Usefulness of Nephrometry Scoring Systems for Predicting Outcomes and Complications of Percutaneous Cryotherapy and Microwave Ablation Therapy at a Regional Medical Center.
1Michael Hood, 1Hope Sprunger, 2Justin Collins, 3Christine Schammel, 4Mike Devane
1University of South Carolina School of Medicine-Greenville, Greenville SC; 2Medical University of South Carolina, Charleston, SC; 3Pathology Associates and Consultants, Greenville SC; 4Department of Radiology, Greenville SC
• Treatment decisions for renal malignancies often
depend on qualitative data including lesion
anatomy and surgical experience.
• Several nephrometry scoring systems, including
RENAL and NePhRO, quantitate certain lesion
characteristics and have been developed in order
to standardize a description of renal tumor
• These scoring systems have demonstrated variable
efficacy in predicting complications of surgical
resection—however, few studies have correlated
their efficacy with interventional oncology
procedures such as cryotherapy (CA) and
microwave ablation (MWA) therapy.
• Our goal was to investigate the utility of RENAL
(Table 1 & Figure 1) and NePhRO (nearness,
physical zones, radius, location) nephrometry
scoring systems of renal tumors treated with CA or
MWA therapy in a regional medical center.
• All renal tumors between 8/1/2009 and 11/1/2015
were retrospectively evaluated. Patients receiving
CA or MWA were included in the study. Exclusion
criteria included radiofrequency ablation,
resection, or no treatment. Typical demographic,
clinicopathologic, imaging, treatment and outcome
data were collected.
• RENAL and NePhRO nephrometry scores, tumor
scores, and tumor-to-skin distances were analyzed
to determine their association with modality of
ablation therapy, outcomes, and complications.
Chi-squared, Fisher's exact, and ANOVA analyses
were performed with an α level of p < 0.05.
• Neither the total RENAL nor NePhRO scores
showed significance for predicting complications,
however their individual score elements did:
• Anterior v. posterior was significantly correlated
with major complications (p=0.008).
• The radius of the tumor was significantly
associated with major complications such as rehospitalization
or residual/recurrent tumor
• Significance was noted between tumor touching a
main renal vessel and complications (p=0.033).
• Significant difference was observed between radius
and re-intervention (p=0.046).
• No statistical correlation was noted in the tumorto-
skin distance and complications.
• The severity of RENAL and NePhRO scores did not
predict complications of either CA or MWA
• We found an equal efficacy between CA and MWA
for small renal tumors for our cohort.
• As expected, the larger the tumor and the
proximity to the main vessel, the greater the
propensity for major complications. Anteriorly
located tumors resulted in increased major
complications as well.
• When assessing treatment options for renal
tumors, location and size are more indicative of
outcome than treatment modality.