title: Stereotactic Radiosurgery in the Treatment of Recurrent CNS Lymphoma.
abstract: BACKGROUND
  Central nervous system lymphoma (CNSL) is typically treated with chemotherapy and external beam radiation therapy (EBRT). Optimal management of recurrent CNSL is poorly defined.
  
  
  OBJECTIVE
  We aim to determine the effectiveness of stereotactic radiosurgery in the treatment of recurrent CNSL.
  
  
  METHODS
  We performed a retrospective analysis of patients having stereotactic radiosurgery (SRS) for recurrent intracranial CNSL between 1999 and 2011.
  
  
  RESULTS
  Fourteen patients (20 tumors) underwent SRS. The median patient age was 71 years (range, 18-82 years). Seven patients (50%) had primary CNSL. All had received prior chemotherapy, and nine patients (64%) had undergone prior whole brain radiotherapy (WBRT) with a median dose of 40 Gy in 25 fractions. The median preoperative Karnofsky Performance Score was 80. The median tumor volume was 6.7 cm(3) (range, 0.5-37.7); the median margin dose was 15.5 Gy (range, 10-18). Eleven patients (79%) had tumor regression (n = 11) shown on MRI after SRS. The median overall survival after SRS was 9.5 months. No patient had a major radiation-related complication.
  
  
  CONCLUSIONS
  Stereotactic radiosurgery for patients with recurrent CNSL is well tolerated and has a high rate of radiographic response. A marginal dose of 15.5 Gy or greater, a Karnofsky score of 80 or greater, and the absence of pre-SRS WBRT were associated with significantly longer overall survival. Stereotactic radiosurgery may be beneficial as an initial salvage therapy in the treatment of recurrent CNSL for properly selected patients.
authors: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: kumar.ravi@mayo.edu.
authors: Ravi
authors: R
authors: Kumar
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Nadia
authors: N
authors: Laack
authors: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors: Bruce E
authors: BE
authors: Pollock
authors: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors: Michael
authors: M
authors: Link
authors: Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Brian P
authors: BP
authors: O'Neill
authors: Department of Neurological Surgery, Mayo Clinic, Rochester, Minnesota, USA.
authors: Ian F
authors: IF
authors: Parney
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D017567:Karnofsky Performance Status; D008223:Lymphoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
keywords: Gamma Knife; Primary CNS lymphoma; Radiosurgery; Secondary CNS lymphoma