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.

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.

Objective: This study explored the predictive value of 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) radiomics for assessing programmed death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC), aiming to noninvasively evaluate PD-L1 status and assist in selecting patients for immunotherapy.

Methods: We retrospectively analyzed 163 NSCLC patients with pretreatment 18F-FDG PET/CT scans, randomly assigning them into training (n = 130) and validation (n = 33) cohorts. Optimal radiomics features were selected via least absolute shrinkage and selection operator and combined with clinical factors to construct five predictive models: CT, PET, radiomics, clinical, and a combined model. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA).

Results: All models showed predictive ability for PD-L1 expression. The combined model demonstrated superior performance, with AUCs of 0.839 [95% confidence interval (CI): 0.771-0.908] in training and 0.782 (95% CI: 0.610-0.954) in validation. Calibration curves indicated good agreement between predicted and observed probabilities (Brier scores: 0.163 and 0.191, respectively). DCA confirmed the highest net clinical benefit for the combined model.

Conclusion: The multimodal combined model, integrating PET/CT radiomics with clinical factors, shows significant potential for noninvasively predicting PD-L1 expression in NSCLC, offering a novel strategy for precise patient selection for anti-PD-L1 immunotherapy.

Purpose: To evaluate the utility of 99m Tc-pentavalent dimercaptosuccinic acid (DMSA-V) brain single-photon emission computed tomography/computed tomography (SPECT/CT) in treated adult glioma with respect to isocitrate dehydrogenase (IDH) mutation status.

Methods: This prospective study included pathologically proven glioma patients. Early and delayed SPECT/CT images were obtained following intravenous administration of 797.90 ± 61.77 MBq 99m Tc DMSA-V. Both qualitative and quantitative analyses were carried out. The reference standard was established by follow-up MRI, histopathology, and clinical evaluation to verify SPECT/CT findings. The predictive value of IDH mutation status was assessed.

Results: Our study recruited 39 patients (24 males and 15 females; mean age: 40.41 ± 14.48 years). Residual/recurrent disease was confirmed in 23 cases, whereas 16 cases were disease free. 99m Tc DMSA-V SPECT/CT revealed a specificity of 100% and a sensitivity of 73.9% in identifying residual/recurrent gliomas. IDH was mutant in 22 (56.4%) and wild in 17 (43.6%) patients. Early, delayed lesion/non-lesion ratios, and retention index were significant predictors of the true disease status in the patients with mutated IDH; the area under the curves were 0.793 [95% confidence interval (CI): 0.566-1], 0.826 (95% CI: 0.648-1), and 0.826 (95% CI: 0.648-1), respectively. Eleven patients died after a mean follow-up of 10.82 months; eight patients with positive scan and wild-type IDH vs. three with negative scan and mutant IDH ( P  = 0.033). The median survival was 14 months for the first group and was not reached for the second.

Conclusion: 99m Tc DMSA-V brain SPECT/CT is a reliable, noninvasive, and specific modality for posttherapy evaluation of glioma. It has significant diagnostic and prognostic values in the mutant IDH glioma.

Objectives: Diagnostic reference levels (DRLs) are essential indicators for optimising medical radiation exposure, although implementation varies by country. In Japan, the Association of Radiological Technologists in National University Hospitals (ARTNU) investigated baseline DRLs for nuclear medicine based on a nationwide survey in 2020. These include the 50 th and 75 th percentile values, providing practical benchmarks for administered activity management. However, comparative insights with Japan DRLs 2025 and international standards remain limited.

Methods: This nationwide survey, conducted in 2025 across 42 Japanese national university hospitals, examined radiopharmaceutical and computed tomography (CT) administered activity indices in single-photon emission computed tomography/CT (SPECT/CT) and PET/CT (PET/CT) examinations and compared the results with Japan DRLs 2020; Japan DRLs 2025; and international benchmarks from the UK, Europe, USA, Korea, Australia, and Thailand. Japan DRLs 2025 introduced procedural refinements and anatomy-based CT classifications, particularly for PET/CT, aligning with evolving clinical protocols.

Results: Data on radiopharmaceutical administered activities and CT parameters (CT dose index volume, dose length product) were collected. 18 F-fluorodeoxyglucose-PET protocols predominantly applied 4.0 MBq/kg weight-based dosing, whereas SPECT/CT uses fixed radiopharmaceutical administered activities. CT exposure was adapted according to imaging purpose and anatomical region, frequently achieving low-administered activity operation. Although ARTNU DRLs 2020 remained clinically useful, they exhibited broader administered activity distributions and lack anatomical specificity.

Conclusion: ARTNU DRLs 2020 should be revised with a follow-up survey to better reflect current practices and align with the increased granularity of Japan DRLs 2025. Japanese institutions have demonstrated concordance with global standards and ongoing administered activity optimisation through technological advancements.