Avinash R Kambadakone MD, FRCR, Presenter: Nothing to Disclose

Naveen Kulkarni MD, Abstract Co-Author: Nothing to Disclose

Sam Yoon MD, Abstract Co-Author: Nothing to Disclose

Dushyant V. Sahani MD, Abstract Co-Author: Grant, General Electric Company

To evaluate the role of CTperfusion in predicting tumor biology and monitoring response to antiangiogenic therapy in soft tissue sarcomas in correlation with tumor size, tumor density, gene expression and serum biomarkers.

In this ongoing clinical trial, 22 patients (15M: 7F, age range 28-75, mean 53 yrs) with STS underwent CTp and diagnostic CECT on 16-MDCT at baseline and 10 days after treatment with antiangiogenic (Bevacizumab) treatment alone as well as after completion of 6 weeks of antiangiogenic and XRT. CTp parameters (BV, BF, PS and MTT) were estimated (GE Perfusion 3). Two blinded readers also recorded the tumor size and density measurements (HU units) on the diagnostic CT images. The percentage change in tumor attenuation and CTp parameters was estimated comparing the baseline and post treatment values. Correlation of the CTperfusion was also performed with microvessel density, gene expression and serum biomarkers (VEGF, TNF and interleukins).

At day 10 following antiangiogenic therapy, significant change in CTp parameters and tumor density was observed (pre-55±22 HU and at 10 days-45±18 HU, mean HU change-9.6 (16.2%), p=0.001 and mean CTp change (17-30%–p=0.05) and similar findings were noted after completion of treatment (6 wks) (pre-55±22 HU and post- 30.9±20.4 HU, mean HU change-25.4 (44.1%), p=0.003 and mean CTp change-59-72%,p=0.001). The change in tumor density showed fair correlation with the changes in BF and BV at 10 days and after completion of treatment (r=0.64-0.68). Median microvessel density (MVD) decreased by 53% after BV alone (p<0.05) while increase in levels of VEGF and PlGF was seen. Tumors with higher baseline perfusion values and higher baseline attenuation (67±25HU vs 45±18HU, p>0.05) showed superior response to treatment. 

CTperfusion is a robust method for monitoring early and late treatment response to antiangiogenic therapy and chemoradiation comparing to tumor size and tumor density. The tumor vascularity changes to treatment depicted by CTp are reflected in reduction in MVD and gene expression signatures and serum biomarkers show correlation with response.

CT perfusion can act as robust surrogate to monitor early antiangiogenic treatment response in soft tissue sarcomas and predict tumor biology. 

Kambadakone, A, Kulkarni, N, Yoon, S, Sahani, D, CT Perfusion in Predicting Tumor Biology and Response Evaluation to Antiangiogenic Therapy in Soft Tissue Sarcoma: Correlation with  Tumor Size, Tumor Density, Gene Expression and Biomarkers.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9016205.html