Cystine stones present in an earlier age and have the likelihood to be large in size. Patients with cystine stones undergo a greater number of procedures, and they have a greater risk to develop chronic renal impairment.

FT during PCNL can be affected by several parameters. Identifying the ones that can affect FT can lead to fluoroscopy and radiation exposure decrease. Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram can all predict complexed cases and the need for increased FT.