| Objectives:Astrocytoma is one of the most common types of gliomas,with high invasive ability.Currently,its recurrence rate is extremely high because they can not be completely cured by surgery,chemotherapy,and/or radiotherapy.The traditional imaging techniques(such as CT,MRI)and stereotactic biopsy show limitations in tumor grading while hydrogen proton magnetic resonance spectrum(1H-MR spectroscopy,hereinafter referred to as MRS)can detect the change of various brain metabolite before surgery.This study mainly focused on the MRS performance in pathological diagnosis of astrocytoma,and its relationship with Ki-67and aimed to reveal the predictive value of MRS of tumor recurrence after surgery,thus provide scientific basis for the establishment of individual treatment for astrocytoma patients.Materials and Methods:A retrospective analysis was performed on 73 astrocytoma patients from January 2012 to January 2015.The clinical characteristics of thepatients were recorded including gender,age,tumor grades,tumor sites and so on.Ki-67 expression in post-operative specimens was examined by immunohistochemical staining.The ratios of tumor parenchyma choline(Cho)/N-acetylaspartate(NAA),Cho/creatine(Cr),NAA/Cr,and occurrence rates of lactate(Lac)and lipid(Lip)signals were examined by MRS.The correlations among clinical characteristics,Ki-67,metabolites ratios from MRS,and tumor recurrence were analyzed.The prognosis value of tumor grade,age,tumor sites,Ki-67,and MRS data in predicting astrocytoma after surgery was investigated by univariate and multivariate Cox regression analysis.Results:1.Ki-67 expression in astrocytoma was positively associated with the ratios of Cho/Cr(r=0.305,P=0.009)and Cho/NAA(r=0.468,P<0.001)but negatively with NAA/Cr(r=-0.480,P<0.001).2.Correlation analyses suggested that Ki-67 was associated with tumor grade and recurrence,Cho/Cr was associated with age and recurrence,Cho/NAA was associated with grade and recurrence,NAA/Cr was associated with grade,Lac was associated with age and recurrence,and Lip was associated with grade and recurrence.Kaplan-Meier curves indicated that tumor grade,age,tumor sites,Ki-67 expression,Cho/Cr,Cho/NAA,NAA/Cr,and Lac were associated with astrocytoma recurrence.3.Multivariate analyses revealed that the clinical parameters grade and metabolite ratios Cho/Cr and Lac were independent prognostic factors for astrocytoma recurrence(Grade,HR=0.337,95%CI=0.135-0.846;Cho/Cr,HR=0.348,95%CI=0.145-0.839;Lac,HR=0.457,95%CI=0.228-0.916).Conclusion:MRS data of astrocytoma were associated with Ki-67 expression and can be used to predict tumor recurrence after surgery,especially Cho/Cr and Lac,which could be used as independent prognostic factors for astrocytoma recurrence,can be used to predict the recurrence of astrocytoma postoperativelyinstead of Ki-67,thereby helped to make reasonable treatment decisions for astrocytoma patients. |
