title: A prospective study of factors predicting clinically occult spinal cord compression in patients with metastatic prostate carcinoma.
abstract: BACKGROUND
  The objective of this study was to identify clinical parameters that predict occult subarachnoid space or spinal cord (SAS/SC) compression, as determined by magnetic resonance imaging (MRI), in patients with metastatic prostate carcinoma.
  
  
  METHODS
  A prospective study was performed in which 68 patients with bone metastases from prostate carcinoma and a normal neurologic examination underwent MRI of the entire spine after documentation of clinical, X-ray, and bone scan parameters potentially predictive of occult SAS/SC compression.
  
  
  RESULTS
  Occult SAS/SC compression was diagnosed in 22 patients (32%) using MRI. Nine patients (13%) had compressions at two discontinuous spinal levels. Extensive disease on bone scan, the duration of continuous hormonal therapy prior to study entry, and hemoglobin concentration were found to predict SAS/SC compression by univariate analysis. The extent of disease on bone scan and the duration of continuous hormonal therapy were independent predictors of SAS/SC compression by multivariate analysis (P = 0.02 and P = 0.04, respectively). The risk of occult SAS/SC compression increased from 32% to 44% in patients with a bone scan that showed > 20 metastases as the duration on hormones increased from 0 to 24 months. The risk in patients with fewer metastases increased from 11% to 17% over the same interval. The presence or absence of back pain was not predictive of SAS/SC compression.
  
  
  CONCLUSIONS
  Patients who are at high risk for occult SAS/SC compression can be identified using clinical parameters and readily available diagnostic tests. These high-risk patients should undergo MRI screening with the aim of diagnosing and treating spinal cord compression before the development of neurologic deficits that may be irreversible.
authors.affiliation: Department of Radiation Oncology, Princess Margaret Hospital and the University of Toronto, Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Bayley
authors.forename: M
authors.initials: M
authors.lastname: Milosevic
authors.forename: R
authors.initials: R
authors.lastname: Blend
authors.forename: J
authors.initials: J
authors.lastname: Logue
authors.forename: M
authors.initials: M
authors.lastname: Gospodarowicz
authors.forename: I
authors.initials: I
authors.lastname: Boxen
authors.forename: P
authors.initials: P
authors.lastname: Warde
authors.forename: M
authors.initials: M
authors.lastname: McLean
authors.forename: C
authors.initials: C
authors.lastname: Catton
authors.forename: P
authors.initials: P
authors.lastname: Catton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000150:complications* / Q000556:secondary*; D002277:Carcinoma / Q000150:complications* / Q000556:secondary*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010808:Physical Examination; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000473:pathology*; D011877:Radionuclide Imaging; D012307:Risk Factors; D013117:Spinal Cord Compression / Q000175:diagnosis* / Q000209:etiology*; D013131:Spine / Q000000981:diagnostic imaging; D013346:Subarachnoid Space / Q000473:pathology