title: Predictive value of prostate-specific antigen, tumour stage and tumour grade for the outcome of bone scintigraphy in patients with newly diagnosed prostate cancer.
abstract: OBJECTIVE
  In order to evaluate the negative predictive value of a low prostate-specific antigen (PSA) for a positive bone scan, we performed a retrospective study in a patient material from the Umea region in Northern Sweden. We also evaluated whether different tumour grades could influence this predictive value.
  
  
  METHODS
  Four-hundred-and-forty-six patients of newly diagnosed prostate cancer were reviewed. We analysed different levels of PSA, tumour grade, tumour stage and combinations of these parameters for their use in making a positive bone scintigraphy (BS) prediction.
  
  
  RESULTS
  Among 214 patients with PSA <20 ng/ml, 9 showed a positive BS. When tumours of grades 2 and 3 were excluded, the number of positive BS predictions decreased to 6. For 350 of these 446 patients, a classification according to TNM was available; 162 of these 350 had a PSA value <20 ng/ml, and when this group comprised only small and well-differentiated tumours (T1-2, G1), only one of the remaining 81 patients had a positive BS result.
  
  
  CONCLUSIONS
  We conclude that in most patients with small and well-differentiated tumours (T1-2, G1) and PSA <20, BS staging need not be carried out.
authors.affiliation: Department of Diagnostic Radiology, University Hospital of Northern Sweden, Umeå. Anders.Rydh@diagrad.umu.se
authors.forename: A
authors.initials: A
authors.lastname: Rydh
authors.forename: R
authors.initials: R
authors.lastname: Tomic
authors.forename: B
authors.initials: B
authors.lastname: Tavelin
authors.forename: S O
authors.initials: SO
authors.lastname: Hietala
authors.forename: J E
authors.initials: JE
authors.lastname: Damber
mesh_terms: D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000556:secondary*; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000473:pathology*; D011877:Radionuclide Imaging; D012189:Retrospective Studies
chemical_list: D017430:Prostate-Specific Antigen