Fig. 3

Detection and numeration of CTCs in 5 RCC patients at 4 different stages and sites. Significant decrease of CTC numbers were noted in all 5 patient. S1, peripheral venous blood sample from internal jugular vein before skin incision, indicative of the circulating tumor cells; S2, blood sampled in the vena cava around thrombus during surgery, indicating direct cells shedding in surgical manipulation; S3, blood after IOCS washing and before LDF filtering, which represents the tumor cell cleaning efficacy with only IOCS; S4, blood sampled after LDF filtration, meaning the actual final filtering result after IOCS–LDF