We read with great interest the article by Dr Sun and colleagues in the March 2009 issue of Radiology (1). The authors reported different patterns of enhancement by using a two–time point dynamic contrast agent–enhanced magnetic resonance (MR) imaging protocol. This approach allowed differentiation of a number of renal cell carcinoma (RCC) subtypes with high sensitivity and specificity. Their two–time point dynamic contrast-enhanced MR protocol was different from that used by other researchers (2–5). Some solid renal lesions are insufficiently enhanced in the first minute after injection or have diminished enhancement 5 minutes after injection of contrast agent (2). To identify maximum enhancement in a renal lesion and to improve diagnostic confidence in the identification of the most prominently enhancing region within the lesion, we believe that at least three dynamic contrast-enhanced MR acquisitions in the same plane should be performed following administration of contrast agent. In the study by Dr Sun and colleagues (1), the benefits of two–time point dynamic contrast-enhanced MR imaging for differentiating RCC subtypes were not clinically important because surgery was always needed in those patients. The three-phase dynamic contrast-enhanced MR technique remains, in our opinion, the most effective method for characterization of renal malignancies with MR imaging (2–5). We are interested in further evaluating the different enhancement patterns in the various types of papillary (ie, solid and papillary) and conventional (ie, solid, alveolar and acinar, and sarcomatoid) RCC (6,7). These architectural subtypes have different vascularization that could result in different enhancement patterns. In the study by Dr Sun and colleagues, the histologic diagnostic criteria for chromophobe RCCs were not described. Diagnosis of this tumor type can be difficult, and the use of immunohistochemical and cytogenetic analysis is sometimes needed to distinguish subtypes (8). We believe that the use of three-phase dynamic contrast-enhanced MR imaging to differentiate the enhancement patterns of RCC subtypes from benign tumors, such as oncocytomas, would be more useful for clinical management and for determining the prognosis in these patients.
Dynamic contrast-enhanced MR imaging for differentiation of renal cell carcinoma subtypes: Myth or reality?
SCIALPI, Michele;
2009
Abstract
We read with great interest the article by Dr Sun and colleagues in the March 2009 issue of Radiology (1). The authors reported different patterns of enhancement by using a two–time point dynamic contrast agent–enhanced magnetic resonance (MR) imaging protocol. This approach allowed differentiation of a number of renal cell carcinoma (RCC) subtypes with high sensitivity and specificity. Their two–time point dynamic contrast-enhanced MR protocol was different from that used by other researchers (2–5). Some solid renal lesions are insufficiently enhanced in the first minute after injection or have diminished enhancement 5 minutes after injection of contrast agent (2). To identify maximum enhancement in a renal lesion and to improve diagnostic confidence in the identification of the most prominently enhancing region within the lesion, we believe that at least three dynamic contrast-enhanced MR acquisitions in the same plane should be performed following administration of contrast agent. In the study by Dr Sun and colleagues (1), the benefits of two–time point dynamic contrast-enhanced MR imaging for differentiating RCC subtypes were not clinically important because surgery was always needed in those patients. The three-phase dynamic contrast-enhanced MR technique remains, in our opinion, the most effective method for characterization of renal malignancies with MR imaging (2–5). We are interested in further evaluating the different enhancement patterns in the various types of papillary (ie, solid and papillary) and conventional (ie, solid, alveolar and acinar, and sarcomatoid) RCC (6,7). These architectural subtypes have different vascularization that could result in different enhancement patterns. In the study by Dr Sun and colleagues, the histologic diagnostic criteria for chromophobe RCCs were not described. Diagnosis of this tumor type can be difficult, and the use of immunohistochemical and cytogenetic analysis is sometimes needed to distinguish subtypes (8). We believe that the use of three-phase dynamic contrast-enhanced MR imaging to differentiate the enhancement patterns of RCC subtypes from benign tumors, such as oncocytomas, would be more useful for clinical management and for determining the prognosis in these patients.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
