Early cystic/necrotic changes after hyperfractionated radiation therapy in children with brain stem gliomas. Data from the Childrens Cancer Group.

BACKGROUND: A higher total dose of radiation therapy administered in fractionated lower individual doses twice daily (hyperfractionated radiation therapy) has been reported to improve survival for children with brain stem gliomas. However, this higher dose of radiation therapy may cause more sequelae.

METHOD: Eighty-eight children with brain stem gliomas were treated with 100 cGy twice daily to a total dose of 7200 cGy. Patients were carefully followed up for treatment-related clinical or radiographic worsening.

RESULTS: Thirteen (15%) had intralesional cystic/necrotic changes within 8 weeks of completion of treatment. Children with these changes had a variable clinical course, including steady deterioration in one child; initial improvement, followed by progressive deterioration in three; and initial improvement, followed by deterioration, with subsequent improvement or prolonged stabilization of condition without additional antineoplastic treatment in nine.

CONCLUSION: This latter "triphasic" course suggests that "early" worsening after hyperfractionated radiation therapy at 7200 cGy may be a sequelae of therapy, rather than a symptom of progressive tumor growth. This has substantial implications for patient care and evaluation of the efficacy of treatment.