This study assessed whether a cycle of `` routine '' therapeutic drug monitoring ( TDM ) for imatinib dosage individualization , targeting an imatinib trough plasma concentration ( C min ) of 1,000 ng/ml ( tolerance : 750-1 ,500 ng/ml ) , could improve clinical outcomes in chronic myelogenous leukemia ( CML ) patients , compared with TDM use only in case of problems ( `` rescue '' TDM ) .