Management of small renal masses: a review.

INTRODUCTION: Recently, small renal masses (SRMs) (< or =4 cm) are found more frequently, especially in the elderly and co-morbid patients. Standard treatment for SRMs is nephron-sparing surgery (NSS). New techniques like energy ablation and surveillance have been introduced. MATERIALS AND METHODS: Overview of treatment options for SRMs, based mainly on the meta-analyses available for NSS, cryoablation, radio-frequency ablation (RFA), and surveillance. RESULTS: NSS for SRMs is the standard therapy with excellent cancer-specific survival rates up to 97%. Cryoablation was mainly performed laparoscopically, and RFA mainly percutaneously. Pretreatment biopsies were used frequently for cryoablation (80%) and less frequently for RFA (50%). Primary failure rate for cryoablation was 4.8% and for RFA 13%. Major complication rates for both procedures are around 5%. Based on 6-month post-ablative biopsies, non-contrast enhancement seems to be an effective surrogate marker after cryoablation, but not after RFA. Follow-up after energy ablation is too short to draw final conclusion. Data on surveillance are based on small, retrospective data with insufficient follow-up. Growth patterns during follow-up do not correlate with the underlying tumour entity. CONCLUSION: Standard therapy for SRMs is still NSS. Energy ablation should be reserved for the elderly patients with co-morbidities and surveillance for the elderly and infirm patients.