Increased carboplatin concentration in liver tumors through temporary flow retardation with starch microspheres (Spherex) and gelatin powder (Gelfoam): an experimental study in liver tumor-bearing rabbits.

Regional chemotherapy of primary and secondary malignant liver tumors is superior to systemic therapy. The regional advantage can be further increased by flow retardation. Absorbable gelatin powder (Gelfoam) and starch microspheres (Spherex) may serve as embolizing agents because of their particle size and embolization time. Carboplatin was for the first time applied as a cytostatic agent in regional chemotherapy. Embolization and flow retardation times were measured. The embolization time of Gelfoam was 27 min, and that of starch microspheres (Spherex), 7 min, on average. Mean flow retardation of Gelfoam was 153 min, and that of starch microspheres (Spherex) 38 min. The concentration differences in systemic and regional chemotherapy were determined in VX-2 liver tumor-bearing rabbits. In regional chemotherapy, the tumor concentration was increased by a factor of 3.6 compared with systemic therapy. Coapplication with an embolizing agent increased the tumor concentration of carboplatin by a factor of 44 to 47. Concentrations of absorbable gelatin powder (Gelfoam) and starch microspheres (Spherex) did not differ significantly.