Sentinel lymph node dissection in more than 1200 prostate cancer cases: Rate and prediction of lymph node involvement depending on preoperative tumor characteristics

Abstract

Abbreviations & Acronyms AUC = area under the curve CT = computed tomography EAU = European Association of Urology ePLND = extended pelvic lymph node dissection GS = Gleason sum LN = lymph node LNI = lymph node involvement MRI = magnetic resonance imaging PCa = prostate cancer PET = positron emission tomography PLND = pelvic lymph node dissection PSA = prostate-specific antigen SLN = sentinel lymph node sPLND = sentinel-guided pelvic lymph node dissection Objectives: To stratify the rate and prediction of lymph node involvement in prostate cancer patients undergoing sentinel-lymphadenectomy depending on preoperative tumor characteristics, and to compare the outcome with the European Association of Urology Guideline indication for lymphadenectomy. Methods: A total of 1229 patients (median age 66 years) were treated with open sentinel-lymphadenectomy and prostatectomy between 2005 and 2009. Median preoperative prostate-specific antigen was 7.4 ng/mL. The rate of lymph node involvement was analyzed for D'Amico risk groups. Multivariable logistic regression was used to estimate the probability of lymph node involvement. Predictor variables included preoperative prostatespecific antigen, clinical T-category and biopsy Gleason sum. Predictive accuracy has been quantified (area under the curve) and lymph node positive patients were verified under consideration of the recommended European threshold for lymphadenectomy (nomogrampredicted lymph node invasion risk of >7%). Results: The median number of lymph nodes removed was 10 (interquartile range 7-13). Overall, 17.1% of patients had lymph node involvement; 3.2% in low-, 14.8% in intermediate-and 37.4% in high-risk disease. The predicted risk for lymph node involvement ranged from 2% (prostate-specific antigen ≤4 ng/mL, T1, Gleason sum ≤6) to 87% (prostatespecific antigen >20 ng/mL, T3, Gleason sum ≥8). The predictive accuracy was 82.1%. According to the European guidelines, 15.9% of all lymph node involved cases would not have been detected. Conclusions:The rate of lymph node involvement seems to be higher in the examined sentinel collective than expected according to the European Guideline nomogram. The first sentinel-based lymph node involvement prediction model can assist in deciding on the indication for sentinel-lymphadenectomy. The validation of a corresponding sentinel-based nomogram is still missing.

Laparoscopic Sentinel Lymph Node Versus Hyperextensive Pelvic Dissection for Staging Clinically Localized Prostate Carcinoma: A Prospective Study of 200 Patients

“…Rather, FNs and detection rates must be interpreted per side in order to be meaningful in terms of prognostication and patient outcome. With this minimal negative rate (2.8%), we are below the limits set by international guidelines for breast cancer (29). In the guidelines of the European Association of Urology, the method of histologic detection of lymph node metastases, such as sPLND (PLND assisted by SLN technique), is regarded as suitable for lymph node staging in PC (30).…”

Advances in sentinel node dissection in prostate cancer from a technical perspective

“…1a). [23][24][25][26][27][28][29][30][31] The main advantage of this technique is that the images are generated easily and quickly, and give a direct overview over the radioactive hotspots. A disadvantage is that SN located near the site of injection can become obscured by the radioactive signal coming from the injection site.…”

“…The detection rate of the SN procedure ranged 76-100%. 5,8,9,12,23,25,29,31,33,36,[43][44][45][46][47][48] A total of 13-75% of the patients showed one or more SN outside the limited PLND template. In addition, SN were detected outside the standard PLND in 51.8-76.9% of the patients with positive LN.…”

“…In 4.1-25% of patients, SN outside the ePLND template were found, whereas 3.5-17% of patients with positive LN had SN metastases outside the ePLND template. 5,7,8,[23][24][25]27,28,31,33,37,[43][44][45]47,[49][50][51][52][53][54] In these studies, the median percentage of positive LN was 20.4% (range 4.7-50) with a FN rate of 1% (range 0-20), respectively.…”

“…Winter et al reported the rate of lymph node metastasis by SN biopsy was higher than expected from the European guideline nomogram. 31 They suggested using a SN biopsy prediction model to determine the outcome for SN procedure without any ePLND. However, validation of this prediction model is still missing.…”