- To compare the frequency of relapse in CNS for patients between 16 and 30 years old with standard risk ALL treated with the PETHEMA LAL-RI-08 Protocol Chemotherapy schedule and receiving DepoCyte® as the only IT CNS prophylaxis, with that observed in an historic group of patients of identical risk that were treated with the PETHEMA LAL-RI/96 protocol (same systemic chemotherapy and double administration of triple intrathecal chemotherapy)