2 Year Overall Survival (OS)

Arm A / MTX + AraC

Arm A Methotrexate 3.5 g/m2 (0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion) d 1 Cytarabine 2 g/m2 1 hr infusion, twice a day (every 12 hs.) d 2 - 3 Methotrexate: Methotrexate 3.5 g/m2 (0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion) on day 1, every 3 weeks for a maximum of 4 courses. Ara-C: Cytarabine 2 g/m2 (1 hr infusion, twice a day every 12 hours), on d 2 - 3 every 3 weeks for a maximum of 4 courses

Arm B / MTX + Ara-C + Rituximab

Arm B Rituximab 375 mg/m2 conventional infusion d -5 \& 0 Methotrexate 3.5 g/m2 0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion d 1 Cytarabine 2 g/m2 1 hr infusion, twice a day (every 12 hs.) d 2 - 3 Methotrexate: Methotrexate 3.5 g/m2 (0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion) on day 1, every 3 weeks for a maximum of 4 courses. Ara-C: Cytarabine 2 g/m2 (1 hr infusion, twice a day every 12 hours), on d 2 - 3 every 3 weeks for a maximum of 4 courses Rituximab: Rituximab 375 mg/m2 conventional infusion on day - 5 \& 0 every 3 weeks for a maximum of 4 cycles

Arm C / MTX + Ara-C + Rituximab+Thiotepa

Arm C Rituximab 375 mg/m2 conventional infusion d -5 \& 0 Methotrexate 3.5 g/m2 0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion d 1 Cytarabine 2 g/m2 1 hr infusion, twice a day (every 12 hs.) d 2 - 3 Thiotepa 30 mg/m2 30 min. Infusion d 4 Methotrexate: Methotrexate 3.5 g/m2 (0.5 g/m2 in 15 min. + 3 g/m2 in 3-hr infusion) on day 1, every 3 weeks for a maximum of 4 courses. Ara-C: Cytarabine 2 g/m2 (1 hr infusion, twice a day every 12 hours), on d 2 - 3 every 3 weeks for a maximum of 4 courses Rituximab: Rituximab 375 mg/m2 conventional infusion on day - 5 \& 0 every 3 weeks for a maximum of 4 cycles Thiotepa: ARM C: Thiotepa 30 mg/m2 (30 min. Infusion) on day 4 every 3 weeks for a maximum of 4 courses ARM E: Thiotepa 5 mg/kg in 250 ml saline sol 2-hr inf. every 12 hrs days -5 \& -4

Arm D / WBRT 36 Gy +/- Boost 9 Gy

ARM D: WBRT with 36 Gy in the case of CR to primary chemotherapy or the same WBRT dose followed by a tumor-bed boost of 9 Gy with 1-2 cm of margin surrounding enhanced residual lesion (total tumor-bed dose 45 Gy) in patients who achieved a PR or SD after primary chemotherapy. Photons of 4-10 Mev, 180 cGy per day, 5 weekly fractions. radiotherapy: Photons of 4-10 Mev, 180 cGy per day, 5 weekly fractions. Whole-brain will be irradiated by two opposite lateral fields including the first two cervical vertebras and the posterior two thirds of the orbits, which must be shielded after 30 Gy (after 36 Gy in the case of evident intraocular disease at diagnosis). Tumor-bed (boost or partial-brain RT) will be irradiated by 2 to 4 isocentric treatment fields based on tumor location, with all portals treated per each RT session.

Arm E / BCNU + Thiotepa + APBSCT

Arm E BCNU 400 mg/m2 in 500 ml saline sol 1-hr inf. day -6 Thiotepa 5 mg/kg in 250 ml saline sol 2-hr inf. every 12 hrs days -5 \& -4 Reinfusion of PBSC ≥5 x 106 CD34+ cells/kg day 0 Thiotepa: ARM C: Thiotepa 30 mg/m2 (30 min. Infusion) on day 4 every 3 weeks for a maximum of 4 courses ARM E: Thiotepa 5 mg/kg in 250 ml saline sol 2-hr inf. every 12 hrs days -5 \& -4 BCNU: BCNU 400 mg/m2 in 500 ml saline sol 1-hr inf. day -6 APBSCT: Autologous peripheral blood stem cell transplant (APBSCT)

Analysis denominator · Participants