ANALYSIS OF OUTCOME IN PATIENTS REIRRADIATED FOR BRAIN METASTASES

Purpose: Patients with newly diagnosed brain metastases generally bene fit from whole brain radiation therapy (WBRT), However, the role of re irradiation for patients who develop progressive brain metastases has been controversial, This retrospective study examines our experience w ith reirradiation of patients for progressive brain metastases after a n initial course of WBRT. Methods and Materials: From 1975-1993, 2658 patients received WBRT for brain metastases at our institution, Eighty -six patients were subsequently reirradiated for progressive brain met astases. The median age of these patients was 58 (range: 31-81), The m ost common primary sites were breast and lung, Fifty patients had meta static disease at other sites, Most patients had an Eastern Cooperativ e Oncology Group (ECOG) performance status of 2 (40 patients) or 3 (38 patients), The median dose of the first course of irradiation was 30 Gy (range: 1.5-50.6 Gy), The median dose of the second course of irrad iation was 20 Gy (range: 8.0-30.6 Gy). Results: Twenty-three patients (27%) had resolution of neurologic symptoms, 37 patients (43%) had par tial improvement of neurologic symptoms, and 25 patients (29%) had eit her no change or worsened after reirradiation, The medial survival fol lowing reirradiation was 4 months (range: 0.25-72 months). The majorit y of patients had no significant toxicity secondary to reirradiation. Five patients had radiographic abnormalities of their brain consistent with radiation-related changes, One patient had symptoms of dementia that was thought to be caused by radiotherapy, Various potential progn ostic factors were evaluated for possible associations with survival, including age, sex, primary site, ECOG performance status, RTOG neurol ogic functional class, absence of extracranial metastases, number of b rain metastases, and dose of reirradiation, Absence of extracranial me tastasis, solitary brain metastasis, and a retreatment dose > 20 Gy we re associated with improved survival in univariate analysis (p = 0.025 , 0.033, and 0.061, respectively), The absence of extracranial disease was the only significant factor in multivariate analysis (p = 0.05). Conclusion: The majority of patients in our series had favorable sympt omatic responses, Clinically significant complications were minimal, R eirradiation should be offered to patients who develop progressive bra in metastases.