Robotic salvage lymph node dissection for nodal-only recurrences after radical prostatectomy: Perioperative and early oncological outcomes.

ABSTRACT

BACKGROUND: Salvage lymph node dissection (sLND) - performed open or minimally-invasive - is a treatment modality that can be offered to patients with nodal recurrence after radical prostatectomy (RP), especially in times where modern imaging methods like choline- or PSMA-PET/CT are available. Yet, there are only very limited data on the safety and oncological effectiveness of robotic sLND. METHODS: We retrospectively identified patients who underwent robotic sLND at our institution between 2013 and 2017 for nodal recurrence after RP, which had been diagnosed either by 18F-choline- or 68Ga-PSMA-PET/CT. We analyzed perioperative data and early oncological outcomes with a focus on the comparison of patients with preoperative choline- vs. those with preoperative PSMA-PET/CT. RESULTS: We identified 36 patients who underwent robotic sLND at a median time of 45.3 months [range 3.1;228.6] after RP, with nodal recurrences detected in 25 patients by PSMA- and in 11 by choline-PET/CT. Median preoperative PSA, operation time and blood loss were 1.98 ng/ml [range 0.09;35.15], 129.5 min [range 65;202] and 50 ml [range 0;400], respectively. No high-grade complications occurred. A median number of 6.5 [range 1;25] lymph nodes were removed with a median of 1 [range 0;9] tumor-occupied node. None of the patients received any adjuvant treatment. Median postoperative PSA-change was -57% [range -100; +58] in the PSMA- and +10% [range -91; +95] in the choline-group (p = 0.015). 44% of patients in the PSMA- and 18% of patients in the choline-group experienced complete biochemical response (cBCR; PSA <0.2 ng/ml). Median time from sLND to the initiation of further therapy was 12 months [range 2;21.5] in the PSMA-group and 4.7 months [range 2.2;18.9] in the choline-group (p = 0.001). CONCLUSIONS: This is the hitherto largest series on robotic sLND for nodal recurrence after RP. Robotic sLND is a feasible therapeutic option with low morbidity, which can at least delay the initiation of further therapy - in some patients up to several years. However, the extend of sLND has to be standardized and randomized trials are needed to finally define the oncological effectiveness of this approach.