Bevacizumab treatment leads to observable morphological and metabolic changes in brain radiation necrosis.
We investigated morphological and metabolic changes of radiation necrosis (RN) of the brain following bevacizumab (BEV) treatment by using neuroimaging. Nine patients with symptomatic RN, who had already been treated with radiation therapy for malignant brain tumors (6 glioblastomas, 1 anaplastic oligodendroglioma, and 2 metastatic brain tumors), were enrolled in this prospective clinical study. RN diagnosis was neuroradiologically determined with Gd-enhanced MRI and 11C-methionine positron emission tomography (MET-PET). RN clinical and radiological changes in MRI, magnetic resonance spectroscopy (MRS) and PET were assessed following BEV therapy. Karnofsky performance status scores improved in seven patients (77.8 %). Both volumes of the Gd-enhanced area and FLAIR-high area from MRI decreased in all patients after BEV therapy and the mean size reduction rates of the lesions were 80.0 and 65.0 %, respectively. MRS, which was performed in three patients, showed a significant reduction in Cho/Cr ratio after BEV therapy. Lesion/normal tissue (L/N) ratios in MET- and 11C-choline positron emission tomography (CHO-PET) decreased in 8 (89 %) and 9 patients (100 %), respectively, and the mean L/N ratio reduction rates were 24.4 and 60.7 %, respectively. BEV-related adverse effects of grade 1 or 2 (anemia, neutropenia and lymphocytopenia) occurred in three patients. These results demonstrated that BEV therapy improved RN both clinically and radiologically. BEV therapeutic mechanisms on RN have been suggested to be related not only to the effect on vascular permeability reduction by repairing the blood-brain barrier, but also to the effect on suppression of tissue biological activity, such as immunoreactions and inflammation.
Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Kizawa Memorial Hospital, 630 Shimokobi, Kobi-cho, Minokamo, Gifu, 505-0034, Japan, syonezawa0712@gmail.com.
Shingo
S
Yonezawa
Kazuhiro
K
Miwa
Jun
J
Shinoda
Yuichi
Y
Nomura
Yoshitaka
Y
Asano
Noriyuki
N
Nakayama
Naoyuki
N
Ohe
Hirohito
H
Yano
Toru
T
Iwama
D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D001921:Brain / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D016371:Cranial Irradiation / Q000009:adverse effects*; D005260:Female; D005910:Glioma / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D011446:Prospective Studies; D011832:Radiation Injuries / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects*; D016896:Treatment Outcome
D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab