title: Management strategies after nondiagnostic results with frameless stereotactic needle biopsy: Retrospective review of 28 patients.
abstract: BACKGROUND
  Although frameless stereotactic needle biopsy is an accepted procedure for the diagnosis of intracranial lesions, findings are nondiagnostic in 2-15% of patients and no recommendations yet exist to guide subsequent care. After reviewing the postoperative course after nondiagnostic biopsy of 28 patients, we developed a paradigm to guide management in the future.
  
  
  METHODS
  In reviewing the medical records of 284 frameless stereotactic needle biopsies (January 2000 to December 2006), we identified a subset of 28 patients who underwent 29 (10.2%) biopsies that did not yield a definitive diagnosis based on permanent pathologic samples. Postoperative treatment plans and clinical courses were further examined in 21 patients; 7 without follow-up were excluded.
  
  
  RESULTS
  Of the 21 patients, lesion location and characteristics guided the surgeon's decision to recommend further surgery or initiate empiric treatment. Soon after initial biopsy, five patients underwent a second procedure (biopsy or resection) that yielded diagnostic pathologic tissue. Of 16 patients who had empiric treatment, 7 (43.7%) subsequently had their treatment plan changed because of a lack of improvement and 5 underwent a second biopsy (4 diagnostic). Evolving clinical information precipitated treatment change in two patients. Of 10 patients who had a second surgery for better diagnostic information, the diagnostic yield was 90%.
  
  
  CONCLUSIONS
  Considering the 90% diagnostic yield, we now recommend repeat surgery for most patients with nondiagnostic biopsies, especially for lesions considered potentially neoplastic or infectious. Empiric management, for lesions likely to be neurodegenerative, is an option but requires close follow-up examination.
authors.affiliation: Department of Neurosurgery, Brain Tumor Center at the University of Cincinnati (UC) Neuroscience Institute and UC College of Medicine, and Mayfield Clinic, Cincinnati, OH.
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Air
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Warnick
authors.forename: Christopher M
authors.initials: CM
authors.lastname: McPherson