Predictive significance of mean apparent diffusion coefficient value for responsiveness of temozolomide-refractory malignant glioma to bevacizumab: preliminary report.
BACKGROUND
Recurrent glioblastoma after initial radiotherapy plus concomitant and adjuvant temozolomide is problematic. Here, patients with temozolomide-refractory high-grade gliomas were treated with bevacizumab (BV) and evaluated using apparent diffusion coefficient (ADC) for response.


METHODS
Nine post-temozolomide recurrent or progressive high-grade glioma patients (seven with glioblastoma and two with anaplastic astrocytoma) were treated with BV monotherapy. Average age was 57 years (range, 22-78), median Karnofsky Performance Scale (KPS) was 70 (30-80) and median BV line number was 2 (2-5). Two had additional stereotactic radiotherapy within 6 months prior to BV. Magnetic resonance (MR) imaging after BV therapy was performed within 2 weeks with calculation of mean ADC (mADC) values of enhancing tumor contours.


RESULTS
Post-BV treatment MR imaging showed decreased tumor volumes in eight of nine cases (88.9 %). Partial response was obtained in four cases (44.4 %), four cases had stable disease, and one had progressive disease. Of 15 evaluable enhancing lesions, 11 shrank and four did not. Pretreatment mADC values were above 1100 (10(-6) mm(2)/s) in all responding tumors, while all non-responding lesions scored below 1100 (p = 0.001). mADC decreased after the first BV treatment in all lesions except one. KPS improved in four cases (44.4 %). Median progression-free survival and overall survival for those having all lesions with high mADC (>1100) were significantly longer than those with a low mADC (<1100) lesion (p = 0.018 and 0.046, respectively).


CONCLUSIONS
Bevacizumab monotherapy is effective in patients with temozolomide-refractory recurrent gliomas and tumor mean ADC value can be a useful marker for prediction of BV response and survival.
Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan, mnagane.g@gmail.com.
Motoo
M
Nagane
Keiichi
K
Kobayashi
Masaki
M
Tanaka
Kazuhiro
K
Tsuchiya
Yukiko
Y
Shishido-Hara
Saki
S
Shimizu
Yoshiaki
Y
Shiokawa
D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology; D000077204:Temozolomide; D016896:Treatment Outcome
D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D003606:Dacarbazine; D000077204:Temozolomide