Clinical Application Of The New Radionuclide Probe ⁶⁸Ga-PSMA-617 PET/CT In Tumor Imagin

Project Ⅰ Imaging features of 68Ga-PSMA-617 PET/CT in pathological classification of gliomaObjective:To explore the use of 68Ga-PSMA-617 to perform PET/CT imaging in patients with glioma,analyze the characteristics of imaging in these patients,and compare the difference in imaging agent uptake and PSMA expression in the lesion area of patients with different pathological types of glioma.Methods:According to the diagnosis and classification of WHO’s diagnostic criteria for gliomas in 2016,the clinical data of 30 patients with gliomas were analyzed retrospectively,including 14 cases of gliomas grade II,4 cases of gliomas grade III,12 cases of gliomas grade Ⅳ.There were 12 cases of gene mutation of IDH 1/2,14 cases of wild typ.25 cases of 1p/19q chromosome detection,including 20 cases of 1p/19q chromosome combined deletion positive patients and 5 cases of negative patients.Before the operation 68Ga-PSMA-617 PET/CT was performed.After obtaining the image and data,semi-quantitative analysis was performed by using the method of visual analysis on the region of interest(ROI).The maximum standardized uptake value(SUVmax),mean standardized uptake value(suvmean)and target/non target ratio(T/NT)was used to evaluate the uptake of 68Ga-PSMA-617 in the lesions of gliomas of different grades and molecular pathological types.Results:38 lesions were detected by 68Ga-PSMA-617 PET/CT in the all patients,80%(24/30)patients were detected one lesion,20%(6/30)patients were detected two or more lesions.The lacation of lesions often include the frontal lobe 43.33%(13/30),temporal lobe 33.33%(10/30),the parietooccipital lobe,thalamus and other regions in the brain.The results showed that there was no significant difference by SUVmean,SUVmax and T/NT between two different WHO grades,and all of which had significant differences(P<0.05).We also used PET/CT to analyze and compare the IDH gene mutation and wild type lesions of glioma.It was found that there were significant differences in SUVmax,SUVmean and T/NT(P<0.05).There was no significant difference in the 1p/19q chromosome combined deletion positive and negative lesions of glioma.Conclusions:There are differences in 68Ga-PSMA-617 imaging of glioma of different grades and molecular pathological classifications,but there is no difference in whether the combined 1p/19q chromosome deletion imaging is combined.68Ga-PSMA-617 PET/CT is expected to become a new examination method for glioma classification and grading in the brain.Project Ⅱ Comparison of 68Ga-PSMA-617 and 18F-FDG PET/CT in gliomaObjective:To compare and characterize metabolic features of high-and low-grade glioma tumors using 68Ga-PSMA-617 and 18F-FDG positron emission tomography/computed tomography(PET/CT).Methods:Thirty patients who underwent both 68Ga-PSMA-617 and 18F-FDG PET/CT over 2 consecutive days and then underwent surgical treatment were retrospectively identified.All tumors were diagnosed histologically.This report includes 16 high-grade glioma(HGG)and 14 low-grade glioma(LGG)tumors.Standard uptake value(SUV)and target to nontarget(T/NT)were quantitatively investigated through the entire tumor region.Statistical analyses were performed using area under the curve(AUC)and comparison of two means.Results:SUVmax and SUVmean were the most effective(AUC,0.96 and 0.94 for PSMAPET;AUC,0.79 and 0.74 for FDG-PET,respectively)for differentiating HGGs from LGGs.These methods distinguished between HGG and LGG effectively(PSMA-PET:SUVmax,5.766±3.945 vs.0.7364±0.5295,P<0.0001;SUVmean,1.666±1.680 and 0.1514±0.1534,P<0.0001,respectively)(FDG-PET:SUVmax,11.67±3.639 and 9.118±6.612;SUVmean,5.648±2.114 and 4.435±2.872;P=0.0083,0.0262,respectively).The Youden index for SUVmax and SUVmean of 68Ga-PSMA-617 and 18F-FDG were 0.82 and 0.79 and 0.54 and 0.61,separately.T/NTmax was helpful for visual inspection of 68Ga-PSMA-617-PET images(T/NTmax:1.291±0.9553 in grade Ⅱ,5.25±2.435 in grade Ⅲ,and 13.61±13.84 in grade Ⅳ).T/NTmax differed significantly between LGG and HGG and between subtypes of LGG.Conclusions:PET/CT with 68Ga-PSMA-617 and 18F-FDG may help distinguish between HGG and LGG,and 68Ga-PSMA-617 PET/CT is superior to 18F-FDG in differentiatingHGG and LGG.Project Ⅲ The clinical value of 68Ga-PSMA-617 PET/CT imaging in the guidance of prostate fine needle punctureObjective:Using imaging methods to guide the puncture of the prostate is very helpful for the location of lesions and the determination of benign and malignant.In this study,the uptake difference of the 68Ga-PSMA-617 in the prostate is used to guide the fine needle puncture by the TRUS in order to improve the detection rate and accuracy of malignant biopsy in the prostate,reduce the number of repeated biopsy,We evaluate the detection rate of 68Ga-PSMA-617 PET/CT to guide fine needle biopsy.Methods:From April 2017 to November 2017,42 suspected prostate cancer patients were included in our hospital for pathological biopsy.Before the patients were included in the biopsy,Surgeon and nuclear medicine doctors read the imaging of PET/CT.According to the results of PET/CT imaging,the prostate was analyzed according to the 5-zone method to judge the location of lesions in determining the puncture location.With the help of the TRUS,12 needle system biopsy was performed by surgeon.At the same time,visual analysis and semi-quantitative analysis of region of interest(ROI)were used to comprehensively judge the prostate lesions.The prostate uptake degree of the probe was measured,and SUVmax was obtained.At last the positive was judged according to the uptake in the prostate.According to the pathological results,the benign and malignant lesions were defined.ROC curve analysis was used to anasis the diagnostic efficiency.Results:According to the analysis of the number of cases,Gleason score was 6-10 in 30 patients with prostate cancer,10 patients with prostatitis and benign prostatic hyperplasia,and 2 patients with prostatic intraepithelial tumor.68Ga-PSMA-617 PET/CT detected positive and negative patients,27 cases and 15 cases respectively,and 3 cases were misdiagnosed.According to the five-zoning analysis in the prostate,PET/CT detected 103 positive zones,107 negative zones,4 misdiagnoses,and 23 missed diagnosis.68Ga-PSMA-617 PET/CT in the diagnosis of prostate cancer was the 4.88 of the cut-off value of SUVmax.The analysis results are as follows:sensitivity:90.00%(27/30),specificity:100.00%(12/12),positive predictive value:100.00%(27/27),negative predictive value:80.00%(12/15),and accuracy:92.86%(39/42).According to the analysis of five-zoning method,It was the 4.85 of the cut-off value of SUVmax between benign and malignant lesions.The sensitivity of PET/CT was 81.15%(99/122),the specificity was 95.45%(84/88),the positive predictive value was 96.12%(99/103),the negative predictive value was 77.14%(84/107),and the accuracy was 87.14%(183/210)respectively.Conclusions:With the help of 68Ga-PSMA-617 PET/CT based on the cut-off value of lesion in the glioma,the diagnostic basis is used to locate and qualitative prostate lesions,which will help guide the prostate TRUS fine needle biopsy more accurately.Project Ⅳ Comparison of diagnostic value of 68Ga-PSMA-617 PET/CT and multi-parameter MRI for primary prostate cancerObjective:To compare the diagnostic efficacy of 68Ga-PSMA-617 PET/CT and multi-parameter MRI in primary prostate cancer.Methods:24 patients with suspected prostate cancer were prospectively enrolled,with an average age of 67.6±7.0 years and PSA:262.29±675.67ng/mL.All patients underwent 68Ga-PSMA-617 PET/CT and multi-parameter MRI examinations.Pathological diagnosis was the gold standard.The diagnostic efficacy of the two methods was analyzed and the difference was evaluated by Jordan index.Results:24 patients underwent puncture biopsy and/or excision biopsy.18 patients were diagnosed as prostate cancer,6 were benign prostatic hyperplasia and chronic prostatitis.According to the five-zone analysis for the prostate,48 and 56 zones were detected by PET/CT and multi-parameter MRI in prostate cancer patients and 56 zones in non-prostate cancer patients,respectively.2 and 15 zones were detected.The cut-off value of 68Ga-PSMA-617 PET/CT in the diagnosis of prostate cancer was SUVmax:4.85,the sensitivity,specificity,positive predictive value,negative predictive value and Yoden index is 75.00%(48/64),96.43%(54/56),96%(48/50),77.14%(54/70),71.44%respectively for prostate cancer by PET/CT,and 87.5%(56/64),73.21%(41/46),78.87%(56/71),83.67%(41/49)and 60.71%respectively in multi-parameter MRI.Conclusions:The diagnostic accuracy of 68Ga-PSMA-617 PET/CT imaging for prostate cancer is higher than that of multi-parameter MRI,but both methods have high diagnostic efficiency.The two methods can be used scientifically as complementary.Project Ⅴ Expression of PSMA in poorly differentiated thyroid cancer and imaging with 68Ga-PSMA PET/CTObjective:Poorly differentiated thyroid cancer(PDTC)is an aggressive tumor and almost uniformly lethal.No curative therapy exists for PDTC.PSMA was reported to be significantly overexpressed in the neovasculature of differentiated thyroid cancer(DTC).The aim of this study is to evaluate the expression of PSMA in PDTC and imaging in the patients with the 68Ga-PSMA-617 PET/CT.Methods:We selected N-PA(poorly differentiated thyroid cancer),FTC-133(follicular thyroid carcinoma),and 22Rv1(prostate cancer)cells.PSMA was knocked down by RNAi.The mRNA and protein levels of PSMA were determined by quantitative RT-PCR and Western blotting,respectively.In order to validate the result of the in vitro experiments,we tested thyroid cancer patients with 68Ga-PSMA PET/CT imaging.Results:The PSMA mRNA levels in N-PA cells were significantly higher than in FTC-133 cells(18.35±1.739 vs.1.000±0.2792,P<0.0001).The PSMA mRNA levels in each group of thyroid cancer cells were inferior to those in prostate cancer cells.One primary lesion analyzed by 68Ga-PSMA PET/CT demonstrated highly intense tracer uptake in PDTC.It was an apparent contradiction that lymph nodes metastasis lesions that were not picked up by 1311 SPECT/CT could be detected with 6sGa-PSMA PET/CT.For one thyroid follicular carcinoma patient,lymph nodes metastasis was detected by 131I SPECT/CT but not by 68Ga-PSMA PET/CT.Conclusion:PDTC cells express PSMA,and the mRNA and protein levels are higher than in follicular thyroid carcinoma cells.Our preliminary results have shown that 68Ga-PSMA-617 PET/CT can help detect PDTC lesions compared to 131I SPECT/CT.