Combination of signal intensity measurements of lesions PSA level the peripheral zone or prostate with MRI and serum PSA level for differentiating benign disease from prostate cancer

The aim of this study was to predict the benign or malignant nature of a pr ostatic lesion by defining a threshold value of signal intensity ratio and a limiting value of serum prostate-specific antigen (PSA) in patients with elevated PSA level. Twenty-six patients with elevated PSA level and no hypo echogenic lesions at endosonography underwent MR imaging using an endorecta l body phased-array coil at 1.5 T (Siemans Magnetom Symphony). A T2-weighte d turbo-spin-echo (TSE) pulse sequence was applied in a transverse orientat ion. Two radiologists evaluated the images. In the presence of a pathologic al finding they defined regions of interest (ROI) in the suspicious patholo gical area of the peripheral zone and in muscle for reference. The quotient of the two ROIs was calculated and then correlated with the actual PSA lev el. Diagnosis was confirmed by prostate biopsy. Ten of 12 patients with quo tients smaller than 4 showed cancer at histology. Nine of 12 men with cance r proven by biopsy had PSA levels higher than 10 ng/ml. A significant diffe rence (p < 0.001) was found between the quotients of cancer and quotients o f chronic prostatitis, fibrosis, or glandular atrophy. The accuracy of tumo r differentiation of the method was 77%. Measurement of signal intensity qu otients in the peripheral zone of the prostate in combination with knowledg e of defined limits of PSA levels the technique could be helpful in detecti ng additional cancer areas for prostate biopsy. False-negative tumor result s of standard sextant biopsy can be reduced. In men with high PSA values th e method has a role in differentiating between patients who require prostat e biopsy and those of clinical observation.