OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is often associated with bone marrow infiltration, and 2-deoxy-2-(18F) fluorodeoxyglucose positron emission tomography/computed tomography ( ¹⁸F-FDG PET/CT) has potential diagnostic significance for bone marrow infiltration in DLBCL. METHODS: A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included. Bone marrow biopsy and ¹⁸F-FDG PET/CT examinations were performed at the time of initial diagnosis. Kappa tests were used to evaluate the agreement of ¹⁸F-FDG PET/CT with the gold standard, and the imaging features of DLBCL bone marrow infiltration on PET/CT were described. RESULTS: The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy ( P = 0.302) or between the two bone marrow biopsies ( P = 0.826). The sensitivity, specificity, and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923 (95% CI, 0.759-0.979), 0.934 (95% CI, 0.855-0.972), and 0.857, respectively. CONCLUSION ¹⁸F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration. PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.
Humans ; Positron Emission Tomography Computed Tomography/methods* ; Fluorodeoxyglucose F18 ; Bone Marrow/pathology* ; Retrospective Studies ; Positron-Emission Tomography/methods* ; Lymphoma, Large B-Cell, Diffuse/pathology*

The American Urological Association (AUA), European Association of Urology (EUA) and International Urological Society (SIU) annual meetings were held in 2022. Studies on prostate cancer reported in the meetings mainly focus on the advances of diagnostic biomarkers (such as α-2, 3-1inked sialylation of terminal N-glycan on free PSA density, SelectMDx) and imaging techniques [such as multiparametric magnetic resonance imaging, prostate specific membrane antigen(PSMA)-PET/CT], the new method for prostate biopsy, the new treatments of prostate cancer including [¹⁷⁷Lu] Ludotadipep and DROP-IN PSMA probe, and the prognosis assessment of prostate cancer (such as AR-V7). This article provides an overview on the research hotspots of three international academic meetings.
Male ; Humans ; Urology ; Positron Emission Tomography Computed Tomography/methods* ; Prostatic Neoplasms/pathology* ; Multiparametric Magnetic Resonance Imaging/methods* ; Gallium Radioisotopes

Biology-guided radiotherapy (BgRT) is a novel technique of external beam radiotherapy, combining positron emission tomography-computed tomography (PET-CT) with a linear accelerator (LINAC). The key innovation is to utilize PET signals from tracers in tumor tissues for real-time tracking and guiding beamlets. Compared with a traditional LINAC system, a BgRT system is more complex in hardware design, software algorithm, system integration and clinical workflow. RefleXion Medical has developed the world's first BgRT system. Nevertheless, its actively advertised function, PET-guided radiotherapy, is still in the research and development phase. In this review study, we presented a number of issues related to BgRT, including its technical advantages and potential challenges.
Positron Emission Tomography Computed Tomography ; Radiotherapy Planning, Computer-Assisted/methods* ; Algorithms ; Particle Accelerators ; Biology ; Radiotherapy, Image-Guided/methods* ; Radiotherapy Dosage

OBJECTIVE: To explore the diagnostic value of ¹⁸F-FDG PET/CT in bone marrow infiltration (BMI) of newly diagnosed diffuse large B-cell lymphoma (DLBCL), compared with the results of bone marrow biopsy (BMB) and investigate whether the BMI diagnosed by ¹⁸F-FDG PET/CT and other factors have independent prognostic values. METHODS: Ninety-four newly diagnosed DLBCL patients who underwent PET/CT in Clinical Medical College of Shanghai General Hospital of Nanjing Medical University were included. BMB was performed within 2 weeks before or after PET/CT, and standardized treatment was performed after PET/CT. The manifestations of bone marrow (BM) FDG uptake were recorded. The diagnostic criteria of BMI were BMB positive or focal BM FDG uptake confirmed by imaging follow-up. The relationship between clinical features and BM FDG uptake and the values of PET/CT and BMB in the diagnosis of BMI was analyzed. The progression-free survival (PFS) was analyzed by Kaplan-Meier survival curves, log-rank test was used to compare PFS rate, and Cox regression model was used to analyze the independent risk factors affecting PFS. RESULTS: Among 94 DLBCL patients, 34 patients showed focal BM uptake (fPET), 7 patients showed super BM uptake (sBMU), 11 patients showed diffuse homogenous uptake higher than liver (dPET), and the other 42 patients had normal BM uptake (nPET) (lower than liver). BMB positive was found in all sBMU patients, in 20.6%(7/34) of fPET patients, and in 27.3% (3/11) of dPET patients. All nPET patients had negative BMB results. dPET patients were associated with lower hemoglobin level and leukocyte count compared with nPET group (P < 0.001, P =0.026). Compared with fPET patients, sBMU patients were more likely to have B symptoms and elevated lactate dehydrogenase (LDH). A total of 44 patients were diagnosed BMI, including 17 cases with BMB⁺. The sensitivity and specificity of BMB in the diagnosis of BMI was 38.6% (17/44) and 100% (50/50), respectively. Using fPET and sBMU as criteria of PET BMI, the diagnostic sensitivity and specificity of PET/CT was 93.2% (41/44) and 100% (50/50), respectively. Kaplan-Meier analysis showed that there was no significant difference in 2-year PFS rate between nPET and dPET patients (P >0.05), while sBMU patients had lower 2-year PFS rate compared with fPET patients (P < 0.001). Multivariate analysis showed that higher Ann Arbor stage (HR=9.010, P =0.04) and sBMU (HR=3.964, P =0.002) were independent risk factors affecting PFS. CONCLUSIONS Increased BM FDG uptake of DLBCL can be manifested as dPET, fPET and sBMU. fPET and sBMU can replace BMB to diagnose BMI. Although dPET cannot completely exclude the possibility of BMI, it does not affect the prognosis, so it can be diagnosed as PET BMI negative. sBMU is an independent prognostic risk factor.
Humans ; Positron Emission Tomography Computed Tomography/methods* ; Fluorodeoxyglucose F18 ; Prognosis ; Bone Marrow/pathology* ; Retrospective Studies ; China ; Positron-Emission Tomography/methods* ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Biopsy

BACKGROUND: In recent years, immunotherapy represented by programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) immunosuppressants has greatly changed the status of non-small cell lung cancer (NSCLC) treatment. PD-L1 has become an important biomarker for screening NSCLC immunotherapy beneficiaries, but how to easily and accurately detect whether PD-L1 is expressed in NSCLC patients is a difficult problem for clinicians. The aim of this study was to construct a Nomogram prediction model of PD-L1 expression in NSCLC patients based on 18F-fluorodeoxy glucose (18F-FDG) positron emission tomography/conputed tomography (PET/CT) metabolic parameters and to evaluate its predictive value. METHODS: Retrospective collection of 18F-FDG PET/CT metabolic parameters, clinicopathological information and PD-L1 test results of 155 NSCLC patients from Inner Mongolia People's Hospital between September 2016 and July 2021. The patients were divided into the training group (n=117) and the internal validation group (n=38), and another 51 cases of NSCLC patients in our hospital between August 2021 and July 2022 were collected as the external validation group according to the same criteria. Then all of them were categorized according to the results of PD-L1 assay into PD-L1+ group and PD-L1- group. The metabolic parameters and clinicopathological information of patients in the training group were analyzed by univariate and binary Logistic regression, and a Nomogram prediction model was constructed based on the screened independent influencing factors. The effect of the model was evaluated by receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) in both the training group and the internal and external validation groups. RESULTS: Binary Logistic regression analysis showed that metabolic tumor volume (MTV), gender and tumor diameter were independent influences on PD-L1 expression. Then a Nomogram prediction model was constructed based on the above independent influences. The ROC curve for the model in the training group shows an area under the curve (AUC) of 0.769 (95%CI: 0.683-0.856) with an optimal cutoff value of 0.538. The AUC was 0.775 (95%CI: 0.614-0.936) in the internal validation group and 0.752 (95%CI: 0.612-0.893) in the external validation group. The calibration curves were tested by the Hosmer-Lemeshow test and showed that the training group (χ2=0.040, P=0.979), the internal validation group (χ2=2.605, P=0.271), and the external validation group (χ2=0.396, P=0.820) were well calibrated. The DCA curves show that the model provides clinical benefit to patients over a wide range of thresholds (training group: 0.00-0.72, internal validation group: 0.00-0.87, external validation group: 0.00-0.66). CONCLUSIONS The Nomogram prediction model constructed on the basis of 18F-FDG PET/CT metabolic parameters has greater application value in predicting PD-L1 expression in NSCLC patients.
Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Positron Emission Tomography Computed Tomography ; Lung Neoplasms/drug therapy* ; Fluorodeoxyglucose F18/therapeutic use* ; Nomograms ; Retrospective Studies ; B7-H1 Antigen/metabolism* ; Glucose/therapeutic use* ; Positron-Emission Tomography/methods*

Objective To investigate the value of ¹⁸F-FDG PET/CT metabolic parameters and metabolic heterogeneity for predicting the expression of human epidermal growth factor receptor 2 (HER2) in patients with gastric cancer. Methods A total of 45 patients with gastric cancer confirmed by surgical pathology between September 2016 and May 2021 were enrolled in this study.All the patients underwent ¹⁸F-FDG PET/CT examination before surgery.The maximum standardized uptake value (SUVmax),metabolic tumor volume (MTV),and total lesion glycolysis (TLG) of primary gastric cancer were measured,and the linear regression slope of MTV corresponding to different SUVmax thresholds (40% SUVmax and 80% SUVmax) was calculated.The absolute value of the slope was deemed to represent the metabolic heterogeneity of primary gastric cancer,termed the heterogeneity index (HI).Univariate and multivariate Logistic regression analyses were conducted to evaluate the correlations of ¹⁸F-FDG PET/CT metabolic parameters and HI with HER2 expression. Results The 45 patients included 10 with positive HER2 expression and 35 with negative result.The MTV (P=0.043) and HI (P=0.048) were lower in the patients with positive HER2 expression than in the patients with negative HER2 expression.The MTV and HI had the optimal thresholds of 12.10 cm³ and 3.71,respectively,which respectively showed the accuracy of 62.2% and 57.8% for predicting HER2 expression.The univariate Logistic regression showed that the tumor differentiation degree,MTV,and HI were correlated with HER2 expression,while the multivariate Logistic regression showed that only the tumor differentiation degree (OR=20.130,95%CI=1.843-219.860,P=0.014) was an independent predictor for HER2 expression.A further stratified analysis of the tumor differentiation degree showed that HER2 expression only varied among different MTV threshold groups in patients with moderately/well differentiated gastric cancer (P=0.031). Conclusions MTV and HI were associated with HER2 expression in gastric cancer,whereas neither played an independent predictive role.Therefore,these factors should be combined with clinicopathological characteristics of patients to jointly guide treatment decisions.
Fluorodeoxyglucose F18 ; Humans ; Positron Emission Tomography Computed Tomography/methods* ; Receptor, ErbB-2 ; Retrospective Studies ; Stomach Neoplasms/diagnostic imaging*

Cross-modality reconstruction of medical images refers to predicting the image from one modality to another so as to achieve more accurate personalized medicine. Generative adversarial networks is the most commonly used deep learning technique in cross-modality reconstruction. It can generate realistic images by learning features from implicit distributions that follow the distributions of real data and then reconstruct the image of another modality rapidly. With the sharp increase in clinical demand for multi-modality medical image, this technology has been widely used in the task of cross modal reconstruction between different medical image modalities, such as magnetic resonance imaging, computed tomography and positron emission computed tomography. It can achieve accurate and efficient cross-modality image reconstruction in different parts of the body, such as the brain, heart, etc. In addition, although GAN has achieved some success in cross-modality reconstruction, its stability, generalization ability, and accuracy still need further research and improvement.
Brain/diagnostic imaging* ; Image Processing, Computer-Assisted/methods* ; Magnetic Resonance Imaging/methods* ; Positron-Emission Tomography ; Tomography, X-Ray Computed

In animal experiments, ischemic stroke is usually induced through middle cerebral artery occlusion (MCAO), and quality assessment of this procedure is crucial. However, an accurate assessment method based on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is still lacking. The difficulty lies in the inconsistent preprocessing pipeline, biased intensity normalization, or unclear spatiotemporal uptake of FDG. Here, we propose an image feature-based protocol to assess the quality of the procedure using a 3D scale-invariant feature transform and support vector machine. This feature-based protocol provides a convenient, accurate, and reliable tool to assess the quality of the MCAO procedure in FDG PET studies. Compared with existing approaches, the proposed protocol is fully quantitative, objective, automatic, and bypasses the intensity normalization step. An online interface was constructed to check images and obtain assessment results.
Animals ; Fluorodeoxyglucose F18 ; Infarction, Middle Cerebral Artery/diagnostic imaging* ; Positron-Emission Tomography/methods*

Objective: Solid and micropapillary pattern are highly invasive histologic subtypes in lung adenocarcinoma and are associated with poor prognosis while the biopsy sample is not enough for the accurate histological diagnosis. This study aims to assess the correlation and predictive efficacy between metabolic parameters in (18)F-fluorodeoxy glucose positron emission tomography/computed tomography ((18)F-FDG PET-CT), including the maximum SUV (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and solid and micropapillary histological subtypes in lung adenocarcinoma. Methods: A total of 145 resected lung adenocarcinomas were included. The clinical data and preoperative (18)F-FDG PET-CT data were retrospectively analyzed. Mann-Whitney U test was used for the comparison of the metabolic parameters between solid and micropapillary subtype group and other subtypes group. Receiver operating characteristic (ROC) curve and areas under curve (AUC) were used for evaluating the prediction efficacy of metabolic parameters for solid or micropapillary patterns. Univariate and multivariate analyses were conducted to determine the prediction factors of the presence of solid or micropapillary subtypes. Results: Median SUV(max) and TLG in solid and papillary predominant subtypes group (15.07 and 34.98, respectively) were significantly higher than those in other subtypes predominant group (6.03 and 10.16, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for prediction of solid and micropapillary predominant subtypes [AUC=0.811(95% CI: 0.715~0.907) and 0.725(95% CI: 0.610~0.840), P<0.05]. Median SUV(max) and TLG in lung adenocarcinoma with the solid or micropapillary patterns (11.58 and 22.81, respectively) were significantly higher than those in tumors without solid and micropapillary patterns (4.27 and 6.33, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for predicting the presence of solid or micropapillary patterns [AUC=0.757(95% CI: 0.679~0.834) and 0.681(95% CI: 0.595~0.768), P<0.005]. Multivariate logistic analysis showed that the clinical stage (Stage Ⅲ-Ⅳ), SUV(max) ≥10.27 and TLG≥7.12 were the independent predictive factors of the presence of solid or micropapillary patterns (P<0.05). Conclusions: Preoperative SUV(max) and TLG of lung adenocarcinoma have good prediction efficacy for the presence of solid or micropapillary patterns, especially for the solid and micropapillary predominant subtypes and are independent factors of the presence of solid or micropapillary patterns.
Adenocarcinoma of Lung/diagnostic imaging* ; Fluorodeoxyglucose F18/metabolism* ; Humans ; Lung Neoplasms/pathology* ; Multimodal Imaging/methods* ; Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography/methods* ; Prognosis ; Radiopharmaceuticals ; Retrospective Studies ; Tomography, X-Ray Computed/methods* ; Tumor Burden

BACKGROUND: Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans. METHODS: We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient. RESULTS: The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion. CONCLUSION Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.
Aged ; Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Arteries ; Atrophy ; Brain/metabolism* ; Cerebral Cortex/metabolism* ; Cerebrovascular Circulation ; Constriction, Pathologic/pathology* ; Female ; Humans ; Magnetic Resonance Imaging/methods* ; Male ; Middle Aged ; Positron-Emission Tomography/methods*