Published in:
01-01-2016 | Original Article
Volumetric measurement of compensatory hypertrophy in the contralateral normal kidney by the tumor growth
Published in: World Journal of Urology | Issue 1/2016
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Purpose
We evaluated the association between tumor size and preoperative volumetric kidney parameters measured with CT in patients with renal cell carcinoma (RCC).
Methods
We prospectively identified 1118 patients who underwent radical or partial nephrectomy for RCC between 2011 and 2014. Contrast-enhanced CT was performed within three months before surgery. Kidney volume was measured using a tissue segmentation tool program from CT images. We classified patients into three groups depending on tumor size (A: ≤4 cm, B: 4–7 cm, C: >7 cm). The preoperative volumetric kidney parameters were compared and multivariable linear regression was used to analyze potential factors associated with compensatory hypertrophy of the contralateral normal kidney before surgery.
Results
Patients in group C had a significantly larger contralateral normal kidney volume than patients in A and B (A: 170.0 mL, B: 171.7 mL, C: 187.2 mL, p < 0.001). The contralateral kidney volume was not significantly different between groups A and B (p > 0.05). However, tumor-side real kidney volume in group C was significantly smaller than that of groups A and B (A: 168.8 mL, B: 164.9 mL, C: 150.9 mL, p < 0.001). On multivariable analysis, increased contralateral kidney volume was positively associated with male gender, higher BMI, DM, higher preoperative GFR, and tumor size (>7 cm), and negatively associated with older age (p < 0.05). Tumor size had the strongest positive association with contralateral kidney volume (>7 cm, partial regression coefficient = 30.2).
Conclusions
Tumor size (>7 cm) is the strongest factor associated with compensatory hypertrophy in the contralateral normal kidney before surgery.