Inter-observer variability amongst surgeons and radiologists in assessment of Guy's Stone Score and S.T.O.N.E. nephrolithometry score: A prospective evaluation.

AUC: area under the curve; GSS: Guy's Stone Score; KUB: kidneys, ureters and bladder; NCCT: non-contrast CT; PCNL: Percutaneous nephrolithotomy; ROC: receiver operating characteristic; SFR: stone-free rate; S.T.O.N.E.: stone size [S], tract length [T], obstruction [O], number of involved calyces [N], and essence or stone density [E].