Oncology - Bladder, Renal, Test
Mid-Atlantic Section 76th Annual Meeting
Introduction & Objective :
To evaluate the impact of anterior tumor location on oncologic efficacy and complication rates for 151 consecutive biopsy-proven cT1a RCC tumors treated with percutaneous microwave (MW) ablation.
This HIPAA-compliant, single center retrospective study was performed under a waiver of informed consent from the institutional review board. One hundred forty-eight consecutive patients [103 M/45 F; median age: 67 years, IQR 61-73] with 151 cT1a biopsy-proven RCC [median diameter: 2.4 cm, IQR 1.9-3.0 cm] were treated with percutaneous MW ablation between March 2011 and August 2017. Patient and procedural data were collected including RENAL nephrometry score, use/volume of hydrodisplacement, number of antennas, MW generator power/time, procedure (anesthesia induction-postprocedure CT) and ablation (preprocedure imaging-postprocedure CT) duration. Technical success, recurrence-free (RFS), overall survival (OS) and complications were assessed at immediate and follow-up imaging. The Kaplan–Meier method was used for survival analyses.
Results : Procedure and ablation duration were similar regardless of tumor location (p>0.05). Mean procedure duration was 180 minutes (range=101-510). Ablation duration was longer for larger (p=0.01), more complex (p=0.05) tumors requiring more than 1 antenna (p=0.0004). Technical success was achieved for all 151 tumors (100%) including 67 anterior, 61 posterior and 23 ‘X’ (neither anterior nor posterior) tumors. Median length of hospitalization was 1 day (range=0-5). Median clinical and imaging follow-up was 30 months (range=0-77) and 23 months (range=0-71), respectively. There were 3 (2%) high-grade (Clavien≥II) procedure-related complications and 6 (4%) delayed complications, all urinomas. Six local recurrences (4%) were identified at a median of 41 months (range=10-50) post-ablation. Three-year RFS was 95% (95%CI: 70-99%) for anterior, posterior and ‘X’ tumors. Three-year OS was 96% (95% CI: 89-98%).
Percutaneous MW ablation of anterior cT1a RCC is safe and effective. Long-term follow-up is needed to establish durable oncologic efficacy.