Abstract
Small Renal Masses (SRM) are defined as incidentally diagnosed, circumscribed solid or cystic tumors of the kidney < 4 cm with signs of saturation on a contrast-enhanced CT scan, corresponding to stage cT1aN0M0. In up to 60% of patients, the kidney tumor is detected incidentally.
The incidence of SRM in elderly and polymorbid patients is also increasing. The standard of care for a localized kidney tumor is surgical treatment.
In elderly patients or patients with serious comorbidities, SRM can only be actively monitored (Active Surveillance - AS). It is known that surgical treatment in the population over 75 years of age does not lead to a prolongation of overall survival.
The AS method can be offered to informed patients over 75 years of age. AS offers the possibility of at least initial monitoring of SRM, in the case of tumor size progression it is possible to switch to active treatment.
The risk of progression of SRM to metastatic disease in cohorts of patients over 75 years of age is small (1-2%). Minimally invasive methods of thermal ablation (TA) of tumors offer the possibility of solving SRM with minimization of the risk of surgical complications and only minimal deterioration of renal functions.
The radiofrequency ablation (RFA) method is effective for treating SRMs up to 3 cm in size. Long-term follow-up results after RFA indicate a 5-year overall survival (OS) of 73-79%.
Cryoablation is effective for treating SRM up to 4 cm in size. The success of TA methods decreases with tumor size.
Long-term results are lacking for TA methods, so it is not possible to draw conclusions regarding the clinical effectiveness of TA compared to radical nephrectomy or kidney resection. Due to these uncertainties, TA methods can only be recommended for frail and/or comorbid patients with small kidney tumors.