BERKELEY, CA (UroToday.com) - Our recent study was designed as a continuation of previously performed similar uroradiologic studies in the field of renal cell carcinoma (RCC) subtypes and oncocytoma differentiation with minimally invasive cross-sectional imaging methods such are ultrasound, computed tomography (CT), and magnetic resonance imaging. To the best of our knowledge, this is the first report to examine CT-based solid renal carcinoma subtypes and oncocytoma differentiation performed with this combination of tumor-enhancement measurements.
The cutoff number for each approach to the tumor enhancement measurement was chosen in order to achieve appropriate sensitivity-specificity balance, with emphasis on the specificity.
The important limitations of this study were its retrospective nature and the small number of patients with non-clear cell tumors and oncocytoma, which prevented the evaluation of the enhancement characteristics of each type of non-clear cell renal carcinomas and oncocytoma. Frequency of ccRCC, non-ccRCC, and oncocytoma in the sample evaluated in this study reflects the frequency of these tumors in the population treated in our institutions. The main obstacle that has prevented the collection of larger research materials was the diversity of CT scanning protocols which were adjusted to the indications, and, consequently, some scanning protocols were different from the protocol described in the materials and methods section. There was a significant number of patients who underwent CT exam because of some other reason, and renal tumor was diagnosed as an incidental finding. The findings of patients who underwent CT exam with different scanning protocols would have been excluded because we considered them inappropriate for inclusion in the study sample. Compliance with proposed research methods (scanning protocol and tumor enhancement measurement method) is essential in studies such as this. The tumor enhancement measurements obtained on the tumors scanned under the different scanning protocols would definitively bias the results. The other limitation was the application of different contrast materials, as well.
In addition, the cutoff values for the differentiation of solid forms of RCC subtypes expressed in the form of attenuation values and tumor enhancement ratios used in this study are influenced by scanning protocol parameters and can be used with the same accuracy only for patients who undergo scanning under the same conditions.
Ivan Žokalj as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Department of Radiology and Ultrasound, County Hospital Čakovec, I.G. Kovačića 1e Čakovec, HR-40000, Čakovec, Croatia