Prospects for using ultrasound of various intensity for the treatment of patients with malignant brain gliomas

Abstract

Background. Treatment for malignant brain gliomas includes surgery, radiation therapy, and chemotherapy with temozolomide. However, this complex treatment does not prevent tumor relapses and progression, which is caused by the activity of tumor cells and a high mutational burden. Researchers are experimenting with different intensity of focused ultrasound (FUS) in the treatment of glioblastoma (GBM). FUS has shown encouraging results in clinical studies.The aim of the study. This review presents brief information on the history of the development of  the studied method, the  results of  its  application in  experiments and   clinical trials, as  well  as the  main possible directions for  its  implementation in  neuro-oncology, in  particular, for  the  treatment of  glioblastomas, depending on parameters, including frequency, power, pulse duration and duty cycle.Methods. We carried out an analysis and interpretation of existing publications; for the search, we used the PubMed database and the keywords “focused ultrasound, glioma, HIFU, LIFU”, as  well  as Yandex and  Google search engines and  the  same keywords in Russian.Results. Low-intensity FUS can be used to temporarily open the blood-brain barrier (BBB), which limits the diffusion of most macromolecules and therapeutic agents into the brain. High-intensity FUS can cause tumor ablation due to a hyperthermic effect, and also stimulate an immunological attack of tumor cells, activate sonosensitizers to exert a cytotoxic effect on tumor tissue, and can increase the sensitivity of tumors to radiation therapy. Histotripsy causes tumor ablation through acoustic cavitation.Conclusion. Focused ultrasound is a promising potential treatment for gliomas. Further study in the form of clinical trials should determine the optimal ultrasound parameters to achieve effective treatment for patients with malignant brain tumors.