Salvage radiotherapy after robot-assisted laparoscopic radical prostatectomy

Abstract

Objective: To assess the incidence and efficacy of salvage radiotherapy (SRT) after robot-assisted radical prostatectomy (RARP). RARP has been linked to an increased use of adjuvant treatments. If RARP would result in an increased local recurrence rate, response rates to SRT could be expected to be better after RARP than after more conventional methods of prostatectomy. The incidence and efficacy of SRT in a RARP population were compared with nomogram prediction.

Methods: Patient data were prospectively registered. Biochemical recurrence (BCR) was defined as a prostate-specific antigen (PSA) ≥0.1 ng/mL. SRT was offered to men with BCR after RARP. The Stephenson nomogram predictions were compared with outcome after SRT.

Results: Of 1087 men, 157 (14.4%) received SRT for BCR or persistent PSA levels during a median follow-up of 1078 days after RARP. Median PSA level before SRT was 0.2 ng/mL. Three-year BCR-free rate was 64% for men after SRT. pN (pNx, pN0, pN1) and PSA level before SRT were independent predictors of the BCR interval after SRT. Men with more extensive fascia preservation were more likely to respond favorably to SRT. The Stephenson nomogram prediction showed a concordance rate of 0.66 in this RARP population. Limitations of the study are the retrospective design and limited follow-up duration.

Conclusion: In our RARP series, the use and efficacy of SRT were comparable with open prostatectomy series. The Stephenson nomogram reliably predicted outcome in patients with RARP with SRT, suggesting that similar characteristics predict response to SRT after RARP compared with open prostatectomy.