Survival benefit from boron neutron capture therapy for the newly diagnosed glioblastoma patients

Objective: Since 2002-2007, we applied boron neutron capture therapy (BNCT) to >50 cases of malignant gliomas (MGs) with epithermal neutron irradiations. Recently, we showed the early radiographical improvement of malignant glioma patients by our modified BNCT, with simultaneous use of BPA (borono-phenylalanine) and BSH (sodium borocaptate). In this time, we focused on the survival benefit from BNCT for the newly diagnosed glioblastoma patients. Methods: BNCT group including 21 newly histological confirmed glioblastoma patients treated with surgical removal followed by BNCT in Osaka Medical College during 2002-2006 period. Ten patients were treated with BNCT only, and in the other 11 patients, 20-30 Gy fractionated external beam X-ray irradiation therapy (XRT) was performed after BNCT. No chemotherapy was administered until tumor progression was observed. Results: Treatments were well tolerated. Any kind of acute systemic or local severe toxicity were not demonstrated. Mean over all survival of the patients treated by BNCT was 20.7 and the median was 15.6 months with 2-years survival of 25%. Stratification by RPA criteria showed 6, 6, 8 and 1 patients, respectively, in classes III-VI. Three patients out of six in class III and one out of eight in class V are alive at the end point of this study. All the patients in classes IV and VI died. Median survival time for the BNCT group compared to the RTOG database was as follows: 20.6 months vs. 17.9 months for class III; 16.9 months vs. 11.1 months for class IV; 13.2 months vs. 8.9 months for class V. Conclusion: The RTOG RPA prognostic criteria were helpful in establishing which class of glioma patients could potentially benefit from BNCT. BNCT showed a survival benefit in all of the RPA classes of the RTOG database not only for the good prognosis group.