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.
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.
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).
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.
Clinical radiology. 2015 Dec 28 [Epub ahead of print]
Y Gao, X H Liao, L Lu, L Wang, Y Ma, H Z Qin, X Yan, P Guo
Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, China. , College of Stomatology, Guangxi Medical University, China.