Renal biopsy performed during microwave ablation of T1 renal cancer using a coaxial guide with a spring-loaded blunt-tip stylet: focus on diagnostic yield and oncologic outcome

Purpose To retrospectively evaluate the feasibility of a coaxial guide with a spring-loaded blunt-tip stylet during single session biopsy and microwave ablation (MWA) of T1 renal cell carcinoma. Materials and methods Institutional database research identified all patients who underwent concomitant percutaneous, computed tomography-guided biopsy and microwave ablation. A 15-gauge coaxial guide with a spring-loaded blunt-tip stylet was percutaneously placed in the target tumor. Coaxially, an 18-gauge biopsy needle was first inserted for sampling, followed by the insertion of a 16-gauge microwave probe. Diagnostic yield, oncologic outcomes, and safety were assessed. International guidelines were used for ablation terminology, and the modified CIRSE classification system was used for complication reporting. All patients were followed up for at least 2 years with either CT or MRI scan. Results A total of 15 patients (mean age: 67.8 ± 3.4 years) with 17 renal tumors (mean diameter 2.77 ± 0.43 cm) were evaluated. Technical success was achieved in all cases. Diagnostic yield was 100% (clear cell RCC n = 13, papillary RCC n = 3, oncocytoma: n = 1). Overall, metastasis-free survival (MFS) was 100% at 2 years, while recurrence-free survival (RFS) was 100% at 1 year and 94.12% at 2 years. One patient (6.67%) demonstrated local recurrence during the 1-year follow-up, and the patient subsequently underwent surgical intervention (radical nephrectomy). Grade 1a complications were recorded in 2 patients (13.3%), consisting of limited perinephric hematomas that required only observation. Conclusion Based on the preliminary current results concomitant performance of percutaneous biopsy and microwave ablation using a coaxial biopsy guide with spring-loaded blunt tip stylet is feasible, safe and efficacious for the management of T1 renal cell cancer.