Hyperfractionated radiation therapy (72 Gy) for children with brain stem gliomas. A Childrens Cancer Group Phase I/II Trial.

BACKGROUND

Most children with brain stem gliomas (BSG) die within 18 months of diagnosis. Early experience suggested that hyperfractionated radiation therapy (RT) at a dose of 72 Gy, administered in 1-Gy fractions twice daily, possibly improved disease-free survival for children with BSG.

METHODS

To better characterize the toxicity and possible efficacy of this dose and fractionation of RT, 53 assessable children with diffuse intrinsic or malignant BSG were treated. Survival figures also were combined with outcome in 36 patients treated in a previous pilot study.

RESULTS

An objective response to treatment was observed in 28 of 53 (53%) patients; a partial response occurred in 7. No child died of treatment-related brain necrosis, although 7 of 53 did have intralesional cystic/necrotic changes within 6 weeks of completion of RT. The overall survival rate for patients in the study was 38% (+/- 6.5) at 1 year, 14% (+/- 5.4) at 2 years, and 8% (+/- 6.5) at 3 years. Leptomeningeal dissemination was observed in 4 of 48 (8%) children who had relapses. A greater than 2-month duration of symptoms before diagnosis was related to a better prognosis. There was no statistical association between any other clinical parameter, neuroradiographic finding, or pathologic finding and outcome. Combined with that in 35 patients treated in the pilot study, the survival rate in 88 children was 14% (+/- 5) at 3 years.

CONCLUSIONS

The radiographic response rate is encouraging; however, it cannot be concluded that hyperfractionated RT, at this dose schedule and total dose, is superior to conventional RT.