Voxel-based whole-lesion enhancement parameters: a study of its clinical value in differentiating clear cell renal cell carcinoma from renal oncocytoma.
The purpose of this study was to compare whole-lesion (WL) enhancement parameters to single region of interest (ROI)-based enhancement in discriminating clear cell renal cell carcinoma (ccRCC) from renal oncocytoma.



In this IRB-approved retrospective study, the surgical database was queried to derive a cohort of 94 postnephrectomy patients with ccRCC or oncocytoma (68 ccRCC, 26 oncocytoma), who underwent preoperative multiphase contrast-enhanced computed tomography (CECT) between June 2009 and August 2013. CT acquisitions were transferred to a three-dimensional workstation, and WL ROIs were manually segmented. WL enhancement and histogram distribution parameters skewness, kurtosis, standard deviation (SD), and interquartile range (IQR) were calculated. WL enhancement parameters were compared to single ROI-based enhancement using receiver operating characteristic (ROC) analysis.



Oncocytoma had significantly higher WL enhancement than ccRCC in nephrographic (mean, p = 0.02; median, p = 0.03) and excretory phases (mean, p = 0.03; median p < 0.01). ccRCC had significantly higher kurtosis than oncocytoma in corticomedullary (p = 0.03) and excretory phases (p < 0.01), and significantly higher SD and IQR than oncocytoma in all postcontrast phases: corticomedullary (SD, p = 0.02; IQR, p < 0.01), nephrographic (SD, p = 0.01; IQR, p = 0.03), and excretory (SD, p < 0.01; IQR, p < 0.01). When compared to single ROI-based enhancement, WL enhancement alone did not demonstrate a statistical advantage in discriminating between ccRCC and oncocytoma (area under ROC curve of 0.78 and 0.72 respectively), but when combined with histogram distribution parameters (area under ROC curve of 0.86), it did demonstrate a slight improvement.



Our study suggests that voxel-based WL enhancement parameters provide only a slight improvement over single ROI-based enhancement techniques in differentiating between ccRCC and renal oncocytoma.
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA. Frank.chen@med.usc.edu.
Frank
0000-0002-0655-1490
F
Chen
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Mittul
M
Gulati
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Darryl
D
Hwang
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Steven
S
Cen
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Felix
F
Yap
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Chidubem
C
Ugwueze
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Bino
B
Varghese
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Mihir
M
Desai
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Manju
M
Aron
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Inderbir
I
Gill
Keck School of Medicine, University of Southern California, 1500 San Pablo St, 2nd Floor Imaging, Los Angeles, CA, 90033, USA.
Vinay
V
Duddalwar
D018249:Adenoma, Oxyphilic / Q000000981:diagnostic imaging* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000601:surgery; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed
D003287:Contrast Media
CT; Clear cell renal cell carcinoma; Histogram distribution; Oncocytoma; Whole-lesion enhancement