Abstract
Major statement: The combination of MRI and PSA density can be safely used to decide whether or not to perform a prostate biopsy in patients with elevated PSA as long as appropriate PIRADS and PSAD thresholds are used. Aim: The aim of this prospective study was to show the benefits of PSA density and MRI in reduction of unnecessary biopsies without compromising detection of significant prostate cancer of patients in first biopsy and rebiopsy groups.
Material and methods: MRI and MRI/TRUS fusion targeted biopsies with subsequent systematic biopsies were performed in 397 patients. First biopsy was carried out in 223 patients and rebiopsy in 174 patients.
Detection rates of clinically significant an insignificant prostate cancer were stratified using the PIRADS score and the number of potentially avoided biopsies and missed significant prostate cancers were calculated. The percentage of avoided biopsies and missed cancers was also calculated using PSA density cut-off values from 0,1-0,5 ng/ml2.
Results: The safest criteria for not performing biopsy were PIRADS < 3 and PSAD <0,2 ng/ml2. When applying these criteria in the first biopsy group, 21,52% (48/223) of biopsies could have been avoided, 16,67% (5/30) of clinically insignificant prostate cancer would not have been diagnosed, and 3,66 % (3/82) of clinically significant prostate cancers would have been missed.
In the rebiopsy group 12,64% (22/174) of biopsies could have been avoided, 4,35% (1/23) of clinically insignificant prostate cancer would have not been diagnosed, and 6,9% (4/58) of clinically significant prostate cancers would have been missed. Conclusion: With appropriate criteria setting the combination of MRI and PSA density can be safely used to decide whether to perform prostate biopsy in patients with PSA elevations especially in the group without previous biopsy.