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Objective:To investigate the predictive values of 18F-FDG PET/CT image feature and metabolic parameters for the malignant potential of gastrointestinal stromal tumor (GIST). Methods:From March 2014 to June 2020, the 18F-FDG PET/CT imaging and surgical pathological data of 35 patients with GIST (27 males, 8 females; age 44-84 years) from Union Hospital, Tongji Medical College, Huazhong University of Science and Technology and Zhongnan Hospital of Wuhan University were analyzed retrospectively. Patients were divided into ring-shaped uptake group and other uptake patterns group according to 18F-FDG PET/CT image feature. Fisher′s exact test was used to analyze the differences of tumor necrosis and National Institutes of Health (NIH) risk classification (short for NIH classification) between different image feature groups. Mann-Whitney U test was used to analyze the differences of SUV max , metabolic parameters at different thresholds (2.5, 40%, 50%) of SUV max (metabolic tumor volume (MTV; MTV 2.5, MTV 40%, MTV 50%) and total lesion glycolysis (TLG; TLG 2.5, TLG 40%, TLG 50%)) between different clinicopathological features (lesion location, tumor diameter, mitotic count, Ki-67, necrosis, image feature, NIH classification) groups. Spearman rank correlation analysis was used to explore the correlation between clinicopathological features and metabolic parameters. ROC curve analysis was used to distinguish NIH classification of different metabolic parameters. Delong test was used to compared differences between different AUCs. Results:Of 35 GIST patients, 11(31.4%) were ring-shaped uptake and 24(68.6%) were other uptake patterns, and the differences of necrosis (7/11 vs 12.5%(3/24); P=0.004) and NIH classification (11/11 vs 25.0%(6/24); P<0.001) between the two groups were significant. There were significant differences of metabolic parameters between different groups of tumor diameter, mitotic count, necrosis, image feature, NIH classification ( z values: from -4.70 to -2.09, all P<0.05), while there were no significant differences of Ki-67 ( z values: from -0.83 to -0.71, all P>0.05). Metabolic parameters were correlated with mitotic count, tumor diameter, necrosis, image feature and NIH classification ( rs values: 0.36-0.81, all P<0.05), while was not correlated with Ki-67 ( rs values: 0.12-0.14, all P>0.05). The differences of AUCs between SUV max and MTV 2.5, TLG 2.5, TLG 40%, TLG 50%were significant (0.752, 0.856, 0.856, 0.882, 0.886; z values: 1.96-2.12, all P<0.05). Conclusions:The NIH classification of GIST with ring-shaped uptake on 18F-FDG PET/CT is higher and more prone to necrosis. The 18F-FDG PET/CT metabolic parameters based on different thresholds of SUV max have certain significance for the prediction of NIH classification of GIST, and may be superior to SUV max.
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Objective:To explore the significance of 99Tc m-sulfur colloid lymphoscintigraphy in the diagnosis of lower limb lymphedema after gynecological tumor surgery. Methods:The clinical data of patients with lower limb lymphedema after gynecological tumor surgery in Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from May 2015 to October 2019 were retrospectively analyzed. 99Tc m-sulfur colloid lymphoscintigraphy was performed in all patients. The results of lymphatic vessel imaging, lymph node imaging and their combination in the diagnosis of lower limb lymphedema were analyzed. The diagnostic efficacy of lymphatic vessel imaging alone, lymph node imaging alone and their combination was evaluated by the receiver operating characteristic (ROC) curve and the area under the curve (AUC), and the Youden index, sensitivity and specificity were calculated. Results:Among the 100 lower limbs of 50 patients, 56 limbs had lymphedema and 44 limbs had no obvious edema. When diagnosis was based on abnormal lymphatic vessel imaging alone, among 56 lower limbs with lymphedema, lower limbs lymphatic vessel imaging was positive in 38 (67.9%) and negative in 18 (32.1%); among 44 lower limbs without obvious edema, lower limbs lymphatic vessel imaging was positive in 6 (13.6%) and negative in 38 (86.4%); the sensitivity was 67.9%, the specificity was 86.4%, and the Youden index was 0.543. When diagnosis was based on abnormal lymph node imaging alone, among 56 lower limbs with lymphedema, lower limbs lymph node imaging was positive in 42 (75.0%) and negative in 14 (25.0%); among 44 lower limbs without obvious edema, lower limbs lymph node imaging was positive in 13 (29.5%) and negative in 31 (70.5%); the sensitivity was 75.0%, the specificity was 70.5%, and the Youden index was 0.455. When diagnosis was based on the combination of lymphatic vessel imaging and lymph node imaging, among 56 lower limbs with lymphedema, lymphatic vessel imaging and lymph node imaging were positive in 48 (85.7%) and negative in 8 (14.3%); among 44 lower limbs without obvious edema, lymphatic vessel imaging and lymph node imaging were positive in 14 (31.8%) and negative in 30 (68.2%); the sensitivity was 85.7%, the specificity was 68.2%, and the Youden index was 0.539. The AUC for the combined diagnosis of lymphatic vessel imaging and lymph node imaging was 0.781, the AUC for the diagnosis of abnormal lymphatic vessel imaging was 0.771, and the AUC for the diagnosis of abnormal lymph node imaging was 0.739 (all P < 0.01). Conclusions:99Tc m-sulfur colloid lymphoscintigraphy is of great help in the diagnosis of lower limb lymphedema after operation of gynecological tumors. The combination of lymph node imaging and lymphatic vessel imaging is more effective in the diagnosis of lower limb lymphedema.
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Objective:To explore the feasibility of pretargeting technique for immunoPET with epidermal growth factor receptor (EGFR) monoclonal antibody in EGFR positive/negative tumor bearing mice.Methods:Cetuximab- Trans-cyclooctene (TCO)was obtained by modifying Cetuximab with TCO- N-hydroxysuccinimide (NHS). 2, 2′-((6-amino-1-(4, 7-bis-(carboxymethyl)-1, 4, 7-triazonan-1-yl)hexan-2-yl)azanediyl)-diacetic acid (L-NETA)was used as a chelating agent to prepare the radioligand 68Ga-L-NETA-tetrazine (Tz), then the labeling rate and in vitro stability of the product were determined. Human basal breast cancer cells MDA-MB-468 (EGFR+ ) and MDA-MB-231 (EGFR-) were cultured in vitro. In vitro experiments were performed to explore the specificity of the probe and the feasibility of pretargeting technique. Nude mice (Balb/c-nu) bearing xenografts of the above two cell lines were established. Cetuximab-TCO (50 μg) was injected into the tumor-bearing mice in advance, then 68Ga-L-NETA-Tz was injected at different time points (48, 36, 24 and 12 h), and pretargeting was realized through " click chemistry" . Small-animal PET imaging and biodistribution were performed to evaluate pharmacokinetic properties and specificity of the probe. The one-way analysis of variance was used to compare the data. Results:The 68Ga-L-NETA-Tz molecular probe was successfully prepared with the labeling yield >95%, and the radiochemical purity was >95% after 2 h. Cetuximab-TCO and 68Ga-L-NETA-Tz were added to MDA-MB-468 cells successively, and the cell uptake rate reached (0.69±0.04)% at 1 h, which demonstrated the feasibility of the pretargeting technique. PET imaging and biodistribution results showed that the best imaging results were obtained in 36 h pre-injection group, in which the tumor uptake was the highest ((0.77±0.05) percentage activity of injection dose per gram of tissue (%ID/g), 1 h) and the tumor/muscle ratio was optimal (4.67±0.46); the tumor uptake in the blocking group, the group without injecting Cetuximab-TCO, and the MDA-MB-231 group were significantly lower ((0.35±0.01), (0.39±0.05), (0.45±0.10) %ID/g; F=15.50, P=0.002). Conclusions:EGFR targeted immunoPET imaging is successfully performed in mouse models of breast cancer by injecting Cetuximab-TCO and 68Ga-L-NETA-Tz successively. It provides an effective method for immunoPET imaging of monoclonal antibodies.
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Fibroblast activation protein (FAP) is a marker protein of cancer-associated fibroblasts(CAFs). It is highly expressed in more than 90% of epithelial cancers and hardly expressed in normal tissues. Therefore, FAP is a very promising target. Radionuclide labeled FAP targeted molecular probes can be used for PET or SPECT imaging. In particular, 68Ga-FAP inhibitors (FAPIs) PET/CT has shown good prospects in the clinic, providing a new idea for early diagnosis, accurate staging and radionuclide treatment of tumors. In addition, FAP is also highly expressed in certain non-tumor diseases, especially those related to fibrosis. In this article, the research progress of radionuclide-labeled FAP targeted molecular probes is reviewed.
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At the end of December 2019, acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China. Different from radiology examinations, the protocols of nuclear medical imaging examinations are complicated, in which more workplaces and staff are needed, resulting more complex management of patients and higher protection requirements. Combined with the characteristics of SPECT and PET imaging procedures, this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected noval coronavirus infec- tion. The main purpose is to protect medical staff from virus infection, effectively reduce the risk of virus transmission during the examination process, and ensure the medical quality and safety.
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At the end of December 2019, acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China. Different from radiology examinations, the protocols of nuclear medical imaging examinations are complicated, in which more workplaces and staff are needed, resulting more complex management of patients and higher protection requirements. Combined with the characteristics of SPECT and PET imaging procedures, this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected novel coronavirus infection. The main purpose is to protect medical staff from virus infection, effectively reduce the risk of virus transmission during the examination process, and ensure the medical quality and safety.
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Objective:To explore the clinical value of 99Tc m-methylene diphosphonate (MDP) SPECT/CT imaging in Langerhans cell histiocytosis (LCH) in children. Methods:From June 2018 to October 2019, the imaging characteristics of 99Tc m-MDP SPECT/CT imaging in 13 children (8 males, 5 females; age: 1-11 (4.2±2.8) years) with LCH confirmed by pathology and immunohistochemistry in Wuhan Children′s Hospital were analyzed retrospectively. The location, number, imaging manifestations, and maximum standardized uptake value (SUV max) of the lesions were evaluated. Results:There were 18 lesions (8 in the vertebral body, 3 in the femur, 3 in the skull, 2 in the rib, 1 in the shoulder blade, 1 in the sciatic and pubic bone) in 13 children, including 9 with single lesion and 4 with multiple lesions. Of 18 lesions, 17 showed different degrees of osteolytic bone destruction, 15 presented as soft tissue masses, and 3 showed marginal sclerosis on CT imaging. All lesions showed increased 99Tc m -MDP uptake (SUV max: 1.22-15.57 (8.67±3.19)). Conclusion:99Tc m-MDP SPECT/CT has the advantage of combining functional and morphological imaging, and is helpful in the early diagnosis, clinical classification and evaluation of curative effect of children′s LCH, which provides objective basis for clinical practice.
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The integrated PET/MR overcomes the problem of interferences between PET and the strong magnetic field of MRI, realizing the simultaneous acquisition of two modalities, which is a milestone in the field of medical imaging. The use of PET/MR requires the radiopharmaceutical as well as avoids interferences to the homogeneity of main magnetic field and stability of radio-frequency field from surrounding environment. Therefore, the site selection and layout design about integrated PET/MR are more complicated than the single mode system, and the results of installation and debugging should satisfy two imaging modalities (imaging quality and quantitative accuracy). In this paper, the room construction, installation and debugging of integrated PET/MR are discussed, which can supply a reference about key issues in the construction of similar projects.
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At the end of December 2019,acute respiratory infectious diseases caused by a new type of coronavirus were prevalent in Wuhan and other cities of China.Different from radiology examinations,the protocols of nuclear medical imaging examinations are complicated,in which more workplaces and staff are needed,resulting more complex management of patients and higher protection requirements.Combined with the characteristics of SPECT and PET imaging procedures,this paper puts forward some suggestions on the protective process of imaging examinations for patients with confirmed or suspected novel coronavirus infection.The main purpose is to protect medical staff from virus infection,effectively reduce the risk of virus transmission during the examination process,and ensure the medical quality and safety.
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Tumor microenvironment is different from the microenvironment formed by normal cells and surrounding tissues.It is composed of tumor cells,stromal cells,extracellular matrix (ECM),vasculature and various cytokines.Tumor microenvironment can promote the genesis,development,metastasis and resistance to therapy of tumor.Using PET molecular imaging to show tumor microenvironment can provide important biological information for early precise diagnosis and treatment intervention,as well as therapeutic effect evaluation and prognosis of tumor.In this paper,the main application categories and prospects of PET molecular imaging in tumor microenvironment are reviewed.
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Neurodegenerative diseases endanger people's physical and mental health. PET/MR can acquire PET and MR images simultaneously, thus avoid interference of external stimuli and spatial differ-ence in different time, and significantly improve image accuracy. PET/MR displays an important value in the pathogenesis, early diagnosis and differential diagnosis of neurodegenerative diseases. This article re-views the application value and research progress of PET/MR in important neurodegenerative diseases, such as Alzheimer's disease ( AD) and Parkinson's disease ( PD) .
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Upconversion luminescence (UCL) is a process during which low-energy light was converted (excitation) to high-energy light.Due to the characteristics of low excitation power density,negligible autofluorescence,lack of photobleaching and high stability,UCL has been increasingly applied for bioimaging.Using the upconversion nanoparticles (UCNP) as agents in multimodality molecular imaging (UCL imaging,CT,MR,PET,etc),we could obtain clearimages with high signal to noise ratio.This review summarizes the applications of UCNP in the field of bioimaging.
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Lung cancer is one of the important causes of human death among the malignant tumors, in which non-small cell lung cancer accounts for about 85％. The treatment of lung cancer is complex. How to predict the prognosis of lung cancer is very important to choose better therapy methods. The traditional prognostic evaluation methods have some disadvantages. With the development of new technology, 18F-FDG PET/CT is applied to stage and re-stage, evaluate therapy effect and predict the prognosis of lung cancer. In this review, the prognosis effect of non-small cell lung cancer via 18F-FDG PET/CT will be discussed.
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Objective To investigate the imaging performance and feasibility of 99Tcm labeled scFv against VCAM-1(99Tcm-scFv-VCAM-1) on atherosclerosis model rabbits.Methods HYNIC was used as a chelator for 99Tcm labeling.The labeling efficiency and radiochemical purity of 99Tcm-scFv-VCAM-1 were measured by instant thin layer chromatography after PD-10 purification.New Zealand white rabbits were employed for establishing atherosclerotic animal models by endothelia immunity injury and high fat diet, and plaques at aorta lesions were examined by HE staining.Model rabbits were sacrificed after administration of 99Tcm-scFv-VCAM-1 at 1 or 2 h respectively, and tissue samples were measured with gamma counter and weighted to obtain in vivo biodistribution data.Planar imaging was performed 1 and 2 h after the injection of 99Tcm-scFv-VCAM-1 to investigate radioactivity of abdominal aorta.After imaging study, atherosclerosis plaque and VCAM-1 expression at aortas were confirmed by the immunohistochemistry (IHC) study.Two-sample t test was used to analyze data.Results 99Tcm-scFv-VCAM-1 was successfully synthesized.Its labeling efficiency was 75%-83%, radiochemistry purity was (98.54±1.03)% and specific activity was 216 MBq/nmol.Atherosclerosis plaque was confirmed at the aortas of experimental rabbits by HE staining, while no plaque was observed in controls.Biodistribution data indicated that the tracer was cleared mainly through the kidneys.Planar imaging showed that the tracer uptake in abdominal aorta of model rabbits was higher than that of control rabbits, the T/B ratios at 2 h of the model group and control group were statistically different (3.68±0.73 vs 2.42±0.39;t=2.950, P<0.05;n=5).Atherosclerosis plaque and high level of VCAM-1 expression were observed at aortas of model rabbits by IHC study.Conclusions It is feasible and effective to detect vulnerable plaques using 99Tcm-scFv-VCAM-1.It may provide a promising way for early diagnosis and accurate evaluation of atherosclerosis.
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Objective To evaluate the influences of FBP and OSEM (with different iteration numbers or subset numbers) on cardiac function parameters with MPI,and to identify a suitable clinical method.Methods The MPI of 66 patients (33 males,33 females,age range: 18-77 years) from January 2012 to December 2014 were retrospectively analyzed.The imaging data was reconstructed with FBP and 5 different OSEM (4-16 subsets and 2-4 iterations) in order to evaluate if there was any difference of cardiac function parameters calculated by QGS between the different image processing methods.In addition,the results were compared with those of cardiac ultrasonography.One-way analysis of variance was used for data analysis.Results The statistical differences of LVEF,EDV,and ESV(F values: 10.73,4.89 and 5.97,all P<0.05) were found among 6 reconstructed methods.The values of LVEF were (66.14±11.12)％,(75.05±12.10)％,(70.09±11.27)％,(66.88±10.38)％,(64.97±10.25)％,and (62.58±9.84)％.Those of EDV were (77.32±27.58),(67.97±27.56),(75.10±27.89),(81.03±28.11),(84.94±29.07),and (89.98±29.71) ml,and the ESV values were (28.71±10.04),(19.71±16.51),(25.13±17.66),(29.01±18.47),(32.10±19.63),and (35.83±20.41) ml respectively.The cardiac function parameters measured by OSEM (with 2 iterations,12 subsets) were much similar to that measured by cardiac ultrasonography.Conclusion Compared with other 5 processing methods of MPI,the OSEM (with 2 iterations,12 subsets) method may be more suitable for practical clinical application.
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Early diagnosis and accurate staging are important for planning therapeutic intervention to improve outcomes in patients with malignant melanoma (MM).Noninvasive molecular imaging has been extensively studied in cancer diagnosis,staging,therapeutic evaluation,and prognosis.Several radiopharmaceuticals have been developed to diagnose and treat MM,such as monoclonal antibodies,melanocortin receptors,benzamide (BZA) and BZA analogs.In this review,the characteristics and limitations of these radionuclide molecular probes are summarized and discussed.
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Objective To prepare a kind of 99Tcm-labeled estrogen receptor (ER) SPECT imaging agent,and evaluate its binding characteristics with ER by in vitro and in vivo studies.Methods EDL was prepared from estrone and then reacted with GAP to synthesize GAP-EDL.Then,GAP-EDL was labeled with 99Tcm to obtain 99Tcm-GAP-EDL.Cell uptake and blocking assays were performed in vitro on MCF-7and MDA-MB-231 cells.The biodistribution study of 99Tcm-GAP-EDL was performed on normal BALB/c mice at 30,60,120,180 and 240 min post injection.Nude mice bearing either MCF-7 or MDA-MB-231derived tumors were injected with 99Tcm-GAP-EDL,and subjected to γimaging at 1,2,4 h post injection.The mice injected with excess unlabeled GAP-EDL or estradiol were used as the blocking control.Two-sample t test was used for data analysis.Results The radiolabeling yield of 99Tcm-GAP-EDL was (98.8 ±0.5) ％ and the radiochemical purity after 24 h was over 90％.The cell uptake rate of MCF-7 cells at 240min was (4.84± 0.21) ％,which was significantly higher than that of MDA-MB-231 cells ((2.11±0.21) ％;t =15.96,P＜0.05).99 Tcm-GAP-EDL uptake rate of MCF-7 cells in blocking groups ((2.31 ± 0.28) ％ and (2.05±0.35) ％) decreased significantly compared to that of non-blocking group(t=11.52,11.16,both P＜0.05).Biodistribution studies showed that 99Tcm-GAP-EDL was mainly metabolized by the liver and kidneys,and exhibited quick blood clearance.Gamma imaging showed high uptake in MCF-7 tumors 1 h post injection and the uptake reached the highest at 4 h,while there was little 99Tcm-GAP-EDL uptake in MDA-MB231 tumors and blocked MCF-7 tumors.Conclusions 99Tcm-GAP-EDL may be prepared under mild conditions with high labeling purity and stability.The in vitro and in vivo characteristics of 99Tcm-GAP-EDL suggest that it may be a promising probe for ER positive tumor imaging.
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Early detection and accurate evaluation of vulnerable plaques is important to clinical prevention and in time intervention of atherosclerosis plaque rupture,which is the main reason of cardiovascular and cerebrovascular emergency events.Molecular imaging reveals the formation and progression mechanisms of atherosclerosis at the molecular level,and thus has obvious superiority in early detection and evaluation of vulnerable plaques.Suitable targets are the major contents of molecular probe research.Probes of different imaging modalities have been used to detect vulnerable plaques.The targets including low density lipoprotein,macrophage,adhesion molecule,micro calcification,activated protease,apoptosis,proliferation gene,integrin and thrombus.The mechanism of detecting different targets is different,and the effectiveness varies as well.This review summarizes the development of imaging probes for molecular detection of atherosclerosis vulnerable plaques.
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Objective To evaluate the application value of 18 F‐FDG PET/CT in patients with fever of unknown origin (FUO) to improve the etiological diagnosis accuracy of PET/CT in patients with FUO and provide better service for clinical prac‐tice .Methods Clinical data and imaging results of 144 cases of FUO patients diagnosed through 18 F‐FDG PET/CT examination in Wuhan union hospital from December 2009 to December 2011 were retrospectively analyzed .The final diagnoses were based on sur‐gical pathology ,aspiration cytology ,or discharge diagnosis combined with more than 12 months of follow‐up results .All the PET/CT images were analyzed and the clinical application value of PET/CT in FUO patients were evaluated through the diagnose rate , diagnose efficiency and clinical staging of malignant tumor .Results Among the 144 patients ,there were 130 cases ultimately had clear diagnosis ,which including 41 cases of malignant tumor ,89 cases of benign lesions and 14 cases the cause of unknown .PET/CT detected abnormal lesions for 97 .6% (40/41) of patients with malignant lesions and 88 .7% (79/89) of patients with benign le‐sions ,and the diagnostic sensitivity ,specificity ,accuracy ,positive predictive value ,and negative predictive value were :97 .6% (40/41) ,86 .5% (77/89) ,90% (117/130) ,76 .9% (40/52) and 98 .7% (77/78) .PET/CT detected the primary lesions for the first time in 46 .3% (19/41) patients with malignant tumor ,and detected more lesions than the traditional imaging methods in 92 .7% (38/41) of these patients .Conclusion 18 F‐FDG PET/CT imaging can provided important reference value for the detection of primary lesions ,the qualitative diagnosis of benign and malignant lesions and clinical staging of malignant lesions .
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Objective To investigate the diagnostic and prognostic values of 18 F?FDG PET/CT in pa?tients with cervical nodal metastases from carcinoma of unknown primary site (CCUP). Methods A total of 137 consecutive patients(95 males, 42 females, age range 24-84 (55.77±11.71) years) with histological proven CCUP who underwent 18 F?FDG PET/CT imaging to find primary tumors from March 2010 to June 2015 were retrospectively analyzed. The gold standard was the final pathological diagnosis or clinical long?term fol?low?up (≥6 months) results. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value of PET/CT imaging in detecting primary tumors were calculated. Kaplan?Meier anal?ysis was conducted for survival analysis and to identify the presence of any prognostic factors, such as age, gender, presence or absence of distant metastasis, region of involved cervical lymph nodes, left (right)?side/both sides of lymph node involvement, histopathologic tumor type and primary site found or not by PET/CT imaging. Results Primary tumors were confirmed in 96 patients, of which 87 patients were diagnosed correct?ly by 18 F?FDG PET/CT imaging. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 90.6% (87/96), 80.5% (33/41), 87.6% (120/137), 91.6% (87/95) and 78.6% (33/42) respectively. Primary tumors were found most commonly in the head, neck and lung. However, the false positive and negative lesions were also mainly seen in those sites. Distant metastasis and the inferior region of cervical lymph node metastasis were associated with the worst survival (χ2=20. 990 and 12?277, both P6.5 were of higher mortality risk than those with SUVmax≤6.5 (χ2=7.120, P<0.01) . Conclusions Whole?body 18 F?FDG PET/CT scan is a significant and valuable tool in the identification of the primary tumor site in patients with CCUP . Further? more, according to the distant metastasis and region of cervical lymph nodes metastasis, 18 F?FDG PET/CT scans are of value in prognostic evaluation even if without the need to identify the primary tumors.