Percutaneous microwave ablation of renal masses in a UK cohort.

To report a tertiary referral centre's experience of microwave ablation (MWA) for suspected renal cell carcinoma (RCC), describing complications and oncological outcomes.

Consecutive MWA procedures (n=113) for renal masses (October 2016 to September 2019) were maintained on a prospective database. Data describing patient, disease, procedure, complications and oncological outcomes were analysed.

Median age was 68 (33-85), 73% were male, and median Charlson Comorbidity Index was 0. Median tumour diameter was 25mm (IQR 20 - 32mm). In total 95% had renal mass biopsy, with histologically proven cancer in 75%. Median R.E.N.A.L. nephrometry score was 7 (IQR 6-8). Median ablation time was 6 minutes, and length of stay was 1 day for 95%. Clavien-Dindo complication grades I, II, IIIb and IV occurred in 18%, 1.8%, 0.9% and 0.9% respectively. Median follow-up was 12 months and median renal function change was -4% (IQR -18-0%). One patient (0.9%) had local recurrence, treated with re-ablation. Two developed metastatic progression. Two (1.8%) had indeterminate findings on follow-up (one lung nodule and one possible local recurrence), managed with ongoing protocolised CT-surveillance. Post-procedure complications were associated with total ablation time (OR 1.152/min, 95% CI 1.040 - 1.277) and total ablation energy (OR 1.017/kJ, 95% CI 1.001 - 1.033).

We describe the largest UK series of MWA treatment for T1a/small T1b renal masses to date. MWA was well tolerated, with 95% discharged the following day and low complication/readmission rates. Current follow-up demonstrates favourable disease control. MWA appears to be safe and effective and should be considered in future prospective comparisons of treatments for T1a/small T1b renal masses.

BJU international. 2020 Sep 01 [Epub ahead of print]

Joseph B John, Moira Anderson, Thomas Dutton, Mark Stott, Malcolm Crundwell, Rhys Llewelyn, Andrew Gemmell, Rory Bufacchi, Alexander Spiers, Nicholas Campain

Clinical Research Fellow in Urology, The Royal Devon and Exeter NHS Foundation Trust, UK., Urology Cancer Nurse Specialist, The Royal Devon and Exeter NHS Foundation Trust, UK., Consultant Urologist, The Royal Devon and Exeter NHS Foundation Trust, UK., Consultant Interventional Radiologist, The Royal Devon and Exeter NHS Foundation Trust, UK., Postdoctoral Researcher, Department of Neuroscience, Physiology and Pharmacology, University College London (UCL), London, UK., Urology Registrar, The Royal Devon and Exeter NHS Foundation Trust, UK.