MICROWAVE ABLATION FOR CT1A STAGE RENAL CARCINOMA- A MULTICENTER STUDY

To provide long-term follow-up and multicenter clinical evidence-based medical evidence for ultrasound-guided MWA treatment of cT1a stage renal cancer; Method: In the present study, patients who received ultrasound-guided percutaneous RFA and MWA therapy for cT1a stage renal carcinoma at one of our national multicenter hospital between April 2006 and December 2022 were included when they satisfied our criteria. The Kaplan-Meier method was used to evaluate the cumulative OS, DFS and CSS. Log-rank test was used to evaluate the differences between the two groups. Univariate and multivariate Cox proportional hazards models were used to determine the risk factors for OS, DFS and CSS. Result: A total of 316 patients (342 tumors) were treated with MWA in 8 hospitals of the multicenter. Among which 231 patients (73.1%) were males. Fifty-six (16.4%) tumors were adjacent to the renal pelvis. The effective rate of MWA was 99.7%(341/342), and the median follow-up time was 67.2 months (1.4-198.4 months). The OS of patients at 1-, 5-, 10- years were 98.1%, 89.6% and 61.5%, respectively. The DFS and CSS of 1-, 5-, 10- years were 93.0%, 78.5%, 48.9% and 99.7%, 95.4%, 88.4%, respectively. The rate of serious complications was 3.5%(11/316). Cox proportional hazard regression model showed that age was an independent risk factor for OS prognosis. Multiple tumors, tumors were close to the renal pelviswas an independent risk factor for DFS. Pathological type was an independent risk factor for CSS. Ultrasound-guided percutaneous microwave ablation provides a safe and effective minimally invasive treatment for stage cT1a renal carcinoma.