⁶⁸GA-PSMA-11 Imaging Of Prostate Lesions And Comparative Study With ¹⁸F-FDG Imaging

[Objective]1.PET/CT examination of ⁶⁸Ga-PSMA-11 and ¹⁸F-FDG was performed on patients with suspected prostate cancer and post-treatment of prostate cancer.And compare the data obtained and summarize their advantages and disadvantages.2.Through multi-center cooperation,the PET/CT image and clinical data of the patients who newly diagnosed and after treatment was analyzed.To investigate the positive role of ⁶⁸Ga-PSMA-11 PET/CT in the early diagnosis,preoperative staging,treatment guidance,recurrence and metastasis of PCa.[Materials and Methods]1.Study objectsCollect and study 42 patients with suspected prostate cancer or after treatment form the First Affiliated Hospital of Guangzhou Medical University and General Hospital of Southern Theatre Command.All patients underwent ¹⁸F-FDG PET/CT and ⁶⁸Ga-PSMA-11 PET/CT.Collect and study 102 patients with suspected prostate cancer or after treatment,including cases from the First Affiliated Hospital of Guangzhou Medical University,the Third Affiliated Hospital of Sun Yat-sen University and General Hospital of Southern Theatre Command.All patients were enrolled in the ⁶⁸Ga-PSMA-11 PET/CT examination and confirmed by pathological results or follow-up as the final diagnosis.2.Method2.1 Method for imaging¹⁸F-FDG PET/CT imaging method:fasting patient over 6h,and WB PET/CT was performed 1h¹.5hafter intravenous injection of ¹⁸F-FDG.After the acquisition is completed,the PET image is subjected to attenuation correction using CT data,and image reconstruction and fusion are performed.⁶⁸Ga-PSMA-11 PET/CT imaging method:The patient did not need to fast,and the WB PET/CT was performed 1h after the intravenous injection of ⁶⁸Ga-PSMA-11.After the acquisition is completed,the PET image is subjected to attenuation correction using CT data,and image reconstruction and fusion are performed.2.2 Clinical data collectionThe patient’s name,age,hospital number or outpatient number,treatment history,serum tPSA level before examination,Gleason score,other examination methods,pathological type,treatment after examination,and efficacy should be collected.2.3 Image analysis and Diagnostic criteriaThe images of the two central patients were analyzed by three experienced physicians with intermediate or higher titles in nuclear medicine.Reading of PET/CT images:The location,size,morphology,and radioactivity of the observed lesions should be recorded;and the SUVmax of the lesions in the region of interest should be calculated.Diagnostic criteria for prostate cancer:confirmed by prostate biopsy or surgical pathology;prostate cancer was considered more than two imagingmethods;bone and lyphm metastases can’t be explained except prostate cancer;treatment has obvious efficacy（follow-up time 3¹2months）.Diagnostic criteria for benign prostatic lesions:confirmed by prostate biopsy;no change in clinical and imaging examinations（follow-up time 3¹2 months）.2.4 Statistic MethodDescriptive statistical methods were used to summarize patient characteristics.Quantitative data were mean±standard deviation（±S）.The same patient used two different test methods to use paired t test.The comparison between groups was performed by independent test t test.Four-squares data were analyzed by chi-square test or Fisher test.The correlation between the two groups of data was analyzed by Pearson correlation analysis.The consistency analysis was performed by Kendall’s W test and statistical analysis was performed by IBM SPSS 19.0 software,when P<0.05,the difference was statistically significant.The ROC curve was used to determine the cut-off value and analyzed by MedCalc using software,when P<0.05,and the difference was statistically significant.[Results]1.Comparative study of ⁶⁸Ga-PSMA-11 and ¹⁸F-FDG imaging in prostate lesions（1）The sensitivity,specificity,positive predictive value,negative predictive value and overall accuracy of ⁶⁸Ga-PSMA-11 PET/CT and ¹⁸F-FDG PET/CT were 100%,83.33%,97.3%,100%,97.61%and 44.44%,50.0%,84.21%,13.04%,45.23%,respectively.According to the receiver operating curve（ROC）,when the ⁶⁸Ga-PSMA-11 measured prostate cancer SUVmax>4.4,the sensitivity and specificity of the diagnosis of PCa were86.96%and 100%,respectively.（2）The ⁶⁸Ga-PSMA-11 SUVmax of primary tumor,bone and lymph node metastases in PCa patients is higher than ¹⁸F-FDG SUVmax.⁶⁸Ga-PSMA-11 imaging can detect all lesions detected by ¹⁸F-FDG imaging and found more lesions than ¹⁸F-FDG imaging.The diagnostic effect on primary tumor,bone and lymph node metastasis is higher than that of 18F-FDG.FDG-PET is more advantageous in diagnosing prostate cancer and guiding clinical treatment.（3）The Kendall’s W coefficient of the ¹⁸F-FDG image interpretation results of the nuclear medicine doctors participating in the study was 0.664,P<0.001,with strong consistency;The Kendall’s W coefficient of the 68Ga-PSMA-11 image interpretation result is 0.913,P<0.001,which has strong consistency.2.Correlation between ⁶⁸Ga-PSMA-11 PET imaging and clinical features（1）The sensitivity,specificity,and overall accuracy of ⁶⁸Ga-PSMA-11PET/CT was 100%,76.92%and 94.12%.⁶⁸Ga-PSMA-11 imaging has important significance in distinguishing benign and malignant prostate lesions.When SUVmax>6.6,the sensitivity and specificity of prostate are both better,82.6%,93.7%,respectively.（2）A total of 30 patients with ⁶⁸Ga-PSMA-11 imaging and pelvic MRI were enrolled in the same period.⁶⁸Ga-PSMA-11 imaging and pelvic MRI sensitivity,specificity,positive predictive value,negative predictive value and accuracy were 92.86%,50.00%,96.30%,33.33%,90.00%and 76.00%,40.00%,86.36,25.00%,70.00%,respectively.（3）The SUVmax of primary cancer,bone metastasis and lymph node metastasis in newly diagnosed patients was positively correlated with serum tPSA and Gleason scores.（4）The tPSA and Glesson scores of distant metastases were higher than those without distant metastasis,and the degree of metastasis was positively correlated with tPSA and Gleason scores.[Conclusion]（1）The sensitivity of ⁶⁸Ga-PSMA-11 imaging diagnosis of PCa can reach 100%,the accuracy rate can reach about 95%;the sensitivity,specificity,positive predictive value,negative predictive value of ⁶⁸Ga-PSMA-11 imaging for PCa patients,the accuracy rate is significantly higher than ¹⁸F-FDG;（2）⁶⁸Ga-PSMA-11 imaging can detect all lesions detected by ¹⁸F-FDG imaging（whether primary,bone metastasis or lymph node metastasis）and more lesions than ¹⁸F-FDG imaging.It plays an important role in the clinical staging,re-segmentation and treatment guidance of patients;（3）The consistency of interpretation results of ⁶⁸Ga-PSMA-11 images by different nuclear medicine doctors was significantly higher than that of¹⁸F-FDG.（4）⁶⁸Ga-PSMA-11 imaging is preferred for the diagnosis of PCa patients;For patients receiving the ⁶⁸Ga-PSMA-11 PET/CT scan,no additional ¹⁸F-FDG PET/CT scan is required.