title: Subarachnoid dissemination of intraventricular tumors following simultaneous endoscopic biopsy and third ventriculostomy.
abstract: OBJECTIVE
  Endoscopic biopsy with concomitant third ventriculostomy (ETV) is a well-established diagnostic and therapeutic maneuver in patients presenting with noncommunicating hydrocephalus resulting from a tumor of the pineal region or posterior third ventricle. Fenestration of the floor of the third ventricle theoretically provides a conduit for the subarachnoid dissemination of an intraventricular tumor. The aim of this study was to ascertain the rate of leptomeningeal dissemination following this surgical procedure.
  
  
  METHODS
  The authors conducted a review of all patients for whom an ETV and simultaneous endoscopic biopsy procedure or tumor resection had been performed at their institutions between 1995 and 2008. Patients were divided into high or low risk groups by leptomeningeal metastatic potential based on pathology. All available postoperative clinical and radiographic data, including MR imaging of the brain and spinal cord, as well as CSF sampling were evaluated when available. A review of the literature was then conducted to establish rates of distant leptomeningeal dissemination for comparative purposes.
  
  
  RESULTS
  Thirty-two patients satisfied the criteria for study inclusion. Pathology revealed that 22 had a high risk for leptomeningeal dissemination. New leptomeningeal disease (1 yolk sac tumor and 1 pineoblastoma) occurred in 2 patients. The median clinical and brain MR imaging follow-ups overall were 34 (range 2-103 months) and 38 months (range 1-94 months), respectively. Follow-up MR imaging of the spine was performed in 12 patients (median 7 months postoperation), and CSF was analyzed in 15 patients (median 1 month postoperation). A Kaplan-Meier survival analysis predicted a 2-year metastasis-free survival of 94.7% for high-risk patients. Baseline rates of dissemination when ETV was not performed were in general between 8 and 24% for various high-risk pathologies according to a literature review.
  
  
  CONCLUSIONS
  The rate of leptomeningeal metastasis of tumors in this biopsy and ETV study was not increased when compared with rates from large series in the literature.
authors.affiliation: Department of Neurological Surgery, Weill Cornell Medical College, New York, New York 10021, USA. nel2003@nyp.org
authors.forename: Neal
authors.initials: N
authors.lastname: Luther
authors.forename: William R
authors.initials: WR
authors.lastname: Stetler
authors.forename: Ira J
authors.initials: IJ
authors.lastname: Dunkel
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Christos
authors.forename: John C
authors.initials: JC
authors.lastname: Wellons
authors.forename: Mark M
authors.initials: MM
authors.lastname: Souweidane
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy / Q000009:adverse effects*; D002551:Cerebral Ventricle Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D008875:Middle Aged; D009366:Neoplasm Seeding; D009373:Neoplasms, Germ Cell and Embryonal / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery*; D010871:Pinealoma / Q000473:pathology* / Q000601:surgery*; D018714:Radiotherapy, Adjuvant; D013346:Subarachnoid Space / Q000473:pathology*; D020542:Third Ventricle / Q000473:pathology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014696:Ventriculostomy / Q000009:adverse effects*; D055815:Young Adult