RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
Assuntos
Humanos , Adenocarcinoma , Diagnóstico por Imagem , Algoritmos , Doenças Autoimunes , Diagnóstico por Imagem , Diagnóstico Diferencial , Fluordesoxiglucose F18 , Neoplasias Pancreáticas , Diagnóstico por Imagem , Pancreatite , Diagnóstico por Imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Máquina de Vetores de SuporteRESUMO
Objective To evaluate preoperative apparent diffusion coefficient (ADC) and exponential apparent diffusion coefficient (eADC) in diffusion weighted imaging (DWI) on microvascular invasion (MVI) of hepatocellular carcinoma (HCC).Methods We retrospectively reviewed 43 HCC patients with DWI data confirmed by surgery and pathology.ADC and eADC values were measured both in neoplasm and hepatic tissue,the ratio of tumor to liver (T/L) on ADC and eADC was calculated.The correlation between MVI and ADC value,T/L of ADC value,eADC value and T/L of eADC value was analysed,the best cut-off value of variables was analysed by ROC curve,multi factor analysis was carried out by Logistic regression model.Results The ADC value,T/L of ADC,eADC value and T/L of eADC were (1.458 ± 0.444) × 10-3 mm2/s,0.787 ± 0.186,0.289 ± 0.144 and 1.383 (1.179,1.655),respectively.Among them,the positive MVI group were (1.232 ± 0.480) × 10-3 mm2/s,0.683 ± 0.229,0.323 ±0.123 and 1.630(1.387,2.066),respectively.The negative MVI group were(1.545 ±0.404) × 10-3mm2/s,0.844 ±0.149,0.277 ±0.152 and 1.303(1.176,1.545),respectively.There was significant difference in ADC value,T/L of ADC value and T/L of eADC value (t =2.164,2.654,z =-2.058,all P ＜0.05),the area under the ROC curve were (1.085 × 10-3) mm2/s,0.685 and 1.475 using MVI as a diagnostic standard.Multivariate analysis showed that T/L of ADC value was an independent factor affecting MVI of HCC (OR=0.002,95％CI:1.380E-5-0.311,P＜0.05).Conclusions The ADC value in HCC patients with positive MVI is lower than in HCC patients with negative MVI,T/L of eADC value is higher than in HCC patients with negative MVI,and T/L of ADC value is an independent factor predicticing MVI of HCC.
RESUMO
Objective@#To investigate the value of 18F-fluorodeoxyglucose (FDG) PET/CT in differentiation of noninvasive and malignant pancreatic cystic lesions (PCL).@*Methods@#A total of 125 PCL patients (66 males, 59 females, age range: 13-83 years), who had pathology or typical imaging performance with ≥12 months follow-up between August 2010 and December 2015, were enrolled in this retrospective study. The diagnostic effects of 18F-FDG PET/CT were calculated. The size, maximum standardized uptake value (SUVmax), delayed SUVmax and retention index (RI) of noninvasive and malignant PCL were analyzed. The results of pathological examination and follow-up were used as the gold standard, and Mann-Whitney u test was used to analyze the data. Receiver operating characteristic (ROC) curves of SUVmax, delayed SUVmax and RI were drawn and compared.@*Results@#A total of 132 PCL were found in 125 patients, including 71 malignant PCL and 61 noninvasive PCL. The size, SUVmax, delayed SUVmax, RI of noninvasive and malignant PLC were 2.2 (1.4, 3.8) cm vs 3.9 (3.0, 5.0) cm, 1.5 (1.2, 1.8) vs 6.4 (4.4, 9.3), 1.5 (1.2, 1.9) vs 6.4 (5.4, 11.7), -6.3%(-19.4%, 5.6%) vs 17.5%(7.6%, 29.4%), respectively. All parameters were significantly different between 2 groups (z values: from -9.267 to -4.904, all P<0.05). The area under curve (AUC) and cut-off value of SUVmax were 0.969 and 2.5, and the corresponding accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) were 92.4%(122/132), 93.0%(66/71), 91.8%(56/61), 93.0%(66/71), 91.8%(56/61), respectively. The AUC and cut-off value of delayed SUVmax were 0.969 and 2.7, and the accuracy, sensitivity, specificity, PPV, NPV were 94.3%(99/105), 96.7%(58/60), 91.1%(41/45), 93.5%(58/62), 95.3%(41/43), respectively. ROC curves of SUVmax and delayed SUVmax were not significantly different (z=1.799, P>0.05).@*Conclusion@#18F-FDG PET/CT has good performance in differentiation of noninvasive and malignant PCL, but the delayed scan cannot further improve the efficacy of differential diagnosis.
RESUMO
Objective To investigate the clinical value of Fluorine-18-fluorodeoxyglucose (18 F-FDG)positron-emission temography/computed tomography (PET/CT) examination to predict microvascular invasion (MVI) of hepatocellular carcinoma (HCC).Methods The retrospective cohort study was conducted.The clinicopathological data of 51 HCC patients who were admitted to Changhai Hospital of the Second Military Medical University (32 patients) and Universal Medical Imaging Diagnostic Center (19 patients) from January 2013 to October 2017 were collected.Of 51 patients receiving postoperative pathological examination,21 diagnosed with positive MVI and 30 diagnosed with negative MVI were respectively allocated into the positive and negative MVI groups.All the patients received preoperative 1s F-FDG PET/CT examination and underwent surgery after related examinations.Two imaging doctors independently read films and made a semi-quantitative analysis.Observation indicators:(1) results of 18F-FDG PET/CT examination;(2) multivariate analysis and diagnostic value affecting MVI of HCC;(3) treatment and follow-up.Follow-up using outpatient examination and telephone interview was performed to detect the postoperative patients' survival up to November 2017.Measurement data with normal distribution were represented as (x)±s,and comparisons between groups were evaluated with the independent-sample t test.Measurement data with skewed distribution were described as M (Qn),and comparisons between groups were analyzed using the independent-sample rank sum test.Comparisons of count data were analyzed using the chisquare test.Logistic regression analysis was performed in variables with statistical significance.The inclusion criteria was 0.05 and exclusion criteria was 0.10 according to Backward (LR) method for screening variables.Receiver Operating Characeristic (ROC) curve analysis was used to evaluate the diagnostic value using MVI as a diagnostic standard.Results (1) Results of 18F-FDG PET/CT examination:of 51 HCC patients,tumors located in the right lobe,left lobe and caudate lobe of the liver were respectively detected in 37,12 and 2 patients.CT examinations of 51 HCC patients:HCCs showed the hypodense shadow or slightly hypodense shadow in liver and were round-like,and some of the larger lesions were irregularly conglomerate,with a relatively clear tumor-liver boundary;tumor necrosis area showed patchy and irregular lower density,with small lesions around the port of tumors.Of 51 patients,34 were positive on PET and 17 were negative on PET,and some necrotic areas showed no uptake and located in the center of tumors.There was no abnormal 18 F-FDG uptake in other parts of the whole body.The maximum diameter of tumor was (6± 3)cm.The maximum standardized uptake value (SUVmax),and ratio of SUVmax of tumor to SUVmax of liver (SUVmax T/L) in all the lesions were 6.38±4.91 and 2.42±1.93,respectively.The mean standardized uptake value (SUVmean),metabolism of volume (MTV),total lesion of glycolysis (TLG) of 40 patients were 4.30± 2.46,43.82 cm3 (8.97 cm3,219.13 cm3) and 165.73 (28.26,794.50),respectively,and software could not automatically delineate lesions in other 11 patients due to low metabolism.Delayed imaging was found in 21 patients,and the delayed SUVmax and retention index (RI) were 7.22±6.26,19.66％ (-7.10％,50.84％),respectively.The cases with positive and negative on PET were 18,3 in the positive MVI group and 16,14 in the negative MVI group,respectively,with a statistically significant difference between groups (x2=5.829,P＜0.05).The maximum diameter of tumor in the positive MVI group and negative MVI group was respectively (7.7±2.9)cm and (5.2±3.1)cm,with a statistically significant difference between groups (t=-2.930,P＜0.05).(2) Multivariate analysis and diagnostic value affecting MVI of HCC:the results of multivariate analysis showed that maximum diameter of tumor was an independent factor affecting MVI of HCC (OR=1.276,95％ confidence interval:1.028-1.585,P＜0.05).The area under the ROC curve of the maximum diameter of tumor was 0.723 using MVI as a diagnostic standard.The sensitivity,specificity and Youden index were respectively 90.5％,50.0％ and 0.405,with 4.55 cm as the critical value.(3) Treatment and followup:all 51 patients underwent tumor resection.Twenty-two patients were followed up for 25 months (range,12-46 months).The 1-and 2-year overall survival rates were 81.8％ (18/22) and 63.6％ (14/22),respectively.The 1-and 2-year tumor-free survival rates were 59.1％ (13/22) and 45.5％ (10/22),respectively.Conclusion The positive rate on PET of 18F-FDG PET/CT examination in HCC patients with positive MVI is higher than that in HCC patients with negative MVI,and the maximum diameter of tumor is an independent factor predicting MVI of HCC,with a certainly reference value.
RESUMO
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.
RESUMO
Objective To evaluate the values of the quantitative parameters obtained from 18F-fluorodeoxyglucose (FDG) PET/CT imaging and MRI in prediction of lymph node metastasis (LNM) in patients with rectal cancer.Methods From May 2013 to October 2015,80 patients with rectal cancer (63 males,17 females,age range:37-85 years) that underwent preoperative MRI-diffusion weighted imaging (DWI) and 18 F-FDG PET/CT were enrolled.All patients had pathological results.Auto-segmentation methods of various thresholds were selected to determine the FDG metabolic parameters and whole volume region of interest (ROI) method was performed to measure apparent diffusion coefficient (ADC) in lymph node.Maximum standardized uptake value (SUVmax) =2.5,20％ SUVmax,30％ SUVmax,40％ SUVmax and 50％ SUVmax were selected as the cut-off values (COV),and named as COV1,COV2,COV3,COV4 and COV5,respectively.ROI was drawn automatically and the corresponding mean standardized uptake value (SUVmean) 1-SUVmean5,metabolic tumor volume (MTV) 1-MTV5 and total lesion glycolysis (TLG) 1-TLG5 were calculated.x2 test and logistic regression analysis were used to analyze the associations between the LNM and pathological factors,as well as 18F-FDG metabolic parameters and ADC.Results LNM was found in 55％ (44/80) of the patients.The metabolic parameters of primary tumor in patients with LNM were significantly higher than those in patients without LNM (u values:152.0-555.0,all P＜0.05);the ADC was significantly lower in LNM positive cases than that in LNM negative cases:0.96 (0.93,1.02) × 10-3 mm2/s vs 1.07(1.01,1.11) ×10-3 mm2/s,u=249.0,P＜0.05.Univariate analysis showed that T stage,SUVmax,SUVmean 1-SUVmean 5,MTV1-MTV5,TLG1-TLG5,ADC value were associated with pathologic lymph node involvement (x2 values:7.730-48.198,all P＜0.05).Multivariate analysis indicated that MTV1 (odds ratio (OR)=0.110,95％ CI:0.014-0.840),MTV2 (OR=0.075,95％ CI:0.007-0.852) and ADC (OR=0.034,95％ CI:0.003-0.381) of tumor were significant risk factors associated with LNM (all P＜0.05).The optimal COV of MTV1,MTV2 and ADC were 20.26 cm3,18.47 cm3 and 1.00× 10-3 mm2/s.Conclusion MTV1,MTV2 measured by 18F-FDG PET/CT and ADC measured by MRI-DWI of the primary tumor are risk factors of LNM from rectal cancer,and they may be useful to predict LNM in patients with rectal cancer.
RESUMO
18F-flurodeoxyglucose(FDG) PET/CT plays an important role in early diagnosis,clinical staging,therapeutic efficacy evaluation,and recurrence monitoring of colorectal cancer (CRC).More and more scholars have focused on the value of PET/CT in CRC prognosis,intending to find out whether PET/CT can predict the survival outcomes (disease-free survival,progression-free survival and overall survival) of CRC patients after radical resection,in liver metastasis stage or in multiple metastases stage.This review summarizes the clinical value of 18F-FDG PET/CT for the prognosis of CRC.
RESUMO
Objective To investigate the value of dual-phase 18F-FDG PET/CT for differentiating pancreatic cancer from pancreatitis.Methods Dual-phase 18F-FDG PET/CT scanning was prospectively performed on patients with suspicious pancreatic lesions.Patients with solid focal pancreatic lesions proved by histopathology or clinical follow-up were enrolled and divided into 3 groups according to the maximum diameter of the focus: ≤2.0 cm (group A), >2.0 cm and ≤ 4.0 cm (group B), >4.0 cm (group C).SUVmax at (60±10) min and (120±15) min after FDG injection was defined as early and delayed SUVmax (SUVearly and SUVdelayed), respectively, and retention index (RI) was calculated.The differences of SUVearly, SUVdelayed and RI between pancreatic cancer and pancreatitis were analyzed with Mann-Whitney u test.ROC curve was used to determine the optimal cutoff values of the above three parameters and corresponding diagnostic efficiencies were obtained.The AUC was compared with MedCalc software.Results A total of 196 patients (152 pancreatic cancers and 44 pancreatic inflammatory lesions) with solid focal pancreatic lesions were enrolled.The AUC of SUVdelayed was significantly larger than that of SUVearly (0.83 vs 0.79, z=3.64, P0.05).The SUVearly, SUVdelayed and RI of pancreatic cancers were all higher than those of pancreatitis in group A and B (z values: from-4.59 to-3.00, all P 3.6 combined with RI > 0 for diagnosing pancreatic cancer were higher than those of SUVearly > 3.6: 96.4%(27/28) vs 75.0%(21/28), 95.6%(43/45) vs 82.2%(37/45).The AUC of SUVdelayed was significantly larger than that of SUVearly in group B (0.81 vs 0.77, z=2.06, P 3.6 combined with RI >0 could be helpful to improve the diagnostic sensitivity and accuracy in patients with the maximum diameter of lesions ≤2.0 cm.The diagnostic value of SUVdelayed might be better than that of SUVearly in patients with the maximum tumor diameter of >2.0 cm and ≤4.0 cm.Only RI could be used for diagnosing pancreatic tumors in patients with the maximum tumor diameter > 4.0 cm.
RESUMO
The hybrid PET/MR has been gradually applied in clinical practice.However,the hybrid PET/MR is a com plex advanced technique,and it brings to the new challenges,especially regarding the workflow and scan protocols.The guidelines for hybrid PET/MR in brain imaging include information related to the indications and contraindications,preparation before examination,procedures of examination (PET imaging,conventional MRI brain imaging and special MRI imaging for brain disease),application of radiopharmaceutical and MRI contrast-enhanced agent.The purpose of the guidelines is to offer a framework that would be practical and helpful for clinical PET/MR brain imaging.In PET tracers,the guidelines only limit to the 18 F-FDG.
RESUMO
The guidelines for standard nursing in the PET/MR imaging examination included preparation of examination,injecting drug,observing during scanning,post scanning care,management of adverse reaction of contrast agent and radiation protection.The purpose of these guidelines could were to provide the practical and effective management for nursing care in PET/MR imaging,and offer a framework for nurses that could provide useful and helpful in clinical practice and research.
RESUMO
Objective To explore the clinical value of CT-guided radiofrequency ablation (RFA) and imaging follow-up for patients with osteoid osteoma.Methods Thirty-seven patients with osteoid osteomas were selected.Their tumors occurred mainly in the femur and tibia (16/37,13/37) with local pain aggravated at night in 32 of the cases.They were treated with CT-guided RFA.One week,1 month and 3 months after the surgery,CT and MRI examinations were conducted to observe the density of the ablated area,any density (signal) changes and the recovery of adjacent tissues.A visual analogue scale (VAS) was used to assess the perceived pain of the patients.Results All of the patients went through the operation successfully and resumed unrestricted normal activity within 2 d to 1 week without complications.Field CT showed a low density of bone defects one month after the ablation,with the bone defect narrowing and peripheral thickened reactive bone thinning slightly 2 months later.One week after the RFA treatment the MRI's T2WI signal was lower than before the treatment and the T1WI signal was low.One month after the RFA the T2WI high signal of 20 of the patients (54.1％) had decreased and the T1WI low signal had narrowed compared to one week after the operation.The signals of the other 17 cases (45.9％) had returned to normal.Three months after the operation the T2WI high signal of 10 of the 20 patients (27％) had decreased further and their T1 WI low signal had also narrowed further compared to one month after the operation,with a total of 27 then normal.After the operation,the average VAS score decreased significantly compared to before the operation.Conclusion CT-guided RFA is a safe and effective minimally invasive method for the treatment of osteoid osteoma.Dynamic imaging is very useful for assessing the therapeutic effect in the short term.