Role of Contrast Enhancement and Corrected Attenuation Values of Renal Tumors in Predicting Renal Cell Carcinoma (RCC) Subtypes: Protocol for a Triphasic Multi-Slice Computed Tomography (CT) Procedure.

Ersen Ertekin,Akın Soner Amasyalı,Saim Acikgozoglu,Faruk Kucukdurmaz,Haluk Erol,Alaaddin Nayman,Bulent Erol

doi:10.12659/pjr.901957

Abstract

SummaryBackgroundTo distinguish RCC subtypes based on contrast enhancement features of CT images.Material/MethodsIn total, 59 lesions from 57 patients were included. All patients underwent multi-slice CT imaging with a triphasic protocol, which included non-contrast, corticomedullary, nephrographic and urographic phases. Contrast enhancement features of renal masses were evaluated in terms of CT attenuation values (AV) and differences in contrast density; the aorta or renal parenchyma were evaluated based on corrected or relative values.ResultsClear cell RCC (ccRCC) showed more intense contrast enhancement than other RCC subtypes. When differentiating ccRCC from other RCC subtypes, a cut-off AV of 86–89 HU, aorta-based corrected AV of 89–95 HU and renal parenchyma-based corrected AV of 87–95 HU showed a diagnostic accuracy of 81–86%, 86–88% and 74–78%, respectively, in the corticomedullary phase. Furthermore, a cutoff of 2.42–2.72 for the relative contrast enhancement ratio, a cutoff of 2.59–2.74 for the aorta-based corrected relative contrast enhancement ratio and a cutoff of 2.63–2.76 for the renal parenchyma-based attenuation ratio showed a diagnostic accuracy of 83–88%, 88–90% and 81%, respectively.ConclusionsThe most reliable parameters for differentiating ccRCC from other RCC subtypes are aorta-based corrected AV and aorta-based corrected relative contrast enhancement values in the corticomedullary phase.

Highlights

Material/Methods: Results: Conclusions: SummaryTo distinguish Renal cell carcinoma (RCC) subtypes based on contrast enhancement features of CT images.In total, 59 lesions from 57 patients were included
Kim et al found that a cut-off value of 84 Hounsfield units (HU) in the corticomedullary phase differentiated Clear cell RCC (ccRCC) from other RCC subtypes with a sensitivity and specificity of 74% and 100%, respectively [5]
Ruppert-Kohlmayr et al reported that aorta-based corrected attenuation values (AV) was not affected by intrinsic factors such as cardiac output and gave a cut-off value of 100 HU, with a sensitivity and specificity for discriminating ccRCC in the corticomedullary phase of 95.7% and 98.3%, respectively [6]

Summary

Introduction

Material/Methods: Results: Conclusions: SummaryTo distinguish RCC subtypes based on contrast enhancement features of CT images.In total, 59 lesions from 57 patients were included. When differentiating ccRCC from other RCC subtypes, a cut-off AV of 86–89 HU, aorta-based corrected AV of 89–95 HU and renal parenchyma-based corrected AV of 87-95 HU showed a diagnostic accuracy of 81–86%, 86–88% and 74–78%, respectively, in the corticomedullary phase. It is accepted that after administration of a contrast agent, tumor enhancement of >15 Hounsfield units (HU) is suggestive of a malignancy [3] This is insufficient for predicting histologic subtypes of RCC and differentiating them from benign tumors such as oncocytoma. Ruppert-Kohlmayr et al reported that aorta-based corrected AV was not affected by intrinsic factors such as cardiac output and gave a cut-off value of 100 HU, with a sensitivity and specificity for discriminating ccRCC in the corticomedullary phase of 95.7% and 98.3%, respectively [6]

Objectives

Methods

Results

Discussion

Conclusion