Nuclear Medicine Communications最新文献

Objective: To evaluate the relationship between posttreatment 18 F-fluorodeoxyglucose ( 18 F-FDG) PET/computed tomography (CT) restaging with metabolic parameters and prognosis of uterine cervical cancer.

Methods: A total of 151 patients with cervical cancer who underwent 18 F-FDG PET/CT examination were retrospectively analyzed. The correlation between PET/CT restaging, maximum standard uptake value, whole body metabolic tumor volume (wbMTV), whole body total lesion glycolysis (wbTLG), related clinical factors, and prognosis was analyzed. Kaplan-Meier survival analysis was used to perform univariate analysis on clinical parameters and imaging parameters, and Cox's proportional hazards regression model was used to perform multifactor analysis to explore the related factors affecting progression-free survival (PFS) and overall survival (OS) of patients with cervical cancer.

Results: With a median follow-up time of 24 months, the median OS of 151 cervical cancer patients was 43 months, and the 5-year survival rate was 50%; the median PFS was 33 months, and the 5-year PFS rate was 29%. Both univariate and multivariate analyses showed that PET/CT restaging and squamous cell carcinoma antigen (SCC-Ag) were significant prognostic factors for OS and PFS. Moreover, patients with downstaged PET/CT restaging showed significantly better 5-year OS and 5-year PFS rates than those no downstaging (87.0 vs. 24.6%; P  < 0.001 for OS; 50.7 vs. 18.5%; P  < 0.001 for PFS). Among patients with positive PET/CT findings, wbTLG and wbMTV were identified as independent prognostic factors for OS and PFS, respectively.

Conclusion: 18 F-FDG PET/CT restaging, serum SCC-Ag, wbMTV, and wbTLG are established as prognostic biomarkers in recurrent cervical cancer. Posttreatment PET/CT represents a sensitive and accurate imaging technique for predicting patient outcomes.

Objective: This study aimed to evaluate metabolic activity profiles of extranodal and atypical lymphoma lesions detected by 18 F-fluorodeoxyglucose ( 18 F-FDG) PET/computed tomography (CT), and to elucidate the predictive value of this modality in the diagnostic and prognostic workflow.

Methods and results: Seventy-four patients diagnosed with lymphoma underwent 18 F-FDG PET/CT. Patients aged greater than or equal to 60 years had significantly higher mean maximum standardized uptake value (SUV max ) and mean standardized uptake value (SUV mean ) values. Lesions larger than 2 cm showed significantly elevated SUV mean values. In patients over 60 years, nodal SUV max was also considerably higher. The SUV mean of extranodal lesions was significantly higher in female patients. A positive correlation was found between extranodal lesion SUV max and both lesion size and nodal SUV max .

Conclusion: The significant increase in SUV values with advancing age and larger lesion size, along with the high sensitivity of 18 F-FDG PET/CT in detecting distant organ involvement such as bone marrow, highlights its potential to reflect tumor behavior. The observed sex-related metabolic differences further emphasize the need for individualized imaging strategies.

Objectives: Fibroblast activation protein (FAP), which is abundantly expressed in cancer-associated fibroblasts, is an attractive target for tumour imaging and therapy. [68Ga]Ga-FAPI-46, a gallium-68-labelled FAP inhibitor, has demonstrated favourable pharmacokinetics for PET. This study evaluated the radiolabelling efficiency, stability, and biodistribution of [68Ga]Ga-FAPI-46 in a breast cancer mouse model using MCF-7 cell line, which is known to lack FAP expression.

Methods: [68Ga]Ga-FAPI-46 was radiolabeled directly from FAPI-46 using 68Ga in acetate buffer and analysed for radiochemical purity (RCP) by radio-TLC. Stability at room temperature was assessed up to 5 h post-radiolabeling. Biodistribution studies were conducted in female BALB/c nude mice with MCF-7 tumours. Organ uptake was determined 1 h after injection and expressed as a percentage of injected dose per gramme of tissue (%ID/g). A comparative study between [68Ga]Ga-FAPI-46 and free 68Ga was also performed.

Results: [68Ga]Ga-FAPI-46 consistently achieved high RCP values (>95%, maximum 99.1%) and remained stable for up to 5 h without added radioprotectant. At 1 h, [68Ga]Ga-FAPI-46 showed higher uptake in kidneys (4.15%ID/g), heart (3.59%ID/g), and liver (1.70%ID/g), and low uptake in muscle (0.31%ID/g) and bone (0.57%ID/g). Mean tumour uptake was low (0.92%ID/g), consistent with the FAP-negative status of MCF-7 cells. In contrast, free 68Ga showed a non-specific distribution in blood (29.13%ID/g), lungs (18.50%ID/g), and bone (13.37%ID/g).

Conclusion: [68Ga]Ga-FAPI-46 showed efficient radiolabelling with high RCP and short-term stability. Its low accumulation in FAP-negative tumours supports tracer selectivity and provides a baseline for comparative studies in FAP-expressing tumour models.

Fibroblast activation protein inhibitor (FAPI) PET/CT has emerged as an investigational alternative which targets cancer-associated fibroblasts, abundant in the ILC tumor stroma. This narrative review synthesizes emerging evidence on radiolabeled FAPI PET/CT in ILC and highlights potential advantages, limitations, and research gaps. A purposive literature search of SCOPUS, PubMed/MEDLINE, and Web of Science up to August 2025 identified 10 clinical publications, including three prospective studies, two retrospective comparisons, and five case reports; mixed-cohort studies were included when ILC-specific findings were extractable. Across these small, heterogeneous early studies, gallium-68 FAPI PET/CT consistently demonstrated higher tumor uptake and greater lesion conspicuity than 18F-FDG PET/CT in several ILC-relevant scenarios, particularly infiltrative soft-tissue metastases, peritoneal and serosal involvement, and sclerotic osseous lesions. Comparative studies also reported identification of additional multifocal or multicentric primary foci and greater nodal involvement, while case reports described enhanced visualization of gastric, orbital, peritoneal, and ovarian metastases, sites often inconspicuous on 18F-FDG PET/CT. Despite these promising findings, available evidence remains limited, predominantly observational, and lacks lesion-level histopathologic confirmation, standardized imaging protocols, and data on management impact or patient outcomes. Overall, early results suggest that gallium-68 FAPI PET/CT may offer improved lesion conspicuity in selected ILC settings; however, these observations remain hypothesis generating. Larger, multicentre prospective studies with standardized acquisition parameters, rigorous lesion validation, and clinically meaningful endpoints are required to establish the diagnostic and therapeutic relevance of FAPI PET/CT and determine whether it has a role in the routine clinical evaluation of ILC.

Objective: Previous studies reported low [18F] fluorodeoxyglucose ([18F]FDG) PET uptake in estrogen receptor-positive breast tumours, potentially missing detection of distant metastases. This study assessed the proportion of estrogen receptor-positive hypometabolic tumours, clinical factors influencing [18F]FDG uptake, and the prognostic impact.

Methods: Baseline [18F]FDG PET/computed tomography (CT) and [18F]FDG PET/MRI exams of female patients diagnosed with estrogen receptor-positive locally advanced (cT3-4N0 or cT1-4N+), metastatic, or recurrent breast cancer between 2013-2022 were retrospectively collected. Different thresholds of maximum standardised uptake value (SUVmax) and tumour-to-background ratio (TBR; SUVmax tumour/SUVmax background) were applied to determine the proportion of hypometabolic [18F]FDG PET exams. Logistic regression and survival analysis were performed.

Results: 119 patients underwent [18F]FDG PET/CT and 31 [18F]FDG PET/MRI. The proportion of hypometabolic tumours for SUVmax thresholds 2.0, 2.5, 3.0, TBR of contralateral breast less than or equal to 1, and TBR of liver less than or equal to 1 was 8.4, 15.1, 21.8, 5.1, and 28.6%, respectively for [18F]FDG PET/CT and 16.1, 19.4, 29.0, 6.9, and 35.5% for [18F]FDG PET/MRI. Clinically tumour status (cT-status), histology type, and tumour grade were associated with the presence of a hypometabolic tumour. No PET-derived variables were associated with recurrence-free survival.

Conclusion: A considerable proportion of estrogen receptor-positive breast tumours showed low SUVmax, indicating potential suboptimal staging on [18F]FDG PET. In patients with lower cT-status, lobular histology and low-grade estrogen receptor-positive tumour, [18F]FDG PET may be less reliable as staging procedure. Further research is necessary to determine the optimal metabolic threshold for defining a hypometabolic tumour.

Rationale: Accurate early prediction of chemotherapy response in non-small cell lung cancer (NSCLC) remains a clinical challenge. This study aimed to evaluate the utility of PET-based radiomic features extracted from [18F]fluorodeoxyglucose ([18F]FDG) PET/computed tomography (CT) scans in predicting treatment response to platinum based chemotherapy in NSCLC patients.

Methods: An ambispective observational study was conducted on 70 histopathologically confirmed NSCLC patients who underwent [18F]FDG PET/CT imaging before and after chemotherapy at a tertiary cancer center. Radiomic features were extracted from the primary lesion using commercially available texture analysis software, applying a fixed standardized uptake value (SUV) threshold-based volume of interest segmentation. Conventional metabolic parameters [SUVmax, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis (TLG)] and 46 radiomic features (GLRLM, NGLDM, GLCM, shape features) were analyzed. Treatment response was assessed using PERCIST criteria and patients were categorized as responders or non-responders. Statistical analysis included Mann-Whitney U test and receiver operating characteristic analysis to determine discriminatory ability of parameters.

Results: Among the radiomic and metabolic parameters evaluated, only a few showed statistically significant differences between responders and non-responders. GLRLM GLNU, GLCM correlation, NGLDM contrast, and shape surface demonstrated fair predictive performance with area under the curve (AUC) values >0.7. Conventional parameters such as SUVmax and TLG did not show statistically significant differences. The optimal cutoff values, sensitivity, specificity, AUCs, and P values of significant features were also obtained.

Conclusion: Select radiomic features derived from [18F]FDG PET/CT scans, particularly GLNU, GLCM correlation, and NGLDM contrast, hold promise in predicting response to platinum-based chemotherapy in NSCLC. These findings suggest the potential utility of radiomics in enhancing personalized treatment strategies, although further validation is warranted.

Purpose: Intracranial calcifications are commonly found in adults and may represent either benign or pathological lesions. Conventional imaging modalities detect static macrocalcifications but do not capture molecular microcalcification. In this study, we used 18F-sodium fluoride (NaF) PET/computed tomography (CT) to idetect intracranial molecular microcalcification.

Methods: A total of 127 subjects underwent 18F-NaF PET/CT 90 min following radiotracer injection. Artificial intelligence-based quantification was performed to obtain regions of interest for the brainstem, basal ganglia (caudate and lentiform nuclei), insula, thalamus, and ventricles. Linear regression models were used to correlate NaF mean standardized uptake value (SUVmean) with various clinical factors.

Results: NaF SUVmean was highest in the insula (0.8 ± 0.4) and brainstem (0.8 ± 0.3), while uptake was lowest in the caudate nucleus (0.1 ± 0.1). No differences were found in NaF SUVmean between healthy volunteers and at-risk patients. On multivariate regression, NaF SUVmean directly correlated with age in the brainstem (β = 0.01, P = 0.01), lentiform nucleus (β < 0.01, P = 0.02), and ventricles (β < 0.01, P < 0.01). Male sex inversely correlated with NaF SUVmean in the insula (β = -0.30, P < 0.01). There was an association between NaF SUVmean and BMI in the brainstem, caudate nucleus, lentiform nucleus, thalamus, and ventricles (β ≤ 0.01, P < 0.01 in all regions). Thalamic and ventricular NaF SUVmean directly correlated with hypertension on univariate but not multivariate analysis.

Conclusion: NaF PET/CT detects intracranial molecular microcalcification that is not visible on conventional CT and may provide insight into pathology associated with this biological process.

Objective: Current evidence regarding radiomics-based assessment of persistent/recurrent cervical lymph node metastasis (CLNM) remains limited, particularly in the field of PET/CT in papillary thyroid cancer (PTC). Therefore, we aimed to construct a prediction model for persistent/recurrent CLNM of PTC by fluoro-18-deoxyglucose (18F-FDG) PET/computed tomography (CT) multimodal radiomics.

Methods: We retrospectively analyzed postoperative patients with PTC who underwent 18F-FDG PET/CT at our hospital between June 2021 and June 2024. A total of 425 CLNs (219 metastatic and 206 nonmetastatic) from 158 patients were included, and the patients were randomly assigned to a training set and a test set at a ratio of 7 : 3. Pearson correlation analysis and least absolute shrinkage and selection operator regression were utilized to select PET/CT radiomic features for model development. Five radiomics models were developed based on distinct feature sets: clinical features alone, CT radiomics, PET radiomics, PET/CT radiomics, and integrated PET/CT radiomics combined with clinical features. Subsequently, a nomogram model was built by combining radscore and clinical features.

Results: The integrated model demonstrated superior diagnostic accuracy, with areas under the curve (AUCs) of 0.944 in the training set and 0.922 in the test set. PET/CT models demonstrated the following AUCs: PET/CT (0.887), PET (0.834), CT (0.775), and clinical features alone (0.783). A nomogram incorporating clinical features and radscores was then developed, achieving C-indices of 0.937 in the training set and 0.895 in the test set.

Conclusion: The integration of PET/CT radiomics and clinical features may provide a noninvasive tool for predicting persistent/recurrent CLNM in postoperative PTC patients, with potential to support clinical decision‑making.

Immune checkpoint inhibitors and anti-angiogenic targeted therapies have improved outcomes in hepatocellular carcinoma (HCC), but responses remain heterogeneous, creating a need for noninvasive biomarkers to enable early treatment adaptation. We review clinical and translational evidence on nuclear medicine approaches - PET/computed tomography (CT), single-photon emission computed tomography (SPECT) , radiomics, machine learning, and theranostics - for response prediction and prognostication in HCC treated with immunotherapy alone or in combination with targeted agents. Metabolic PET/CT, most commonly with 18 F-fluorodeoxyglucose , supports pragmatic risk stratification; volumetric indices such as metabolic tumor volume (MTV) and total lesion glycolysis generally provide stronger prognostic enrichment than single-voxel metrics, and an MTV threshold of greater than or equal to39.65 cm³ has been reported to associate with poorer outcomes. Immune-targeted PET/SPECT extends beyond metabolism by mapping target availability and heterogeneity (e.g. PD-L1) and immune activation or effector function (e.g. CD137, granzyme B), although current studies are often small and retrospective. PET-based radiomics and machine learning can generate imaging surrogates of immune phenotypes and aggressive biology, but reproducibility is limited by acquisition/reconstruction differences, segmentation variability, and scarce external validation. Theranostics offers an image-guided 'select-and-treat' paradigm for radionuclide therapy, yet target heterogeneity, dosimetry standardization, cost, and infrastructure remain barriers. Translation to routine care will require harmonized protocols, multicenter prospective validation, and demonstration of decision impact.

Meningiomas account for 41.7% of primary central nervous system (CNS) tumors and overexpress somatostatin receptor 2 (SSTR2) receptors, enabling superior tumor-to-background contrast compared with MRI and computed tomography imaging, which have limited ability to distinguish neoplastic tissue from normal dural enhancement. This review aimed to evaluate SSTR-targeted PET radiotracers for diagnosis, treatment planning, surveillance, and theranostic applications in meningioma management. Literature review of PubMed, Google Scholar, Embase, and Web of Science databases from inception to November 2025. Studies evaluating [68Ga]Ga-DOTATATE, [68Ga]Ga-DOTATOC, [68Ga]Ga-DOTANOC, and novel fluorine-18 tracers in meningioma patients were analyzed. SSTR-PET demonstrated superior diagnostic sensitivity (95-100%) with 10-fold higher SSTR2-binding affinity than conventional scintigraphy. Osseous involvement detection exceeded MRI (98.5 vs. 53.7%; n = 82). PET-guided radiation planning reduced target volumes by 84% (71.39 → 11.12 cm3; P < 0.05) while decreasing critical structure exposure by greater than or equal to 50%. Posttreatment surveillance detected residual tumor in 41-63% of patients deemed completely resected by Simpson grading and MRI (n = 37). SSTR-PET altered management in 42% of cases by identifying occult disease. The theranostic paradigm using [177Lu]Lu-DOTATATE achieved 60-80% disease stabilization in recurrent/progressive cases. Next-generation [18F]SiTATE tracers offer improved logistics and cost-effectiveness. Technical heterogeneity in acquisition protocols and lack of standardized uptake value thresholds (range: 2.3->4.0) limit generalizability. SSTR-targeted PET provides superior molecular characterization, enhancing diagnostic accuracy, treatment precision, and surveillance beyond conventional imaging. The theranostic platform enables both precise visualization and targeted radionuclide therapy. Prospective multicenter trials with standardized protocols are essential to establish evidence-based clinical guidelines.