BackgroundThe comparative outcome with GreenLight (GL) photoselective vaporisation of the prostate and transurethral resection of the prostate (TURP) in men with lower urinary tract symptoms due to benign prostatic obstruction (BPO) has been questioned. ObjectiveThe primary objective of the GOLIATH study was to evaluate the noninferiority of 180-W GL XPS (XPS) to TURP for International Prostate Symptom Score (IPSS) and maximum flow rate (Qmax) at 6 mo and the proportion of patients who were complication free. Design, setting, and participantsProspective randomised controlled trial at 29 centres in 9 European countries involving 281 patients with BPO. Intervention180-W GL XPS system or TURP. Outcome measurements and statistical analysisMeasurements used were IPSS, Qmax, prostate volume (PV), postvoid residual (PVR) and complications, perioperative parameters, and reintervention rates. Noninferiority was evaluated using one-sided tests at the 2.5% level of significance. The statistical significance of other comparisons was assessed at the (two-sided) 5% level. Results and limitationsThe study demonstrated the noninferiority of XPS to TURP for IPSS, Qmax, and complication-free proportion. PV and PVR were comparable between groups. Time until stable health status, length of catheterisation, and length of hospital stay were superior with XPS (p<0.001). Early reintervention rate within 30 d was three times higher after TURP (p=0.025); however, the overall postoperative reintervention rates were not significantly different between treatment arms. A limitation was the short follow-up. ConclusionsXPS was shown to be noninferior (comparable) to TURP in terms of IPSS, Qmax, and proportion of patients free of complications. XPS results in a lower rate of early reinterventions but has a similar rate after 6 mo. Trial registrationClinicalTrials.gov, identifier NCT01218672.