Intraoperative Photodynamic Evaluation of Surgical Margins During Endoscopic Extraperitoneal Radical Prostatectomy with the Use of 5-Aminolevulinic Acid

Abstract

Today there are no established techniques to image positive surgical margins (PSM) intraoperatively in endoscopic extraperitoneal radical prostatectomy (EERPE). The intention of this study was to describe the specific technique of photodynamic diagnosis (PDD) in patients undergoing EERPE and report on the potential to detect PSM under PDD. Twenty-four patients with clinically organ-confined prostate cancer received 5-aminolevulinic acid 20 mg/kg body weight orally 3 hours prior to nonnerve-sparing EERPE. An endoscopic PDD system (Karl Storz, Tuttlingen, Germany) including a Tricam PDD 3-chip camera head linked with a straight 10-mm telescope and a D-light C system was used. During EERPE, visualization of the surgical margins was performed by means of both white light and PDD at specific steps during standardized prostatectomy in all patients. Positive PDD areas on the prostate specimen were marked with white ink and consequently processed in pathology. In white light endoscopy, no suspicion of a PSM was raised. Six out of the eight PSM were detected by PDD. In two cases, areas of positive PDD findings were free of prostate cancer and two PSM were not detected by PDD ( one bladder neck, one lateral). The overall sensitivity and specificity were 75% and 88.2%, respectively. Laparoscopy offers an appropriate setting for the use of PDD in prostate cancer to visualize possible PSM. Although imaging of PSM by PDD is promising with the technique being feasible and safe, larger series are needed to prove the reproducibility of our results.