title: Recursive partitioning analysis of prognostic factors for patients with four or more intracranial metastases treated with radiosurgery.
abstract: The purpose of this study was to devise a new recursive partitioning analysis (RPA) of patients with four or more intracranial metastases treated with a single radiosurgery procedure to identify a class of patients with extended survival. 205 patients underwent Gamma Knife radiosurgery for four or more intracranial metastases (median = 5, range 4-18) during one session. The median total treatment volume was 6.8 cc (range 0.6-51.0 cc). Radiosurgery was used as sole management (17% of patients), or in combination with WB-RT (46%), or after failure of WB-RT (38%). The median marginal radiosurgery dose was 16 Gy (range 12-20 Gy). RPA assessed the effects of age, Karnofsky >70, extracranial disease, visceral metastases, number of metastases, total treatment volume, history of breast and melanoma primaries on survival. The median overall survival after radiosurgery for all patients was 8 months. RPA identified a favorable subgroup of 78 patients (43% of the series) with a total treatment volume <7 cc and < 7 brain metastases (Class 1), with a median survival of 13 months. This subgroup's survival was significantly better (p <0.00005) than the remaining patients (Class 2) (n=111) with a median survival of 6 months. In conclusion, RPA of multiple brain metastasis patients identified 2 distinct cohorts of patients. Class 1 patients have a total treatment volume <7 cc and < 7 metastases (4-6) with favorable survival after Radiosurgery and Class 2 patients have a total treatment volume > or = 7 cc and/or > or = 7 metastases and have a significantly poorer survival.
authors.affiliation: Deptartments of Radiation Oncology, Neurological Surgery, Center for Image-Guided Neurosurgery, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
authors.forename: A K
authors.initials: AK
authors.lastname: Bhatnagar
authors.forename: D
authors.initials: D
authors.lastname: Kondziolka
authors.forename: L Dade
authors.initials: LD
authors.lastname: Lunsford
authors.forename: John C
authors.initials: JC
authors.lastname: Flickinger
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D005260:Female; D006801:Humans; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016634:Radiosurgery; D016019:Survival Analysis; D016896:Treatment Outcome