Whole lesion quantitative CT evaluation of renal cell carcinoma: differentiation of clear cell from papillary renal cell carcinoma

Abstract

PurposeClear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell cancer (RCC), followed by papillary RCC (pRCC). It is important to distinguish these two subtypes because of prognostic differences and possible changes in management, especially in cases undergoing active surveillance. The purpose of our study is to evaluate the use of voxel-based whole-lesion (WL) enhancement parameters on contrast enhanced computed tomography (CECT) to distinguish ccRCC from pRCC.Materials and methodsIn this institutional review board-approved study, we retrospectively queried the surgical database for post nephrectomy patients who had pathology proven ccRCC or pRCC and who had preoperative multiphase CECT of the abdomen between June 2009 and June 2011. A total of 61 patients (46 with ccRCC and 15 with pRCC) who underwent robotic assisted partial nephrectomy for clinically localized disease were included in the study. Multiphase CT acquisitions were transferred to a dedicated three-dimensional workstation, and WL regions of interest were manually segmented. Voxel-based contrast enhancement values were collected from the lesion segmentation and displayed as a histogram. Mean and median enhancement and histogram distribution parameters skewness, kurtosis, standard deviation, and interquartile range were calculated for each lesion. Comparison between ccRCC and pRCC was made using each imaging parameter. For mean and median enhancement, which had a normal distribution, independent t-test was used. For histogram distribution parameters, which were not normally distributed, Wilcoxon rank sum test was used.ResultsccRCC had significantly higher mean and median whole WL enhancement (p < 0.01) compared to pRCC on arterial, nephrographic, and excretory phases. ccRCC had significantly higher interquartile range and standard deviation (p < 0.01) and significantly lower skewness (p < 0.01) compared to pRCC on arterial and nephrographic phases. ccRCC had significantly lower kurtosis compared to pRCC on only the arterial phase.ConclusionOur study suggests that voxel-based WL enhancement parameters can be used as a quantitative tool to differentiate ccRCC from pRCC. Differentiating between the two main types of RCC would provide the patient and the treating physicians more information to formulate the initial approach to managing the patient’s renal cancer.

Differential radiologic characteristics of renal tumours on multiphasic computed tomography

“…Previous studies have demonstrated that multiphasic CT (12)(13)(14) and magnetic resonance imaging (15) can be useful in differentiating ccRCCs from pRCCs. The results of the present study provided independent validation and showed that both attenuation and degree of enhancement in the nephrographic phase are significantly lower for pRCCs than ccRCCs.…”

“…mixed RCCs), such as those with clear cell and papillary appearances, are generally less well described. Previous studies have focused on differentiating ccRCCs from pRCCs using multiphasic computed tomography (CT) (12)(13)(14) and there has been little emphasis on oncocytomas or chRCCs. To the best of our knowledge, the radiological characteristics of mixed RCCs have not been described.…”

Differentiating solid, non-macroscopic fat containing, enhancing renal masses using fast Fourier transform analysis of multiphase CT

“…This is in agreement with the literature. 31,32 Here, in addition, we also observe that the heterogeneity of pRCC increases with the increase in grade, potentially due to increased areas of necrosis etc. (which has not been studied separately here, but warranted), which may theoretically decrease the capability of FFT-based metrics to differentiate higher-grade ccRCC from pRCC.…”

Diagnostic accuracy of image-guided biopsies in small (<4 cm) renal masses with implications for active surveillance: a systematic review of the evidence

“…Results of the search A total of 7212 titles and abstracts were identified by the literature search. Of the 85 full-text publications, 65 were excluded for the following reasons: renal lesions >4 cm; [23][24][25][26][27][28][29][30][31] no final histopathology as reference standard; 9,32-40 no description of tumour size, 41,42 RTB not performed, 43,44 not SRM's, and [45][46][47][48][49][50][51][52][53][54] descriptive narrative papers and one ex-vivo study 55 (Figure 1 for PRISMA). This list is available from the authors on request.…”