MP19-07 THREE-DIMENSIONAL EVALUATION OF PERIRENAL ADIPOSE TISSUE VOLUME PREDICTS RENAL CORTICAL NEOPLASM HISTOPATHOLOGY

INTRODUCTION AND OBJECTIVES: Contemporary imaging technology allows for three-dimensional (3D) visualization of human anatomy. Volumetric data acquisition allows for 3D imaging and accurate estimation of organ sizes and volumes. Visceral and perirenal adipose tissue (PAT) have been shown to be metabolically active. Previously, we have demonstrated that linear two-dimensional PAT measurements are associated with more aggressive renal cell carcinoma (RCC) subtypes. In this study, we evaluated total PAT volume as a predictor of renal tumor histopathology using novel 3D imaging software. METHODS: We retrospectively evaluated patients who underwent laparoscopic radical or partial nephrectomy for renal cortical neoplasms (RCN). We measured the PAT volume through post-processing of preoperative CT images using Vitrea software (Vital Images, Inc., Minnetonka, MN). We measured the total perirenal space volume by manual contouring. We subtracted out the structures with densities greater than adipose tissue using organ segmentation, thereby yielding only a total PAT volume. We recorded and analyzed demographic, clinical and operative parameters, PAT volume, and their association with tumor histopathology. RESULTS: In this pilot analysis, a total of 102 patients with 104 tumors were included: 50 (49%) men and 52 (51%) women with a median body mass index (BMI) of 28.5 kg/m. The median tumor size for overall cohort was 2.7 cm (0.9-4.4 cm), and the median PAT volume was 395.4 cm. Mean PAT for malignant and benign histopathology was 436.7 cm and 269.3 cm respectively (p1⁄40.002). The mean PAT for each subtype showed 396.8, 633.3, 119.8, and 269.3 cm for clear cell (n1⁄457), papillary (n1⁄413), chromophobe (n1⁄45), and benign (n1⁄425) tumors, respectively (p1⁄40.000). To date, a total of 42 patients underwent bilateral PAT volume determination. The mean PAT volume was 19.6% higher on the tumor side (p1⁄40.001). CONCLUSIONS: In this preliminary pilot analysis, increased PAT volume is a significant predictor of RCC histopathology for small RCN. Similarly, there was a significant direct correlation for tumor laterality and PAT volume versus the contralateral kidney for the individual patient. Further data is being collected.