Clinical application of MRS in the diagnosis of brain tumor: investigation of tumormetabolites؛ A Systematic review

Introduction: Magnetic resonance spectroscopy(MRS)is a technique that combines the ability of nuclearmagnetic resonance(NMR)to distinguish molecules with imaging properties to reveal complementary noninvasiveinformation about the biochemical composition of the imaged tissue.MRS is useful in the earlydiagnosis of brain tumors and helps distinguish tumors from possible mimics such as metastaticdisease,lymphoma,demyelination,and infection,as well as in the follow-up of patients after resection andchemoradiation. The purpose of this study is to investigate the clinical application of MRS for early diagnosisand treatment planning.Methods: In a systematic review conducted in ۲۰۲۳, all articles published from ۲۰۱۸to۲۰۲۳ were searchedusing advanced keywords and MeShterms in the search engines Web of Science, Scopus, PubMed Medline andGoogle Scholar with inclusion criteria (studies only in English, only considered). human study, only clinicaltrial studies, no restrictions on access to the full text) Finally, among the ۱۲۰studies reviewed by reading firstthe title, then the abstract and finally the full text, according to the charter guidelines, also to ensure thecompleteness of the search results, the sources of reviewed articles are placed. Finally,۱۰studies were includedin the research.Results: Hydrogen MR spectroscopy revealed significant differences in the content of metabolites betweentumor types.Compared to tumors of the neuroectodermal tissue,tumors of the meningovascular series werecharacterized by minimal values of the proportion of N-acetylaspartate and the presence of alaninemetabolite.Glial tumors were characterized by intermediate values of the shares of Nacetylaspartate, creatine,as well as the absence of alanine content.N-Acetyl-aspartate was demonstrated in normal tissues but could notbe detected in nonneuroectodermal tumors.Total creatine was decreased in all brain tumors in comparison withnormal brain tissues,but was relatively higher in neuroectodermal tumors than in other brain tumors.Cholinecontainingcompounds were present in all tumors except craniopharyngioma, and their concentrations wereparticularly high in a metastatic brain tumor from hepatocellular carcinoma.The concentration of glycine washigh in neuroectodermal tumors,whereas that of taurine was high in medulloblastoma,pituitary adenoma,andrenal cell carcinoma.Alanine was increased in meningioma,glioma, andpituitary adenoma.Neurinoma had thelargest inositol content among the tumors examined.Conclusion: Future developments are likely to increase the importance of MRS for early diagnosis, treatmentplanning, and early detection of relapse. Unfortunately, the spectroscopic appearance of many pathologies canoverlap, and ultimately follow-up or biopsy may be required for definitive diagnosis. Nevertheless, MRScontinues to provide substantial and useful insight into metabolomics of the brain tumors.