Ablative Therapies for Renal Tumors: Patient Selection, Treatment Planning, and Follow-Up

Abstract

The increased use of abdominal imaging has led to a major increase in small renal tumors incidence particularly in the elderly population. Their management is evolving with the development of percutaneous ablation, particularly radiofrequency ablation, cryoablation, and microwave ablation. The typical indications that must be validated by a multidisciplinary committee include solid tumors less than 3cm in patients with multiple comorbidity factors (including age), contraindications to surgery, hereditary renal cancer, bilateral renal tumors, solitary kidney, pre-existing chronic kidney disease, or at high risk of predialysis renal function after partial nephrectomy. As tumor ablation offers almost similar oncologic outcome when compared with surgery, new indications are appearing such as larger tumors, benign, or cystic neoplasms. The biopsy of solid renal masses is recommended in most cases. Careful and systematic treatment planning is required to avoid complications, paying specific attention of the relationships to the bowel structures, and urinary tract. Specific maneuvers can be necessary such as gas or liquid dissection and pyeloperfusion. The technique of ablation depends on availability, training, and tumor size and location, with a preference to cryotherapy for central and large lesions. Evaluation of therapeutic efficacy relies on contrast-enhanced imaging (computed tomography, magnetic resonance imaging or even ultrasound). The follow-up must be continued up to 10 years after ablation. The overall efficacy is more than 90% with a reduced complication rate less than 10%. Renal tumor percutaneous ablation is sparing the renal function and should be the preferred treatment in the case of pre-existing chronic kidney disease.