Objective: The aim of the study is to evaluate the need to perform directed biopsies to hypoechoic areas at transrectal ultrasound associated with a prostatic mapping in patients with normal and elevated levels of PSA.
Materials and methods: Since January 1987, 517 consecutive patients (mean age: 65.5 +/- 5.2 yrs) underwent selective prostatic biopsies of hypoechoic areas and systematic sextant biopsies with 10 samples in patients with a prostatic volume < 60 g and 12 samples in prostatic volume > 60 g.
Results: The median PSA value was 7.2 +/- 4.6 ng/ml (SD). 52% of the patients had a positive digital rectal examination. Cancer was detected in 47% of the patients (245/517), in 18% (14/78) of patients with PSA level < 4.0 ng/ml, in 42% (109/256) with PSA level from 4 to 10 ng/ml, in 66% (122/183) with PSA > 10 ng/ml. The PSA value was statistically higher (PSA = 14.9 +/- 17) in patients with positive prostatic biopsies compared to patients with negative biopsies (PSA = 8.5 +/- 8.3 ng/ml) (p > 0.0001). The PPV (positive predictive value) of the hypoechoic lesions was 36% (187/517). Cancer was detected only in directed biopsies of the hypoechoic areas regardless of PSA value in the 20% of patients (49/245). Sextant biopsies were positive with negative directed biopsies in 24% (58/245) of the patients, while both directed and sextant biopsies were positive in 56% (138/245) of the patients.
Comments: The hypoechoic lesion is the prostatic area in which prostatic cancer is most likely to be located in spite of the fact that the PPV of a hypoechoic area is less than 40%. The combination of sextant and lesion-directed biopsies maximizes the detection rate using the lowest possible number of biopsy cores. In the case of a TRUS visible lesion, the optimal number and placement of added systematic biopsies is yet to be defined. Due to the multifocality of prostate cancer, in the future, it is probable that, by adding more biopsies to the sextant standard scheme, the necessity of biopsying single small hypoechoic lesions will no longer be necessary.