Positron Emission Tomography/computed Tomography Research Articles

First in-human study of 64Cu-DOTATATE positron emission tomography/computed tomography(PET/CT) in infective endocarditis: a prospective head-to-head comparison with 18-FDG PET/CT

Abstract Background Infective endocarditis (IE) is a severe and potentially fatal condition, which can be challenging to diagnose. Positron emission tomography/computed tomography (PET/CT) with [18F]fluorodeoxyglucose ([18F]FDG) is proposed as a diagnostic tool in the ESC endocarditis guidelines, but holds limitations. Purpose To compare the tracer uptake between [64Cu]Cu-DOTATATE and [18F]FDG in patients with IE, and to examine sensitivity and specificity in patients with prosthetic valve endocarditis (PVE) or native valve endocarditis (NVE). Methods The CuDOS-study was a prospective study including 20 cases with IE (10 with PVE and 10 with NVE) and 20 controls. [64Cu]Cu-DOTATATE and [18F]FDG PET/CT were performed in all participants. Scans were read blinded to clinical data. Tracer uptakes were measured as maximum standardized uptake values (SUVmax) in each heart valve. A visual interpretation of the presence or absence of IE was recorded for [64Cu]Cu-DOTATATE and [18F]FDG, respectively. Results The median age of the cases and controls was 68 years [IQR 53-71] and 61 years [IQR 56-67], respectively. In cases and controls, 85% and 70% were men, respectively. [64Cu]Cu-DOTATATE uptake (median SUVmax [IQR]) in patients with IE was higher than in controls (2.38 [1.87-2.90] vs. 1.43 [1.30-1.56], p<0.001), although this difference was mainly driven by PVE-cases (2.99 [2.22-3.75] vs. 1.43 [1.30-1.56 (controls), p<0.001) and to a lesser extent the NVE-cases (1.78 [1.22-2.33] vs. 1.43 [1.30-1.56 (controls), p=0.079), Figure 1. The sensitivity of [64Cu]Cu-DOTATATE and [18F]FDG PET/CT in 20 cases and the 20 controls were comparable, and the specificity was 90% and 75%, respectively. The analysis of PVE versus the 20 controls showed equal sensitivity (80%) for [64Cu]Cu-DOTATATE and [18F]FDG PET/CT and a specificity of 90% and 75%, respectively. The difference in the specificity between [64Cu]Cu-DOTATATE and [18F]FDG was 15% [IQR -5.9-36%], p=0.38. Conclusion [64Cu]Cu-DOTATATE PET/CT showed relevant uptake in the infected valve in patients with infective endocarditis. [64Cu]Cu-DOTATATE had a numerically higher specificity than [18F]FDG in prosthetic valve endocarditis, although the difference was not statistically significant. Both tracers were limited in the detection of native valve endocarditis.Figure 1 [64Cu]Cu-DOTATATE and [18F]FDG

Can the presence of aortic or coronary artery calcifications in the standard of care baseline CT or PET-CT scan of patients with Hodgkin or non-Hodgkin lymphoma be used as a predictor of MACE?

Abstract Background Major adverse cardiovascular events (MACE), commonly defined as acute myocardial infarction, acute coronary syndrome/ischemic heart disease requiring revascularization, stroke, and heart failure, represent a significant cause of mortality among patients with cancer. With increased rates of both cancer and cancer survivorship, the identification of new predictive markers for the development of MACE in this population is crucial for implementing effective preventive and risk-mitigation strategies. Purpose To determine whether the presence of calcifications in the coronary arteries (CAC) or aorta (CA) of lymphoma patients, as reported in standard-of-care PET-CT (Positron Emission Tomography-Computed Tomography) or chest CT (Computed Tomography) scan, can predict the occurrence of MACE. Methods A Retrospective analysis was conducted on a cohort of patients diagnosed with Hodgkin or non-Hodgkin lymphoma and treated with anthracycline-based chemotherapy. Patients were diagnosed from January 1, 2013, and followed through to June 30, 2023. The reference point for the study was the radiologist’s report of the PET-CT or chest CT conducted before the initiation of anthracycline therapy. Patients who did not undergo a PET-CT or CT before the start of treatment, and/or developed MACE before treatment initiation were excluded. Univariate and multivariate adjusted Cox regression models were employed to assess whether the presence of CA and CAC was associated with the development of MACE. Associations with outcomes were evaluated using the Kaplan-Meier method and Cox regression. Results 326 patients were included with a mean age of 55 years (range: 52-60), predominantly male 201 (61%) and white 314 (96%), CAC was reported in 75 patients (23%) and CA in 18 (6%). In the univariate regression model, a statistically significant association was found between the presence of both CA and CAC with the risk of MACE. CAC showed a stronger association with the development of MACE than CA (HR: 3.7 [1-7.9], p=0.0005 vs HR: 2.9 [1- 8.5], p=0.050). In multivariable analysis CAC emerged as the strongest predictor of MACE (HR: 2.9 [1.3 – 6.4], p=0.01), after accounting for hypertension, diabetes, dyslipidemia, and GFR <60 (Table 1), while the association with CA attenuated (HR: 2.01 [0.7-6.5], p=0.2010) and was no longer significant (Table 2). Conclusion CAC in the standard-of-care PET/-CT scans was a predictor of MACE in lymphoma patients treated with anthracyclines, while the association with CA weakened in multivariable analyses and was likely underpowered given the small number of patients with CA. If replicated, this finding warrants closer surveillance of this group of patients and can be considered as a non-invasive cardiovascular risk marker.

Same-Day Positron Emission Tomography/Computed Tomography with 68Ga-Radiolabeled Fibroblast Activation Protein Inhibitors and 18F-Fluorodeoxyglucose Imaging for Gastrointestinal Cancers.

Objective: We investigated the clinical practicability of same-day 68Ga-radiolabeled fibroblast activation protein inhibitors (68Ga-FAPI)-first and 18F-fluorodeoxyglucose (18F-FDG) imaging and compared it with same-day 18F-FDG-first or 2-day procedures in diagnosing gastrointestinal cancers. Materials and Methods: Sixty-five patients with confirmed gastrointestinal cancers were divided into same-day 68Ga-FAPI-first group (Group A), same-day 18F-FDG-first group (Group B), and 2-day group (Group C). Low-dose CT and low injection activity were performed on 68Ga-FAPI positron emission tomography/computed tomography (PET/CT). Interval times, radiation dose, diagnostic performance, and detectability were assessed among groups. Additionally, the uptake, tumor-to-liver ratio (TLR), diagnostic efficacy, and TNM stage were compared between the two modalities. Results: The total waiting time for Group C was significantly longer than that for Group A or B (both p < 0.001). The total dose-length product and effective dose decreased in all groups. There were comparable detectability and diagnostic performance among groups (all p > 0.05). The within-group analysis in Group B indicated that 68Ga-FAPI PET/CT had higher uptake in the primary and recurrent lesions than 18F-FDG without differences in TLR, due to higher liver background on 68Ga-FAPI PET than Group A or C (both p < 0.001).68Ga-FAPI PET/CT possessed higher accuracy than 18F-FDG and changed staging in 14 patients (14/65, 21.54%). Conclusions: The same-day 68Ga-FAPI-first and 18F-FDG imaging reduced examination waiting time without increased radiation dose, simultaneously achieving excellent diagnostic performance and improving clinical staging in diagnosing gastrointestinal cancers.

Assessment of impact of left ventricular flow state on myocardial blood flow using positron emission tomography and echocardiography

Abstract Background The relationship between left ventricular (LV) mass and myocardial blood flow (MBF) has been recognized as an important physiological measure of myocardial perfusion to match global metabolic demand. However, there is little information on the association between LV flow state and MBF. Purpose To investigate impact of LV flow state on MBF. Methods The study included 104 patients undergoing cardiac positron emission tomography (PET) and echocardiography for chest pain and/or dyspnoea. CT attenuation corrected rest/regadenoson stress 13N-ammonia myocardial perfusion imaging was acquired with a PET CT camera. All images were acquired in 3-D list mode. Sixteen dynamic frames were reconstructed and analyzed with QPET software to obtain rest quantitative MBF measurements adjusted for rate-pressure product in ml/min/g, with a myocardial flow reserve (MFR) derived as the ratio of stress MBF/resting MBF. All patients had no ischaemia or infarction with LV ejection fraction ≥55%. Echocardiography was performed within 6 months of PET in clinically stable conditions allowing for. SV was measured by Doppler echocardiography using the continuity equation and was indexed by body surface area (SVi). The patients were divided to normal flow group (NFS: SVi &amp;gt; 35 ml/m2) and low flow group (LFS: SVi≤35 ml/m2). Results The mean SVi was 40 ml/m2 for NFS and 29 ml/m2 for LFS (p&amp;lt;0.001). LFS group was younger (57 ± 11 vs. 67 ± 11 years, p&amp;lt;0.001) with higher body mass index (43±8 vs. 37±8 kg/m2, p&amp;lt;0.001) and lower resting MBF (0.84±0.22 vs. 1.02±0.34 ml/min/g, p&amp;lt;0.01) than NFS groups. There were no significant differences of hypertension (81% vs. 82%, p&amp;gt; 0.05), LV mass index (82±21 vs. 88±82 g/m2, p&amp;gt;0.05), LVEF (63% vs. 65%, p&amp;gt;0.05) between LFS and NFS groups. SVi was positively associated with MBF as a whole group (r= 0.38, p&amp;lt;0.01). However, this significant association was only observed in NFS group (r=0.62, p &amp;lt;0.001), but not in LFS group (r=0.048, p= 0.46, Figure). Conclusion LFS expressed low MBF and the dissociation between SVi and MBF in comparison with NFS group suggesting potential alterations in relationships between myocardial work (SV) and oxygen consumption (MBF) in LFS. Further studies are warranted to investigate the pathophysiology behind the findings and to correlate with a long-term clinical outcome.

Sex differences in coronary atherosclerotic plaque activity using 18F-sodium fluoride positron emission tomography

Abstract Background There are sex differences in the extent, severity, and outcomes of coronary artery disease. Purpose To assess the influence of sex on coronary atherosclerotic plaque activity measured using coronary 18F-sodium fluoride (18F-NaF) positron emission tomography (PET), and to determine whether 18F-NaF PET has prognostic value in both women and men. Methods In a post-hoc analysis of observational cohort studies of patients with coronary atherosclerosis who had undergone 18F-NaF PET CT angiography, we compared the coronary microcalcification activity (CMA) in women and men. Results Baseline 18F-NaF PET CT angiography was available in 999 participants (151 (15%) women) with 4282 patient-years of follow-up. Compared to men, women had lower coronary calcium scores (116 [interquartile range, 27-434] versus 205 [51-571] Agatston units; p=0.002) and CMA values (0.0 [0.0-1.12] versus 0.53 [0.0-2.54], p=0.01). Following matching for plaque burden by coronary calcium scores and clinical comorbidities, there was no sex-related difference in CMA values (0.0 [0.0-1.12] versus 0.0 [0.0-1.23], p=0.21) and similar proportions of women and men had no 18F-NaF uptake (53.0% (n=80) and 48.3% (n=73); p=0.42), or CMA values &amp;gt;1.56 (21.8% (n=33) and 21.8% (n=33); p=1.00). Over a median follow-up of 4.5 [4.0-6.0] years, myocardial infarction occurred in 6.6% of women (n=10) and 7.8% of men (n=66). Coronary microcalcification activity greater than 0 was associated with a similarly increased risk of myocardial infarction in both women (HR: 3.83; 95% CI:1.10-18.49; p=0.04) and men (HR: 5.29; 95% CI:2.28-12.28; p&amp;lt;0.001). Conclusions Although men present with more coronary atherosclerotic plaque than women, increased plaque activity is a strong predictor of future myocardial infarction regardless of sex.Sex differences in CAD activityCase examples

Impact of CT attenuation correction on viable myocardium detection in combined SPECT and PET/CT: A retrospective cohort study.

The influence of computed tomography attenuation correction (CTAC) on the accuracy of diagnosing viable myocardium using Tc-99m-MIBI dedicated cardiac cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) combined with F-18-FDG Positron Emission Tomography/Computed Tomography (PET/CT) metabolic imaging, compared with conventional SPECT MPI, remains to be fully elucidated. To evaluate the impact of CTAC on the accuracy of diagnosing viable myocardium using Tc-99m-MIBI dedicated cardiac CZT SPECT MPI combined with F-18-FDG PET/CT, compared to conventional SPECT MPI. 193 patients underwent CZT SPECT and F-18-FDG PET/CT imaging, while 39 patients underwent conventional SPECT and F-18-FDG PET/CT imaging, with both groups utilizing CT for attenuation correction. The injured myocardium (hibernating and scarring) was quantified using the Q.PET software. After CTAC, both groups showed significant improvements in perfusion of the injured myocardial areas, particularly in the inferior wall (INF). The reduction in perfusion was more notable in the CZT SPECT group than that in the conventional group, particularly in the inferior and lateral walls. Among patients with large cardiac chambers, those undergoing MPI with CZT, with normal weights, or males, hibernating myocardium (HM) and scar post-CTAC reductions were particularly significant in the INF. If HM ≥ 10% is considered an indicator for recommended revascularization, among the 87 patients without prior cardiac bypass, 25 (28.7%) might not require revascularization treatment. Dedicated cardiac CZT SPECT and conventional SPECT MPI combined with F-18-FDG PET/CT significantly influenced the assessment of viable myocardium. The impact of CTAC was more profound in dedicated cardiac CZT SPECT, particularly in the INF region. CTAC significantly enhances the accuracy of viable myocardial assessment and may influence clinical decisions regarding revascularization therapy. Therefore, CTAC should be routinely used in dedicated cardiac CZT SPECT MPI combined with F-18-FDG PET/CT for myocardial viability diagnosis.

Laparoscopic extraperitoneal approach for lateral lymph node dissection for patients with metachronous lateral pelvic lymph node metastases following surgery for rectal cancer: a case series and short-term outcomes.

There have been few reports of a totally extraperitoneal approach for laparoscopic lateral lymph node dissection (LLND) for patients with metachronous lateral pelvic lymph node metastases following surgery for rectal cancer. Therefore, this study reports the short-term outcomes of LLND via an extraperitoneal approach. A total of 10 patients underwent LLND through a laparoscopic extraperitoneal approach in our hospital since October 2018. Patients with suspected resectable lateral lymph node recurrence after surgery for rectal cancer on computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography CT (PET-CT) were selected for this procedure. Nine of the 10 cases were completed using this procedure, but one case was converted to an intraperitoneal approach. The median operative time was 231min, and the median estimated blood loss was 10ml. There was one case of wound infection, but no other postoperative complications were seen. In one patient, no metastases were found in the retrieved lymph nodes. The short-term outcomes of LLND through a laparoscopic extraperitoneal approach were acceptable. Because this procedure can be performed without violating the peritoneum, it is less invasive than the conventional intraperitoneal approach and is useful for metachronous lateral pelvic lymph node metastases.

Pre-malignant conditions diagnosed following a positive cancer signal from a multi-cancer early detection test.

Blood-based tests for multi-cancer early detection (MCED) are being developed to facilitate the detection of various cancer types. The Detecting cancers Earlier Through Elective mutation-based blood Collection and Testing study (DETECT-A) study evaluated an MCED test in 9,911 women, age 65-75, without personal history of cancer. In a post-hoc analysis, we report on the detection of precancerous neoplasms consequent to MCED testing and follow-up. Participants with positive baseline and confirmatory MCED testing underwent 2-deoxy-2[fluorine-18] fluoro-D-glucose positron emission tomography-computed tomography (PET-CT) and diagnostic evaluation as indicated by PET-CT results. We reviewed the electronic health records of participants with a precancerous neoplasm and summarized their clinical course. MCED results were positive in 134 participants. Clinically significant pre-malignant conditions were identified in three of these participants: A 71-year-old with an ovarian mucinous cystadenoma, a 67-year-old with an appendiceal mucinous neoplasm, and a 70-year-old with colon adenomas displaying high-grade dysplasia. All three participants underwent surgical treatment and remain alive and cancer-free as of last follow up. The diagnostic evaluation of a positive MCED test may occasionally reveal clinically significant pre-cancerous conditions amenable to interventions. The frequency of such findings and their clinical impact warrants further study.

Progressive Unilateral Proptosis and [18F]FDG-Avid Lesions Connoting Aggressive Disease in Radioiodine-Refractory Differentiated Thyroid Carcinoma

AbstractRadioiodine-refractory differentiated thyroid carcinoma (RAIR-DTC) have poor prognosis as compared with radioiodine concentrating thyroid carcinoma. We present a case of follicular thyroid carcinoma presenting as a disseminated disease initially, underwent thyroid surgery and radioiodine (RAI) therapy. Following RAI, the patient developed a sudden-onset unilateral proptosis, finally diagnosed as orbital metastasis. [18F]-Fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography identified FDG-avid metastatic lesions more numerous than the RAI-avid lesions. The patient was treated with local and systemic targeted therapy, but despite these treatments, he developed progressive disease indicating aggressive nature of the disease consistent with [18F]FDG-avid RAIR-DTC.

Imaging in Large Vessel Vasculitis-A Narrative Review.

Vasculitis refers to a group of rare conditions characterized by the inflammation of blood vessels, affecting multiple systems. It presents a diagnostic and therapeutic challenge due to its broad clinical manifestations. Vasculitis is classified based on the size of the affected vessels: small, medium, large, or variable-sized. Large vessel vasculitis (LVV), particularly giant cell arteritis (GCA) and Takayasu arteritis (TAK), has garnered attention due to its significant morbidity and mortality. Both conditions involve immune-mediated inflammation of the vascular wall, despite differing in epidemiology and presentation. Early identification is crucial to prevent complications like organ ischemia and hemorrhage. Diagnostic accuracy can be hampered by false negative results, making comprehensive investigation essential. Vascular imaging, including computed tomography angiography (CTA), ultrasound (US), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT), is key in diagnosing vasculitis, revealing vessel wall thickening and other suggestive features. This article reviews typical and atypical CT and CTA findings in LVV, discusses imaging modalities, and highlights their role in therapeutic management and prognosis. It emphasizes the importance of a multidisciplinary approach and the critical role of radiologists in improving patient outcomes in LVV.

Granulomatosis with polyangiitis with lacrimal gland enlargement and pancreatic swelling: case report and literature review.

A 62-year-old man had bilateral eyelid swelling for 4 months. Two months before admission, he developed fatigue and lost 5 kg of bodyweight. Further examination revealed elevated serum C-reactive protein, normal angiotensin-converting enzyme, elevated proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA), and normal IgG4 concentration. Chest X-ray and computed tomography showed no enlarged hilar lymph nodes, but positron emission tomography-computed tomography showed fluorodeoxyglucose accumulation in both lacrimal glands, in lung nodules, and in the pancreas. Tissue biopsies of the lacrimal glands and pulmonary nodules showed granuloma with giant cells, but no IgG4-positive cells or fibrosis. Pancreatic tissue showed no findings of autoimmune pancreatitis. In the 2022 ACR/EULAR classification criteria for granulomatosis with polyangiitis, the total score was 10 points. Final comprehensive diagnosis was granulomatosis with polyangiitis, based on the negative results of differential diseases, such as IgG4-related diseases and sarcoidosis. Prednisolone 60 mg/day was started on day 8, and rituximab 500 mg/body/week on day 12. After beginning treatment, general malaise and lacrimal gland enlargement were resolved, PR3-ANCA and C-reactive protein became negative, and the nodular shadow in the lungs disappeared. This is the first report of granulomatosis with polyangiitis presenting both lacrimal gland and pancreatic lesions.

Metabolic tumor volume assessed by 18F FDG - PET CT scan as a predictive biomarker for immune checkpoint blockers in advanced NSCLC and its biological correlates.

This study aimed to explore metabolic tumor volume (tMTV) as assessed 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT), and understand its biological meaning in patients with NSCLC exposed to immune checkpoint blockers(ICBs). In this study, patients with advanced NSCLC and a positive PET scan within 42 days of first line treatment were enrolled in 11 institutions across 4 countries. Total MTV (tMTV) was analyzed, with a 42% SUVmax threshold. Survival was analyzed according to high tMTV (≥ median). Plasma proteomic profile, whole exome, transcriptome and other analysis were performed on monocentric cohorts to explore its biological correlates. Of the 518 patients included, 167 received ICBs, 257 had chemotherapy plus ICBs, and 94 had chemotherapy. Median tMTV was 99 cm3. Median overall survival (OS) for patients with high tMTV treated with ICBs was 11.4 months vs 29.6 months (P<0.0012) for those with low tMTV. In patients receiving chemotherapy-ICB tMTV did not correlate with OS (P=0.099). In patients with PD-L1≥1% and high tMTV, chemotherapy-ICB combination was associated with longer OS compared with ICBs alone (20 vs 11.4 months,p=0.026), while no survival differences observed in low tMTV group. High tMTV correlated (and its detrimental effect seems to be driven by) a specific proteomic profile and increase in genomic instability. Our analysis indicates high tTMV is linked to an increase in systemic inflammation, specific cytokines production and chromosomal instability. tTMV may serve as one of the biomarker to select the best upfront strategy in patients with PD-L1 positive advanced NSCLC.

Fibroblast activation protein inhibitor PET/CT as an emerging diagnostic modality in interstitial lung disease and other fibrotic conditions.

Interstitial lung diseases (ILD) encompass a wide range of disorders characterized by alveolar inflammation and fibrotic tissue remodeling, marked by significant morbidity and mortality. Systemic sclerosis (SSc), among other connective tissue diseases, is a frequent cause of ILD. Assessment of pulmonary fibrosis is frequently constrained by the delayed manifestations of profibrotic activation of fibroblasts, which results in late macroscopic alterations detectable by standard imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) scans. 68Ga-labeled fibroblast activation protein inhibitors (68Ga-FAPI [fibroblast activation protein inhibitor]) are novel radionuclides used in the selective positron emission tomography/computed tomography (PET/CT) detection of profibrotic fibroblasts, a key player in fibrotic tissue remodeling. Application of 68Ga-FAPI in different target organs undergoing fibrosis, such as lung and heart, highlights its efficacy in detecting ongoing fibrotic processes, since FAPI tracer uptake has been correlated with clinical disease progression markers in SSc-ILD. This feature could enable physicians to detect subclinical fibrotic activity and tailor an individualised therapy plan on a case by case basis. The use of 68Ga-FAPI in ILD and other fibrotic conditions may emerge as a novel tool in future clinical practice for both activity monitoring and treatment optimisation. Other tracers tested in ILD of different etiologies have shown promising results and may in future also be considered for potential application in SSc-ILD.

Uncommon Presentation of Multiple Myeloma: Pleural Effusion and Extensive Extramedullary Involvement

A 60-year-old female presented with abdominal pain, weight loss, and fatigue. Imaging revealed a pancreatic mass, bilateral pleural effusion, ascites, and lytic bony lesions. Investigations confirmed multiple myeloma with lambda light chain disease. Positron emission tomography-computed tomography (PET-CT) scan demonstrated extensive metabolically active soft tissue masses involving the pancreatic region, retroperitoneum, mediastinum, paravertebral regions, and multiple skeletal lesions with extraosseous soft tissue involvement, along with bilateral pleural effusions with metabolically active pleural and extrapleural deposits. The patient was initiated on a bortezomib, cyclophosphamide, and dexamethasone chemotherapy regimen with therapeutic thoracentesis for pleural effusion management. After two cycles, the patient showed remarkable clinical improvement. A repeat PET-CT scan revealed significant interval regression of soft tissue masses, metabolic activity resolution, and regression of pleural and extrapleural deposits. The extensive skeletal lytic lesions showed morphological stability but regression of associated metabolic activity and extraosseous soft tissue. This case highlights the potential of novel agent-based regimens in achieving exceptional responses in multiple myeloma patients with extensive extramedullary disease (EMD), including uncommon manifestations like pleural effusion. Early recognition and prompt initiation of appropriate therapy are crucial for improving outcomes in such cases.

Positron Emission Tomography/Computed Tomography Imaging in Therapeutic Clinical Trials in Alzheimer's Disease: AnOverview of the Current State of the Artof Research.

The integration of positron emission tomography/computed tomography (PET/CT) has revolutionized the landscape of Alzheimer's disease (AD) research and therapeutic interventions. By combining structural and functional imaging, PET/CT provides a comprehensive understanding of disease pathology and response to treatment assessment. PET/CT, particularly with 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG), facilitates the visualization of glucose metabolism in the brain, enabling early diagnosis, staging, and monitoring of neurodegenerative disease progression. The advent of amyloid and tau PET imaging has further propelled the field forward, offering invaluable tools for tracking pathological hallmarks, assessing treatment response, and predicting clinical outcomes. While some therapeutic interventions targeting amyloid plaque load showed promising results with the reduction of cerebral amyloid accumulation over time, others failed to demonstrate a significant impact of anti-amyloid agents for reducing the amyloid plaques burden in AD brains. Tau PET imaging has conversely fueled the advent of disease-modifying therapeutic strategies in AD by supporting the assessment of neurofibrillary tangles of tau pathology deposition over time. Looking ahead, PET imaging holds immense promise for studying additional targets such as neuroinflammation, cholinergic deficit, and synaptic dysfunction. Advances in radiotracer development, dedicated brain PET/CT scanners, and Artificial Intelligence-powered software are poised to enhance the quality, sensitivity, and diagnostic power of molecular neuroimaging. Consequently, PET/CT remains at the forefront of AD research, offering unparalleled opportunities for unravelling the complexities of the disease and advancing therapeutic interventions, although it is not yet enough alone to allow patients' recruitment in therapeutic clinical trials.

18F-FDG-PET/CT Scan for Detection of Large Vessel Involvement in Giant Cell Arteritis: Arteser Spanish Registry.

Background/Objectives: Imaging studies have transformed the diagnosis of large vessel vasculitis (LVV) involvement in giant cell arteritis (GCA). A positron emission tomography/computed tomography (PET/CT) scan with 18-fluorodeoxyglucose (18F-FDG) has emerged as a valuable tool for assessing LVV. We aimed to determine the utility of an 18F-FDG-PET/CT scan in detecting LVV in GCA in the ARTESER registry. Methods: The ARTESER study is a large multicenter, retrospective, longitudinal, and observational study, promoted by the Spanish Society of Rheumatology. It included patients newly diagnosed with GCA across 26 tertiary hospitals from 1 June 2013 to 29 March 2019. Patients with a diagnosis of incidental GCA were included if they fulfilled specific criteria, including the ACR 1990 criteria, positive imaging examinations, or the expert clinical opinion of investigators. Differences between patients with positive and negative 18F-FDG-PET/CT scan results were analyzed using a bivariate model. A regression model assessed associations in patients with a positive scan, and the predictive capacity of the cumulative dose of glucocorticoids (GC) on PET scan outcomes was evaluated using ROC curve analysis. Results: Out of 1675 GCA patients included in the registry, 377 met the inclusion criteria of having an 18F-FDG-PET/CT scan. The majority were diagnosed with a cranial GCA phenotype, and 65% had LVV. The thoracic aorta was the most frequently affected. Cardiovascular disease, diabetes, and older age had a negative association with a positive scan outcome. The OR for having a positive 18F-FDG-PET/CTC scan was lower as the number of days increased. Depending on the cumulative dosage of the GC, the 18F-FDG-PET/CT scan showed an AUC of 0.74, with a Youden index > 60 mg/day. Conclusions: Younger patients showed a higher probability of presenting LVV as detected by the 18F-FDG-PET/CT scan. The timing of the examination and the cumulative dosage of the GC influenced the likelihood of a positive result, with earlier tests being more likely to detect inflammation.

Enhancing Lymphoma Diagnosis, Treatment, and Follow-Up Using 18F-FDG PET/CT Imaging: Contribution of Artificial Intelligence and Radiomics Analysis.

Lymphoma, encompassing a wide spectrum of immune system malignancies, presents significant complexities in its early detection, management, and prognosis assessment since it can mimic post-infectious/inflammatory diseases. The heterogeneous nature of lymphoma makes it challenging to definitively pinpoint valuable biomarkers for predicting tumor biology and selecting the most effective treatment strategies. Although molecular imaging modalities, such as positron emission tomography/computed tomography (PET/CT), specifically 18F-FDG PET/CT, hold significant importance in the diagnosis of lymphoma, prognostication, and assessment of treatment response, they still face significant challenges. Over the past few years, radiomics and artificial intelligence (AI) have surfaced as valuable tools for detecting subtle features within medical images that may not be easily discerned by visual assessment. The rapid expansion of AI and its application in medicine/radiomics is opening up new opportunities in the nuclear medicine field. Radiomics and AI capabilities seem to hold promise across various clinical scenarios related to lymphoma. Nevertheless, the need for more extensive prospective trials is evident to substantiate their reliability and standardize their applications. This review aims to provide a comprehensive perspective on the current literature regarding the application of AI and radiomics applied/extracted on/from 18F-FDG PET/CT in the management of lymphoma patients.

Clinical development and proof of principle testing of new regenerative vascular endothelial growth factor-D therapy for refractory angina: rationale and design of the phase 2 ReGenHeart trial

BackgroundDespite tremendous therapeutic advancements, a significant proportion of coronary artery disease patients suffer from refractory angina pectoris, that is, quality-of-life-compromising angina that is non-manageable with established pharmacological and interventional treatment...

Prognostic Role of PSMA-Targeted Imaging in Metastatic Castration-Resistant Prostate Cancer: An Overview.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has gained a primary role in prostate cancer (PCa) imaging, overcoming conventional imaging and prostate-specific antigen (PSA) serum levels, and has recently emerged as a promising technique for monitoring therapy response in metastatic castration-resistant prostate cancer (mCRPC) patients treated with novel hormonal therapy, taxanes, and radioligand therapy (RLT). In this review, we aim to provide an overview of the most relevant aspects under study and future prospects related to the prognostic role of PSMA PET/CT in mCRPC. A systematic literature search was performed in the following databases: MEDLINE, PubMed, and EMBASE databases. The study focused exclusively on English-language studies, excluding papers not pertinent to the topic. PSMA PET imaging offers a higher sensitivity and specificity than conventional imaging and provides accurate staging and efficient diagnosis of distant metastases. The data presented herein highlight the usefulness of PET in risk stratification, with a prognostic potential that can have a significant impact on clinical practice. Several prospective trials are ongoing and will shortly provide more evidence supporting the prognostic potential of PET PSMA data in this clinical scenario. Current evidence proves the prognostic role of PSMA PET/CT in different settings, with raising relevance also in the context of mCRPC.

Prognostic evaluation using radiomics after stereotactic body radiotherapy in early-stage lung cancer

Non-small cell lung cancer (NSCLC), the leading cause of cancer-related deaths, is the most common subtype of lung cancer with an incidence of 85%. Stereotactic body radiotherapy (SBRT) is a curative treatment option for patients with early-stage NSCLC who cannot undergo surgery due to medical reasons or who refuse surgery. Radiomics non-invasively extracts advanced imaging features invisible to the human eye from medical images. Radiomics has prognostic value in predicting oncological outcomes after lung SBRT. Although studies on this subject are available in the literature, they are quite heterogeneous. There is a need for large-scale multicenter studies in which standard imaging techniques are used to obtain radiomic features, artificial intelligence-based segmentations are used to eliminate differences between contours, and SBRT dose schemes with appropriate therapeutic indexes are applied. This review aimed to interpret the existing studies and emphasize the clinical importance of radiomics, which can contribute to personalized treatment. A comprehensive literature search was conducted through the PubMed database using a wide range of keywords, which yielded 11 peer-reviewed articles published between 2017 and 2024. Seven articles evaluated computed tomography radiomics, and four evaluated fluorodeoxyglucose positron emission tomography-computed tomography radiomics. Oncological outcomes are not always identical in patients with a similar history receiving similar treatments at the same stage and age. Clinical, demographic, or treatment-related data are insufficient to predict prognosis and determine personalized treatment. Incorporating radiomics to these data can help establish models with higher accuracy and achieve personalized treatment.