title: Contrast-enhanced transrectal ultrasonography for the detection of diffuse prostate cancer.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of contrast-enhanced transrectal ultrasonography (CE-TRUS) versus baseline TRUS (combination of grey-scale and colour Doppler imaging) for diffuse prostate cancer.
  
  
  METHODS
  Forty-six patients without an obvious focal mass on baseline TRUS (grey-scale and colour Doppler), underwent additional CE-TRUS and TRUS-guided biopsy due to elevated levels of prostate-specific antigen (PSA ≥4 ng/ml) and/or abnormal digital rectal examination (DRE). In all patients, CE-TRUS was performed with intravenous injection of a contrast agent (sulphur hexafluoride microbubble; SonoVue, 2.4 ml) before biopsy. TRUS-guided biopsy targeted suspicious areas detected on CE-TRUS imaging or sampled the outer gland of the normal prostate. The final diagnosis was based on results of the TRUS-guided biopsy. The diagnostic accuracy of baseline TRUS and CE-TRUS for diffuse prostatic lesions was evaluated using receiver operating characteristic (ROC) curve analysis.
  
  
  RESULTS
  Diffuse prostate cancer was present in 32 (69.5%) patients and absent in 14 (30.5%) patients. Nineteen patients had diffuse prostate cancer that was not detected by baseline TRUS, whereas 15 cases were identified using CE-TRUS. Conversely, five patients had benign prostatic hypertrophy (BPH) that was diagnosed as cancer by CE-TRUS, and two of these patients were diagnosed with BPH by baseline TRUS. The combined sensitivity, specificity, and accuracy were 87.5%, 64.2%, and 80.4%, respectively, for CE-TRUS, and 40.6%, 78.5%, and 52.1%, respectively, for baseline TRUS. The area under the ROC curve (AUC) values for the diagnostic accuracy of baseline CE-TRUS versus TRUS for diffuse prostate cancer differed significantly at 0.904 and 0.667, respectively (Z=4.098, p<0.0001).
  
  
  CONCLUSIONS
  CE-TRUS exhibited greater diagnostic accuracy for diffuse prostate cancer than baseline TRUS. CE-TRUS may improve cancer detection over baseline TRUS imaging for the diagnosis of diffuse prostate cancer in patients with an elevated PSA level. CE-TRUS detects diffuse prostate cancer without an obvious focal mass on routine TRUS or clinical examination, and therefore, may help identify patients who do not need a repeat biopsy or who do not need to undergo systematic 12-core invasive sampling biopsies.
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. Electronic address: gaopipi@sina.com.
authors.forename: X H
authors.initials: XH
authors.lastname: Liao
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: L
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: H Z
authors.initials: HZ
authors.lastname: Qin
authors.affiliation: Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China.
authors.forename: X
authors.initials: X
authors.lastname: Yan
authors.affiliation: College of Stomatology, Guangxi Medical University, China.
authors.forename: P
authors.initials: P
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D006801:Humans; D061705:Image-Guided Biopsy; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D018615:Ultrasonography, Doppler, Color
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride