P13.13 * INTRAOPERATIVE RADIOTHERAPY WITH INTRABEAM IN PRIMARY BRAIN TUMORS AFTER RESECTION: PRELIMINARY REPORTS OF 26 CASES

Abstract

OBJECTIVES: To evaluate the preliminary results of intraoperative radiotherapy (IORT) with Intrabeam (Zeiss) in patients with primary brain tumors. METHODS AND MATERIALS: Primary brain tumor patients were selected and treated with Intrabeam IORT to the tumor beds in our center after resection, the doses range from 8-12Gy with depth of 2mm from applicator surface. All patients were evaluated in serials CT/MRI scans and neurological function, blood cell counting and wound healing duration. RESULTS: Up-to-now, 26 cases of adult patients (age from 8-75) with malignant brain tumor were treated with IORT, which included 1 recurrent medulloblastoma, 3 recurrent glioblastoma,1 recurrent astrocytoma, 5 anaplastic mixed glioma, 2 astrocytoma (grade 2) and 12 new diagnosis glioblastoma, 2 epydenoma . 3 of them had been previously irradiated. Follow-up was 1month to 15 months. Until now, 6 patients died (2 died within 1 month after surgery, 4 died of recurrent tumors). Other 20 patients are still alive without tumor recurrence (1-14 month), follow-up MRI /CT scans did not show significant necrosis after IORT; 1 patients had bleeding in the tumor cavity (thalamus, died 20days later), 1 patient have paralysis 1 day after operation and recovered 10 days later because of cerebral artery spasm, others are all recovered totally from surgery without any complications, blood counting and wound healing duration were the same as no-IORT patients. No other toxicity was observed at the last follow-up visit. CONCLUSION: Our preliminary results of 26 cases during 1-15 months follow- up demonstrated that Intrabeam IORT to a dose of 8-12 Gy to 2 mm in the treatment of primary brain tumors beds are safe without increase post-operative complications, but long term follow up for recurrent malignant brain tumors were not satisfy, but for new diagnosis brain tumor patients showed good local tumor control with relatively long term survival. Further researches are needed to evaluate long term efficacy, especially for ependymomas and low grade glioma.