Objective: To study the oncological outcome of adjuvant radiotherapy after extra-peritoneal laparoscopic radical prostatectomy (ELRP).

Materials and Methods: From 2008 to December 2016, 112 patients underwent ELRP for localized prostate cancer by the same
urologist (SP). We analyzed the patient demographics, perioperative outcomes, and compared the oncological outcomes between patients, with and without adjuvant radiotherapy, by biochemical failure.

Results: The median follow-up time in the present study was 35 months (IQR: 26 to 64). Due to indications of high risk, the adjuvant
radiotherapy rate after ELRP was 20.5% (23/112 cases). The biochemical failure rate in this group was 8.7%. In non-adjuvant
radiotherapy patients, the biochemical failure, salvage radiation and the overall survival rates were 28.1% (25/89 cases), 14.6% (13 cases), and 92.1% (82/89), respectively. Interestingly, there was no significant difference in either biochemical progression free survival (p = 0.051) or overall survival (p = 0.787), with or without adjuvant RT. However, biochemical control tended to be better in patients who received adjuvant radiotherapy.

Conclusion: The present study indicated the positive oncologic outcome of adjuvant radiotherapy after ELRP radiotherapy in terms of biochemical failure. Further prospective study design with longterm follow-up is needed to draw a conclusion.

Keywords: Adjuvant Radiotherapy, Extra-peritoneal laparoscopic radical prostatectomy, Prostate cancer, Biochemical failure