Solitary brain metastases treated with the Leksell gamma knife: prognosticfactors for patients

Purpose: To analyze treatment results, complications, prognostic factors an d their statistical significance in surviving patients treated with the Lek sell gamma knife (LGK) for solitary brain metastases. Materials and methods: Between 1992-1998, 237 patients were treated with so litary brain metastasis (SBM). The histological subtypes were as follows: 1 01 patients (42.6%) non small-cell lung cancer, 42 (17.7%) renal cell carci noma, 36 (15.2%) breast carcinoma, 30 (12.7%) colorectal carcinomas and 28 (11.8%) melanoma. Results: A complete or partial regression was observed in 193 (81.4%) patie nts, cessation of growth activity in 32 (13.5%) and local progression in 12 (5.1%). Local recurrence was observed in nine (4.7%) of 193 patients with complete or partial regression. Acute toxicity appeared in 24 (10%) patient s (score 3.4), late complications (score 3.4) were observed in 13 patients (5.5%). Out of 237 patients, 182 patients died with a median survival of 6 months and 55 patients are still alive with a median survival 12 months and with a minimal follow up period of 10 months. The significant prognostic f actors for longer survival in these series of patients were: Karnofsky perf ormance status (70% or more), the extent of extra-cerebral disease (no extr a-cerebral disease), pretreatment neurological symptoms neurological functi onal class (NFC 1), histology (renal cell and breast carcinomas) and the do se to the planning target volume (20 Gy and higher). Conclusions: Radiosurgery provides an effective local control for 90% of tr eated patients with low morbidity. Several significant prognostic factors w ere detected for patients' survival. These factors can help to predict bett er patients' survival after the LGK treatment. (C) 2000 Elsevier Science Ir eland Ltd. All rights reserved.