Effect of transcatheter intra-arterial therapies on tumor interstitial fluid pressure and its relation to drug penetration in a rabbit liver tumor model

Purpose To determine the change in tumor interstitial fluid pressure (IFP) after transcatheter intra-arterial (IA) therapies and its relation to drug penetration in liver cancer. Materials and Methods VX2 tumors were grown in the livers of 16 rabbits. The rabbits were treated with intravenous injection of doxorubicin (group 1; n = 4), hepatic IA injection of doxorubicin (group 2; n = 4), hepatic IA injection of doxorubicin followed by embolization with polyvinyl alcohol particles (group 3; n = 4), or hepatic IA injection of doxorubicin mixed with Lipiodol followed by polyvinyl alcohol embolization (group 4; n = 4). Tumor IFP was measured with a Mikro-Tip pressure catheter before and 1 hour after treatment. Doxorubicin penetration was evaluated by immunofluorescence. Results Tumor IFP after treatment decreased by 5.0% ± 2.8, 3.9% ± 9.0, 27.1% ± 5.2, and 31.8% ± 7.4 in groups 1-4, respectively. The difference in IFP reduction between embolization-treated groups (groups 3 and 4) and nonembolized groups (groups 1 and 2) was significant (P <.001). Doxorubicin penetration distances were 20.3 μm ± 3.7, 45.7 μm ± 10.5, 69.5 μm ± 9.3, and 47.9 μm ± 6.4 in groups 1-4, respectively. IFP reduction was significantly correlated with doxorubicin penetration distance (r =.671, P =.004). Conclusions A greater reduction of tumor IFP was associated with embolization in a preclinical liver tumor model, and embolization may indirectly contribute to increased drug penetration.