Correlation of doxorubicin delivery and tumor necrosis after drug-eluting bead transarterial chemoembolization of rabbit vx2 liver tumors

Purpose: To quantify the correlation between doxorubicin (DOX) delivery and tumor necrosis after drug-eluting bead (DEB) transarterial chemoembolization (TACE). Materials and Methods: In this animal care committee-approved study, New Zealand white rabbit VX2 liver tumors were treated transarterially with DOX-loaded 70-150-mm DEBs in five treatment groups with varying drug doses: sham (saline), 0 mg, 12.5 mg, 25 mg, and 37.5 mg. DEB TACE was followed by 3-and 7-day sacrifice, tumor harvest, and sectioning. Drug delivery was assessed by using fluorescence imaging, and tumor necrosis was quantified by means of histologic analysis. Statistical correlation of DOX delivery and tumor necrosis was performed by using the Spearman rank correlation coefficient (r). Results: Thirty-six VX2 tumors (median diameter, 1.3 cm) in 20 rabbits (median weight, 2.8 kg) underwent successful DEB TACE. Treatment groups included eight, seven, eight, five, and eight tumors of similar size (P . .05). Tumors showed progressively greater DOX extent (sham, 0%; 0 mg, 0%; 12.5 mg, 3%; 25 mg, 20%; and 37.5 mg, 27%) and intensity (sham, 0.4; 0 mg, 1.9; 12.5 mg, 8.5; 25 mg, 9.6; and 37.5 mg, 18.3) and higher median percentage necrosis (sham, 68%; 0 mg, 64%; 12.5 mg, 76%; 25 mg, 78%; and 37.5 mg, 83%) across DOX treatment groups. Correlation of DOX extent (r = 0.975, P = .005) and intensity (r = 0.900, P = .037) with percentage tumor necrosis was statistically significant. Conclusion: Incremental increases in DOX correlate with greater necrosis in rabbit VX2 liver tumors after DEB TACE. This result indicates an essential role for chemotherapy-induced cytotoxicity in TACE effectiveness and supports the use of chemotherapeutic drugs in transarterial therapy.