Stereotactic Radiosurgery Using The Leksell Gamma Knife Perfexion Unit In The Management Of 10 Or More Brain Metastases

R Grandhi1, Panczykowski D.1, Parry P.1, Monaco E.A. III1, Kano H.1, Kondziolka D.S.1, Niranjan A.1, Flickinger J.C.1, Lunsford L.D.1

1Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA

Keywords: brain metastasis, gamma knife, cancer, outcome, radiosurgery

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Abstract

     Stereotactic radiosurgery is increasingly used as a minimally-invasive means of managing intracranial metastatic disease.
     The purpose of this study was to assess clinical outcomes and identify prognostic factors for survival and intracranial disease control amongst patients with 10 or more brain metastases irradiated on the Leksell Gamma Knife Perfexion unit (LGK PFX) over a two year period.
     59 patients underwent stereotactic radiosurgery using the LGK PFX for the management of 783 metastatic tumors. Primary histology for these patients was: melanoma 18 (31%), non-small cell lung cancer 17 (29%), breast cancer 15 (25%), small cell lung cancer 5 (8%), and other 4 (7%).
     A mean of 13.2 tumors were irradiated (range 10-28, median 12) per patient. Prior cerebral treatment of metastases using WBRT only was seen amongst 23 (39%) patients, with GKRS only employed in 11 (18.6%) of patients, and both modalities used in 17 patients (28.8%).
     The median survival was 4 months (range 0.25-21 months) after undergoing LGK PFX for treatment of 10 or more brain metastases. Patients survived a median of 14 months (range 2-209 months) following the diagnosis of brain metastases and 31 months (range 5-322 months) after the diagnosis of the primary tumor. Survival was better amongst patients with fewer metastases, controlled systemic disease, and Karnosfsky performance scores of 90 and above. For those with 13 or fewer metastases and a Karnofsky score =90, median survival was 7 months (range 0.5-21 months); 9 (28%) were still alive at the end of follow-up (median 8 months; range, 2-19 months). Prior cerebral treatment and modality of prior cerebral treatment did not influence patient survival. Sustained local control of tumors was achieved in 72.9% of patients, while distant progression was seen in 39% of patients. Prior WBRT was a predictor of developing adverse radiation effects, which occurred in 10.2% of patients. Overall, 79.7% of patients improved or remained clinically stable. CNS disease was the cause of death in 22.9% of patients.
     This is a retrospective study.
     Stereotactic radiosurgery using the Leksell Gamma Knife Perfexion unit to treat intracerebral disease amongst patients with 10 or more brain metastases is a safe and effective tool, with an excellent rate of sustained local control.
     Factors associated with improved patient survival include fewer brain metastases, controlled systemic disease, and a high Karnofsky performance score. Prior treatment of brain metastases, regardless of modality, did not confer a survival benefit.


Acknowledgements

Project Roles:

R. Grandhi (), P. D. (), P. P. (), M. III (), K. H. (), K. D.S. (), N. A. (), F. J.C. (), L. L.D. ()