GCT-58. BRAZILIAN CENTRAL NERVOUS SYSTEM GERM CELL TUMOR CONSORTIUM PROTOCOL

INTRODUCTION: Primary central nervous system (CNS) germ cell tumors (GCT) account for 2–3% brain tumors children/adolescents in Western hemisphere. The report aim is to present the results of a Brazilian CNSGCT consortium protocol. METHODS: Since 2013, 45 patients with histologic and/or tumor marker (TM) diagnosis of germinoma with/without HCGβ levels≤200mIU/ml (n=33), four between 100-200mIU/ml and NGGCT (n=12), received carboplatin/etoposide/cyclophosphamide (4–6 cycles), followed by 18Gy ventricular field irradiation and primary site(s) boost. Autologous bone marrow transplant (ABMT) was conducted for NGGCT low responders. RESULTS: Mean age 12.9 years (4.7-20y), 34 males. Diagnosis was made by TM (n=9), surgery (n=19), both (n=15). Two bifocal cases, (-)TM were treated as germinoma. Primary tumor location was pineal (n=20), suprasellar (n=13), bifocal (n=11) and basal ganglia/thalamus (n=1). Fourteen had ventricular/spinal spread. Second-look surgery occurred in 5 patients. For the germinoma group, 26 achieved complete response (CR) after chemotherapy, seven showed residual teratoma/scar. For the NGGCT after 2/4 cycles, four patients showed CR, 2 failure/progression and 6 partial response (4 (-)TM). Two were submitted to ABMT. Radiotherapy was performed as described, except in three. One recurrence to date. Two patients died (endocrinologic complications/progression). Toxicity was mostly grade ¾ neutropenia/thrombocytopenia during chemotherapy. At a median follow-up of 38 months, OS was 100% for Germinoma and 85% NGGCT. CONCLUSION: The treatment is tolerable and VFI dose reduction to 18Gy seems to preserve efficacy. Further follow-up is warranted to assess the NG group and the slow-responder patients.