Re: Singh A et al. Robot-assisted retroperitoneal lymph node dissection: Feasibility and outcome in postchemotherapy residual mass in testicular cancer. Indian J Urol 2017;33:304-9.

Dear Editor,

We read with interest the recent article by Singh et al.[1] on the safety and feasibility of robot-assisted retroperitoneal lymph node dissection (RA-RPLND) in testicular cancer patients with postchemotherapy residual mass. We congratulate the authors and wish to highlight some issues.

Although the authors claimed that their study is the largest case series of RA-RPLND in patients with postchemotherapy residual mass (13 cases), a similar study including 12 patients was published by Kamel et al.[2] in 2016. However, literature about RA-RPLND in residual disease after chemotherapy is still very limited. Open RPLND (O-RPLND) is accepted as the gold standard method for RPLND in testicular cancer patients. But, to the best of our knowledge there is no study comparing the RA-RPLND with O-RPLND.[3] The aim of the current study is clearly identified as evaluating the surgical feasibility and outcomes of RA-RPLND for postchemotherapy residual mass in patients with testicular cancer. However, we believe that in this study, the authors could have compared RA-RPLND and O-RPLND as some O-RPLND cases were performed during the same period at the same institution. In the conclusion section, the authors state that RA-RPLND is a promising alternative to O-RPLND. They also concluded that RA-RPLND has similar surgical, oncological outcome and lymph node yield. How was this comparison made? With O-RPLND or previous studies about RA-RPLND? We think that comparing RA-RPLND and O-RPLND would be better than comparing RA-RPLND with data of previous reports. On the other hand, the reported chyle leak rate (30.7%) is higher than expected in comparison with the literature that reports an overall 7%–20.8% incidence.[4] The authors explained this to be due to difficulty in identification of lymphatic in the postchemotherapy setting. However, previously, Evans et al.[5] reported the overall incidence of chyle leak as 7% in O-RPLND for postchemotherapy residual mass. Thus the safety of RA-RPLND cannot be superior and we believe that the best inferences on safety and efficacy of RA-RPLND may be derived in a study comparing it with O-RPLND. If the authors had compared RA-RPLND and O-RPLND, this study would have been enriched.

Respectfully