAP-positive cells and xenografts in both in vitro and animal model studies, respectively. However, the majority of [99mTc]Tc-FAPi tracers have exhibited variable levels of lipophilicity, leading to preferential excretion through the hepatobiliary route and undesirable binding to lipoproteins. Consequently, efforts have been made to synthesize more hydrophilic FAPi-based compounds to improve pharmacokinetic properties and achieve a more favorable biodistribution, particularly in the abdominal region. SPECT imaging with [99mTc]Tc-FAPi has yielded promising results in patients with gastrointestinal tumors, demonstrating comparable or superior diagnostic performance compared to other imaging modalities. Similarly, encouraging outcomes have been observed in subjects with gliomas, lung cancer, breast cancer, and cervical cancer. Beyond oncological applications, [99mTc]Tc-FAPi-based imaging has been successfully employed in myocardial and idiopathic pulmonary fibrosis. Conclusions: This overview focuses on the various radiochemical strategies for obtaining [99mTc]Tc-FAPi tracers, highlighting the main challenges encountered and possible solutions when applying each distinct approach. Additionally, it covers the preclinical and initial clinical applications of [99mTc]Tc-FAPi in cancer and inflammation
The impact of PET imaging on triple negative breast cancer: an updated evidence-based perspective
No full textIntroductionTriple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by the absence of estrogen, progesterone, and HER2 receptors. It predominantly affects younger women and is associated with a poor prognosis. This systematic review aims to evaluate the current role of positron emission tomography (PET) in the management of TNBC patients and to identify future research directions.MethodsWe systematically searched the PubMed, Scopus, and Web of Science databases up to February 2024. A team of five researchers conducted data extraction and analysis. The quality of the selected studies was assessed using a specific evaluation form.ResultsTwenty-eight studies involving 2870 TNBC patients were included in the review. Key clinical applications of PET in TNBC included predicting pathological complete response (pCR) in patients undergoing neoadjuvant chemotherapy (NAC), assessing the prognostic value of baseline PET, and initial disease staging. Two studies utilized PSMA-ligand agents, while the majority used [18F]FDG-based PET. Significant associations were found between baseline [18F]FDG uptake and molecular biomarkers such as PDL-1, androgen receptor, and Ki67. Baseline [18F]FDG PET led to the upstaging of patients from stage IIB to stage IV, influencing treatment decisions and survival outcomes. In the NAC setting, serial PET scans measuring changes in [18F]FDG uptake, indicated by maximum standardized uptake value (SUVmax), predicted pCR with varying cut-off values correlated with different response rates. Semiquantitative parameters such as metabolic tumor volume (MTV) and PET lung index were prognostic for metastatic disease.ConclusionsIn TNBC patients, [18F]FDG PET is essential for initial disease staging in both localized and metastatic settings. It is also useful for assessing treatment response to NAC. The ability of PET to correlate metabolic activity with molecular markers and predict treatment outcomes highlights its potential in TNBC management. Further prospective studies are needed to refine these clinical indications and establish its definitive role
Considerations on the preliminary results of the NETTER-2 trial: is the glass half full or half empty?
No full textConsiderations on the preliminary results of the NETTER-2 trial: is the
glass half full or half empty
Phosphorus-32 microparticles for locally advanced pancreatic cancer: how and when?
No full textPhosphorus-32 microparticles for locally advanced pancreatic cancer: how and
when
Synthetic imaging for research and education in nuclear medicine: Who’s afraid of the black box?
No full textNot availabl
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Girentuximab imaging in renal cancer: diamond in the rough or just ZIRCON?
No full textSmall renal masses (SRM), especially those under 7 cm pose significant diagnostic challenges when
using conventional imaging (CT/MRI). PET/CT with [89Zr]Zr-girentuximab offers a promising alternative
in this setting by enabling molecular-level imaging. The ZIRCON trial, a phase 3 multicenter study,
evaluated the diagnostic accuracy of [89Zr]Zr-girentuximab PET/CT in detecting clear cell renal cell
carcinoma (ccRCC) in SRM. A total of 300 patients with indeterminate renal masses received a single
intravenous dose of [89Zr]Zr-girentuximab, followed by PET/CT imaging 5 days post-injection. Generally,
sensitivity and specificity for ccRCC detection were 85.5% and 87.0%, respectively. However, smaller
masses (maximum diameter: ≤4 cm) demonstrated strong diagnostic performance, with mean sensitivity
and specificity of 85% and 89.5%, respectively. PET positivity was observed exclusively in malignant
lesions. Nevertheless, both benign and malignant non-ccRCC tumors are ‘cold’ at [89Zr]Zr-girentuximab,
thus differential diagnosis remains an unresolved issue. Despite its strengths, the trial highlights
limitations: restricted imaging scope to the abdomen, lack of a cost-effectiveness analysis, concerns
over radiation exposure given zirconium-89’s 78.4-h half-life, and the daily scheduling of the examination.
Only further studies and time will reveal whether the ZIRCON trial’s findings will shine like
a diamond or remain akin to zircon – brilliant but constrained in value
Molecular Imaging in Cancer Chemoresistance: What's Brewing?
No full text: Cancer therapy has advanced with molecularly targeted approaches and immunotherapy, yet chemotherapy remains essential for many aggressive cancers, including breast, lung, ovarian, pancreatic, bladder, sarcoma, and lymphomas. A major challenge is chemoresistance, in which cancer cells evade chemotherapy's cytotoxic effects. Overexpression of adenosine triphosphate-binding cassette transporters, especially P-glycoprotein, significantly contributes to this resistance. Thus, imaging biomarkers are urgently needed to detect P-glycoprotein overexpression in vivo, identify resistant cancer cell clones, and map their distribution and heterogeneity within tumors. This article reviews the applications of SPECT, PET, and optical imaging in addressing chemoresistance. It emphasizes the potential of these modalities to enhance cancer treatment by enabling early identification of resistant clones and improving therapeutic strategies. The article outlines key steps required for the integration of molecular imaging into clinical practice, aiming to overcome chemoresistance and optimize patient outcomes
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