Efficacy and Safety of Temozolomide Combined with Radiotherapy in the Treatment of Malignant Glioma

MG is a clinical common intracranial tumor, with the characteristics of strong invasion. In our study, we aim to explore the efficacy and safety of temozolomide combined with radiotherapy in the treatment of malignant glioma (MG) and its influence on postoperative complications and survival rate of patients. 120 MG patients admitted to our hospital (January 2019-January 2020) were chosen as the research objects and were randomly divided into group A (n = 60) and group B (n = 60). All patients were treated with radiotherapy, and patients in group A were additionally treated with temozolomide. The clinical efficacy, quality of life, incidence of adverse reactions, incidence of postoperative complications, survival rates, and average survival time of the two groups were compared. The objective remission rate (ORR), disease control rate (DCR), survival rates after one year and two years of follow-up, and the number of patients with improved quality of life in group A were markedly higher compared with group B (P < 0.05). The incidence of postoperative complications in group A was remarkably lower compared with group B (P < 0.05). The average survival time of group A was dramatically longer compared with group B (P < 0.001). There was no significant difference in the incidence of adverse reactions between the two groups (P > 0.05), and no new adverse reactions occurred in the patients. Temozolomide combined with radiotherapy can effectively improve the quality of life, treatment effect, and survival rate of MG patients, with a lower incidence of postoperative complications and better tolerance. Our finding indicates that temozolomide combined with radiotherapy has a high clinical application value. In addition, it indicates that this treatment method should be promoted in practice.

Glutamate Is a Noninvasive Metabolic Biomarker of IDH1-Mutant Glioma Response to Temozolomide Treatment

Although lower grade gliomas are driven by mutations in the isocitrate dehydrogenase 1 (IDH1) gene and are less aggressive than primary glioblastoma, they nonetheless generally recur. IDH1-mutant patients are increasingly being treated with temozolomide, but early detection of response remains a challenge and there is a need for complementary imaging methods to assess response to therapy prior to tumor shrinkage. The goal of this study was to determine the value of magnetic resonance spectroscopy (MRS)-based metabolic changes for detection of response to temozolomide in both genetically engineered and patient-derived mutant IDH1 models. Using 1H MRS in combination with chemometrics identified several metabolic alterations in temozolomide-treated cells, including a significant increase in steady-state glutamate levels. This was confirmed in vivo, where the observed 1H MRS increase in glutamate/glutamine occurred prior to tumor shrinkage. Cells labeled with [1-13C]glucose and [3-13C]glutamine, the principal sources of cellular glutamate, showed that flux to glutamate both from glucose via the tricarboxylic acid cycle and from glutamine were increased following temozolomide treatment. In line with these results, hyperpolarized [5-13C]glutamate produced from [2-13C]pyruvate and hyperpolarized [1-13C]glutamate produced from [1-13C]α-ketoglutarate were significantly higher in temozolomide-treated cells compared with controls. Collectively, our findings identify 1H MRS-detectable elevation of glutamate and hyperpolarized 13C MRS-detectable glutamate production from either pyruvate or α-ketoglutarate as potential translatable metabolic biomarkers of response to temozolomide treatment in mutant IDH1 glioma. SIGNIFICANCE: These findings show that glutamate can be used as a noninvasive, imageable metabolic marker for early assessment of tumor response to temozolomide, with the potential to improve treatment strategies for mutant IDH1 patients.