High-dose chemotherapy and autologous bone marrow rescue followed by interstitial and external-beam radiotherapy in newly diagnosed pediatric malignant gliomas

Purpose: Evaluation of high-dose chemotherapy with autologous bone marrow rescue (ABMR) in pediatric malignant gliomas. Patients and Methods: Newly diagnosed (n = 11) and recurrent (n = 2) malignant glioma patients received high-dose chemotherapy within 4 weeks of surgery; three had near total and 10 had subtotal resection/biopsy. High-dose thiotepa (300 mg/m²) and cyclophosphamide (2 g/m²) daily for 3 days were followed by ABMR; response was evaluated at day 30. At day 60, patients with at least stable disease received hyperfractionated (n = 9) or conventional external-beam radiotherapy (n = 2) preceded by local radioactive iodine 125 implantation (n = 2) or radiosurgery (n = 1). Results: Grade III and IV toxicities after ABMR consisted of mucositis (n = 12), cardiomyopathy (n = 1), acute abdomen (n = 1), pneumonitis (n = 2), and infection (n = 2). One complete and three partial responses were observed; the objective response rate was 31% (95% confidence interval, 9% to 61%). Seven had stable disease, one had disease progression, and one died of toxicity before response evaluation. The median overall and progression-free survival durations after combined modality therapy were 14 months (range, 4 to 30 +) and 9 months (range, 0 to 30 +), respectively. One patient remains progression-free at 30 + months. Radionecrosis and white matter changes occurred in three patients: one after hyperfractionated irradiation, and two after ¹²⁵I implants. Conclusion: For patients with bulky residual disease after surgery, survival with this aggressive chemotherapy and radiation regimen is no better than that reported for conventional treatment regimens.