Effect of bevacizumab on radiation necrosis of the brain.
OBJECTIVE
Because blocking vascular endothelial growth factor (VEGF) from reaching leaky capillaries is a logical strategy for the treatment of radiation necrosis, we reasoned that bevacizumab might be an effective treatment of radiation necrosis.


METHODS
Fifteen patients with malignant brain tumors were treated with bevacizumab or bevacizumab combination for their tumor on either a 5 mg/kg/2-week or 7.5 mg/kg/3-week schedule. Radiation necrosis was diagnosed in 8 of these patients on the basis of magnetic resonance imaging (MRI) and biopsy. MRI studies were obtained before treatment and at 6-week to 8-week intervals.


RESULTS
Of the 8 patients with radiation necrosis, posttreatment MRI performed an average of 8.1 weeks after the start of bevacizumab therapy showed a reduction in all 8 patients in both the MRI fluid-attenuated inversion-recovery (FLAIR) abnormalities and T1-weighted post-Gd-contrast abnormalities. The average area change in the T1-weighted post-Gd-contrast abnormalities was 48% (+/-22 SD), and the average change in the FLAIR images was 60% (+/-18 SD). The average reduction in daily dexamethasone requirements was 8.6 mg (+/-3.6).


CONCLUSIONS
Bevacizumab, alone and in combination with other agents, can reduce radiation necrosis by decreasing capillary leakage and the associated brain edema. Our findings will need to be confirmed in a randomized trial to determine the optimal duration of treatment.
Gonzalez
Javier
J
Department of Neuro-Oncology, The University of Texas M D Anderson Cancer Center, Houston, TX 77230-1402, USA.
Kumar
Ashok J
AJ
Conrad
Charles A
CA
Levin
Victor A
VA
D000328:Adult; D000368:Aged; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D001706:Biopsy; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000532:radiotherapy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology; D011832:Radiation Injuries / Q000188:drug therapy* / Q000473:pathology; D012189:Retrospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors*
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab