To demonstrate the utility of anatomical 3D image guidance during robot-assisted salvage lymph node dissection (RA-sLND) in “node-only” prostate cancer recurrence after primary robot-assisted radical prostatectomy (RARP).
Between May 2015 and February 2017, ten patients (mean age: 64.2±11.3 years) underwent RA-sLND for Choline-C11 or Fluciclovine-F18 PET/CT-detected lymph node recurrence after RARP. Mean duration between initial RARP and RA-sLND was 31.5±24.2 months. Median PSA before RA-sLND was 0.58 ng/dl (range: 0.32-12.6). Targeted node dissection was performed during RA-sLND by simultaneous guidance of preoperative 3D-reconstructed PET/CT images that were visible on the surgeon’s smart phone through an application (VisiblePatient SAS, Strasbourg, France). In addition, bilateral extended pelvic LND was performed in all cases. Histopathological evaluation of extracted lymph nodes was compared with intraoperative 3D image-guided data.
In total, 126 lymph nodes were removed and 21 showed metastatic involvement at histological analysis. The median maximum diameter of metastatic nodes was 13 millimeters (range: 1-21). In 8 of 10 men, positive lymph nodes on 3D guided imaging were correctly identified as metastatic. Lymph node involvement on preoperative PET/CT was false-positive compared with histological evaluation in 2 patients. In 2/10 (20%) men, a PSA decline to <0.2 ng/dl was achieved 6 weeks after RA-sLND. Postoperatively, all patients were kept on hormonal therapy and 4 men required adjuvant radiation therapy. At a mean follow-up of 10±8.4 months, 50% of patients were free of biochemical recurrence.
Anatomical 3D image guidance helps easier targeting of positive lymph nodes during RA-sLND. However, the current sensitivity and specificity rates of preoperative PET/CT imaging make it impossible to recommend only targeted LND against bilateral, extended LND in patients with “node-only” prostate cancer recurrence.