Excellent event-free survival (EFS) in newly diagnosed patients with supratentorial primitive neurectodermal tumors (SPNET) treated with risk-adapted craniospinal (CSI) radiation (RT) therapy followed by 4 cycles of high-dose chemotherapy and stem cell rescue

Abstract

8553 Purpose: To estimate the EFS of average-risk (AR) and high-risk (HR) SPNET treated with risk-adapted CSI and conformal primary site boost followed by 4 cycles of high-dose chemotherapy supported by stem cell rescue. Patients and Methods: Between 1996 and 2003, 19 children with SPNET were enrolled. Patients with HR disease were differentiated from AR by the presence of residual tumor (M0 = 1.5 cm2) or disseminated neuraxis disease (M1–3) as defined by the Chang staging system. All patients received risk-adapted CSI (M0 with residual < 1.5 cm2, 23.4 Gy; M0 with residual tumor = 1.5 cm2 and M1, 36 Gy; M2-3, 36–39.6 Gy CSI). The tumor bed received 55.8 Gy using a 2 cm clinical target volume margin. Six weeks after RT, patients received chemotherapy consisting of 4 cycles of high-dose cyclophosphamide with cisplatin and vincristine. Results: The median age was 7.3 yrs (3.8–12.9). There were 8 females and 11 males, 4 patients with pineoblastoma, and 9 were classified as AR. 14 pts are alive at a median follow-up of 2.4 yrs (1.1–5.6). The 3 yr PFS for all patients with SPNET was 63%±16 and OS was 79%±12. The 3 yr PFS for AR patients was 61%±22. The 3 yr PFS for HR patients was 67% ± 19%. There were no toxic deaths on study. Conclusions: 4 cycles of high-dose cyclophosphamide based chemotherapy with stem cell support following risk-adapted CSI in patients with SPNET has resulted in excellent EFS with tolerable toxicity. Dose-intensive chemotherapy may allow for reduced CSI in AR patients with SPNET. No significant financial relationships to disclose.