The efficacy of radiation therapy in the management of grade I astrocytomas.
BACKGROUND
The purpose of this study was to analyze the outcome of patients with grade I astrocytomas treated with radiation therapy, specifically looking at the prognostic significance of age, timing of radiation therapy (immediately after surgery or delayed until progression) and tumor location.


METHODS
The records of patients with grade I astrocytomas treated at Washington University Medical Center between 1982 and 2002 were reviewed. Twenty patients with grade I pilocytic astrocytoma (n=19) or subependymal giant cell astrocytoma (n=1) were treated with radiation therapy with curative intent.


RESULTS
The median follow-up was 6.4 years. The 5-year overall survival for all patients was 100%. The 5-year progression-free survival (PFS) following radiation therapy for all patients was 68%. Patients who received radiation therapy immediately after biopsy or surgery had a 5-year PFS of 77% versus 50% for patients who received radiation therapy after initial disease progression (P=0.013). Patients with infratentorial tumors had an improved outcome with a 5-year PFS of 80% versus 59% for those with supratentorial tumors (P=0.0076). Patient age did not significantly influence outcome. All tumor recurrences were local.


CONCLUSIONS
While this study reports an excellent overall survival, approximately one third of patients with grade I astrocytomas had progressive disease following radiation therapy. In particular, patients with supratentorial tumors and delayed radiation therapy had a worse PFS. Additional investigation is needed to improve the outcome in these patients.
Kidd
Elizabeth A
EA
Department of Radiation Oncology and Mallinckrodt Institute of Radiology, St. Louis, MO, USA.
Mansur
David B
DB
Leonard
Jeffrey R
JR
Michalski
Jeff M
JM
Simpson
Joseph R
JR
Perry
Arie
A
D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000473:pathology / Q000532:radiotherapy*; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome