Non-Surgical Ablative Therapy for Management of Small Renal Masses-Current Status and Future Trends

A large number of small renal masses (SRMs) with size less than 4 cm are being identified due to advances in diagnostic imaging. As the natural history of these tumours remains unknown, there is no reliable way to predict their behaviour or future growth. Although, partial nephrectomy is the gold standard for treatment of these tumours, ablative non-surgical therapies such as cryoablation and radiofrequency ablation provide a less invasive option of treatment with comparable oncological outcomes. In this systematic review, the principle, indications, methods of treatment, oncological control, complication and renal function of ablative therapies are critically reviewed. Cryotherapy utilizes the principle of inducing tissue destruction by freezing and thawing using argon and helium gasses, respectively. Radiofrequency ablation (RFA) works on the principle of tissue heating. Ablative treatments are particularly useful in the elderly patients, those with comorbidities or in patients with SRMs in solitary kidneys or renal impairment. Ablative therapies have less procedure-related complications and have promising medium-term oncological outcome. Longer-term results are accumulating. Cryotherapy may be a better modality for oncological control than RFA. Ablative therapy has emerged as a viable treatment options for SRMs with recurrence free survival rates approaching that of extirpative surgery. However, there is no consensus in the literature on the best selection criteria and this needs further refinement. Prospective long-term data with regards to oncological control is still needed.