MUSIC-KIDNEY commenced data collection in September 2017 at 8 diverse MUSIC practices. Data was collected for 581 patients with RM≤7cm, of which only 71 (12.2%) underwent a RMB. A frequency of RMB across the 8 sites ranged from 0-23% (median 11%), with 11% of RMB performed by a urologist (fig. 1). There was no statistical difference in patient and tumor characteristics between those having or not having RMB. In 2 cases out of 71, an emergency admission was required (with 1 hospitalization). The non-diagnostic rate of RMB across the collaborative was only 5.6% (n=4); the remaining RMB were categorized as benign (n=16, 22.5%), favor malignancy (n=4, 5.6%), or malignant (n=47, 66.2%). Active surveillance was suggested more often to the patients with a benign biopsy in comparison with patients without RMB (81% vs 48%, p=0.009). In addition, 15 patients (25%) with malignancy at RMB chose surveillance. The benign histology rate at surgery in RMB naïve patients was 13.1% vs 3.03% with RMB (p=0.09).
Figure 1: Use of RMB per tumor size
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Authors concluded that this pilot study showed significant variability in the utilization of RMB and a favorable non-diagnostic rate compared to the literature. Only 3% of patients in the RMB cohort had benign histology at surgical intervention as compared to 13% with no prior biopsy. No patient with a benign result of RMB underwent radical nephrectomy. As was pointed out during the discussion, benign pathology rate in the literature is about 15-20%, but in some studies, this value reached up to 30%. Also, prof. Patel A. mentioned that even in case of RM > 7 cm, RMB can still have a diagnostic role, e.g. in differentiating metastases and primary tumor.
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Presented by: Amit Patel, MD, Department of Urology, Henry Ford Health System, Vattikuti Urology Institute, Detroit, Michigan, United States
Written by: Kirill Shiranov, MD, Fellow, Department of Urology, Rostov University, Rostov on Don, Russia, Twitter: @endourologist and Zhamshid Okhunov, MD, Twitter: @OkhunovZham, Department of Urology, University of California-Irvine at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain from March 15-19, 2019.