Chaan Soong Ng MD, Presenter: Nothing to Disclose

Silvana Castro Faria MD, Abstract Co-Author: Nothing to Disclose

Edward Franklin Jackson PhD, Abstract Co-Author: Nothing to Disclose

Roy S Herbst, Abstract Co-Author: Nothing to Disclose

Chusilp Charnsangavej MD, Abstract Co-Author: Nothing to Disclose

To determine the ability of dceCT to detect changes in tumor perfusion parameters within 48 hours of commencement of an anti-angiogenic therapy, selective for inhibition of vascular endothelial growth factor receptor (VEGFR) /platelet derived growth factor receptor (PDGFR) tyrosine kinases.

DceCT was undertaken at baseline and at 48 hours after initiation of therapy with an anti-angiogenic drug, selective for inhibition of VEGFR/PDGFR tyrosine kinases, as part of a Phase I dose escalation clinical trial. Cine CT data was acquired utilizing a multislice scanner (4 x 0.5 cm axial slab, 1 second rotation, single 30 second breath-hold), and intravenous injection of non-ionic contrast medium (40 ml, 7 ml/sec). Tumor regions of interest were evaluated for tumor blood flow, blood volume, mean transit time, and permeability surface area product utilizing CT perfusion software (version 3, GE Medical Systems, Milwaukee, USA). Eleven evaluable lesions in 9 patients, with a variety of primary tumors including lung, thyroid, skin and nasomaxillary cancers, formed the basis of this study. Evaluated tumor locations included thorax, liver, bone, and subcutaneous tissues. Changes in perfusion parameters between baseline and 48 hours were compared utilizing the Wilcoxon sign-rank test.

Tumor blood flow and blood volume were significantly lower 48 hours after commencement of therapy compared to baseline (mean change (SD)): -12.9 (22.1) ml/min/100gm tissue (p = 0.02), and -0.94 (1.12) ml/100gm tissue (p = 0.03), respectively. Permeability surface area product also fell after 48 hours of therapy in the majority of lesions (9 of 11 lesions), but not to a significant degree (-3.2 (5.4) ml/min/100gm tissue, p = 0.10). There was no significant change in mean transit time.

This preliminary data suggests that the above anti-angiogenic drug is able to mediate an effect on tumor blood flow and volume, and furthermore that dceCT is able to detect such changes, as early as 48 hours after commencement of therapy. This suggests that dceCT may be a valuable non-invasive technique for assessing the early efficacy of anti-angiogenic therapies in tumors.

Ng, C, Faria, S, Jackson, E, Herbst, R, Charnsangavej, C, Changes in Dynamic Contrast-enhanced CT (dceCT) Parameters in Patients Undergoing Anti-VEGFR/PDGFR Therapy.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4405798.html