Professor of Urology University College London London, United Kingdom
Background: There is a dearth of high-level evidence on management of small renal tumours (cT1a, < 4cm), partly due to recruitment challenges of standard randomised controlled trials (RCTs). Our objective was to assess feasibility of recruitment to a pragmatic, cohort-embedded RCT comparing percutaneous cryoablation (CRA) and robot-assisted partial nephrectomy (RPN).
Methods: Adults with T1aN0M0 renal tumours were recruited to a longitudinal cohort study (ISRCTN18156881, funder NIHR). An embedded open-label RCT randomised participants meeting additional eligibility criteria 1:1 to consider CRA (intervention arm) or standard care, RPN (control arm) with 6 months follow up. Primary outcome was feasibility of recruitment to the RCT.
Results: From May 2019-July 2021, 200 participants were recruited to the cohort from a single centre. The primary endpoint of feasibility of RCT recruitment was met with 50 patients (25% of the cohort [95%CI 19-31%]). Of those invited to consider CRA, 84% consented (CI 64-95%) and 76% received CRA (CI 55-91%). All patients on the control arm proceeded to RPN (CI 86-100%). Figure 1 shows screened patients that were eligible, approached and consented. Retention was 90% (95% CI 79-96%) at 6 months. Treatment complications at 30-days were 3/25 (12%) for CRA versus 7/25 (28%) for RPN. Median length of hospital stay was shorter for cryoablation (1 versus 2 days).
Conclusions: Recruitment to an open-label cohort-embedded RCT of CRA versus RPN for T1aN0M0 renal tumours is feasible. These data inform future plans for a multi-centre trial to provide level 1 evidence in this field.
