Eleni A. Liapi MD, Presenter: Research grant, ContextVision AB

Laurie Pipitone, Abstract Co-Author: Nothing to Disclose

Juls Blevins, Abstract Co-Author: Nothing to Disclose

Jorge Guzman RT, Abstract Co-Author: Nothing to Disclose

Jeffrey P. Leal BA, Abstract Co-Author: Nothing to Disclose

Jean-Francois H. Geschwind MD, Abstract Co-Author: Nothing to Disclose

To investigate neoangiogenic changes of VX2 tumors implanted in thigh muscle with CT perfusion imaging over the common experimental time period of 9 days.

VX2 tumors were implanted in thighs of 10 NZW rabbits, which were scanned at day 13, 16 and 22 after implantation in a 320-slice CT scanner (Toshiba, Japan) following contrast injection of 7 ml for 67 sec (scan delay 7 sec, first pass: 1 acquisition/2 sec, delayed phase: 1 acquisition/3 sec). Images were analyzed based on the deconvolution technique. Manual ROIs including the tumor perimeter at the level of maximal diameter and circular ROIs with similar surface area were drawn at the same level on the contralateral thigh muscle. Functional parameters included blood flow (BF), blood volume (BV), microvessel permeability surface area product (PS), and mean transit time (MTT) for tumors and thigh muscles. Tumor axial diameters and volumes were acquired for all studies.

Tumors at all stages had a hypervascular rim and hypovascular center. Tumor volumes and MTT at day 16 significantly increased compared to day 13 (p=0.02 and 0.04, respectively), tumor BV and PS slightly increased and BF slightly decreased (p>0.05). Tumor volumes and axial diameters significantly increased from day 16 to 22 (p=0.08 and 0.007 respectively), while BF, BV and PS slightly increased and MTT slightly decreased (p>0.05). From day 13 to 22, tumor volumes and BV statistically increased (p=0.01 and 0.02, respectively), while BF, PS and MTT increased but not significantly. Muscle functional values remained unchanged over time (p<0.05 for all comparisons).

CT perfusion can adequately evaluate neoangiogenic changes over time in the thigh VX2 tumor. While tumors may significantly grow over a short period, fluctuations in tumor functional values during this period reflect the complex interplay between angiogenesis and tumor growth.

CT perfusion may a adequately evaluate neoangiogenic changes over time in animal tumors and may be adopted as a tool of monitoring early human soft tissue tumor response to treatment.

Liapi, E, Pipitone, L, Blevins, J, Guzman, J, Leal, J, Geschwind, J, Dynamic Evolutionary Changes in Neovasculature Formation by CT Perfusion in Soft Tissue VX2 Tumors over Time.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9016204.html