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

Abstract

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.

Figure 1.

Diagram depicting the ccLS and renal mass biopsy pathways.

Figure 2.

Schematic of the decision tree model from TreeAge.

Figure 3.

Tornado diagram of one-way sensitivity analyses. The width of the bar indicates how sensitive the model is to a particular variable. NMB, Net Monetary Benefit; ccLS, Clear Cell Likelihood Score; RMB, Renal Mass Biopsy; MRI, Magnetic Resonance Imaging; US, Ultrasound; CT, Computed Tomography.

Figure 4.

(A) Two-way sensitivity analysis varying costs of MRI and the sensitivity of the ccLS. (B) Two-way sensitivity analysis varying cost of MRI and the specificity of ccLS. (C) Two-way sensitivity analysis varying cost of MRI and sensitivity of RMB. (D) Two-way sensitivity analysis varying cost of MRI and sensitivity of RMB. ccLS, clear cell likelihood score; RMB, renal mass biopsy; MRI, magnetic resonance imaging.