Janio Szklaruk, Presenter: Nothing to Disclose

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

James C Yao, Abstract Co-Author: Nothing to Disclose

Chaan Soong Ng MD, Abstract Co-Author: Nothing to Disclose

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

To assess interobserver variability and changes in functional CT (fCT) parameters (blood flow (BF), blood volume (BV), and permeability surface area (PS)) in patients with metastatic carcinoid treated with anti-angiogenic therapy (Bevacizumab, BEV). BEV is a monoclonal antibody that binds to vascular endothelial growth factor (VEGF).

Ten patients with a clinical history of metastatic carcinoid who were part of a phase II trial with anti-angiogenic treatment with BEV were enrolled in our study. All patients had a standard CT of the abdomen and pelvis with intravenous contrast. The fCT data was obtained using a four-slice CT scanner (GEMS, Milwaukee, WI) with a 4 x 0.5 cm axial slab at 1 second per rotation during a 30 sec breath-hold. Intravenous contrast was injected at 7 cc/sec (40cc). fCT was obtained by two radiologist with the CT perfusion 3 Software (GEMS) at baseline and following therapy (at 48-96 hours). The fCT calculations were performed in metastatic sites and in the spleen. The BF, BV, and PS were calculated before and after treatment. Interobserver variability was evaluated using the Pearson correlation coefficient. The change in fCT parameters following treatment was evaluated with a paired t-test.

The correlation of interobserver variability for the calculated BF, BV, and PS was 0.981, 0.984, and 0.988, respectively. The mean pre- and post-treatment fCT changes of the metastatic lesions for BF (Δ = - 17.5 ml/min/100gm tissue, p <0.005), BV (Δ = - 1.3 ml/100gm tissue, p <0.005), and PS (Δ = - 8.8 ml/min/100gm tissue, p <0.005) were significantly different. The mean pre- and post-treatment fCT changes of the spleen for the BF (Δ = -3 ml/min/100gm tissue, p = 0.91), BV (Δ = -0.4 ml/100gm tissue, p = 0.78), and PS (Δ = + 3 ml/min/100gm tissue, p = 0.38) did not demonstrate significant change.

There was very high interobserver correlation for all fCT measurements. BEV significantly decreased perfusion parameters of the tumors at 48-96 hours after treatment but had no effects on normal organs (spleen). fCT at 48 hours after treatment appears to be an effective method for monitoring anti-VEGF therapy.

Szklaruk, J, Faria, S, Yao, J, Ng, C, Charnsangavej, C, Evaluation of Interobserver Variability and Changes in Functional CT Parameters in Patients with Metastatic Carcinoid Treated with Anti-VEGF Anti-Angiogenic Therapy.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4409946.html