Introduction and objective
The impact of multiparametric MRI on surgical approach during radical prostatectomy (RP) and on oncological outcomes after surgery is still controversial. We aimed at performing a detailed topographic description of the site of PSM according to the topographic location of IL at MRI.
Methods
Overall, 111 PCa patients undergoing MRI-targeted biopsy and bilateral nerve sparing RP at our centre between 2016 and 2022. All patients had PSM at final pathology. All patients had a single visible suspicious IL at MRI (PIRADS ≥3). We evaluated the site of PSM based on the IL location at MRI. IL and PSM location were categorized using the 3 regions scheme (Right vs Left vs Bilateral). We graphically described the site of PSM based on the IL using the alluvial plot. We evaluated whether the IL was correlated with the location of PSM (right vs left) using Pearson’s chi-square test.
Results
PIRADS score was 3, 4, and 5 in 22 (20%), 44 (40%), and 48 (40%) patients, respectively. Median IL volume was 1.3 cc. Overall, 10 (9%), 42 (38%) and 59 (53%) ILs were bilateral, on the left and right hemigland, respectively. Clinically significant PCa (defined as a Gleason score ≥7) was found in 93 (84%) patients at biopsy. At final pathology, extra capsular extension was found in 58 (52%) patients. Overall, 13 (12%), 41 (37%), and 57 (51%) patients had bilateral, left, and right PSM, respectively. The topographic distribution of the site of PSM according to the topographic location of the ROI is reported in Figure 1. The majority of PSMs were ipsilateral to the IL location. For instance, among the 59 patients with IL in the right emigland, 93% (n=55) had ipsilateral PSM, 3% (n=2) had contralateral PSM and 3% (n=2) had bilateral PSM. After excluding bilateral PSM, IL location was strongly associated with the site of PSM (p<0.001).
Conclusions
Our analyses demonstrated that the majority of PSM are located on the same side of the MRI-visible lesion. A conservative nerve sparing RP approach could thus be safely considered to be performed on the contralateral side of IL at mpMRI.