The treatment effect of primary and metastatic hepatic carcinoma after local intervention?al therapy is closely related to the prognosis of patients. Traditional imaging modalities such as CT, MRI and ultrasound can only provide anatomical information in monitoring treatment response. In recent years, PET/CT has been widely used in monitoring treatment response for tumors. Many studies have compared the effi?cacy of PET/CT with that of traditional imaging modalities in monitoring the response of primary and meta?static hepatic carcinoma after interventional therapy. This review summarizes recent progress in this field.

Objective To assess risk factors in NSCLC with N2 metastasis.Methods A total of 177 NSCLC patients (109 males,68 females; age:(60.1 ± 10.6) years) who underwent both 18F-FDG PET/CT scan and surgery were enrolled.They were divided into two groups.One was with N2 metastasis (N2+) and the other was without (non-N2+).The gender,age,location,size,primary tumor SUVmax,histopathologic type and differentiation grade between N2+ group and non-N2+ group were compared with x2 test and two-sample t test.After assignment of significant factors and groups,correlations between each factor and group were analyzed with uni-and multivariate analyses,and then the risk factors were identified finally with logistic regression analysis.Results Significant difference among factors of tumor size ((36.1±19.7) mm vs (49.3±24.4) mm),SUVmax(8.81±6.23 vs 11.21±4.43) and differentiation grades (high:3 vs 0; moderate:74 vs 11; poor:65 vs 24) were observed between non-N2+ group and N2+ group (t =-2.969,-2.633,x2 =6.143,all P＜0.05).Besides,the univariate analysis showed significant correlations between tumor size,SUVmax,differentiation grade and N2 status (r=0.201,0.245,0.185,all P＜0.05).However,multivariate logistic regression revealed that only SUVmax had a predictive value (β=0.546,P＜0.01).The incidence of N2 metastasis went up along with the increase of SUVmax.There was no N2 metastasis in the patients with SUVmax ≤2.5,and the incidence rate of metastasis increased to 0.29 in those with SUVmax＞7.5.Conclusion SUVmax may be an independent risk factor to predict N2 metastasis in NSCLC patients.

The imaging field of view ( FOV) used for most oncological 18 F-fluorodeoxyglucose (FDG) PET/ CT studies, from skull to mid-thigh, is typically a limited whole-body (LWB). This methodol-ogy has been suggested by the Society of Nuclear Medicine and Molecular Imaging and European Association of Nuclear Medicine guidelines. Using routine FOV for LWB may underestimate the true tumor extent because malignancy beyond the FOV might be missed. This review summarizes the optimum scan FOV for different types of tumors. For some tumors (such as lung cancer) that commonly spread to the brain, brain and (or) head should be included in the FOV. For lymphoma, especially pediatric lymphoma, which commonly in-volves lower extremities, true whole-body (TWB) scan should be used for cancer staging and follow up. LWB scan is optimal for melanoma which confined in the field of LWB.

Objective    To investigate the relationship between the expression of programmed cell death ligand-1 (PD-L1) and the maximal standardized uptake value (SUVmax) in 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and the correlation of clinical factors between SUVmax values and PD-L1. Methods    The clinical data of 84 patients with invasive lung adenocarcinoma diagnosed pathologically in West China Hospital, Sichuan University from August 2016 to November 2018 were analyzed retrospectively, including 38 males and 46 females, aged 60 (32-85) years. The tumor was acinar-predominant in 37 patients, papillary in 20, lepidic in 19, solid in 5 and micropapillary in 3. Multivariate analysis of the relationship between SUVmax value and other clinicopathological features was performed by linear regression. Logistic regression analysis was used to analyze the relationship between PD-L1 protein expression and other pathological features. Results    The SUVmax of the PD-L1 expression group was significantly higher than that of the non-PD-L1 expression group in the whole invasive lung adenocarcinoma group (P=0.002) and intermediate-grade histologic subtype (P=0.016). The SUVmax cut-off value of PD-L1 expression in the whole invasive lung adenocarcinoma group and intermediate-grade histologic subtype was 5.34 (AUC: 0.732, P=0.002) and 5.34 (AUC: 0.720, P=0.017), respectively. Multivariate analysis showed that pleura involvement, vascular tumor thrombus and the increase of tumor diameter could cause the increase of the SUVmax value, while the SUVmax value decreased in the moderately differentiated tumor compared with the poorly differentiated tumor. The SUVmax cut-off value between low-grade histologic subtype and intermediate-grade histologic subtype, intermediate-grade histologic subtype and high-grade histologic subtypes was 1.54 (AUC: 0.854, P<0.001) and 5.79 (AUC: 0.889, P<0.001), respectively. Multivariate analysis of PD-L1 expression showed pleura involvement (P=0.021, OR=0.022, 95%CI 0.001 to 0.558) and moderate differentiation (opposite to poor differentiation) (P=0.004, OR=0.053, 95%CI 0.007 to 0.042) decreased the expression of PD-L1. Conclusion    The SUVmax of the PD-L1 expression group is significantly higher than that of the non-PD-L1 expression group in the whole invasive lung adenocarcinoma group and intermediate-grade histologic subtype. The level of SUVmax and the expression of PD-L1 in invasive lung adenocarcinoma are related to many clinical factors.