Objective:To investigate the utility of 68Ga-fibroblast activation protein (FAP) inhibitor (FAPI)-04 PET imaging in assessing the therapeutic response in pressure overload-induced heart failure. Methods:Rat models of pressure overload-induced heart failure were established by abdominal aortic constriction (AAC). Thirty rats were categorized into AAC group, 7 days reverse AAC (rAAC) group, and sham operation (sham) group ( n=10 per group) using completely random grouping method. All rats underwent 68Ga-FAPI-04 PET/CT imaging at 4 and 8 weeks after the ACC operation, while echocardiography, pathological examination, and immunohistochemical analysis were performed at 8 weeks postoperation. One-way analysis of variance, independent-sample t test and Pearson correlation analysis were used for data analysis. Results:68Ga-FAPI-04 PET/CT imaging showed that the target-to-background ratios of the heart and liver had significant differences among three groups both at 4 and 8 weeks postoperation ( F values: 2 547.12, 2 041.71, 462.65, 1 210.97, all P<0.001). Echocardiography revealed left ventricular ejection fraction (LVEF), left ventricular internal diameter at end-diastole (LVIDd), and left ventricular internal diameter at end-systole (LVIDs) in three groups at 8 weeks postoperation were significantly different ( F values: 118.92, 9.11, 10.63, all P<0.01). Rats were sacrificed at 8 weeks postoperation, and Masson staining showed that the fibrosis in the heart and liver of the rAAC group was significantly improved compared with that of the AAC group, and immunohistochemical analysis revealed significantly lower FAP levels in the heart and liver of the rAAC group compared with those of the AAC group ( t values: from -11.27 to -4.16, all P<0.01). FAPI uptake in the heart of the AAC group and rAAC group at 8 weeks postoperation were significantly positively correlated with FAPI uptake in the liver, LVIDd and LVIDs, FAPI uptake in the heart was significantly negatively correlated with LVEF, and FAPI uptake in the heart and liver were significantly positively correlated with fibrosis degree and FAP levels of corresponding organs ( r values: -0.89, -0.88, 0.72-0.97, all P<0.05). Conclusions:68Ga-FAPI-04 PET/CT can show the improvement process of cardio-liver fibrosis following the unloading of excessive pressure in heart failure. Myocardial FAPI uptake is closely related to the extent of heart failure improvement.

Objective:To explore the predictive value of 18F-FDG PET/CT metabolic parameters combined with inflammatory markers for the medium-term efficacy of chemotherapy in patients with primary gastrointestinal diffuse large B cell lymphoma (PGI-DLBCL). Methods:From April 2011 to May 2020, 67 patients (37 males, 30 females, age: 28-85 years) with PGI-DLBCL examined by 18F-FDG PET/CT before chemotherapy in Changhai Hospital, Navy Medical University were retrospectively analyzed. All patients were treated with cyclophosphamide+ doxorubicin+ vincristine+ prednisone (CHOP) or rituximab+ CHOP (R-CHOP) regimens, and the medium-term efficacy was evaluated after 2-4 cycles of chemotherapy. The effect outcome was divided into complete remission (CR) group and non-CR (NCR) group based on the Lugano lymphoma response evaluation criteria. Mann-Whitney U test was used to compare the differences of SUV max, peak of SUV (SUV peak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio (NLR) between two groups. The independent risk factors of NCR were analyzed by multivariate logistic regression and the binary logistic regression model was established according to the results. The model was tested with external validation data ( n=15). Results:Of 67 PGI-DLBCL patients, 28(41.8%) were CR and 39(58.2%) were NCR. SUV peak, MTV, TLG, PLR and NLR in NCR group (17.3(12.3, 28.1), 73.8(42.9, 141.7) cm 3, 887.5(300.9, 2 075.3) g, 203.9(155.7, 297.1), 3.9(3.0, 4.9)) were significantly higher than those in CR group (9.5(6.2, 15.2), 11.3(4.7, 23.2) cm 3, 85.2(35.5, 214.6) g, 149.3(102.8, 173.1), 2.2(1.8, 4.6); z values: from -6.41 to -2.33, all P<0.05). The logistic regression model was as follows: P=1/(1+ e - x), x=0.100×MTV+ 0.024×PLR-8.064. The prediction accuracy for NCR risk was 86.57%(58/67), with the accuracy of 13/15 tested by external validation data. Conclusion:MTV combined with PLR has a good predictive value for medium-term efficacy of CHOP/R-CHOP chemotherapy in patients with PGI-DLBCL.

Objective:To optimize the preparation conditions and methods of Al 18F-prostate specific membrane antigen (PSMA)-11 and evaluate the feasibility of clinical transformation. Methods:PSMA- N, N′-bis(2-hydroxy-5-(carboxyethy)benzyl)ethylenediamine- N, N′-diacetic acid (HBED-CC) dissolved in CH 3COONH 4 buffer (pH=4.8) was reacted with AlCl 3·3H 2O dissolved in pure water at a molar ratio of 1∶1 (60 ℃, 10 min), and then purified by tC18 column and freeze-dried to obtain [Al]-PSMA-11. [Al]-PSMA-11 was labeled by 18F - and the effects of reaction temperature and pH value on the labeling rate were investigated. The labeled products were purified by tC18 column and filtered through sterile filter to obtain Al 18F-PSMA-11. The comparison of biodistribution between Al 18F-PSMA-11 and 68Ga-PSMA-11 was analyzed on 5 healthy volunteers (age (56±8) years). The differences of SUV max between two groups were analyzed by independent-sample t test. Besides, the early and delayed imaging of Al 18F-PSMA-11 PET/CT were performed on a patient (70 years old) with recurrent prostate cancer for assessment of its potential for prostate cancer recurrence monitoring. Results:The labeling rate was (42.3±3.2)% reacting in aqueous phase (60 ℃, pH=4.8) for 15 min. After being purified with tC18 cartridge, the radiochemical purity of the product was still more than 95% after placement at room temperature for 3 h. Preliminary application demonstrated that there was no significant difference in the biodistribution of Al 18F-PSMA-11 and 68Ga-PSMA-11 among lacrimal gland, parotid gland, submandibular gland, liver, spleen, kidney, bladder and part of intestine and SUV max of targeted organs were also not different ( t values: 0.19-1.95, all P>0.05) between two groups. Multiple bone metastases were observed by Al 18F-PSMA-11 PET/CT delayed imaging (3 h) in a patient with recurrent prostate cancer. Conclusion:Al 18F-PSMA-11 produced with pre-conjugated [Al]-PSMA-11 meets the requirement of the PET imaging application, and it has good potential of localization and imaging for prostate cancer metastatic lesions.

Neuroendocrine neoplasms (NEN) are tumors that originate from neuroendocrine cells or peptidergic neurons. NEN can be found in a variety of organs with high heterogeneity in pathology and large difference in prognosis. Conventional imaging methods and pathological biopsy have important roles in the diagnosis of NEN, while both of them have limitations. Most NEN cells highly express several peptide receptors, especially somatostatin receptors (SSTR). Moreover, some of them have high glycolysis activity because of high proliferative activity. ⁶⁸Ga-somatostatin analogs (⁶⁸Ga-SSA) combined with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT imaging can comprehensively evaluate both the expression of SSTR and the activity of glycolysis in NEN, providing effective information for diagnosis, treatment, monitoring and prognosis. This review summarizes the current studies of combined ⁶⁸Ga-SSA/¹⁸F-FDG PET/CT imaging in patients with NEN.

Objective To explore the predictive value of 18F-fluorodeoxyglucose (FDG) PET/CT related metabolic parameters for Kras mutation in colorectal cancer (CRC) patients.Methods Retrospective analysis was conducted in 150 patients (105 males,45 females,median age:63 years) with CRC who underwent 18F-FDG PET/CT in Changhai Hospital of Navy Medical University between November 2011 and August 2017.The primary tumors were removed by surgery and patients received genetic testing within 1 month after PET/CT.18F-FDG PET/CT related metabolic parameters were measured,including maximum standardized uptake value (SUVmax),metabolic tumor volume (MTV;including MTV2.5,MTV20％,MTV30％,MTV40％,MTV50％),total lesion glycolysis (TLG;including TLG2.5,TLG20％,TLG30％,TLG40％,TLG50％).Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were used to analyze the data.Results There were 78 Kras-mutated type patients and 72 wild-type patients.Logistic regression analysis showed that SUVmax (odds ratio (OR) =1.176,95％ CI:1.043-1.327) and MTV2.5 (OR =1.125,95 ％ CI:1.002-1.263) were predictors of Kras mutation.With SUVmax =15.5 and MTV2.5 =23.79 cm3 as the cut-off value,the prediction accuracies of Kras mutation were 67.33％(101/150) and 65.33％(98/150),respectively.The accuracies of SUVmax and MTV2.5 for predicting Kras mutation were higher in recta or sigmoid colon cancers (70.79％(63/89) and 68.54％(61/89)).Conclusion SUVmax and MTV2.5 can predict Kras mutation in CRC patients,but there is a significant gap of predictive efficiency between PET/CT and gene detection.

Autoimmune pancreatitis (AIP) is a unique subtype of chronic pancreatitis, which shares many clinical presentations with pancreatic ductal adenocarcinoma (PDA). The misdiagnosis of AIP often leads to unnecessary pancreatic resection. F-FDG positron emission tomography/ computed tomography (PET/CT) could provide comprehensive information on the morphology, density, and functional metabolism of the pancreas at the same time. It has been proved to be a promising modality for noninvasive differentiation between AIP and PDA. However, there is a lack of clinical analysis of PET/CT image texture features. Difficulty still remains in differentiating AIP and PDA based on commonly used diagnostic methods. Therefore, this paper studied the differentiation of AIP and PDA based on multi-modality texture features. We utilized multiple feature extraction algorithms to extract the texture features from CT and PET images at first. Then, the Fisher criterion and sequence forward floating selection algorithm (SFFS) combined with support vector machine (SVM) was employed to select the optimal multi-modality feature subset. Finally, the SVM classifier was used to differentiate AIP from PDA. The results prove that texture analysis of lesions helps to achieve accurate differentiation of AIP and PDA.
Adenocarcinoma ; diagnostic imaging ; Algorithms ; Autoimmune Diseases ; diagnostic imaging ; Diagnosis, Differential ; Fluorodeoxyglucose F18 ; Humans ; Pancreatic Neoplasms ; diagnostic imaging ; Pancreatitis ; diagnostic imaging ; Positron Emission Tomography Computed Tomography ; Support Vector Machine

Objective To study the features and clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT in prosthetic vascular graft infections (PVGIs) after endovascular aortic repair (EVAR).Methods Data of 27 patients (22 males and 5 females,age range:21-77 years,average age:42 years) who underwent PET/CT imaging after EVAR from October 2011 to January 2017 were studied retrospectively.A total of 11 cases were finally diagnosed as PVGIs (PVGIs group),and the remaining 16 cases were defined as the negative group.PET/CT imaging features were compared between two groups.The detection rates of PET/CT and aortic CT angiography (CTA) for PVGIs were calculated and compared.Two-sample t test and Fisher exact test were used for data analysis.Results Significant uptake of FDG around the stents was detected by PET/CT in all patients in PVGIs group.The maximum standardized uptake value (SUVmax) of 11 patients in early imaging was 14.9±3.3 (10.8-21.8) and that of 9 patients in delayed imaging was 13.8±3.4 (10.6-19.1).Six patients of the negative group underwent the delayed imaging.No uptake or mild uptake of FDG around the stents was observed in negative group,with the SUVmax of 1.7±0.8(1.0--2.9) in early imaging and 1.6±0.7(1.1-2.5) in delayed imaging.SUVmax in negative group was significantly lower than that in PVGIs group (t values:12.6 and 11.8,both P＜0.001).Five patients in PVGIs group were diagnosed as graft infections by the aortic CTA,while the remaining 6 cases showed no definitive infection signs on aortic CTA.The detection rate of aortic CTA was 5/11,which was significantly lower than that of PET/CT (P＜0.05).In negative group,6 patients had abnormal FDG uptakes in other areas and were finally confirmed as infectious lesions (n=3) or malignant tumors (n=3).Conclusion Compared with aortic CTA,18F-FDG PET/CT is more sensitive and accurate in detection and diagnosis of PVGIs after EVAR.

Objective To investigate the inhibitory effect of 188 Re-labeled BaGdF5-poly ( ethylene glycol) ( PEG) nanoparticles ( NPs) on hepatoma cells, and explore the application of the radiolabeled NPs for SPECT imaging. Methods BaGdF5-PEG NPs were synthesized by hydrothermal method, and were fur-ther radiolabeled with 188Re using diethylene triamine pentaacetic acid (DTPA) as a coupling agent. The human hepatoma cells SMCC 7721 were treated with different concentrations of BaGdF5-PEG NPs, 188 ReO-4 or 188Re-DTPA-BaGdF5 NPs (14.8, 74.0, 370.0×104 Bq/ml) for 24 h, and then the cell proliferation rates were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. 188ReO-4 and 188 Re-DTPA-BaGdF5 NPs were administrated into normal rabbits via the ear vein, respectively. For the former, static SPECT/CT imaging were performed at 30, 60 min post-injection, and for the latter, dynamic SPECT images were captured within 10 min, and static SPECT/CT images at 30, 60, 120 min post-injec-tion. The rabbit VX2 tumor model was established, and a microcatheter was inserted into hepatic artery via the rabbit femoral artery, and then the mixture of 188 Re-DTPA-BaGdF5 NPs and lipiodol was injected into the tumor region. SPECT/CT imaging for VX2 tumor was performed at 30 min later. Data were analyzed by two-sample t test. Results The BaGdF5-PEG NPs were nearly square and the particle size was about 10 nm. The labeling yield of 188 Re-DTPA-BaGdF5 was 94.1％ at the optimum conditions. Moreover, it showed high stability in vitro and in vivo. In vitro, BaGdF5-PEG NPs did not exhibit obvious cytotoxicity even at a high concentration. Both 188 ReO-4 and 188 Re-DTPA-BaGdF5 could inhibit the proliferation of SMCC 7721 cells, but 188 Re-DTPA-BaGdF5 showed a significantly stronger inhibitory effect at the doses of 74.0 and 370.0×104 Bq/ml ( t values:4.21,4.09, both P<0.01) . In vivo, 188 ReO-4 was absorbed by maxillary glands and was quickly elimi-nated from blood via the kidneys. The 188 Re-DTPA-BaGdF5 NPs mainly accumulated in the liver and spleen. In addition, retention and accumulation of 188 Re-DTPA-BaGdF5 NPs in the liver tumor could be achieved by using transarterial intervention technique for drug delivery. Conclusion 188Re-DTPA-BaGdF5 NPs have cer-tain killing effects on hepatoma cells in vitro, and with the help of transarterial intervention technique, the NPs can be aggregated within liver tumor, where they not only can be used for SPECT imaging, but also have potential therapeutic effects.

Objective To evaluate the differential diagnostic value of 18F-FDG PET/CT between pancreatic lymphoma (PL) and pancreatic carcinoma (PC).Methods The 18 F-FDG PET-CT data of 16 patients who were pathological diagnosed with PL were retrospectively reviewed and compared with those of 32 consecutive pancreatic cancer patients who were pathologically diagnosed and randomly enrolled.The age,location,diameter and the maximum standard uptake values (SUVmax) of pancreatic lesions,pancreatic ductal dilatation,distal pancreatic atrophy,serum CA19-9 level and extrapancreatic organs involvement were analyzed.Results The 16 patients with PL included 8 men and 8 women,the mean age was (46 ± 17)year,and 11.1％ (1/9) patients had elevated CA19-9.The 32 patients with PC included 15 men and 17 women,the mean age was (61 ± 12)year,and 81.3％ patients had elevated CA19-9.There were no significant differences on gender between the two groups,while the mean age of PL patients was younger than that of PC,elevated CA19-9 was less common than that in PC,and the differences were statistically significant (all P＜0.05).There were 12 cases of diffusive large B cell lymphoma,2 cases of B lymphoblastic lymphoma/leukaemia,1 case of follicular lymphoma and 1 case of dysplastic large T cell lymphoma in 16 PL patients.There was no significant difference on the site of pancreatic lesions between the two groups,but long diameter of PL lesions was larger than that of PC [(6.6 ± 3.3) vs (4.3 ± 1.8) cm,P =0.038].Dilated pancreatic duct and distal parenchyma atrophy in PL were less than those in PC (3/16 vs 17/32,1/16 vs 13/32),and SUVmax of PL lesions was significantly higher than that of PC (12.0 ± 5.5 vs 8.6 ± 3.8),indicating that the differences were statistically significant (all P ＜ 0.05).The cut-off value of SUVmax was 9.95,and Youden's index was 0.406 with the sensitivity and specificity of 68.8％ and 71.9％ for differentiating PL from PC.The incidence of extrapancreatic lesions including bone marrow and kidney and spleen infiltration was significantly more frequent in patients with PL than that in patients with PC(56.3％ vs 6.25％,43.8％ vs 3.1％,50.0％ vs 6.3％),while the incidence of liver metastases was significantly lower than that in PC (12.5％ vs 5.0％),indicating that the differences were statistically significant (all P ＜0.01).There were no significant differences on the incidence of other extrapancreatic lesions.Conclusions PL should be considered in relatively younger patients and manifested as a bulky mass with significant FDG uptake and extrapancreatic involvement of bone,kidney and spleen but without distinct pancreatic ductal dilation or distal parenchymal atrophy or liver metastasis.

Objective To evaluate the diagnostic value of the metabolic parameters for differentiating focal autoimmune pancreatitis (F-AIP) and pancreatic cancer (PC) by dual time 18F-FDG PET/CT scan.Methods Ten F-AIP patients and 20 PC patients in Changhai Hospital from May 2011 to November 2014 were enrolled in this study.All the AIP patients were histological confirmed or diagnosed by clinical follow up.The PC patients were histological confirmed and gender-and age-matched with F-AIP patients.50％ SUVmax was set as the threshold to fine-tune the boundary of interest.The extracted parameters included SUV SUV metabolic tumor volume (MTV),total lesion glycolysis (TLG),target-to-background ratio (TBR) and the retention indexes(RI) of all the parameters above.The PET/CT imaging features were also observed.Results The high metabolic lesions were observed in both F-AIP patients and PC patients.There were 6 F-AIP patients whose lesion was located in pancreas head,4 F-AIP patients whose lesion was located in pancreas body and tail.There were 12 PC patients whose lesion was located in pancreas head,8 PC patients whose lesion was located in pancreas body and tail.In F-AIP patients,2 cases had dilated pancreatic duct,6 had dilated biliary duct,8 had increased metabolism in mediastinal lymph node and 2 had abdominal lymphadenopathy,which were 8,5,5 and 14 cases in PC patients.The positive rate of mdeiastinal lymphadenopathy in F-AIP patients was statistically higher than that in PC patients,while the positivity rate of abdominal lymphadenopathy in AIP patients was lower than that in PC patients.The difference was statistically significant (both P ＜ 0.05).There were no statistical differences on the positivity rate of the dilated pancreatic duct,intra-and extra-hepatic bile duct between two groups.SUVmax,SUVmean and MTV in F-AIP were 5.37 ± 0.88,3.48 ± 0.66,21.79 ±15.60 in early stage and 6.45 ±1.51,4.23 ± 1.10,19.36 ± 14.63 in delayed stage,and those in PC were 8.31 ±3.08,5.41±1.95,9.26±8.35 in early stage,and 9.75±3.86,6.36±2.56,9.09±10.71 in delayed stage.SUVmax and SUVmean in F-AIP were lower than those in PC,whereas MTV were larger in F-AIP than that in PC.ROC curves for SUVmax,SUVmean and MTV were made.The AUC of SUV was the highest at 0.85,the cut-off value was 4.45,the corresponding sensitivity was 65％ and the specificity was 90％.TLG,TBR and RI of all the parameters were not statistically different in F-AIP and PC.Conclusions The 18F-FDG PET/CT metabolic parameters,such as SUVmax,SUVmean,MTV,could be of special diagnostic significance in discriminating F-AIP from PC.