1. Introduction & Objectives Using strict criteria, solitary muscle invasive TCC of the bladder can be managed favorably in a bladder sparing manner with brachytherapy. Hollow catheters used for after-loading radiotherapy are placed in the bladder wall. Until now, this is performed by open surgery worldwide. In order to reduce the morbidity and toxicity of this procedure, our goal was to replace the open surgery (O-BI) by laparoscopy (L-BI) and eventually robot laparoscopy (RAL-BI). We report the first experiences and clinical outcome. Introduction of new techniques: First experiences in robot assisted laparoscopic brachytherapy catheter implantation in muscle invasive transitional cellcarcinoma of the bladder Smits, G.A.H.J. 1, Wijburg, C.J. 1, Kums, A.C.M. 1, Campschroer, T. 1, Van Der Steen-Banasik, E. 2 1) Rijnstate Hospital, Dept. of Urology, Arnhem, 2) Arnhem Radiotherapeutic Institution, ARTI, Arnhem, The Netherlands 870 Material & Methods Ten patients with solitary muscle invasive T2 TCC of the bladder (N = 8) or TCC of the distal ureter (N = 2) were treated between June 2009 and October 2010. Laparoscopy and cystoscopy were performed simultaneously in order to identify the exact location of the tumor area. Using specially developed needles (Nucletron), 3 to 4 brachytherapy catheters were inserted by laparoscopy in the 'clinical target volume' under cystoscopic control. The last 2 procedures were performed with the da Vinci Si® robot, using the Tilepro application (RAL-BI). Results and outcome are compared with the earlier series OBI in our institute (n=96, 1996- 2009). Results The laparoscopic placement of the brachytherapy-catheters appeared feasible, uneventful and without perforation of the mucosa and resulted in a perfect geometry and anatomic position. The Tilepro application of was of great benefit for the console surgeon during RAL-BI. The operating time decreased from 258 minutes in the first (laparoscopic) case to 70 minutes in the last (robot assisted) cases (150 min mean-time in O-BI). Blood loss was nihil and there were no per-and post-operative complications. Average hospitalization was 6 days (5-12 days), in the O-LI group this was 10 days (7-25 days). The irradiation consisted of pre-operative external radiotherapy (three fractions of 3.5 Gy or 20 fractions of 2 Gy for T1 or T2 tumors, respectively) and the brachytherapy (equivalent to 60 or 30 Gy). Position of the catheters appeared to be superior in the laparoscopy group as depicted by imaging techniques and, in contrast to the O-BI, no interruptions caused by radiation source jamming occurred. There was no early toxicity in the laparoscopy group. Conclusions By using specially developed needles, the application of brachytherapy catheters by laparoscopy appears feasible in solitary muscle invasive TCC of the bladder and results in superior per en postoperative outcomes. In addition, an improved accuracy in after loading is established. We are aware of the still limited experience and follow-up, however, these favorable results prompt us to continue the laparoscopic approach using the da Vinci Si® platform.