Geetika Khanna MD, Presenter: Nothing to Disclose

Nancy S. Rosen MD, Abstract Co-Author: Nothing to Disclose

James Anderson PhD, Abstract Co-Author: Nothing to Disclose

Peter Ehrlich, Abstract Co-Author: Nothing to Disclose

Douglas Barnhart, Abstract Co-Author: Nothing to Disclose

Kenneth Gow, Abstract Co-Author: Nothing to Disclose

Paul Grundy MD, Abstract Co-Author: Nothing to Disclose

Intravascular tumor extension, present in about 11% of Wilms tumor cases, increases the perioperative complication risk. The accuracy of different imaging modalities in detection of tumor thrombus is not well known. Currently, ultrasound with doppler is the standard modality to diagnose tumor thrombus in children with Wilms tumor. In view of significant advances in CT technology, our aim is to evaluate the diagnostic performance of contrast enhanced CT (CECT) in detection of tumor thrombus in Wilms tumor using the surgical findings as the gold standard.  

The first 1,000 children enrolled in the AREN03B2 study of the Children's Oncology Group were studied. CT scans of children found to have a thrombus at surgical review (n= 44) were mixed with 125 randomly selected children without tumor thrombus. 110 patients had primary nephrectomy, while 59 received preoperative chemotherapy. The 169 scans were independently interpreted by two radiologists for presence and extent of tumor thrombus. The radiologists were blinded to all patient information. Discrepancies were resolved by consensus. The diagnostic accuracy of central CT review for detection of tumor thrombus was calculated and compared to the local doppler ultrasound.

Tumor thrombus was found at surgery to extend into the renal vein in 20 cases, to the inferior vena cava (IVC) in 21 cases, and to the heart in 3 cases. The sensitivity and specificity of CECT for detection of any level tumor thrombus were 0.70 and 0.77. The sensitivity, specificity of CT for detection of IVC tumor thrombus was 0.75 and 0.74, and for detection of cardiac tumor thrombus was 1.0 and 0.98. Doppler ultrasound reports were available in 129/169 cases. Sensitivity and specificity of local ultrasound for detection of any level tumor thrombus was 0.46, 0.91, for detection of IVC thrombus was 0.61, 0.92, and for detection of cardiac thrombus was 1.0, 1.0.

Contrast enhanced CT has high sensitivity and specificity for detection of tumor thrombus in patients with Wilms tumor. Its diagnostic performance is comparable to ultrasound with doppler evaluation. As this study continues, further data will be available to refine the estimates of sensitivity and specificity of CECT.

CECT and doppler US appear to have similar diagnostic performance for detecting Wilms tumor thrombus, suggesting that either modality can be used to asses vascular extension.

Khanna, G, Rosen, N, Anderson, J, Ehrlich, P, Barnhart, D, Gow, K, Grundy, P, Evaluation of Diagnostic Performance of CT for Detection of Tumor Thrombus in Children with Wilms Tumor: A Report from the Children's Oncology Group.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9004466.html