Treatment of children with central nervous system primitive neuroectodermal tumors/pinealoblastomas in the prospective multicentric trial HIT 2000 using hyperfractionated radiation therapy followed by maintenance chemotherapy.

ABSTRACT

PURPOSE: The prognosis for children with central nervous system primitive neuroectodermal tumor (CNS-PNET) or pinealoblastoma is still unsatisfactory. Here we report the results of patients between 4 and 21 years of age with nonmetastatic CNS-PNET or pinealoblastoma diagnosed from January 2001 to December 2005 and treated in the prospective GPOH-trial P-HIT 2000-AB4. METHODS AND MATERIALS After surgery, children received hyperfractionated radiation therapy (36 Gy to the craniospinal axis, 68 Gy to the tumor region, and 72 Gy to any residual tumor, fractionated at 2 × 1 Gy per day 5 days per week) accompanied by weekly intravenous administration of vincristine and followed by 8 cycles of maintenance chemotherapy (lomustine, cisplatin, and vincristine). RESULTS: Twenty-six patients (15 with CNS-PNET; 11 with pinealoblastoma) were included. Median age at diagnosis was 11.5 years old (range, 4.0-20.7 years). Gross total tumor resection was achieved in 6 and partial resection in 16 patients (indistinct, 4 patients). Median follow-up of the 15 surviving patients was 7.0 years (range, 5.2-10.0 years). The combined response rate to postoperative therapy was 17 of 20 (85%). Eleven of 26 patients (42%; 7 of 15 with CNS-PNET; 4 of 11 with pinealoblastoma) showed tumor progression or relapse at a median time of 1.3 years (range, 0.5-1.9 years). Five-year progression-free and overall survival rates (± standard error [SE]) were each 58% (± 10%) for the entire cohort CNS-PNET was 53% (± 13); pinealoblastoma was 64% (± 15%; P=.524 and P=.627, respectively). CONCLUSIONS: Postoperative hyperfractionated radiation therapy with local dose escalation followed by maintenance chemotherapy was feasible without major acute toxicity. Survival rates are comparable to those of a few other recent studies but superior to those of most other series, including the previous trial, HIT 1991.