Published in: 01-04-2014 | Review Stone-free rate (SFR): a new proposal for defining levels of SFR Authors: Bhaskar K. Somani, Mahesh Desai, Olivier Traxer, Sven Lahme Published in: Urolithiasis | Issue 2/2014 Login to get access Abstract There is a lack of consensus in the definition of stone-free rate (SFR) after ureteric or renal stone surgery. We propose a simple classification to define levels of SFR post-treatment.