Objective: Multiparametric Magnetic Resonance Imaging (mpMRI) has joined increasing enthusiasm as a diagnostic tool able to identify clinically significant Pca (csPCa). However, the role of mpMRI for patients who are included in AS protocols is still a matter of debate. The aim of our study was to evaluate the impact of mpMRI in the early identification (within 3 months) of csPCa in patients fulfilling AS criteria.
Material and methods:
From May 2015 to March 2019, 93 very low and low risk PCa patients were included in our AS protocol. Inclusion criteria for AS were: 35-75 year-old men; diagnosis of PCa within 8 weeks; PSA≤10 ng/ml; Clinical T1c or T2 assessed with DRE and TRUS; Gleason Score<7; < 3 positive cores; at least 12 biopsy cores taken; PSA density (PSAd) less or equal to 0.2; ASA score ≤ 3; central revision of the biopsy core confirming the presence of indolent Pca. Patients were randomized (1:1) in two groups: group 1 (n=38) were given an mpMRI at 3 months from the beginning of AS; group 2 (control group, n= 33) did not receive the mpMRI within 12 months of surveillance. Patients in both Groups had a PSA dosage every 3 months and underwent digital rectal examination (DRE) every 6 months. In group 1, patients with at least one PIRADS ≥3 lesion at mpMRI underwent a Fusion biopsy (FB) plus systematic random biopsy; patients with negative mpMRI (namely PIRADS≤2 lesion at mpMRI) in group 1 and patients included in group 2 underwent a confirmation systematic biopsy 12 months after the beginning of the study and subsequent prostate biopsy at 48 and 72 months. In case of reclassification (both due to upgrading and to upsizing) patients were scheduled for radical treatments (including radical prostatectomy or primary radiotherapy).
Results:
Table 1 shows the clinical characteristics of the entire patient population. The two groups of patients were comparable in terms of initial Age, PSA, PSA density, clinical stage, number of positive and total cores. Table 2 shows the percentage of reclassified patients at 3 and 12 months. Of the 48 patients who underwent mpMRI at 3 months, 14 (26.9%) had at least one significant lesions nine of these patients (18.7%) were reclassified: 8 (87.5%) men due to upgrading and 1 patient due to upsizing. At 12-month random re-biopsy, only 2 out of 25 patients in group 1 (8%) and 11 out of 33 patients in group 2 (33%) were reclassified (p=0.03). Kaplan-Meyer plots (figure 3) estimate active treatment free survival among the 2 groups.
Conclusion
The early implementation of a mpMRI into an AS protocol was able to obtain earlier reclassification rates and to significantly reduce the percentage of patients who would be reclassified at 12 months with a systematic biopsy. Therefore, our data suggest to include a mpMRI in AS protocols in order to offer timely radical treatments in patients with csPCA. A larger study population and longer follow up may help to achieve more accurate results.
