Application Of High Resolution Diffusion-weighted Magnetic Resonance Imaging In Predicting The Methylation Status Of The MGMT Promoter In Invasive Pituitary Adenoma

Objective:In order to find specific molecular markers of aggressiveness of pituitary adenomas,the differences between MGMT promoter methylation status in pituitary adenoma imaging,proliferation,and endocrine grouping were analyzed combined with preoperative MRI and high-definition diffusion-weighted imaging to explore the correlation of MGMT promoter methylation status and pituitary adenoma aggressive behavior.The ADC value of pituitary adenoma was measured by MRI high-resolution diffusion weighted imaging,the correlation between the methylation status of MGMT promoter and ADC value was analyzed,and the establishment of molecular imaging predictive index of methylation status of MGMT promoter was explored as invasive.Lays the foundation of multidisciplinary comprehensive diagnosis and treatment of pituitary adenoma.Methods:1.Select patients with pituitary adenoma who underwent surgical treatment in Hainan Provincial People's Hospital from November 2018 to November 2019,and perform pituitary MRI plain scan + enhancement,high-definition diffusion weighted imaging,and serological hormone examination to confirm the diagnosis.Sign informed consent and perform surgical treatment.Tumor tissue specimens were examined by HE staining,endocrine and Ki-67 immunohistochemistry.2.Pyrosequencing was used to detect the methylation status of the MGMT promoter in pituitary adenoma specimens,and the invasive and non-invasive groups were determined according to the Knosp classification of preoperative MRI images;the proliferation group was determined according to the classification of WHO endocrine organ tumors in 2017 And non-proliferative groups;functional and non-functional groups were determined based on preoperative serum hormonal levels and postoperative endocrine immunohistochemical results.The expression differences of MGMT promoter methylation status in invasive and non-invasive groups,proliferative and non-proliferative groups,functional groups and non-functional groups were compared.To investigate the correlation between MGMT promoter methylation status and aggressive behavior of pituitary adenomas.3.MRI high-resolution diffusion-weighted imaging was used to measure ADC value of pituitary adenoma.The correlation between methylation status of MGMT promoter and ADC value was analyzed and compared.Results:From November 2018 to November 2019,33 effective cases werecollected.Patients were grouped according to invasive and non-invasive,proliferative and non-proliferative,functional and non-functional.The MGMT promoter methylation status and the statistical value of ADC were compared between the groups.It was found that there was a statistically significant difference in the methylation status of the MGMT promoter in the invasive and non-invasive groups(p = 0.030).The results of the other two grouping methods were not statistically significant(p> 0.05).There was no statistical significance in the ADC value statistics among the groups(p> 0.05).No correlation was found between gender and age and MGMT promoter methylation status.Conclusion:1.The methylation status of MGMT promoter in patients with pituitary adenoma may be related to the aggressive grouping of tumor imaging.At present,founded patients with MGMT promoter methylation belong to the non-invasive group.It is suggested that the prognosis of patients with methylation of MGMT promoter may be relatively well.2.The methylation status of MGMT promoter in patients with pituitary adenoma has no significant correlation with tumor proliferative group,functional group,and patient gender and age.3.There is no significant correlation between the MRI ADC value and the aggressive,proliferation and functional groups in patients with pituitary adenoma.There is no relevant evidence to predict the prognosis of patientswith ADC value.