[Staging of prostatic carcinoma: TRUS prospective study versus endocoil MRI]

Accurate staging of prostatic cancer is important for planning an optimal treatment, such as radical prostatectomy in clinical stage T2. About 40-50% of patients operated for cT2 disease show a pathological stage T3 disease. In a prospective study we analysed accuracy of TRUS and endocoil MRI in a group of patients before radical prostatectomy.

33 consecutive patients suspicious of prostate neoplasms were studied and staged with TRUS and endocoil MRI before prostatic biopsy and before radical prostatectomy. One urologist trained in TRUS conducted the exam, while one radiologist interpreted the MRI studies in a blind mode. The criteria evaluated were accuracy of global staging, extracapsular extension (ECE) and seminal vesicle invasion (SVI). These results were correlated with the histopathological findings after radical prostatectomy.

The histopathological results showed 14 patients (42%) with pT2 disease, 18 patients (54%) with pT3 disease and 1 case (4%) of pT4 disease. TRUS showed a low sensitivity (38%) and a good specificity (78%), with an overall accuracy of 50%; the best result was 96% specificity for SVI. Endocoil MRI showed a good sensitivity (70%) and specificity (76%), with an overall accuracy of 73%. Endocoilc was also useful to stage T1c disease when TRUS is negative. TRUS tends to understage, whereas endocoil MRI over-stages prostate cancer.

TRUS and endocoil MRI may help in decision making about the appropriate treatment of prostatic cancer, even if they have limited current value, due to understaging or overstaging.