Decision analysis model comparing cost of multiparametric magnetic resonance imaging vs. repeat biopsy for detection of prostate cancer in men with prior negative findings on biopsy.

ABSTRACT

PURPOSE: We compared cost of multiparametric magnetic resonance imaging (MP-MRI) vs. repeat biopsy in detection of prostate cancer (PCa) in men with prior negative findings on biopsy. METHODS: A decision tree model compared the strategy of office-based transrectal ultrasound-guided biopsy (TRUS) for men with prior negative findings on biopsy with a strategy of initial MP-MRI with TRUS performed only in cases of abnormal results on imaging. Study end points were cost, number of biopsies, and cancers detected. Cost was based on Medicare reimbursement. Cost of sepsis and minor complications were incorporated into analysis. Sensitivity analyses were performed by varying model assumptions. RESULTS: The baseline model with 24% PCa found that the overall cost for 100 men was $90,400 and $87,700 for TRUS and MP-MRI arms, respectively. The MP-MRI arm resulted in 73 fewer biopsies per 100 men but detected 4 fewer cancers (16 vs. 20.4) than the TRUS arm did. A lower risk of PCa resulted in lower costs for the MP-MRI arm and a small difference in detected cancers. At lower cancer rates, MP-MRI is superior to TRUS over a wide range of sensitivity and specificity of MRI. A lower sensitivity of MP-MRI decreases the cost of the MP-MRI, as fewer biopsies are performed, but this also reduces the number of cancers detected. CONCLUSIONS: The use of MP-MRI to select patients for repeat biopsy reduced the number of biopsies needed by 73% but resulted in a few cancers being missed at lower cost when compared with the TRUS arm. Further studies are required to determine whether cancers missed represent clinically significant tumors.