Current Impact of Transrectal Ultrasonography in Prostate Cancer Diagnosis

Abstract

Aims

We evaluate the diagnostic accuracy of transrectal prostate ultrasonography (TRUS) in prostate cancer (PCa) diagnosis in a group of patients who underwent prostate biopsy in 2008.

Material and Methods

100 patients (mean age 65 years) underwent transrectal prostate biopsy at our center. Indications to biopsy were: suspected malignancy at rectal examination or increase of total PSA and/or PSA velocity and/or PSA density and/or low percentage of free PSA. 10–12 biopsies and additional ones in case of suspected ecographic images in every patient were carried out. We classified the ecographic aspects as: highly suggestive for heteroplasia (focal or widespread hypoechoic area in the peripheral zone), weakly suggestive (small hypoechoic focal alterations), and isohecoic areas.

Results

At ultrasound examination, highly suggestive images were found in 20 patients, weakly suggestive images in 39 patients, and isoechoic images in 41 patients. PCa was diagnosed in 45 patients. 40% of cancers (18 pts) appeared as highly suggestive hypoechoic images, 31% (14 pts) as weakly suggestive, and 29% (13 pts) as isoechoic. 32% was the positive predictive value of isoechoic areas biopsies, 90% of highly suggestive hypoechoic images, and 36% of weakly suggestive images. In the last ones, the diagnosis was often coincidental, i.e. in the opposite lobe, or in a different sextant of the same lobe (serendipity). Detection rate was 60% for prostate volumes ≤50 cc and 24% for volumes >50 cc.

Discussion

The result analysis allowed us to formulate the following considerations: - 60% of currently diagnosed PCa are not detectable by ultrasonography, or there are aspecific ecographic findings

- 40% of cancers are detectable by ultrasonography with specific ecographic findings

- The clinical value of the hypoechoic focal alterations is similar to isoechoic ones

- Detection rate is positively influenced by prostate volume.

Conclusions

The study of hypoechoic and isoechoic bioptised areas shows a significant difference in TRUS accuracy in prostate cancer diagnosis. In this set of patients, prostate volume and transrectal ultrasonographic findings proved to be the most informative variables about PCa risk at the moment of first biopsy at any age.