Objective:To analyze the differentially diagnostic ability of metabolic parameters of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography(18F-FDG PET/CT)in thymic epithelial tumors(TETs)of different histological types.Methods:A total of 72 patients who underwent 18F-FDG PET/CT examination and were confirmed as TETs before treatment at the Department of Nuclear Medicine of the First Medical Center of Chinese PLA General Hospital between January 2013 to May 2022 were analyzed.The patients were divided into thymic tumor with low risk group(9 cases),thymic tumor with high risk group(15 cases)and thymic cancer group(9 cases)according to histological type.The clinical data of patients were recorded,and the patients were staged according to pathological Masaoka-Koga staging of thymic tumor surgery.The maximum standardized uptake value(SUVmax),average standardized uptake value(SUVmean),metabolic tumor volume(MTV),total lesion glycolysis(TLG)and standardized uptake value ratio(SUVR)of the lesions were recorded respectively.The differences of metabolic parameters of various group were compared.The area under curve(AUC)value of receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of 18F-FDG PET/CT in TETs of different histological types.Results:The results of analyzing each metabolic parameter of three groups indicated that the SUVmax,SUVmean and SUVR values of thymic tumor with high risk group and thymic cancer group were significantly higher than them of thymic tumor with low risk group,and the differences were significant(F=10.315,8.336,11.593,P<0.05),respectively.SUVR has the highest diagnostic efficacy in the differential diagnosis for thymic tumor and thymic cancer(AUC:0.864,sensitivity:83.3%,specificity:75.0%),and for thymic tumor with high-risk and thymic cancer(AUC:0.832,sensitivity:56.3%,specificity:100.0%).In addition,SUVR has the highest diagnostic efficacy for thymic tumor with high-risk and thymic tumor with low-risk(AUC:0.748,sensitivity:80.0%,specificity:66.7%).Conclusion:The metabolic parameters of 18F-FDG PET/CT have a certain of differential and diagnostic value in identifying TETs of different histological types.

Nuclear medicine plays a pivotal role in diagnosis and treatment of tumors.The development of radionuclide probes with high affinity and specificity is an effective approach to achieve precise diagnosis and treatment of tumors.With high binding affinity,rapid tissue penetration and excellent pharmacokinetic properties,bicyclic peptide-based radionuclide probes demonstrate remarkable advantages in diagnosis and targeted therapy of tumors.The structural characteristics and design strategies of bicyclic peptide-based radionuclide probes were reviewed in this article,mainly focused on research progresses in targeting tumor-associated receptors.

Objective:To analyze the differentially diagnostic ability of metabolic parameters of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography(18F-FDG PET/CT)in thymic epithelial tumors(TETs)of different histological types.Methods:A total of 72 patients who underwent 18F-FDG PET/CT examination and were confirmed as TETs before treatment at the Department of Nuclear Medicine of the First Medical Center of Chinese PLA General Hospital between January 2013 to May 2022 were analyzed.The patients were divided into thymic tumor with low risk group(9 cases),thymic tumor with high risk group(15 cases)and thymic cancer group(9 cases)according to histological type.The clinical data of patients were recorded,and the patients were staged according to pathological Masaoka-Koga staging of thymic tumor surgery.The maximum standardized uptake value(SUVmax),average standardized uptake value(SUVmean),metabolic tumor volume(MTV),total lesion glycolysis(TLG)and standardized uptake value ratio(SUVR)of the lesions were recorded respectively.The differences of metabolic parameters of various group were compared.The area under curve(AUC)value of receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of 18F-FDG PET/CT in TETs of different histological types.Results:The results of analyzing each metabolic parameter of three groups indicated that the SUVmax,SUVmean and SUVR values of thymic tumor with high risk group and thymic cancer group were significantly higher than them of thymic tumor with low risk group,and the differences were significant(F=10.315,8.336,11.593,P<0.05),respectively.SUVR has the highest diagnostic efficacy in the differential diagnosis for thymic tumor and thymic cancer(AUC:0.864,sensitivity:83.3%,specificity:75.0%),and for thymic tumor with high-risk and thymic cancer(AUC:0.832,sensitivity:56.3%,specificity:100.0%).In addition,SUVR has the highest diagnostic efficacy for thymic tumor with high-risk and thymic tumor with low-risk(AUC:0.748,sensitivity:80.0%,specificity:66.7%).Conclusion:The metabolic parameters of 18F-FDG PET/CT have a certain of differential and diagnostic value in identifying TETs of different histological types.

Nuclear medicine plays a pivotal role in diagnosis and treatment of tumors.The development of radionuclide probes with high affinity and specificity is an effective approach to achieve precise diagnosis and treatment of tumors.With high binding affinity,rapid tissue penetration and excellent pharmacokinetic properties,bicyclic peptide-based radionuclide probes demonstrate remarkable advantages in diagnosis and targeted therapy of tumors.The structural characteristics and design strategies of bicyclic peptide-based radionuclide probes were reviewed in this article,mainly focused on research progresses in targeting tumor-associated receptors.

Objective To explore the value of 11C-methionine(MET)PET/CT radiomics model for evaluating isocitrate dehydrogenase1(IDH1)status of glioblastoma.Methods Data of 157 patients with glioblastoma who underwent 11C-MET PET/CT examination,including 68 cases of IDH1 mutation and 89 cases of IDH1 wild-type were retrospectively analyzed.The patients were divided into training set(n=125)and validation set(n=32)at the ratio of 8:2.Based on PET/CT images,lesions ROI were delineated and radiomics features were extracted and screened to establish radiomics models with logistic regression(LR),support vector machine(SVM)and decision trees(DT),respectively.Meanwhile,the nomogram based on patients'age and radiomics features was drawn.The efficacy of radiomics models and clinical-radiomics nomogram for evaluating IDH1 status were comparatively observed.Results The area under the curve(AUC)of DT radiomics model for evaluating IDH1 status of glioblastoma in training set was 0.910,higher than that of LR(0.697)and SVM(0.698)models(both P＜0.05).In validation set,the AUC of DT model for evaluating IDH1 status of glioblastoma was 0.805,which was higher than that of LR model(0.740)and clinical-radiomics nomogram(0.704)(both P＜0.05).Conclusion 11C-MET PET/CT radiomics model based on DT was helpful for evaluating IDH1 status of glioblastoma.

Objective:To investigate the effect of different acquisition duration of brain image of 18F-florbetaben(18F-FBB)positron emission tomography(PET)on standardized uptake value(SUV).Methods:Eight subjects who underwent 18F-FBB PET examination in Chinese PLA General Hospital from May 2021 to June 2021 were selected,including 5 persons of healthy control and 3 patients with mild cognitive impairment(MCI).All subjects underwent 18F-FBB PET imaging,and the dynamic PET images of them on brains were continuously acquired for 20 min between 90 and 110 min after the 18F-FBB injection was injected as(3.7-5.5 MBq/kg).Under the situation that other reconstruction parameters did not change,the images were reconstructed at 0-1,0-3,0-5,0-10,0-15 and 0-20 min,respectively.The same of region of interest(ROI)ranges were delineated in bilateral frontal cortex,bilateral temporal cortex,bilateral parietal cortex,posterior cingulate gyrus and cerebellar cortex of each group of images.And then,the corresponding mean standardized uptake value(SUVmean)of each region was obtained.The differences of SUVmean values of different ROI values between each group of data images and the images of 0-20 min were compared and analyzed.Results:There were significant differences in SUVmean between the acquired images in 0-1,0-3,0-5 and 0-10 min and the acquired standard images of 0-20 min(t=-7.569--2.410,P<0.05),respectively.There were no significant differences in SUVmean between the acquired images of 0-15 min and the acquired standard images of 0-20 min in the bilateral frontal lobe,bilateral temporal lobe,bilateral parietal cortex and posterior cingulate gyrus(P>0.05),only there was significant difference in the cerebellar cortex area between them(t=-5.597,P<0.001).Conclusion:The results of 15 min can reach to the similar results of 20 min in acquiring images,which can shorten the time of examination,and enhance the degrees of comfort and cooperation of patients in examination.It has clinical application value.

Objective::To explore the approach of minimally invasive transthoracic intramyocardial cellular transplantation under echocardiographic guidance to promote ischemic myocardial repair in a preclinical big-animal study.Methods::Female Guangxi Bama miniature pigs (weight: 25–30 kg) were randomly allocated into the sham group, untreated myocardial infarction (MI) group (MI group), the MI and surgical intramyocardial injection (SIM) group (MI-SIM group), and the MI and transthoracic echocardiography-guided percutaneous intramyocardial injection (TTEPIM) group (MI-TTEPIM group) ( n = 4 each) using a lottery method. A swine MI model was established in the 3 groups excluding the sham group, and human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) labeled with the herpes simplex virus type-1 thymidine kinase reporter gene (hiPS-CM TK+) were transplanted by SIM in MI-SIM group and TTEPIM in MI-TTEPIM group. The operation time, postoperative recovery time of animals and volume of blood loss were collected for comparison between MI-SIM group and MI-TTEPIM group. 9-(4-[ 18F] fluoro-3-(hydroxymethyl) butyl) guanine positron emission tomography/computed tomography imaging was performed to track the hiPS-CM TK+in vivo. Cardiac function and morphology were evaluated by echocardiography. Results::The operation time and postoperative recovery time of MI-TTEPIM group were significantly shorter than those of MI-SIM group ((28.3 ± 3.6) min vs. (97.0 ± 6.7) min, P < 0.001; (1.3 ± 0.3) d vs. (7.5 ± 0.9) d, P < 0.001). MI-TTEPIM also showed significantly lesser volume of blood loss during cell transplantation than MI-SIM group ((4.3 ± 0.8) mL vs. (47.0 ± 4.1) mL, P < 0.001). The transplanted cells could be traced more accurately in vivo in MI-TTEPIM than in MI-SIM. The circumferential strain of intervention region in the MI-TTEPIM group (–25.07% ± 0.27%) was significantly higher than that of the MI-SIM (–20.39% ± 0.67%) and MI groups (–19.68% ± 0.67%), respectively ( P < 0.01). Conclusion::A minimally invasive TTEPIM protocol with stem cells for treating the ischemic myocardium was established in this study. Transplantation of hiPS-CM TK+ with this method could promote the recovery of the circumferential strain of the ischemic myocardium. The findings of this study lay a foundation for the clinical transformation of this auxiliary means of treatment in the future.

Objective::To explore the approach of minimally invasive transthoracic intramyocardial cellular transplantation under echocardiographic guidance to promote ischemic myocardial repair in a preclinical big-animal study.Methods::Female Guangxi Bama miniature pigs (weight: 25–30 kg) were randomly allocated into the sham group, untreated myocardial infarction (MI) group (MI group), the MI and surgical intramyocardial injection (SIM) group (MI-SIM group), and the MI and transthoracic echocardiography-guided percutaneous intramyocardial injection (TTEPIM) group (MI-TTEPIM group) ( n = 4 each) using a lottery method. A swine MI model was established in the 3 groups excluding the sham group, and human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) labeled with the herpes simplex virus type-1 thymidine kinase reporter gene (hiPS-CM TK+) were transplanted by SIM in MI-SIM group and TTEPIM in MI-TTEPIM group. The operation time, postoperative recovery time of animals and volume of blood loss were collected for comparison between MI-SIM group and MI-TTEPIM group. 9-(4-[ 18F] fluoro-3-(hydroxymethyl) butyl) guanine positron emission tomography/computed tomography imaging was performed to track the hiPS-CM TK+in vivo. Cardiac function and morphology were evaluated by echocardiography. Results::The operation time and postoperative recovery time of MI-TTEPIM group were significantly shorter than those of MI-SIM group ((28.3 ± 3.6) min vs. (97.0 ± 6.7) min, P < 0.001; (1.3 ± 0.3) d vs. (7.5 ± 0.9) d, P < 0.001). MI-TTEPIM also showed significantly lesser volume of blood loss during cell transplantation than MI-SIM group ((4.3 ± 0.8) mL vs. (47.0 ± 4.1) mL, P < 0.001). The transplanted cells could be traced more accurately in vivo in MI-TTEPIM than in MI-SIM. The circumferential strain of intervention region in the MI-TTEPIM group (–25.07% ± 0.27%) was significantly higher than that of the MI-SIM (–20.39% ± 0.67%) and MI groups (–19.68% ± 0.67%), respectively ( P < 0.01). Conclusion::A minimally invasive TTEPIM protocol with stem cells for treating the ischemic myocardium was established in this study. Transplantation of hiPS-CM TK+ with this method could promote the recovery of the circumferential strain of the ischemic myocardium. The findings of this study lay a foundation for the clinical transformation of this auxiliary means of treatment in the future.

Objective:To evaluate the value of 18F-prostate specific membrane antigen (PSMA)-3Q PET/CT imaging in prostate cancer patients with serum prostate specific antigen (PSA) less than 1.00 μg/L after radical prostatectomy. Methods:From May 2021 to August 2022, 18F-PSMA-3Q PET/CT images and clinical data of 58 patients with prostate cancer (age 52-82 years) after radical prostatectomy with PSA less than 1.00 μg/L in Chinese PLA General Hospital were analyzed retrospectively. According to the level of PSA, patients were divided into three groups (0-0.19 μg/L group, 0.20-0.49 μg/L group, and 0.50-0.99 μg/L group). 18F-PSMA-3Q PET/CT images were analyzed according to the standardized evaluation criteria of molecular imaging, and lesions with the scores of molecular imaging PSMA (miPSMA)≥1 were defined as recurrent or metastatic lesions. The detection rates of 18F-PSMA-3Q PET/CT for patients in different PSA level groups were compared ( χ2 test). The PSA levels of patients with positive and negative scans were compared by using independent-sample t test. Results:Of the 58 patients, 36(62.1%, 36/58) patients and 85 lesions were found by 18F-PSMA-3Q PET/CT. There was 91.7%(33/36) with oligofocal lesions (1≤number of foci≤3) and 8.3%(3/36) with multiple lesions (number of foci>3). According to the location, 5.2%(3/58) of the recurrent lesions were found in the prostatic bed, 39.7%(23/58) in the bone lesions, 37.9%(22/58) in the pelvic lymph nodes, 12.0%(7/58) in the retroperitoneal lymph nodes and 5.2%(3/58) in the left clavicular lymph node metastases. There were 15 cases in 0-0.19 μg/L group, 22 cases in 0.20-0.49 μg/L group, and 21 cases in 0.50-0.99 μg/L group. The detection rates of 18F-PSMA-3Q PET/CT in the above groups were 5/15, 59.1%(13/22) and 85.7%(18/21), respectively ( χ2=10.33, P=0.006). There was significant difference in PSA level between patients with positive ( n=36) and negative ( n=22) 18F-PSMA-3Q PET/CT scans ((0.48±0.28) vs (0.28±0.25) μg/L; t=2.67, P=0.010). Conclusions:18F-PSMA-3Q PET/CT can be used to detect the recurrence or metastasis in prostate cancer patients with PSA level lower than 1.00 μg/L after radical prostatectomy. In this kind of patients, the common sites of lesions are bone, pelvic lymph nodes, retroperitoneal lymph nodes, left clavicular lymph nodes and prostatic bed, and oligofocal patients are more common.

Objective:To investigate the risk factors of recurrence after surgical resection of differentiated thyroid carcinoma combined with iodine-131 and TSH（Thyroid stimulating hormone） inhibition therapy. Methods:From January 2015 to April 2020, the clinical data of patients with structural recurrence and without recurrence were retrospectively collected after surgical treatment combined with iodine-131 and TSH inhibition therapy in the First Medical Center of PLA General Hospital. The general conditions of the two groups of patients were analyzed and the measurement data in line with the normal distribution was used for comparison between groups. For measurement data with non-normal distribution, the rank sum test was used for inter-group comparison. The Chi-square test was used for comparison between the counting data groups. Univariate and multivariate regression analyses were used to determine the risk factors associated with relapse. Results:The median follow-up period was 43 months（range 18-81 months） and 100 patients（10.5%） relapsed among the 955 patients. Univariate analysis showed that tumor size, tumor multiple, the number of lymph node metastases>5 in the central region of the neck, and the number of lymph node metastases>5 in the lateral region were significantly correlated with post-treatment recurrence（P<0.001, P=0.018, P<0.001, P<0.001）. Multivariate analysis showed that tumor size（adjusted odds ratio OR: 1.496, 95%CI: 1.226-1.826, P<0.001）, tumor frequency（adjusted odds ratio OR: 1.927, 95%CI: 1.003-3.701, P=0.049）, the number of lymph node metastases in the central neck region>5（adjusted odds ratio OR: 2.630, 95%CI: 1.509-4.584, P=0.001） and the number of lymph node metastases in the lateral neck region>5（adjusted odds ratio OR: 3.074, 95%CI: 1.649-5.730, P=0.001） was associated with tumor recurrence. Conclusion:The study showed that tumor size, tumor multiple, the number of lymph node metastases in the central region of the neck>5 and the number of lymph node metastases in the side of the neck >5 are independent risk factors for recurrence of differentiated thyroid cancer after surgical resection combined with iodine-131 and TSH inhibition therapy.
Humans ; Thyroid Cancer, Papillary/surgery* ; Lymphatic Metastasis/pathology* ; Retrospective Studies ; Neck Dissection ; Thyroidectomy/adverse effects* ; Neoplasm Recurrence, Local/pathology* ; Thyroid Neoplasms/surgery* ; Risk Factors ; Adenocarcinoma ; Thyrotropin ; Lymph Nodes/pathology*