Achille Mileto MD, Presenter: Nothing to Disclose

Daniele Marin MD, Abstract Co-Author: Nothing to Disclose

Alfredo Blandino, Abstract Co-Author: Nothing to Disclose

Juan Carlos Ramirez Giraldo PhD, Abstract Co-Author: Employee, Siemens AG

Christian Eusemann PhD, Abstract Co-Author: Employee, Siemens AG

Emanuele Scribano, Abstract Co-Author: Nothing to Disclose

Giorgio Ascenti MD, Abstract Co-Author: Nothing to Disclose

To investigate the diagnostic performance of dual energy MDCT with iodine quantification for distinguishing clear cell from papillary renal cell carcinoma (RCC).

Eighty-eight patients (57 men, 31 women), with diagnosis of either clear cell or papillary RCC at pathology, underwent contrast-enhanced dual-energy nephrographic phase study between December 2007 and June 2013. Five readers, blinded to pathologic diagnosis, independently evaluated all cases by determining the lesion iodine concentration on color-coded iodine maps. The receiving operating characteristic curve (ROC) analysis was adopted to estimate the optimal threshold for discriminating between clear cell and papillary RCC. Inter-observer agreement was assessed using the k test. The correlation between tumor iodine concentration and tumor grade was investigated.

A tumor iodine concentration of 0.9 mg/mL represented the optimal threshold for discriminating between clear cell and papillary RCC, yielding sensitivity of 98.2% (95% CI: 97.7%, 98.7%), specificity of 86.3% (95% CI: 85.0%, 87.7%), positive predictive value of 95.8% (95% CI: 95.0%, 96.6%), negative predictive value of 93.7% (95% CI: 92.8%, 94.7%), area under the curve of 0.92 (95% CI: 0.91 , 0.93), with overall accuracy of 95.3% (95% CI: 94.6%, 96.2%). Substantial agreement was found among the five readers (k, 0.79). Significant correlation was found between tumor iodine concentration and tumor grade for both clear cell (τ = .85; P <.001) and papillary RCC (τ = .53; P <.001).

Dual energy MDCT with iodine quantification enables a highly accurate and reliable distinction between clear cell and papillary RCC at a single-time-point.

By virtue of the noninvasive discrimination between clear cell and papillary RCC, dual energy iodine quantification may streamline patients’ management while, potentially, serving as an in-vivo prognostic imaging biomarker in predicting survival.

Mileto, A, Marin, D, Blandino, A, Ramirez Giraldo, J, Eusemann, C, Scribano, E, Ascenti, G, Diagnostic Performance of Dual Energy MDCT with Iodine Quantification for Differentiating Clear Cell from Papillary Renal Cell Carcinoma.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007995.html