Dushyant Vasudeo Sahani MD, Presenter: Nothing to Disclose

Sanjeeva Prasad Kalva MD, Abstract Co-Author: Nothing to Disclose

Christopher G Willett, Abstract Co-Author: Nothing to Disclose

Peter Florin Hahn MD, Abstract Co-Author: Nothing to Disclose

Sanjay S. Saini MD, Abstract Co-Author: Nothing to Disclose

Peter R Mueller MD, Abstract Co-Author: Nothing to Disclose

To demonstrate the physiologic changes in tumor perfusion by CT in patients with rectal cancer, following a single dose of anti-angiogenic therapy (anti-VEGF antibody; Avastin)

Ten patients (6M:4F; age range 35-66; mean 54) with locally advanced (T3) rectal cancer underwent perfusion CT on 4-slice MDCT before and 10-12 days after the administration of single dose of anti-VEGF antibody (Avastin). Dynamic CT at a static table position was performed for 60 seconds after the administration of IV contrast. The data was analyzed using CT perfusion software (GE). Blood perfusion maps and absolute value of blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were obtained for the tumor. The perfusion parameters were correlated with endoscopy findings, tumor interstitial pressure (IP) and tumor micro-vessel density (MVD) measurements obtained before and after the therapy.

Perfusion CT was performed in all patients with no complications. Among the ten patients, BF decreased in nine patients (average decrease 36%); BV decreased in six patients (average decrease 19%); MTT increased in nine patients (average increase 57%) and PS decreased in six patients (average decrease 36%). The decrease in BF was statistically significant (p=0.02). Decrease in BF and increase in MTT corresponded to decreased IP and diminished tumor size on endoscopy. Change in micro-vessel density available in five patients correlated with decrease in blood flow

Perfusion CT is a reliable method to monitor response to Avastin therapy in rectal cancer.

Sahani, D, Kalva, S, Willett, C, Hahn, P, Saini, S, Mueller, P, Anti-Angiogenic Therapy of Rectal Cancer: Monitoring Treatment Response with Perfusion CT in Comparison to Tumor Interstitial Pressure and Micro-Vessel Density.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4408241.html