title: [Reliability of CT for determining lymphatic involvement in patients with prostate cancer].
abstract: OBJECTIVE
  To determine the utility of CT in assessment of lymph node metastasis in patients with prostatic cancer.
  
  
  METHODS
  We conducted a retrospective study of 131 patients with prostatic cancer and a negative bone scan, in whom CT was utilized to assess lymph node metastasis. The mean age was 67.7 +/- 7.1 years. Lymphadenectomy of both obturator chains was performed in 85 patients (65%); by surgery in 65 patients (76%) and laparoscopy in 20 (24%).
  
  
  RESULTS
  6% had a positive CT scan. In the univariate analysis only PSA (p = 0.04) was shown to be a predictive factor for a positive CT. The maximum yield of CT was at cut-off 30 ng/ml PSA; patients with lower values had a negative predictive value of 98%. When lymphadenectomy was performed, 14% of the patients with a negative CT presented lymph node invasion, for a sensitivity of 8%, specificity of 100% and diagnostic accuracy of 86%.
  
  
  CONCLUSIONS
  Due to the scanty prevalence of positive CT scans and its low sensitivity, this imaging technique may be obviated in patients undergoing radical treatment with PSA < or = 30 ng/ml.
authors.affiliation: Servicio de Urología, Hospital General Universitario Gregorio Marañón, Madrid, España.
authors.forename: F H
authors.initials: FH
authors.lastname: Amo
authors.forename: F
authors.initials: F
authors.lastname: Verdú Tartajo
authors.forename: J M
authors.initials: JM
authors.lastname: Díez Cordero
authors.forename: E
authors.initials: E
authors.lastname: Lledó García
authors.forename: G
authors.initials: G
authors.lastname: Bueno Chomón
authors.forename: F
authors.initials: F
authors.lastname: Leal Hernández
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D006801:Humans; D010535:Laparoscopy; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000097:blood; D009367:Neoplasm Staging / Q000379:methods*; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D017430:Prostate-Specific Antigen