Boron neutron capture therapy (BNCT) is a promising modality for biochemically targeted highly selective radiation treatment of various cancers, including malignant gliomas. Currently available results demonstrate the beneficial effect of such a therapy on survival of patients with both recurrent and newly diagnosed malignant gliomas, including glioblastomas. On the other hand, the main drawback of BNCT in cases of previously irradiated neoplasms in the brain is the high rates of symptomatic pseudoprogression and radiation necrosis. To treat these complications, we advocated the use of bevacizumab. Even for prevention of these complications, the combined use of bevacizumab may be helpful. Further studies are needed to establish the optimal therapeutic protocols and to define the exact role of this management option in the multimodality treatment strategies. Recent technological developments of accelerator-based neutron sources may simplify the setting of the device for BNCT for recurrent malignant gliomas. In this chapter, we indicate the effective MR images of recurrent malignant gliomas treated with BNCT with the use of bevacizumab from our series.