title: Delayed toxicity from gamma knife radiosurgery to lesions in and adjacent to the brainstem.
abstract: The aims of this study were to assess the incidence of, and risk factors for, delayed toxicity following gamma knife stereotactic radiosurgery (GKRS) to lesions in and adjacent to the brainstem. We retrospectively evaluated the delayed toxicity of GKRS following the treatment of 114 lesions in and adjacent to the brainstem in 107 patients. The median tumor volume was 6.2 cm(3) and the median dose to the tumor margin was 16Gy. The mean follow-up was 40 months. Thirteen patients (12%) demonstrated clinical evidence of delayed toxicity, with a median latency to the development of toxicity of 6 months. The actuarial incidence of toxicity at 1 year and 5 years was 10.2% and 13.8%. Larger tumor volume (p=0.02) and larger treatment volume (p=0.04) were associated with an increased incidence of delayed toxicity. Large lesions adjacent to the brainstem have a higher than previously suspected rate of delayed toxicity.
authors: Department of Neurological Surgery, University of Southern California, Keck School of Medicine, 1200 North State Street, Suite 5046, Los Angeles, California 90033, USA. ldavidso@usc.edu
authors: Laurence
authors: L
authors: Davidson
authors: Gabriel
authors: G
authors: Zada
authors: Cheng
authors: C
authors: Yu
authors: Zbigniew
authors: Z
authors: Petrovich
authors: Paul G
authors: PG
authors: Pagnini
authors: Chi-Shing
authors: CS
authors: Zee
authors: Steven L
authors: SL
authors: Giannotta
authors: Vladimir
authors: V
authors: Zelman
authors: Michael L J
authors: ML
authors: Apuzzo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology* / Q000601:surgery*; D020295:Brain Stem Neoplasms / Q000473:pathology / Q000601:surgery; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000453:epidemiology / Q000209:etiology; D011183:Postoperative Complications / Q000453:epidemiology* / Q000523:psychology*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult