Classification of Focal Prostatic Lesions on Transrectal Ultrasound (TRUS) and the Accuracy of TRUS to Diagnose Prostate Cancer

Classification of Focal Prostatic Lesions on Transrectal Ultrasound (TRUS) and the Accuracy of TRUS to Diagnose Prostate CancerObjective: To improve the diagnostic efficacy of transrectal ultrasound (TRUS)-guided targeted prostatic biopsies, we have suggested the use of a new scoring system for the prediction of malignancies regarding the characteristics of focal suspicious lesions as depicted on TRUS. Materials and Methods:A total of 350 consecutive patients with or without prostate cancer who underwent targeted biopsies for 358 lesions were included in the study.The data obtained from participants were randomized into two groups; the training set (n = 240) and the test set (n = 118).The characteristics of focal suspicious lesions were evaluated for the training set and the correlation between TRUS findings and the presence of a malignancy was analyzed.Multiple logistic regression analysis was used to identify variables capable of predicting prostatic cancer.A scoring system that used a 5-point scale for better malignancy prediction was determined from the training set.Positive predictive values for malignancy prediction and the diagnostic accuracy of the scored components with the use of receiver operating characteristic curve analysis were evaluated by test set analyses.Results: Subsequent multiple logistic regression analysis determined that shape, margin irregularity, and vascularity were factors significantly and independently associated with the presence of a malignancy.Based on the use of the scoring system for malignancy prediction derived from the significant TRUS findings and the interactions of characteristics, a positive predictive value of 80% was achieved for a score of 4 when applied to the test set.The area under the receiver operating characteristic curve (AUC) for the overall lesion score was 0.81. Conclusion:We have demonstrated that a scoring system for malignancy prediction developed for the characteristics of focal suspicious lesions as depicted on TRUS can help predict the outcome of TRUS-guided biopsies.ransrectal ultrasound (TRUS) is generally recognized as the method of choice for prostatic biopsy guidance, however, only 20% of urologists perform targeted biopsies based on sonographic findings (1, 2).Most contemporary prostate biopsy protocols have concentrated on the use of the systematic prostate biopsy approach and currently require the acquisition of 10 or more cores (3).Ultrasound (US) criteria used to identify and characterize suspicious lesions for diagnosing a malignancy are controversial and have not been well defined (1, 4).Moreover, the low positive predictive value (PPV) for the presence of prostate cancer remains a considerable weakness (5, 6).Although increased cancer detection has been reported for the use of color Doppler US (7, 8), the combined sensitivity of gray-scale