RSNA 2007 

Abstract Archives of the RSNA, 2007


SSK03-05

Radiofrequency Ablation: Effect of Tumor Blood Flow Modulation by Vasoactive Drugs and Chemotherapy on Coagulation Size in a Rat Subcutaneous Tumor Model

Scientific Papers

Presented on November 28, 2007
Presented as part of SSK03: Vascular/Interventional (Ablation)

 Trainee Research Prize - Fellow

Participants

Hanping Wu MD, PhD, Presenter: Nothing to Disclose
Agata A. Exner PhD, Abstract Co-Author: Nothing to Disclose
Tianyi M. Krupka BS, Abstract Co-Author: Nothing to Disclose
Brent Derek Weinberg BS, Abstract Co-Author: Nothing to Disclose
John Robert Haaga MD, Abstract Co-Author: Nothing to Disclose

PURPOSE

To assess the effect of vasoactive drugs on tumor blood flow and the coagulation size induced by radiofrequency ablation (RFA) with or without chemotherapy in a rat subcutaneous tumor model.

METHOD AND MATERIALS

54 BD-IX rats were inoculated in each shoulder with a DHD/K12/TRb colorectal cell line. Blood flow, permeability and blood volume in 24 tumors of 12 rats before and after i.v. phenylephrine (PE, 10 µg/kg) or hydralazine (HYZ, 5 mg/kg) was measured by functional CT. The remaining 30 rats were divided into 5 groups (6 rats per group). The left side tumors were treated with RFA (80°C ± 2 for 2 min). The right side tumors were treated with i.v. PE, HYZ, carboplatin (CBP, 20 mg/kg), CBP+HYZ or CBP+PE followed by RFA 1, 5 or 15 minutes after PE, HYZ or CBP administration, respectively. Tumor sections were stained with 2% 2,3,5-triphenyltetrazolium chloride to determine coagulation size 24 hours later. Perfusion parameters (before and after vasoactive drugs) and the size of coagulation (with and without drugs) were compared.

RESULTS

HYZ produced a marked decrease in entire tumor and tumor rim blood flow of 31.1% and 29.3% (P0.05). PE also significantly decreased the permeability of the entire tumor and tumor rim by 12.0% and 10.2%, respectively, while HYZ significantly increased the permeability of tumor rim by 13.6%. No differences in the size of RF-induced coagulation were found between ablation only and PE with ablation or CBP+PE with ablation. However, treatment of tumors with HYZ, CBP, or CBP+HYZ increased the diameter of RF-induced coagulation by 17.1%, 14.8% and 18.2%, and increased the area by 22.6%, 27.6% and 31.8%, respectively (P<0.05).

CONCLUSION

Functional CT is a good tool to monitor tumor blood flow. HYZ decreases tumor blood flow and enhances the coagulation size induced by RFA; adjuvant chemotherapy is also benificial.

CLINICAL RELEVANCE/APPLICATION

Hydralazine can decrease tumor blood flow and enhance the coagulation size induced by RFA, and adjuvant chemotherapy is also benificial to RFA for tumor, particularly when combined with hydralazine.

Cite This Abstract

Wu, H, Exner, A, Krupka, T, Weinberg, B, Haaga, J, Radiofrequency Ablation: Effect of Tumor Blood Flow Modulation by Vasoactive Drugs and Chemotherapy on Coagulation Size in a Rat Subcutaneous Tumor Model.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5002026.html