GCT-18. Endoscopic third ventriculostomy (ETV) and tumor biopsy are not associated with relapse rate or patterns in primary central nervous system (CNS) germ cell tumor (GCT)

Abstract BACKGROUND: ETV and tumor biopsy are central to the surgical management of children with primary CNS GCT. An creates a communication between intraventricular compartment subarachnoid spaces decompartmentalizes ventricular system. “Tumor spill” or shedding may result from interventions, such as biopsy. simultaneous impart greater tendency for dissemination possible distant relapse. This is concern in GCT given attempts irradiation field dose reduction following chemotherapy. METHODS: We performed retrospective review prospective database Children’s Oncology Group (COG) ACNS1123 study. Possible associations were explored among ETV, endoscopic biopsy, combined ETV+biopsy relapse, progression free survival (PFS), time RESULTS: Among 244 eligible patients, 97 ETV+/-biopsies performed, 30 relapses occurred. There no and/or relapse (Cochran-Mantel-Haenszel [CMH] test, histology (germinoma vs. nongerminomatous germ cell (NGGCT)) stratification variable: ETV: p=0.3167, biopsy: p=0.3375, combined: p=0.3066), (CMH p=0.4631, ETV+biopsy: p=0.6795), PFS (log-rank NGGCT p=0.1632, germinoma p=0.9288; p=0.1682, p=0.9701; ETV+Biopsy: p=0.1306, p=0.7758), death/local competing risk (Gray’s p=0.5694, p=0.2327; p=0.3505, p=0.5747; p=0.3988, p=0.6839). CONCLUSIONS: Based on secondary analysis data trial, did not likelihood treated chemotherapy irradiation. However, three tract recurrences occur (all germinoma), suggesting that they affect pattern Current future trials should continue explore these variables including patterns