Radio guided radical prostatectomy: evaluation of feasibility, safety and clinical outcomes

BACKGROUND: The standard surgical treatment of PCa consists of radical prostatectomy (RP). Lymphadenectomy with removal of the sentinel lymph node (SLN) is now evolving towards the concept of radio guided surgery as an instrument for the removal of the lymph nodes of primary drainage. METHODS: From October 2012 to September 2013 laparotomic SLN dissection was performed in 43 patients during standard open radical prostatectomy. Twenty hours before surgery, 240 MBq of 99mTc nanocolloid were injected into the prostate gland under transrectal ultrasound guidance. A planar scintigraphy and a SPET/CT scan were performed 1-2 hours after the injection. Intraoperatively, all LNs detected by gamma-probe with an activity significantly higher than background were removed and classified as SLNs. We evaluated operative time, complications, postoperative outcomes and costs of the procedures of patients who underwent radio guided surgery. We measured radioactive exposure rates. RESULTS: The intraoperative detection of SLNs occurred in all 43 patients, while the scintigraphic localization was observed in 42/43 patients. A total of 77 SLNs were found, at histopathological analysis 7/77 SLNs resulted positive for metastases (4/43 patients): 3 were in the obturator fossa while the remaining SLNs were in the internal iliac chain (1), common iliac chain (1), external iliac chain (2). Global radiation exposure was not significant. CONCLUSION: Our preliminary data confirm the feasibility and the safety of SLN biopsy in nodal staging of PCa. The intraoperatively SLN detection rate resulted 100%. In 3 patients (7%) a micrometastases was found outside of obturator fossa in a not routinely sampled site.