Objective: This present study aimed to evaluate the short- and mid-term results and outcomes, efficacy, safety, and possible prognostic contributions of ultrasound (US)-guided percutaneous microwave ablation (MWA) treatment performed on small renal masses (SRM).

Methods: We retrospectively analyzed the patients who had undergone US-guided percutaneous MWA of SRM using both their patient files that contained all of the follow-up informations and all the radiological images on the local picture archiving and communication system between July 2016 and July 2019. Age and gender of the patients were recorded. The following data and parameters were also obtained: histopathologic type of the SRM, pre and postablative tumor size in three dimensions (width, length, and height), tumor localization, the ablation procedure data (patient position, time, energy, presence of repeated ablation, adjacent structures, usage of protective techniques such as hydrodissection), time of local recurrence, and renal function test and parameters (urea, creatinine, and glomerular filtration rate).

Results: Thirteen patients with thirteen solitary SRMs that were ablated using MWA under USG-guidance were found. We performed one session for six lesions (46%), two sessions for six lesions (46%), and three sessions for one lesion (8%). Mean ablation time for each session was 2.54 minutes (range: 1.5-4). We demonstrated a complete ablation, which is a primary success, in eleven patients (84%) in the first month control computed tomography imaging. Two residual tumors were detected in two patients (16%).

Conclusion: MWA for the treatment of SRM is an effective and safe method with high technical success and low complication rates and good short- and mid-term results and outcomes.