Sentinel lymph node in prostate carcinoma: Methodology, feasibility, surgical, and oncological consequences: A prospective study about 93 patients.
69 Background: There are few studies in the field of prostatic sentinel lymph node (SLN) procedure: in the literature at the most 10 publications are found. However the interest of urological surgeons is growing fast. We want to evaluate the rate of SLN SPECT-CT detection, the rate of SLN involvement, and the incidence of the SLN biopsy on the surgical and oncological management of patients. Methods: 93 patients with prostate cancer were included (gleason 6-9). All patients were elected for a radical laparoscopic prostatectomy. Nanocis* was intratumorally injected, guided by transrectal ultrosonography. 2 injections 0.6 ml in each lobe of the prostate were performed. Patient underwent planar imaging and SPECT-CT 2 hours after injections. Surgery was performed 18 hours after. Results: A lymphatic pelvic drainage was seen in 95,6 % (89/93) by SPECT-CT (external or internal iliac arteries areas). For 27 patients lymphatic drainage was on the right side, for 24 patients it was on the left side, for the 37 remaining patients migration was bilateral. The radioguided lymphadenectomy was assisted by a laparoscopic gamma-probe (Clerad, France), the SLN detection rate was 97.7% (87/89); the average number of resected radioactive nodes was 1.6 (range 1 to 5). By all the ways, a limited pelvic lymph node dissection was performed (including external iliac to common iliac arteries areas) in all 93 cases. An SLN involvement was found in 6 cases (5/87= 5.75%); in these 6 cases and in the 81 cases without SLN involvement, no metastatic involvement was found in the other lymph nodes, as well as in the 6 patients for which no SLN could be selectively resected (4 with no drainage seen and 2 not detected intra-operatively although visualized on lymphoscintigraphy). Conclusions: The low rate of lymphatic involvement is not surprising considering the Gleason score range 6 to 9 (low metastatic risk). So, the preliminary results are very attractive, especially for these patients that could have been falsely considered as N0. Our study is still in progress, and if these results are confirmed on a larger scale, then SLN procedure could be considered in the routine management of low risk prostatic carcinomas.