Cost-Effectiveness Analysis of the Clear Cell Likelihood Score Against Renal Mass Biopsy for Evaluating Small Renal Masses.

OBJECTIVE: To examine the cost-effectiveness of the clear cell likelihood score compared to renal mass biopsy (RMB) alone. METHODS: The clear cell likelihood score, a new grading system based on multiparametric magnetic resonance imaging, has been proposed as a possible alternative to percutaneous RMB for identifying clear cell renal carcinoma in small renal masses and expediting treatment of high-risk patients. A decision analysis model was developed to compare a RMB strategy where all patients undergo biopsy and a clear cell likelihood score strategy where only patients that received an indeterminant score of 3 undergo biopsy. Effectiveness was assigned 1 for correct diagnoses and 0 for incorrect or indeterminant diagnoses. Costs were obtained from institutional fees and Medicare reimbursement rates. Probabilities were derived from literature estimates from radiologists trained in the clear cell likelihood score. RESULTS: In the base case model, the clear cell likelihood score was both more effective (0.77 vs 0.70) and less expensive than RMB ($1629 vs $1966). Sensitivity analysis found that the nondiagnostic rate of RMB and the sensitivity of the clear cell likelihood score had the greatest impact on the model. In threshold analyses, the clear cell likelihood score was the preferred strategy when its sensitivity was greater than 62.7% and when an MRI cost less than $5332. CONCLUSION: The clear cell likelihood score is a more cost-effective option than RMB alone for evaluating small renal masses for clear cell renal carcinoma.

Comparison of microwave ablation and partial nephrectomy for T1a small renal masses.

OBJECTIVE: To compare the oncological and renal function outcomes of microwave ablation (MWA) compared to partial nephrectomy (PN) in two small renal mass (SRM) tumor size cohorts, <3 cm and 3-4 cm. MATERIALS AND METHODS: This study included retrospective data from 2009 to 2015 and prospective data since 2015 from a single-institution database. Patient demographics, renal mass characteristics, and treatment outcomes were collected. Survival curves and hazard analysis were used to assess oncological outcomes. Changes in eGFR and CKD stage following surgery were used to assess renal function outcomes. RESULTS: A total of 80 PN and 126 MWA patients were analyzed. Median age and Charlson Comorbidity Index (CCI) of MWA patients were greater than PN for each tumor size cohort. Cumulative progression free survival at 36-months was 91% for MWA and 90% for PN. Preoperative renal function was significantly lower in patients undergoing MWA for both tumor sizes, however there was no significant difference in the postoperative change in renal function between MWA and PN for tumors up to 4 cm. CONCLUSIONS: Oncological outcomes and renal preservation were comparable between MWA and PN cohorts for SRMs <3cm and 3-4cm despite the MWA cohort being older and having more comorbidities. Our findings suggest that MWA can be used as a safe and effective alternative to PN for T1a renal tumors up to 4 cm.

Microwave ablation of the T1a small renal mass: expanding beyond 3 cm.

PURPOSE: To compare the oncological and renal function outcomes for patients receiving microwave ablation (MWA) in tumors < 3 and 3-4 cm. METHODS: Retrospective analysis of a prospectively maintained database identified patients with < 3 or 3-4 cm renal cancers undergoing MWA. Radiographic follow-up occurred at approximately 6 months post-procedure and annually thereafter. Serum creatinine and estimated glomerular filtration rate (eGFR) were calculated before and 6-months post-MWA. Local recurrence-free survival (LRFS) was estimated using the Kaplan-Meier method. Tumor size was evaluated as a prognostic factor using Cox proportional-hazards regression. Predictors for change in eGFR and chronic kidney disease (CKD) stage were modeled using linear and ordinal logistic regression. RESULTS: A total of 126 patients fit the inclusion criteria. Overall recurrences were 2/62 (3.2%) and 6/64 (9.4%) for < 3 versus 3-4 cm. Both recurrences in the < 3 cm group were local, 4/6 in the 3-4 cm group were local and 2/6 were metastatic without local progression. For < 3 versus 3-4 cm, cumulative LRFS at 36 months was 94.6% versus 91.4%. Tumor size was not a significant prognostic factor for LRFS. Renal function did not change significantly after MWA. Patient comorbidities and RENAL nephrometry score significantly affected change in CKD. CONCLUSION: With comparable oncological outcomes, complication rates, and renal function preservation, MWA is a promising management strategy for renal masses of 3-4 cm in select patients. Our findings suggest that current AUA guidelines, which recommend thermal ablation for tumors < 3 cm, may need review to include T1a tumors for MWA, regardless of size.

Factors influencing knee adduction moment measurement: A systematic review and meta-regression analysis.

The external knee adduction moment has been identified as a key biomarker in biomechanics research, with associations with this variable and degenerative diseases such as knee osteoarthritis. Heterogeneity in participant characteristics and the protocols used to measure this variable may however complicate its interpretation. Previous reviews have focused on interventions or did not control for potential moderator variables in their analysis. In this meta-regression analysis, we aimed to determine the influence of factors including the cohort type, footwear, and walking speed on the measurement of knee adduction moment. We performed a systematic review of the literature, identifying articles that used the Plug-in-Gait inverse dynamics model to calculate the knee adduction moment during level walking, and used a mixed effect model to determine the effect of the previously described factors on the measurement. Results for 861 individuals were described in 19 articles. Walking speed had the largest influence on knee adduction moment (p<0.001), and participants with medial knee osteoarthritis had an increased knee adduction moment (p=0.008) compared to healthy subjects. Footwear was found to have a significant overall effect (p=0.024). Participants tested barefoot or wearing their own shoes had lower adduction moments than those tested in footwear provided by the researchers. Overall, the moderators accounted for 60% of the heterogeneity in the results. These results support the hypothesis that an increased knee adduction moment is associated with medial compartment knee osteoarthritis, and that footwear choice can influence the results. Gait speed has the largest effect on knee adduction moment measurement and should be carefully controlled for in studies investigating this variable.