Radical Prostatectomy Combined with Prostate Specific Membrane Antigen-radioguided Lymph Node Dissection is Associated with Longer Treatment-free Survival for Patients with Primary Lymph Node-positive Prostate Cancer.

[BACKGROUND AND OBJECTIVE] The optimal treatment for patients with prostate cancer with primary lymph node metastases (LNMs) is still a matter of debate. Radical prostatectomy (RP) combined with prostate-specific membrane antigen (PSMA)-radioguided surgery (RGS) may be a helpful technique in removal of LNMs detected on preoperative PSMA positron emission tomography (PET) in comparison to conventional lymph node dissection (LND). The aim of our retrospective analysis was to determine whether addition of PSMA-RGS at primary radical prostatectomy (RP) is associated with longer survival.

[METHODS] Technetium-PSMA-I&S was administered preoperatively to facilitate LND during RP in the RGS group. Standard descriptive statistics were used to outline differences in patient characteristics. To address imbalance of covariates, we created matched samples using exact matching before assessing survival outcomes using Cox regression analyses.

[KEY FINDINGS AND LIMITATIONS] Matched samples were created for a cohort comprising 46 patients who underwent RP with RGS, and 42 patients who underwent RP without RGS, with matching according to LNM distribution, number of LNMs on preoperative PSMA PET scans, and surgical margin status. Multivariate Cox regression revealed an association between longer treatment-free survival (TFS) and PSMA RGS (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.30-0.94). A higher number of positive lymph nodes (HR 1.29, 95% CI 1.07-1.56) and positive surgical margins (HR 1.86, 95% CI 1.06-3.25) were associated with shorter TFS. The main limitations are the retrospective design and small sample size.

[CONCLUSIONS AND CLINICAL IMPLICATIONS] Addition of PSMA-RGS at primary RP was associated with longer TFS for patients with limited PSMA PET-positive locoregional LNMs.

[PATIENT SUMMARY] We looked at whether a technique to label and detect lymph node metastases during prostate cancer surgery is linked to better cancer control for patients whose preoperative scans showed limited spread to the lymph nodes. We found that this approach may lead to better cancer control after surgery and a longer time before additional treatment is needed.