Pelvic lymph node dissection for patients with elevated risk of lymph node invasion during radical prostatectomy: comparison of open, laparoscopic and robot-assisted procedures

Abstract

Background and purpose: Published outcomes of pelvic lymph node dissection (PLND) during robot-assisted laparoscopic prostatectomy (RALP) demonstrate significant variability. The purpose of the study was to compare PLND outcomes in patients at risk for lymph node involvement (LNI) who were undergoing radical prostatectomy (RP) by different surgeons and surgical approaches.

Patients and methods: Institutional policy initiated on January 1, 2010, mandated that all patients undergoing RP receive a standardized PLND with inclusion of the hypogastric region when predicted risk of LNI was ≥ 2%. We analyzed the outcomes of consecutive patients meeting these criteria from January 1 to September 1, 2010 by surgeons and surgical approach. All patients underwent RP; surgical approach (open radical retropubic [ORP], laparoscopic [LRP], RALP) was selected by the consulting surgeon. Differences in lymph node yield (LNY) between surgeons and surgical approaches were compared using multivariable linear regression with adjustment for clinical stage, biopsy Gleason grade, prostate-specific antigen (PSA) level, and age.

Results: Of 330 patients (126 ORP, 78 LRP, 126 RALP), 323 (98%) underwent PLND. There were no significant differences in characteristics between approaches, but the nomogram probability of LNI was slightly greater for ORP than RALP (P=0.04). LNY was high (18 nodes) by all approaches; more nodes were removed by ORP and LRP (median 20, 19, respectively) than RALP (16) after adjusting for stage, grade, PSA level, and age (P=0.015). Rates of LNI were high (14%) with no difference between approaches when adjusted for nomogram probability of LNI (P=0.15). Variation in median LNY among individual surgeons was considerable for all three approaches (11-28) (P=0.005) and was much greater than the variability by approach.

Conclusions: PLND, including hypogastric nodal packet, can be performed by any surgical approach, with slightly different yields but similar pathologic outcomes. Individual surgeon commitment to PLND may be more important than approach.

FIG. 1.

All patients with a ≥2% risk of lymph node involvement received at minimum a pelvic lymph node dissection with a template that included, at minimum, the external iliac, obturator, and hypogastric (internal iliac) lymph node packets—corresponding with zones 1, 2, and 3 in the Figure.