Boron neutron capture therapy using mixed epithermal and thermal neutron beams in patients with malignant glioma-correlation between radiation dose and radiation injury and clinical outcome.
OBJECTIVE
To clarify the correlation between the radiation dose and clinical outcome of sodium borocaptate-based intraoperative boron neutron capture therapy in patients with malignant glioma.


METHODS
The first protocol (P1998, n = 8) prescribed a maximal gross tumor volume (GTV) dose of 15 Gy. In 2001, a dose-escalated protocol was introduced (P2001, n = 11), which prescribed a maximal vascular volume dose of 15 Gy or, alternatively, a clinical target volume (CTV) dose of 18 Gy.


RESULTS
The GTV and CTV doses in P2001 were 1.1-1.3 times greater than those in P1998. The maximal vascular volume dose of those with acute radiation injury was 15.8 Gy. The mean GTV and CTV dose in long-term survivors with glioblastoma was 26.4 and 16.5 Gy, respectively. A statistically significant correlation between the GTV dose and median survival time was found. In the 11 glioblastoma patients in P2001, the median survival time was 19.5 months and 1- and 2-year survival rate was 60.6% and 37.9%, respectively.


CONCLUSIONS
Dose escalation contributed to the improvement in clinical outcome. To avoid radiation injury, the maximal vascular volume dose should be <12 Gy. For long-term survival in patients with glioblastoma after boron neutron capture therapy, the optimal mean dose of the GTV and CTV was 26 and 16 Gy, respectively.
Kageji
Teruyoshi
T
Department of Neurosurgery, Graduate School of Health Biosciences, The University of Tokushima, Tokushima, Japan. kageji@clin.med.tokushima-u.ac.jp
Nagahiro
Shinji
S
Matsuzaki
Kazuhito
K
Mizobuchi
Yoshifumi
Y
Toi
Hiroyuki
H
Nakagawa
Yoshinobu
Y
Kumada
Hiroaki
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D001894:Borohydrides / Q000627:therapeutic use*; D016754:Boron Neutron Capture Therapy / Q000379:methods*; D001932:Brain Neoplasms / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005909:Glioblastoma / Q000532:radiotherapy*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D018242:Neuroectodermal Tumors, Primitive / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D013438:Sulfhydryl Compounds / Q000627:therapeutic use*
D001894:Borohydrides; D013438:Sulfhydryl Compounds; C014651:mercaptoundecahydrododecaborate