World Journal of Nuclear Medicine最新文献

Objectives: The objective of this study was to assess the performance of positron emission tomography/magnetic resonance imaging (PET/MRI) compared with PET/computed tomography (PET/CT) in the clinical management of patients with neoplastic hepatic lesions.

Materials and methods: This is a retrospective study and includes a sample size of 15 patients, referred for diagnostic evaluation and staging of neoplastic hepatic lesions. The patients included in this study underwent a simultaneous PET/CT scan on uMI-Vista and a complementary liver PET/MRI scan on uPMR 790. PET/CT and PET/MRI were compared based on the number of detected lesions, the smallest detected lesion diameter, and tumor-to-liver ratio (TLR). The histopathological analysis was considered the standard of reference.

Results: PET/MRI reported extra information in 87% (13/15) of patients, and additional lesions were identified in 73% (11/15) of patients. Furthermore, PET/MRI could identify subcentimeter liver lesions and added great value in the evaluation of lesion viability. Overall, 40 additional lesions were detected with PET/MRI in contrast with PET/CT within the given patient cohort. The smallest revealed lesion measured 2 mm in the long-axis diameter, and the average long-axis diameter of small lesions detected by PET/MRI across 15 patients was 3.4 mm with a standard deviation of 1.3 mm. These findings significantly affected the final outcomes in 12 out of 15 patients, leading to modifications in the response assessment category in 5 patients and defined the malignant hepatic lesions on staging/restaging scans (10/15).

Discussion: PET/MRI has been found to outperform PET/CT in terms of conspicuity of liver lesions, with better sensitivity and specificity. Overall, coregistered PET and MR images have been shown to outperform PET/CT in the imaging of liver lesions, with better delineation of small lesions as well as reliable localization of lesions to the corresponding liver segment.

Conclusion: In addition to a significant decrease in radiation exposure, the PET/MRI combination resulted in higher detection rates and more precise characterization of small malignant liver lesions and tends to be more powerful than PET/CT, which has a direct impact on the patient's diagnosis, staging, and further therapeutic strategies.

Introduction: Protein losing enteropathy (PLE) is usually a diagnosis of exclusion, which requires cumbersome tests to confirm. In the quest for a simpler diagnostic test, we hypothesized that a spot stool sample estimation of α-1 antitrypsin will be sufficient to make a diagnosis of PLE, if we control for serum α-1 antitrypsin concentration and degree of stool dilution.

Materials and methods: Consecutive patients with a clinical suspicion of PLE and who had been advised a scintigraphy study were recruited after getting informed consent. The study excluded patients less than 1 year of age, pregnant women, and those with a clinical suspicion of chronic pancreatitis. Serum α-1 antitrypsin, spot stool α-1 antitrypsin, and stool elastase was assessed in all the patients. The diagnostic value of the index test was estimated from the patients with positive scintigraphy scan compared with a negative scan, expressed as sensitivity and specificity and the area under the receiver operating characteristic curve (AUROC).

Result: A total of 33 patients underwent scintigraphy with a clinical suspicion of PLE. Twenty patients (60%) showed tracer activity in the gut suggestive of PLE. Spot stool α-1 antitrypsin below 0.26 mg/g had a sensitivity of 100% to rule out PLE; however, the specificity was only 46%. Spot stool α-1 antitrypsin/(serum α-1 antitrypsin * elastase) ratio performed similar to spot stool α-1 antitrypsin as a diagnostic test (AUROC: 0.814 [0.61-1.0] vs. 0.796 [0.54-1.0]).

Conclusion: Random stool antitrypsin is a sensitive test for diagnosing PLE; however, it lacks specificity. Spot stool α-1 antitrypsin/(serum α-1 antitrypsin * stool elastase) does not provide any additional value in the diagnosis of this syndrome.

Background: Association of [ ^99m Tc]Tc-pyrophosphate (PYP) uptake with survival of cardiac amyloidosis (CA) is still unknown. This study aimed to describe the scintigraphic findings of CA suspected cases and determine the prognostic value of scintigraphy.

Methods: Between September 2020 and December 2023, all [ ^99m Tc]Tc-PYP scintigraphy images of CA suspected cases were evaluated retrospectively. The scintigraphy images were obtained 1 and 3 hours after intravenous injection of 740 MBq [ ^99m Tc]Tc-PYP. The quantitative and semiquantitative results of scintigraphy were analyzed, and their correlation with survival was evaluated.

Results: Among the 268 cases (147 females, 121 males; median age: 65), 12 (4.5%) were diagnosed with transthyretin (ATTR) CA and 19 (7.1%) with light chain (AL) CA. The median follow-up time was 386 days. ATTR CA cases exhibited significantly higher [ ^99m Tc]Tc-PYP uptake than AL CA and non-CA cases. The 1- and 3-hour heart-to-contralateral lung ratios were positively highly correlated with each other, and SPECT/CT (single-photon computed tomography/computed tomography) imaging reduced equivocal results from 82 to 37%. Eight of the AL CA cases (42.1%), 1 ATTR CA case (8.3%), and 15 of non-CA cases (6%) died on follow-up. Median survival was 22 days in ATTR CA, 201 days in AL CA, and 105 days in non-CA deceased cases. Survival analysis indicated significantly lower survival in non-CA cases compared with ATTR CA and AL CA.

Conclusion: [ ^99m Tc]Tc-PYP scintigraphy is highly sensitive and specific for detecting ATTR CA and differentiating from AL CA. Even in the absence of a diagnosis of CA, the fact that survival may be short in cases with high uptake on scintigraphy should be considered in the follow-up of these cases.

Background: Colorectal cancer (CRC) ranks among the leading causes of cancer-related mortality worldwide. Accurate detection of lymph node metastases plays a crucial role in determining disease stage and guiding treatment decisions. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET/magnetic resonance imaging (MRI) are advanced imaging modalities widely used in clinical practice. The study aimed to compare the diagnostic accuracy of [ ¹⁸ F]FDG PET/CT and [ ¹⁸ F]FDG PET/MRI in detecting lymph node metastases in CRC patients.

Methods: A comprehensive literature search was conducted across PubMed, Embase, and Web of Science databases to identify relevant studies published up to February 2025. Inclusion criteria encompassed studies evaluating the diagnostic performance of [ ¹⁸ F]FDG PET/CT and [ ¹⁸ F]FDG PET/MRI for detecting lymph node metastases in CRC patients. Sensitivity and specificity were analyzed using the DerSimonian and Laird random-effects model, with results adjusted by the Freeman-Tukey double arcsine transformation. The quality of the included studies was appraised using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

Results: This meta-analysis incorporated 24 studies with a cumulative total of 3,369 patients. The findings revealed that [ ¹⁸ F]FDG PET/CT exhibited significantly lower sensitivity (0.75 vs. 0.93, p  = 0.0096) and a lower AUC value (0.81 vs. 0.96) compared with [ ¹⁸ F]FDG PET/MRI in detecting lymph node metastases among CRC patients. Both [ ¹⁸ F]FDG PET/CT and [ ¹⁸ F]FDG PET/MRI demonstrated similar specificity (0.77 vs. 0.88, p  = 0.1892). Furthermore, the funnel plot asymmetry test indicated no significant publication bias across any of the outcomes (Egger's test: all p  > 0.05).

Conclusions: Our meta-analysis demonstrated that [ ¹⁸ F]FDG PET/MRI has higher sensitivity and comparable specificity to [ ¹⁸ F]FDG PET/CT in detecting lymph node metastases in CRC patients, suggesting its potential superiority for preoperative staging and postoperative surveillance. However, the limited number of direct head-to-head studies (only two) underscores the need for larger, prospective studies to validate these findings and assess their impact on clinical decision-making and patient outcomes.

Objective: Epilepsy, a prevalent neurological disorder in children, manifests through recurrent seizures due to abnormal neuronal activity. Drug-resistant epilepsy (DRE) is a significant clinical challenge, often necessitating advanced diagnostic approaches to optimize treatment strategies. Single photon emission computed tomography (SPECT) imaging, particularly using the radiopharmaceutical 99mTc-ethyl cysteinate dimer (99mTc-ECD), offers potential in localizing epileptogenic zones, especially when conventional magnetic resonance imaging (MRI) and electroencephalography (EEG) findings are inconclusive. This study was performed to evaluate patterns of brain perfusion using 99mTc-ECD SPECT in children aged < 18 years diagnosed with DRE, and to correlate these findings with clinical evaluations, MRI, and video EEG reports.

Materials and methods: A descriptive observational study was conducted over 18 months on 60 children with DRE. Each participant underwent a detailed clinical history, video EEG, MRI, and a 99mTc-ECD brain perfusion SPECT scan. The SPECT images were analyzed visually and semiquantitatively for hypoperfusion and hyperperfusion patterns. Data were cross-referenced with clinical lateralization, MRI findings, and EEG results to assess concordance.

Results: A total of 60 children with DRE and mean age of 11.02 + 3.8 years (1-< 18 years) including 16 (26.7%) female and 44 (73.3%) male patients were prospectively analyzed. Forty of 60 (66.7%) patients had normal MRI brain study and 23/60 (38.3%) patients had normal EEG records. Medial temporal lobe hypoperfusion was seen in all patients, while 16/60 (26.67%) patients had additional foci of hyperperfusion in left frontal lobe and 14/60 (23.3%) patients in right frontal lobe. Thirty-six of 60 (60%) patients had involvement of one hemisphere, 24/60 (40%) showed perfusion abnormalities in both hemispheres. Moderate to severe hypoperfusion was seen in left temporal lobe in 39/60 (65%) patients whereas 30/60 (50%) patients showed moderate to severe hypoperfusion in right temporal lobe. SPECT findings were concordant with EEG in 16/60 (26.67%) of cases and concordant MRI, EEG, and 99mTc-ECD was seen in 5/60 (8.3%) cases.

Conclusion: 99mTc-ECD brain perfusion SPECT is a valuable diagnostic tool in the comprehensive evaluation of pediatric DRE. It enhances lateralization and localization of epileptogenic zones, especially when conventional imaging is nondiagnostic. Interictal brain SPECT, is easily available, indispensable, and complementary in diagnosis. Combining it with clinical and electrophysiological evaluation can significantly improve clinical outcome and management of patients with DRE.

Theranostics is a rapidly growing field, providing new therapeutic options for cancer patients. Clinical trials have a key role in establishing the efficacy and safety of new treatments and determining impact on patient care. Multicenter clinical trials with radiopharmaceuticals provide robust data to support clinical implementation; however, there are important considerations to ensure high-quality and reliable clinical data. Australasian Radiopharmaceutical Trials Network (ARTnet) is a multidisciplinary clinical trials network established in 2014 to facilitate multicenter clinical trials with radiopharmaceuticals in Australia. Over the last decade, ARTnet has supported impactful, prospective clinical trials through quality activities and engagement. In theranostics, Australia has had a key role in clinical translation and generating evidence for safety and efficacy, resulting in regulatory approval and health care funding internationally. This report describes the development of ARTnet as a clinical trials network, highlighting the intent, current status, and operations of ARTnet, with a particular focus on theranostics.

There is a global rise in the number of new cancer diagnoses and cancer deaths. Rising new cancer diagnoses and deaths from low- and middle-income countries (LMICs) are the biggest contributors to this global trend. Efforts geared toward prevention, timely diagnosis, effective treatment, and efficient cancer survivorship programs are needed to address the rising scourge of cancer in LMICs. Radiotheranostics entails using radiopharmaceuticals for diagnostic imaging and therapy of diseases. Functional imaging, as in radiotheranostics, is more sensitive for disease detection and treatment response assessment than conventional cross-sectional imaging. Therefore, radiotheranostics has the potential to address some of the strategies to curtail the rising scourge of cancer and its mortality in LMICs, including timely diagnosis, effective management, and disease surveillance. Many key issues hinder the widespread availability, access, and utilization of nuclear medicine (NM) and radiotheranostics services in LMICs. These issues include scarcity of trained (NM) professionals, lack of training for (NM) personnel, poor infrastructure, inadequate awareness of NM and radiotheranostics, poor funding, and poorly conceived regulations that stifle NM practice. Despite these hindrances, many success stories have emerged from LMICs regarding clinical application of radiotheranostics. For example, many practice-defining studies have been published by groups from LMICs regarding prostate-specific membrane antigen-targeted imaging and therapy of prostate cancer. Specifically, notable contributions have been made to the literature by groups from South Africa, India, and Türkiye on the safety and efficacy of 225Ac-PSMA-617 for therapy of advanced prostate cancer. Through the intervention of many international organizations, governments, and private sectors, there has been a steady improvement in the awareness, availability, access, and utilization of NM and radiotheranostics services in LMICs.

Neuroblastoma is the most common extracranial solid tumor in children. Tumor heterogeneity is a hallmark of neuroblastoma and prognosis can be dismal in the presence of high-risk factors such as N-myc gene amplification, aneuploidy, genetic rearrangement, and age at presentation. I-131 MIBG therapy has traditionally been the radionuclide therapy agent used in pediatric neuroblastoma and is incorporated in many treatment protocols. The high cost and limited availability of I-131 MIBG and the required radiation safety measures are barriers to its widespread use. LuTATE has emerged as a more practical radionuclide therapy agent requiring less stringent radiation safety measures and coupled with GaTATE PET/CT forms a potentially useful theranostic pairing for children with neuroblastoma. LuTATE therapy in adults with neuroendocrine tumors uses an empiric dosing schedule with good results. However, a previous study using empiric dosing of LuTATE in pediatric neuroblastoma was not shown to be effective. We present our use of individualized patient dosimetry to optimize the dose of LuTATE in three children with relapsed/resistant neuroblastoma.

Theranostics and clinical trials are driving the future of nuclear medicine and require a multidisciplinary approach to achieve the best possible care for the patient. Theranostics refers to using chemical compounds with similar diagnostic and radiotherapeutic applications. Therefore, the biodistribution remains the same for the imaging and therapy portions, a low radiation dose being delivered during imaging, and a higher radiation dose being delivered to the target disease areas during the treatment phase. The new era of theranostics has revolutionized nuclear medicine through the prospective phase 3 clinical trials, which have resulted in its adoption into the treatment paradigms of patients, particularly those with neuroendocrine tumors and prostate cancer. Molecular imaging can be used to assess the role and utility of new tracers and molecular endpoints to help improve the understanding of tumor biology and evaluation of treatment response, leading to intelligent clinical trial design and more rapid drug development. Clinical trials networks such as EANM Research Ltd. (EARL), SNMMI Clinical Trials Network (CTN), and Australasian Radiopharmaceutical Trials Network (ARTnet), encourage a standardized approach and promote a collaborative approach to clinical trials in molecular imaging. Clinical Trials in Theranostics require the skills and expertise of a multidisciplinary team including the principal investigator, nuclear medicine specialists, study coordinators, medical physicists, radiopharmaceutical scientists, nuclear medicine technologists, research nurses, and research assistants. All personnel involved in theranostics clinical trials should be certified in Good Clinical Practice (GCP). Accurate documentation and record keeping in clinical trials provides validation that clinical trials is conducted at the highest ethical and clinical standards, meets the expectation of the study protocol, and adheres to GCP. Radiation safety is a critical factor for staff, patients, and the public in theranostics and clinical trials and must follow country-specific guidelines and international guidelines to ensure basic safety standards are met. As theranostics and clinical trials continue to stamp their mark in molecular imaging and radionuclide therapy, it is imperative that nuclear medicine professionals remain upskilled and adequately trained in these two aspects of the profession to ensure optimal care is delivered to the patient.