Diagnostic Value Of ^99mTc-3PRGD₂ SPECT/CT Imaging For Cerebral Glioma

BackgroundGliomas are the most common tumors in the central nervous system,accounting for more than 70%of brain malignant tumors.Glioblastoma is the most common and the most malignant,with an incidence of 3.2/100,000.According to the current maximum safe range of surgical resection criteria,the median survival time is less than 2 years,even with combined chemotherapy and alkylating agent temozolomide treatment,it still has a high mortality and recurrence rate.Therefore,imaging techniques for diagnosis of glioma and recurrence of glioma have become a research hotspot.Malignant tumors can induce the formation of new blood vessels,and the malignant proliferation and invasion of tumor cells are also dependent on new blood vessels.Early observation of functional angiogenic activity of tumor angiogenesis has important clinical value for early diagnosis,recurrence,evaluation of therapeutic efficacy and prognosis of glioma.^99mTc-3PRGD₂ is a novel radiopharmaceutical with high affinity for integrin?v?3,which is highly expressed in tumor neovascular endothelial cells,for detecting angiogenesis and metastasis,and capable of non-invasive imaging observation of tumor neovascularization.It can be used to diagnose glioma and identify postoperative recurrence and radiation brain damage in glioma.Objective1.To investigate the clinical value of imaging in the diagnosis of glioma.2.To investigate the clinical value of ^99mTc-3PRGD₂ SPECT/CT imaging in the diagnosis of postoperative recurrence and radiation-induced brain injury in glioma.Method18 patients with suspected glioma before surgery and 17 patients with suspected glioma recurrence after radiotherapy and chemotherapy were included in the study.All patients did not need special preparation before the examination.^99mTc-3PRGD₂was injected intravenously at rest,and the imaging agent was injected at a body mass of 11.1MBq/Kg?0.3mCi/Kg?for 2h,and then SPECT was performed.Image analysis adopts two analytical methods:visual analysis and semi-quantitative analysis.Semi-quantitative analysis calculates the T/N ratio of tumor to contralateral normal brain tissue by delineating the region of interest?ROI?.An independent sample t-test was used to compare the difference in T/N ratio between different grades of glioma,glioma recurrence,and radiation-induced brain injury.The ROC characteristic curve was used to evaluate the diagnostic value of T/N ratio in the identification of high and low grade gliomas,glioma recurrence and radiation-induced brain injury.Results1.A total of 18 preoperative patients were confirmed by pathology and follow-up.Among them,9 cases of ^99mTc-3PRGD₂ SPECT/CT imaging were positive?2 cases of low-grade glioma,6 cases of high-grade glioma,1 case of inflammation?,9 cases of negative imaging results?4 cases of low-grade glioma,1 case of high-grade glioma,4 cases of cerebral infarction?.The accuracy of diagnosing glioma is 66.7%,the sensitivity is 61.5%,the specificity is 80%,the positive predictive value is 88.9%,the negative predictive value is 44.4%,and the sensitivity for the diagnosis of high-grade glioma is 88.9%.The sensitivity of low-grade gliomas was 33.3%.Semi-quantitative analysis showed high-grade glioma?T/N ratio:4.61±1.89?and low-grade glioma?T/N ratio:2.46±0.95?,and the difference in T/N ratio between the two was statistically significant?P=0.019?.The T/N ratio of 3.25 was used as the boundary value for diagnosis of benign and malignant glioma.The area under the ROC curve was 0.857,and the diagnostic value was higher.2.17 patients with suspected glioma recurrence after radiotherapy and chemotherapy,confirmed by pathology or follow-up,including 13 cases of high-grade recurrent glioma imaging positive,4 cases of radioactive damage imaging negative.For recurrent glioma,the detection rate was 76.5%.Semi-quantitative analysis showed postoperative recurrence of glioma?T/N ratio:5.65±2.14?and radiation-induced brain injury?T/N ratio:2.18±0.97?,and the difference in T/N ratio between the two groups was statistically significant?P=0.007?.The T/N ratio of 3.35was used as the boundary value for the diagnosis of postoperative recurrence and radiation brain damage in glioma.The area under the ROC curve was 0.942,and the diagnostic value was higher.Conclusion1.^99mTc-3PRGD₂ as a tumor angiogenesis positive drug has certain clinical value for the diagnosis of glioma,especially for high-grade glioma;semi-quantitative analysis can be used to evaluate the malignant degree of glioma.2.It was preliminarily confirmed that ^99mTc-3PRGD₂ SPECT/CT imaging has high clinical value in distinguishing postoperative recurrence and radiation brain damage of glioma.