GC-17: THE CHILDREN'S ONCOLOGY GROUP (COG) CURRENT TREATMENT APPROACH FOR CHILDREN WITH NEWLY DIAGNOSED CENTRAL NERVOUS SYSTEM (CNS) LOCALIZED GERMINOMA (ACNS1123 STRATUM 2)

Germinomas account for two-thirds of intracranial germ cell tumors. It is hypothesized that pre-irradiation chemotherapy may allow for a safe reduction in irradiation dose and volume while maintaining high survival rates. Stratum 2 of COG study ACNS1123 is evaluating whether chemotherapy (carboplatin 600mg/m2 on day 1 and etoposide 150mg/m2 on days 1-3) every 21 days x 4 cycles, followed by response based whole ventricular irradiation (WVI) is effective in treating patients with localized primary CNS germinoma allowing for elevation of hCG□ ≤100 mIU/mlbut mandating negative AFP in CSF and serum. Patients achieving a complete response following chemotherapy receive 18Gy WVI and a boost of 12Gy to the primary tumor. Patients with >0.5 cm (suprasellar) or >1 cm (pineal) but ≤1.5 cm residual, not undergoing second-look surgery, will be treated with WVI to 24Gy followed by local boost of 12Gy to a total dose of 36Gy. Mandatory enrollment on ALTE07C1 with prospective neuropsychological evaluation at 9, 30 and 60 months after diagnosis is also required. To-date, 93 eligible patients have been enrolled. The median age at diagnosis is 14.62 years with a male to female ratio of 3:1. Bifocal disease is present in 15 patients. Forty eight patients had hCG□ levels between 5-50mIU/ml and two patients between 50-100 mIU/ml. Toxicities included expected myelosuppression and electrolyte abnormalities with no deaths attributable to the therapy. Thus far, this strategy of chemotherapy followed by response-based WVI is tolerable. Additionally, with 93 patients enrolled, no stopping rules have been met.