Objective:To explore the value and efficacy of the risk model based on the metabolic parameters of 18F-FDG PET-CT in predicting epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC). Methods:This retrospectives study reviewed 105 NSCLC patients who were tested for EGFR gene expression and underwent 18F-FDG PET-CT exam prior to treatment from Jan 2017 to June 2018 in our hospital. The patients were divided into EGFR mutations group ( n=40) and EGFR wild type group ( n=65). The differences between the different groups were analyzed in several clinical characteristics and three metabolic parameters based on 18F-FDG PET-CT, including the maximal standard uptake value (SUV max), metabolic tumor volume (MTV), total lesion glycolysis (TLG) of the primary tumor. Multivariate logistic regression analysis was performed to identify predictors of EGFR mutations, and the risk prediction model and nomogram graph were constructed. Diagnostic efficiency of the model was done by the receiver operating characteristics (ROC) curve analysis, and the Calibration plot was performed by Hosmer-Lemeshow (H-L) test to evaluate the calibration scale of the model. Results:There were statistically significant differences in gender, smoking status, serum CEA level, length of tumor, pathological types, TTF-1 and NapsinA expression between the EGFR mutant groups and EGFR wild-type groups (all P<0.05). The MTV and TLG of EGFR mutation group were 4.4 (4.5，37.1) cm 3 and 46.6 (21.2，118.2), respectively. The MTV and TLG of EGFR wild type group were 7.4 (3.2，13.5) cm 3 and 95.4 (26.4，345.1), respectively. The MTV and TLG of EGFR mutation group were significantly lower than those of EGFR wild type group ( Z=-2.452, P=0.014; Z=-2.379, P=0.017). ROC curve analysis showed area under the curve (AUC) predicted by SUV max, MTV and TLG for EGFR mutations was 0.597, 0.643 and 0.639, respectively. Multivariate analysis demonstrated that gender, length of tumor, SUV max and MTV were independent predictors of EGFR mutations, with the odds ratio (OR) values (95 %CI) as 3.811 (1.508-9.629), 1.679 (0.899-3.136), 0.928 (0.848-1.015) and 0.924 (0.865-0.986), respectively. The predictive model and nomogram graph was established, with the sensitivity, specificity, positive predictive value, negative predictive value and AUC of 80.0%, 66.2%, 68.8%, 75.3% and 0.775 (0.687-0.864), respectively. The H-L test showed the model had excellent accuracy (χ 2=3.872, P=0.869). Conclusion:The risk model based on the metabolic parameters of 18F-FDG PET-CT has a good performance in predicting the mutations of EGFR gene in patients with NSCLC.

Objective:To investigate the effect of 18F-FDG combined with 18F-prostate specific membrane antigen (PSMA)-1007 PET/CT on TNM staging and clinical treatment decision of patients with prostate cancer. Methods:Clinical data and PET/CT images of 31 patients (age (69.9±9.2) years) with prostate cancer who underwent PET/CT imaging with 18F-FDG and 18F-PSMA-1007 (dual-tracer imaging) in the Second Xiangya Hospital of Central South University from June 2020 to March 2022 were retrospectively analyzed. Paired χ2 test was used to compare the diagnostic efficacy of 18F-FDG, 18F-PSMA-1007 and combined imaging for diagnosing primary prostate cancer, regional lymph node metastases and distant metastases, and to analyze the influence of combined imaging on clinical treatment decision. Results:There were 282 metastatic sites in 31 patients, including 46 regional lymph node metastases in 13 patients and 236 distant metastases in 15 patients. The detection rates of 18F-PSMA-1007 PET/CT and combined imaging for primary lesions were higher than the detection rate of 18F-FDG PET/CT (100%(31/31), 100%(31/31) vs 64.5%(20/31); χ2=13.37, P<0.001). Based on analysis of patients, the detection rates of 18F-PSMA-1007 PET/CT and combined imaging for regional lymph node metastases were higher than the detection rate of 18F-FDG PET/CT (12/13, 12/13 vs 6/13; χ2=4.51, P=0.034), and the 3 detection rates for distant metastases were also significantly different (15/15, 15/15 vs 10/15; χ2=6.00, P=0.042). Based on analysis of lesions, the detection rates of 18F-PSMA-1007 PET/CT and combined imaging for regional lymph node metastases were higher than the detection rate of 18F-FDG PET/CT (95.7%(44/46), 97.8%(45/46) and 45.7%(21/46); χ2 values: 25.37-49.56, all P<0.001). The detection rate of combined imaging for distant metastases was higher than that of 18F-FDG or 18F-PSMA-1007 PET/CT alone (96.2%(227/236) vs 68.6%(162/236), 58.9%(139/236)); and the detection rate of 18F-FDG PET/CT was higher than that of 18F-PSMA-1007 PET/CT ( χ2 values: 4.85-94.22, all P<0.05). Clinical treatment decisions in 10 patients (32.3%, 10/31) were changed based on the results of combined imaging. Conclusion:For prostate cancer with suspected distant metastases, 18F-FDG and 18F-PSMA-1007 dual-tracer PET/CT imaging can improve staging and guide clinical treatment decisions.

To determine the clinicopathological and imaging features in 18F-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography and computed tomography (PET/CT) for paraganglioma of testis, and to increase the diagnostic accuracy.
 Methods: A case of paraganglioma of testis with multiple lymph node and lung metastasis were reported. PET/CT and pathological findings in the case were retrospectively analyzed.
 Results: The patient presented with high blood pressure, high level of catecholamine, and urinary vanillylmandelic acid. The patient underwent 18F-FDG PET/CT, which showed the features including the right testis nodule with a star lesion nearby, the right spermatic cord, the lymphadenopathy of bilateral inguinal and retroperitoneum, the posterior basal segment of right lung nodule, and a lot of brown adipose tissues (BAT) in the whole body with intense FDG uptake. 18F-FDG PET/CT showed that the intense FDG uptake of the BAT disappeared after the excision of the right testis and metastasis of paraganglioma.
 Conclusion: PET/CT shows great value in localization diagnose, clinical staging and curative evaluation. PET/CT plays a helpful role in revealing the BAT with 18F-DG avidity in the patients with paraganglioma with elevated blood pressure, high level catecholamine, and urinary vanillylmandelic acid.
Fluorodeoxyglucose F18 ; Humans ; Lymph Nodes ; diagnostic imaging ; pathology ; Lymphatic Metastasis ; Male ; Neoplasm Staging ; Paraganglioma ; diagnostic imaging ; surgery ; Positron Emission Tomography Computed Tomography ; Retrospective Studies ; Sensitivity and Specificity ; Testicular Neoplasms ; diagnostic imaging ; surgery ; Testis ; diagnostic imaging ; surgery