Introduction:
Prostate cancer is the most frequently diagnosed cancer in men and the second leading cause of cancer-related death in men. For detecting prostate cancer, multiparametric prostate MRI (mpMRI) has become an important tool. It can also provide useful information for determining the prostate cancer management plan, because prostate MRI helps in detecting suspicious cancer foci and assessing cancer stage and aggressiveness. To make use of MRI capabilities, an MRI-ultrasound (MR/US) fusion biopsy was developed. The European Society of Urogenital Radiology published the Prostate Imaging Reporting and Data System (PI-RADS). This scoring system assigns suspicious, clinically significant cancer lesions visualized on prostate MRI into five categories.
Objective
The objective is to evaluate the value of PI-RADS score in detecting prostate adenocarcinoma lesions by mpMRI fusion biopsy-transrectal ultrasound.
Materials/Methods
157 patients with a mean age of 65 years underwent trans-rectal ultrasound fusion MRI biopsy between 2015 and 2018. 353 PIRADS lesions between 3 and 5 were biopsied. On average, 5 fragments were removed per suspected zone . Of the patients who underwent biopsy, 30 had not undergone prior ecoguided transectal biopsy. PI-RADS scores were correlated with biopsy results and their calculated positive predictive values.
Results
Overall, 157 biopsies were positive (44%). By PIRADS, in PIRADS 3, 23 out of 192 were positive, in PIRADS , 89 out of 115 were positive and PIRADS 5, 45 out of 46 were positive. Considering only Gleason greater than 6, in PIRADS3, 4 out of 192 were positive, in PIRADS 4, 77 out of 115 were positive and in PIRADS 5, 41 in 46 were positive. The positive predictive value (PPV) for PIRADS scores 3, 4, 5 was 11%, 77% and 97%, respectively. Considering Gleason 6, the PPV was 2%, 67% and 89%, respectively.
Conclusion
This study demonstrated a correlation between detection of prostate cancer and PIRADS score in patients undergoing fusion biopsy. The results obtained were in agreement with the existing literature. The use of mpMRI and the PIRADS system in now an important source of information in the decision to perform prostate re-biopsies.
