STMO-03 ROLE OF INTRAOPERATIVE COMPUTED TOMOGRAPHY IN GLIOBLASTOMA RESECTION GUIDED BY 5-ALA

OBJECTIVE: To improve resection rate, multiple operative modalities have been essential for glioblastoma (GBM) surgery. Aim of this study is to clarify the impact of intraoperative computed tomography (i-CT) for GBM surgery with 5-aminolevulinic acid photodynamic diagnosis (5-ALA PDD). METHODS: Consecutive 24 patients newly diagnosed GBM were analyzed, retrospectively. To exclude 6 patients decided timing for i-CT based on neural monitoring, 18 patients performed i-CT after total resection of 5-ALA positive lesion were included, finally. RESULTS: The median age was 58 years old, and average preoperative tumor volume was 47.78 cm3. Tumor locations were frontal lobe 5 (27%), parietal lobe 3 (17%), temporal lobe 9 (50%), and corpus callosum 1 (6%). Seventeen tumors (78%) harbored in eloquent area. After i-CT performed, 7 (39%) were confirmed residual tumor, and additional resections were needed. Subtotal resection (STR) was 5 and partial resection (PR) was 2 on volumetry in i-CT before additional resection. After additional resection, those cases were judged as 2 gross total resection (GTR), 4 STR and 1 PR in postoperative magnetic resonance imaging (MRI). 11 cases without additional resection were judged as 4 GTR, 3 STR and 4 PR in postoperative MRI. In 18 patients confirmed total resection of 5-ALA positive lesion, i-CT and postoperative MRI revealed 14 (78%) residual tumors. I-CT revealed 7 (50%) in all residual tumor. DISCUSSION: Hemorrhage, brain edema, air, invasive lesion, and limitation of resolution of CT might make difficult to detect residual tumor. CONCLUSION: I-CT may be useful to detect residual tumor even with 5-ALA and improve resection rate.