An ideal ionizing radiation biomarker should be able to quickly,conveniently and accurately assess the radiation dose received by individuals,and can predict the effect of radiation-induced damage.Radiation dose assessment based on gene or molecular expression profiles is a research focus in the field of radiation biodosimetry.Non-coding RNA and proteomics have the characteristic of high-throughput that allows for rapid and real-time detection,making them highly potential for radiation biodosimetry research.This paper summarizes the research progress of non-coding RNA and proteins as potential radiation biomarkers in recent years,and also reviews their influencing factors and application scenarios.

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.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly ravaged the world and infected hundreds of millions of people since its outbreak. Early diagnosis of COVID-19 is conducive to the control of virus transmission and the timely treatment of patients. Among the imaging techniques, chest CT is an important basis for the diagnosis and evaluation of COVID-19. 18F-FDG PET is not generally recommended as a routine diagnostic tool for COVID-19, but it plays an important role in the assessment of SARS-CoV-2-related events based on the characteristic of whole-body multi-systemic scan and functional imaging diagnosis. In this paper, the application of 18F-FDG PET in COVID-19 diagnosis, prognostic evaluation and long-term sequelae evaluation, and clinical performance of 18F-FDG PET after COVID-19 vaccine are summarized on the basis of literature research and clinical reports analysis. Furthermore, the application and development direction of other new molecular probes for nuclear medicine in COVID-19 are prospected.

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.

Objective:To investigate the imaging features of pancreatic hypervascular tumors in computed tomography (CT) and magnetic resonance imaging (MRI) examinations.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 53 patients with pancreatic hypervascular tumors who were admitted to two medical centers, including 32 cases in the Affiliated Hospital of Medical School, Ningbo University and 21 cases in the First Affiliated Hospital of Naval Medical University, from March 2007 to February 2021 were collected. There were 21 males and 32 females, aged (48±23)years. Of the 53 patients, there were 19 cases with pancreatic neuroendocrine tumor (PNET), 9 cases with pancreatic metastasis from renal cell carcinoma (PRCC), 8 cases with solid pseudopapillary tumors of pancreas (SPTP), 7 cases with intrapancreatic accessory spleen (IPAS), 6 cases with serous cystadenoma of pancreas (SCP) and 4 cases with aneurysms. All the 53 patients underwent CT and MRI. Observation indicators: (1) imaging feature of PNET; (2) imaging feature of PRCC; (3) imaging feature of SPTP; (4) imaging feature of IPAS; (5) imaging feature of SCP; (6) imaging feature of aneurysms. Measurement data with normal distribution were represented as Mean±SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. Results:(1) Imaging feature of PNET: of the 19 cases with PNET, there were 1 case with Von Hippel-Lindau disease (VHLD), 8 cases with multiple endocrine neoplasia type 1 (MEN1) and 10 cases with neuroendocrine tumor (NET). Of the 19 cases, 16 cases had single tumor and 3 cases had 2 tumors, 9 cases had tumor located at head of pancreas and 10 cases had tumor located at body and tail of pancreas. Morphology of tumors in the 19 cases were mostly round or elliptical, with some shallow lobes and clear boundary. There were 4 cases with cluster-like calcifications in the center of tumors and 15 cases with no cluster-like calcification in the center of tumors. The tumor diameter of 19 cases was (26.7±10.3)mm. Of the 19 cases, 1 case underwent pancreatic atrophy and segmental expansion of the main pancreatic duct and 18 cases underwent no pancreatic atrophy or segmental expansion of the main pancreatic duct, 2 cases underwent dilated bile ducts and 17 cases underwent no dilated bile ducts. The enhance-ment mode of imaging examination of PNET was wash in and wash out. (2) Imaging feature of PRCC: Of the 9 cases with PRCC, 2 cases had single tumor and 7 cases had multiple tumors. Of the 2 cases with single tumor, 1 case had tumor located at neck of pancreas and 1 case had tumor located at body and tail of pancreas. All the 7 cases with multiple tumors had tumor located at head, neck, body and tail of pancreas. Morphology of tumors in the 9 cases were round or quasi-circular, with clear boundary. The tumor diameter were (18.0±5.0)mm of the 2 cases with single tumor and 2.0-50.0 mm of the 7 cases with multiple tumors, respectively. Of the 9 cases, 2 cases underwent pancreatic ducts dilatation and 7 cases underwent no pancreatic ducts dilatation. The enhancement mode of imaging examination of PRCC was wash in and wash out. (3) Imaging feature of SPTP: all 8 cases with SPTP had single tumor, including 4 cases with tumor located at head of pancreas and 4 cases with tumor located at body and tail of pancreas. Morphology of tumors in the 8 cases were lobulated with clear boundary. Of the 8 cases, there were 2 cases with no calcifications of tumors and 6 cases with calcification of tumors, 2 cases with no cystic necrosis of tumors and 6 cases with cystic necrosis of tumors, 3 cases with no bleeding in the tumors and 5 cases with bleeding in the tumors. The tumor diameter of 8 cases was (51.6±11.8)mm. All the 8 cases were negative for pancreatic ducts dilatation, but the adjacent organs were compressed and moved. The enhancement mode of imaging examination of SPTP was asymptotic enhancement. (4) Imaging feature of IPAS: all the 7 cases with IPAS had single tumor located at tail of pancreas. Morphology of tumors in the 7 cases were round or quasi-circular shape with clear boundary. Of the 7 cases, 1 case with solid-cystic and uneven density tumor was epidermoid cyst in the accessory spleen of the tail of the pancreas, and 6 cases had solid and uniform density tumors. The tumor diameter of 7 cases was (25.5±8.5)mm. All the 7 cases were negative for pancreatic ducts dilatation and the surrounding structures of pancreatic ducts were clear. The enhancement mode of imaging examination of IPAS was asymptotic enhancement. (5) Imaging feature of SCP: all 6 cases with SCP had single tumor, including 1 case with tumor located at neck of pancreas and 5 cases with tumor located at body and tail of pancreas. Morphology of tumors in the 6 cases were round or quasi-circular, with clear boundary. Of the 6 cases, 2 cases had cystic tumors and 4 cases had solid tumors. The tumor diameter of 6 cases was (35.5±15.4)mm. Of the 6 cases, 2 cases were positive for pancreatic ducts dilatation and 4 cases were negative for pancreatic ducts dilatation. The enhancement mode of imaging examination of SCP was wash in and wash out. (6) Imaging feature of aneurysms: all the 4 cases with aneurysms had single tumor, including 1 case with tumor located at body of pancreas and 3 cases with tumor located at tail of pancreas. One case with tumor located at body of pancreas was superior duodenal aneurysm and 3 cases with tumor located at tail of pancreas were splenic aneurysms. Morphology of tumors in the 4 cases were round, with clear boundary. Of the 4 cases, 1 case was negative for tumor marginal calcification and 3 cases were positive for tumor marginal calcification. The tumor diameter of 4 cases was (11.3±2.5)mm. All the 4 cases were negative for pancreatic ducts dilatation. The enhance-ment mode of imaging examination of aneurysms was wash in and wash out.Conclusions:The imaging features of pancreatic hypervascular tumors in CT and MRI examinations show diversity. The enhancement mode of imaging examination of PNET, PRCC, SCP and aneurysms is wash in and wash out. The enhancement mode of imaging examination of SPTP and IPAS is asymptotic enhancement.

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.

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 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.

The therapeutic efficiency of radionuclides for cancer is closely related to the accumula-tion level, residence time and distribution in tumor, and is also influenced by the radiation resistance and hypoxia microenvironment of tumor. Nanomaterials, with a series of characteristics including special dimen-sion effect and functionally modifiable surface, can not only work as the isotopic carrier to transport nuclide into tumor, but also combine with chemical, thermal or photodynamic therapies to generate synergistic thera-peutic effect or destroy the hypoxic microenvironment of tumor to reduce radiation resistance, thus achieving the radiosensitization effect. This article reviews the application of nanomaterials in enhancing the therapeu-tic efficiency of radionuclide for cancer.