Metastatic Tumor Burden Does Not Predict Overall Survival Following Cytoreductive Nephrectomy for Renal Cell Carcinoma; a Novel 3-Dimensional Volumetric Analysis

• Published in: Urology (Ridgewood, N.J.) N.J.), 2017-02, Vol.100, p.139-144
• Main Authors: Blute, Michael L, Ziemlewicz, Timothy J, Lang, Joshua M, Kyriakopoulos, Christos, Jarrard, David F, Downs, Tracy M, Grimes, Matthew, Shi, Fangfang, Mann, Michael A, Abel, E. Jason
• Format: Article
• Language: English
• Subjects: Urology
• ISSN: 0090-4295; 1527-9995
• DOI: 10.1016/j.urology.2016.09.016

Abstract Objective To compare one dimensional (1D) and three dimensional (3D) volume measurements and determine whether primary tumor (PT) burden is predictive of overall survival (OS) following cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC). Methods Records and imaging studies of mRCC patients treated with CN from 2006-2015 were included with tumor volumes measured by a faculty radiologist blinded to clinical outcomes using Advantage Workstation Volume Share (Ver 4.6 GE Waukesha, WI). Results Complete PT and metastatic tumor volumes were measured for 67 patients. For 15 (22.3%) patients, 1Dvolume was within ± 10% of the measured 3Dvolume. In 40 (59.7%) patients, the calculated 1Dvolume overestimated of the 3Dvolume by > 10% including 12 (18.1%) patients, where 1Dvolume overestimated by > 100%. Fractional percentage tumor volume removed during CN (FPTV) was calculated using the formula PT volume/ (PT+met volume). FPTV was not associated with OS when analyzed as a continuous variable. Patients were divided into 2 groups based on previously published cut point of 90% FPTV. No differences between cohorts in age, gender, grade, subtype, number of metastatic sites, performance status, MSKCC risk group or IMDC risk group were identified. OS was not different between cohorts (p=0.38). Conclusion 1D measurements of PT diameter frequently overestimates mRCC primary tumor volume. In mRCC patients selected for cytoreductive nephrectomy, the ratio of primary to metastatic tumor does not predict overall survival.