Purpose
Current guidelines do not provide strong recommendations on the preservation of the neurovascular bundles during RP in case of HR PCa and/or suspicious EPE. We aimed to evaluate when, in case of unilateral HR disease, contralateral NS should be considered or not.
Methods
Within a multi-institutional dataset we selected patients with unilateral HR PCa defined as: unilateral EPE and/or SVI on mpMRI or unilateral ISUP 4-5 or PSA ≥20 ng/ml. To evaluate when to perform NS based on the risk of contralateral EPE, we relied on CHAID, a recursive machine learning partitioning algorithm developed to identify risk groups, which was fit to predict the presence of EPE on final pathology, contralaterally to the prostate lobe with HR disease.
Results
705 patients were identified. Contralateral EPE was documented in 87 (12%) patients. The CHAID identified three groups: i) absence of SVI on mpMRI and index lesion’s diameter ≤15 mm; ii) index lesion’s diameter ≤15 mm and contralateral ISUP 2-3 or index lesion’s diameter >15 mm and negative contralateral biopsy or ISUP 1 iii) SVI on mpMRI or index lesion’s diameter >15 mm and contralateral biopsy ISUP 2-3. We named those groups as low- intermediate- and high-risk for contralateral EPE. The rate of EPE and PSMs across the groups were: 4.8%, 14%, 26% and 5.6%, 13%, 18%, respectively.
Conclusions
Our study challenges current guidelines by proving that wide bilateral excision in men with unilateral HR disease is not justified. Pending external validation, we propose performing NS and incremental NS in case of contralateral low- and intermediate EPE risk, respectively.